Display device

Abstract

Provided is a display device having high display quality. The display device comprises a first light-emitting device and a second light-emitting device, the first light-emitting device and the second light-emitting device comprise common electrodes with light transmission, and the first light-emitting device comprises a first electrode, a first EL layer and a first auxiliary electrode with light transmission. The first light-emitting device comprises a first electrode, a first EL layer and a common electrode, the second light-emitting device comprises a second electrode, a second EL layer and a second auxiliary electrode with light transmission, 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. The first auxiliary electrode is thicker than the second auxiliary electrode.

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-mentioned technical field. As an example of the technical field of one embodiment of the present invention disclosed in this specification, etc., a semiconductor device, a display device, a light-emitting device, a power storage device, a storage device, an electronic device, a lighting device, an input device, an input-output device, a driving method thereof, or a manufacturing method thereof can be cited. A semiconductor device refers to all devices that can work by utilizing semiconductor characteristics. Background Art

[0002] In recent years, high-definition display panels have been in demand. Devices that require high-definition display panels include smartphones, tablet terminals, and notebook computers. In addition, fixed display devices such as television devices and monitoring devices are also required to have higher resolutions as they become higher resolution. Devices that require the highest resolution include those used in virtual reality (VR) or augmented reality (AR).

[0003] In addition, typical display devices that can be applied to display panels include liquid crystal display devices, light-emitting devices including light-emitting devices such as organic EL (Electro Luminescence) elements and light-emitting diodes (LEDs), and electronic paper that displays by electrophoresis or the like.

[0004] For example, the basic structure of an organic EL element is a structure in which a layer containing a light-emitting organic compound is sandwiched between a pair of electrodes. By applying a voltage to the element, light emission from the light-emitting organic compound can be obtained. Since a display device using the above-mentioned organic EL element does not require a backlight source required by a liquid crystal display device, a thin, lightweight, high-contrast, and low-power display device can be realized.

[0005] Various methods are known as methods for manufacturing organic EL elements. As one of the disclosed manufacturing methods, a method for manufacturing an organic compound layer using an inkjet method can be cited (Patent Document 1). The organic EL element formed using the manufacturing method described in Patent Document 1 includes an optical adjustment layer and performs optical adjustment.

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2022-80879 Summary of the invention

[0007] In the manufacturing method disclosed in Patent Document 1, after forming an organic compound layer by an inkjet method, the same optical adjustment layer is provided in each organic EL element. Therefore, it is difficult to perform an appropriate optical design for each organic EL element.

[0008] One of the purposes of one embodiment of the present invention is to provide a display device with high display quality. One of the purposes of one embodiment of the present invention is to provide a display device with low power consumption. One of the purposes of one embodiment of the present invention is to provide a display device that is easy to achieve high definition. One of the purposes of one embodiment of the present invention is to provide a display device with both high display quality and high definition. One of the purposes of one embodiment of the present invention is to provide a display device with high contrast.

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

[0010] Note that the description of these objects does not prevent the existence of other objects. Note that one embodiment of the present invention does not necessarily achieve all of the above objects. Note that objects other than the above objects can be extracted from the description of the specification, drawings, claims, etc.

[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 including a common electrode having light transmittance, the first light-emitting device including a first electrode, a first EL layer and a first auxiliary electrode having light transmittance, the second light-emitting device including a second electrode, a second EL layer and a second auxiliary electrode having light transmittance, the first EL layer being located between the first electrode and the common electrode, the second EL layer being located between the second electrode and the common electrode, the first auxiliary electrode being located between the first EL layer and the common electrode, the second auxiliary electrode being located between the second EL layer and the common electrode, and the thickness of the first auxiliary electrode being thicker than the thickness of the second auxiliary electrode.

[0012] In addition, 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 including a common electrode having light transmittance, the first light-emitting device including a first electrode, a first EL layer and a first auxiliary electrode having light transmittance, the second light-emitting device including a second electrode and a second EL layer, the first EL layer being located between the first electrode and the common electrode, the second EL layer being located between the second electrode and the common electrode and in contact with the common electrode, and the first auxiliary electrode being located between the first EL layer and the common electrode.

[0013] In addition, 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 including a common layer and a light-transmitting common electrode, the common electrode being located on the common layer, the first light-emitting device including a first electrode, a first EL layer and a first light-transmitting auxiliary electrode, the second light-emitting device including 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 structure, the common layer preferably contains an alkali metal or an alkaline earth metal.

[0015] Furthermore, one embodiment of the present invention is a display device, wherein in the display device of each of the above structures, the light emission color of the first light emitting device is different from the light emission color of the second light emitting device.

[0016] Furthermore, one embodiment of the present invention is a display device, wherein in the display device of each of the above structures, the wavelength of light emitted by the first light emitting device is longer than the wavelength of light emitted by the second light emitting device.

[0017] Furthermore, one embodiment of the present invention is a display device, wherein in the display device of each of the above structures, the first auxiliary electrode includes silver and magnesium.

[0018] In the display device having the above structure, the thickness of the first auxiliary electrode is preferably not less than 1 nm and not more than 50 nm.

[0019] In the display device of each of the above structures, it is preferable that the display device further includes an insulating layer, wherein the insulating layer is located between the first EL layer and the second EL layer.

[0020] According to one embodiment of the present invention, a display device with high display quality can be provided. According to one embodiment of the present invention, a display device with low power consumption can be provided. According to one embodiment of the present invention, a display device that can easily achieve high definition can be provided. According to one embodiment of the present invention, a display device with both high display quality and high definition can be provided. According to one embodiment of the present invention, 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 a display device can be provided. According to one embodiment of the present invention, a method for manufacturing the above-mentioned display device with a 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 improved.

[0022] Note that the description of these effects does not prevent the existence of other effects. In addition, one embodiment of the present invention does not necessarily have all of the above effects. Note that effects other than the above can be extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0024] The following describes the embodiments with reference to the accompanying drawings. Note that the embodiments can be implemented in a number of different ways, and a person skilled in the art can easily understand that the methods and details can be transformed into various forms without departing from the purpose and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents described in the following embodiments.

[0025] Note that in the inventive structure described below, the same reference numerals are used in common in different drawings to show the same parts or parts with the same function, and repeated descriptions are omitted. In addition, when showing parts with the same function, the same hatching is sometimes used without adding a reference numeral in particular.

[0026] Note that in each of the drawings described in this specification, the size of each component, the thickness of a layer, and a region may be exaggerated for clarity, and therefore, the present invention is not limited to the sizes in the drawings.

[0027] The ordinal numbers such as “first” and “second” used in the present specification and the like are provided to avoid confusion among constituent elements and are not intended to limit the number of constituent elements.

[0028] In this specification, "film" and "layer" may be interchanged. For example, "conductive layer" or "insulating layer" may be replaced with "conductive film" or "insulating film", respectively.

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

[0030] In this specification, etc., a display panel which is one form of a display device refers to a panel which can display (output) an image etc. on a display surface. Therefore, a display panel is one form of an output device.

[0031] In addition, in this specification, etc., a structure in which a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) is installed on a display panel substrate, or a structure in which an IC is installed on a substrate using a COG (Chip On Glass) method, etc. is sometimes 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 with a high hole-injecting property, a substance with a high hole-transporting property, a substance with a high electron-transporting property, a substance with a high electron-injecting property, a bipolar substance, and the like.

[0033] Implementation Method 1 In this embodiment, a configuration example of a display device and an example of a method for manufacturing the display device, which are one embodiment of the present invention, are described.

[0034] One embodiment of the present invention is a display device including a light-emitting device (also referred to as a light-emitting element). The display device includes at least two light-emitting devices that emit light of different colors. Each of the light-emitting devices includes a pair of electrodes and an EL layer between the pair of electrodes. As the light-emitting device, an electroluminescent device such as an organic EL element, an inorganic EL element, etc. can be used. In addition, a light-emitting diode (LED) can also 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 include an EL layer containing different materials. For example, a full-color display device can be realized by including three light-emitting devices that emit red (R), green (G) or blue (B) light, respectively.

[0035] Here, it is known that when the EL layers are manufactured separately between light-emitting devices of different colors, a vapor deposition method using a shadow mask such as a metal mask is used. However, this method is not easy to achieve high definition and high aperture ratio because the shape and position of the island-shaped organic film are different from the design due to various influences such as the accuracy of the metal mask, the misalignment between the metal mask and the substrate, the bending of the metal mask, and the expansion of the outline of the deposited film due to the scattering of vapor. In addition, particles are sometimes generated due to the material attached to the metal mask during vapor deposition. Such particles may cause a defective pattern of the light-emitting device. In addition, a short circuit caused by the particles may occur. In addition, a cleaning process of the material attached to the metal mask is required. Therefore, the definition (also called pixel density) is simulated by adopting a special pixel arrangement 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. Therefore, a display device with high resolution and high aperture ratio, which is difficult to achieve at present, can be realized. In addition, since the EL layer can be manufactured separately, a display device with extremely high resolution and high display quality can be realized.

[0037] Here, for the sake of simplicity, the case of manufacturing the EL layers of the light-emitting devices of two colors separately is described. First, a first EL film and a first sacrificial film are formed by stacking to cover the pixel electrode (step A). ​​Next, a resist mask is formed on the first sacrificial film. Next, a portion of the first sacrificial film and a portion 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 stacked. Next, a portion of the second sacrificial film and a portion 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. Through the above steps, the first EL layer and the second EL layer can be formed respectively. Finally, the first sacrificial layer and the second sacrificial layer are removed to form a common electrode, thereby forming two color light-emitting devices respectively.

[0039] Furthermore, by repeating the above steps, EL layers of light-emitting devices of three or more colors can be formed respectively, thereby realizing a display device including light-emitting devices of three or four or more colors.

[0040] In addition, a display device of one embodiment of the invention includes at least an auxiliary electrode located between an EL layer of a light-emitting device and a common electrode. The auxiliary electrode has light-transmitting properties and is also used as an optical adjustment layer. Since the auxiliary electrode and the EL layer of the light-emitting device are processed simultaneously by photolithography, the end (outline) of the EL layer and the end of the auxiliary electrode are roughly aligned in a direction perpendicular to the substrate.

[0041] When the auxiliary electrode is provided in each of the two-color light-emitting devices, a first EL film, a first conductive film to be the first auxiliary electrode, and a first sacrificial film are formed by stacking the pixel electrodes. Next, a resist mask is formed on the first sacrificial film. Then, a portion of the first sacrificial film, a portion of the first conductive film, and a portion 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] After step A, a second EL film, a second conductive film to be a second auxiliary electrode, and a second sacrificial film are stacked. Next, a portion of the second sacrificial film, a portion of the second conductive film, and a portion of the second EL film are etched using a resist mask 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. Through the above steps, the first auxiliary electrode and the second auxiliary electrode can be manufactured respectively. Finally, the first sacrificial layer and the second sacrificial layer are removed to form a common electrode, thereby manufacturing two color light-emitting devices including different auxiliary electrodes.

[0043] When an auxiliary electrode is provided in one of the two color light-emitting devices and the auxiliary electrode is not provided in the other, after step A, the second EL film and the second sacrificial film are stacked and formed. 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. Through the above steps, the first EL layer and the second EL layer can be formed respectively. Finally, the first sacrificial layer and the second sacrificial layer are removed to form a common electrode, thereby manufacturing a light-emitting device including an auxiliary electrode and a light-emitting device not including an auxiliary electrode, respectively.

[0044] By manufacturing the auxiliary electrode for each light-emitting device, the structure (thickness, material, etc.) of the auxiliary electrode for each light-emitting device can be changed. Therefore, the optical adjustment of each light-emitting device can be easily optimized. Note that in this embodiment, the optical adjustment of the light-emitting device can be performed by controlling the auxiliary electrode, so the auxiliary electrode can also be called an optical adjustment layer.

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

[0046] In addition, when adjacent light-emitting devices include auxiliary electrodes, the spacing between the auxiliary electrodes can be reduced to less than 3 μm, less than 2 μm, or less than 1 μm by using photolithography. For example, by using an exposure device for LSI, the spacing can also be reduced to less than 500 nm, less than 200 nm, less than 100 nm, or even less than 50 nm.

[0047] In addition, the pattern of the EL layer itself can also be significantly reduced compared to the case of using a metal mask. In addition, for example, when the EL layer is formed separately using a metal mask, the thickness of the center and the end of the pattern is different, so the effective area that can be used as the light-emitting area in the entire area of ​​the pattern becomes smaller. On the other hand, by processing using a photolithography method, a film with a uniform thickness can be processed and deposited, thereby making the thickness of the pattern uniform, and even if a fine pattern is used, almost the entire area of ​​the pattern can be used as the light-emitting area. Therefore, by the above-mentioned manufacturing method, both high definition and high aperture ratio can be achieved.

[0048] In this way, the above-mentioned manufacturing method can realize a display device that is integrated with fine light-emitting devices, a so-called stripe arrangement and has a clarity of more than 500ppi, more than 1000ppi, or more than 2000ppi, or even more than 3000ppi, or even more than 5000ppi.

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

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

[0051] The display device 100 includes a pixel portion 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] When describing matters common to the sub-pixel 110R, the sub-pixel 110G, and the sub-pixel 110B, they may be simply referred to as the sub-pixel 110. Similarly, when describing matters common to other components distinguished by letters, symbols with letters omitted may be used.

[0053] Sub-pixel 110R emits red light, sub-pixel 110G emits green light, and sub-pixel 110B emits blue light. Thus, an image can be displayed on the pixel portion 177. In the present embodiment, sub-pixels of three colors, red (R), green (G) and blue (B), are used as examples for explanation, but a combination of sub-pixels of other colors may also be used. In addition, the number of sub-pixels is not limited to three, and four or more may be used. As four sub-pixels, for example: sub-pixels of four colors, R, G, B, and white (W); sub-pixels of four colors, R, G, B, and yellow (Y); and sub-pixels of four colors, R, G, B, and infrared light (IR); etc. In addition, a sensor may be provided on the inner side of pixel 178, and the sensor is preferably an organic photodiode sensor using an organic compound. The organic photodiode sensor using an organic compound uses a material common to the light-emitting device to form a portion of the carrier transport layer.

[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 intersect.

[0055] exist Figure 1A In the example shown, sub-pixels of different colors are arranged in the X direction, and sub-pixels of the same color are arranged in the Y direction. Note that sub-pixels of different colors may be arranged in the Y direction, and sub-pixels of the same color may be arranged in the X direction.

[0056] The connection portion 140 is provided outside the pixel portion 177, and a region 141 may be provided. For example, the region 141 is provided between the pixel portion 177 and the connection portion 140. The EL layer 103 is provided in the region 141. In addition, the connection portion 140 is provided with a conductive layer 151C.

[0057] exist Figure 1A In the example shown, the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but there is no particular limitation on the positions of the region 141 and the connection portion 140. In addition, the region 141 and the connection portion 140 may be one or more.

[0058] Figure 1B is along Figure 1A An example of a cross-sectional view along the dot-dash line A1-A2 in FIG. Figure 1BAs shown, the display device 100 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and 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 disposed on a substrate (not shown). The insulating layer 175, the insulating layer 174, and the insulating layer 173 are provided with openings that reach the conductive layer 172, and a plug 176 is provided in a manner of being embedded in the opening.

[0059] In the pixel portion 177, a light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B are provided on the insulating layer 175 and the plug 176. Note that in the following description of matters common to the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B, they are sometimes simply referred to as the light-emitting device 130. A protective layer 131 is provided on the second electrode 102 included in the light-emitting device 130 so as to cover the light-emitting device 130. The protective layer 131 can be formed by a method such as a vacuum evaporation method, a sputtering method, a chemical vapor deposition (CVD: Chemical Vapor Deposition) method, or an ALD (Atomic Layer Deposition) method. When the protective layer 131 is an inorganic insulating film formed by a plasma enhanced atomic layer deposition (PEALD: Plasma enhanced Atomic Layer Deposition) method, a film with high barrier properties can be formed at a low temperature. Therefore, damage to the EL layer included in each light-emitting device can be reduced, and a display device with high display quality can be easily obtained. In addition, the entry of substances that deteriorate the EL layer and the second electrode 102, such as water, oxygen, and trace components in the atmosphere, can be effectively suppressed, and a display device with high display quality can be obtained. In addition, since the inorganic insulating film formed by the PEALD method is a film with high barrier properties, the protective layer 131 can be formed thin, and a display device with high display quality can be realized. Note that the protective layer 131 may have a stacked structure of two or more layers.

[0060] The substrate 120 is bonded to the protective layer 131 via the resin layer 122. In addition, it is preferable to provide a second insulating layer 125a between adjacent light-emitting devices 130 and a first insulating layer 127 on the second insulating layer 125a.

[0061] The second insulating layer 125a is provided in contact with the side surfaces of each EL layer in the light-emitting device 130. In addition, the second insulating layer 125a is preferably provided in contact with the side surfaces of each pixel electrode (the first electrode 101R, the first electrode 101G, and the first electrode 101B) in the light-emitting device 130. In addition, the second insulating layer 125a is preferably provided in contact with the side surfaces and the bottom surface of the first insulating layer 127.

[0062] By adopting the above structure, the first insulating layer 127 and the EL layer included in the light emitting device 130 can be separated by the second insulating layer 125a.

[0063] The second insulating layer 125a is used as a protective insulating layer for the EL layer included in the light-emitting device 130. The second insulating layer 125a preferably has a barrier property against at least one of oxygen and moisture. By using such a second insulating layer 125a to separate the first insulating layer 127 from the EL layer, it is possible to suppress the entry of oxygen, moisture, or constituent elements thereof from the side of the EL layer into the interior, and thus a highly reliable display device can be realized.

[0064] Note that the thickness of the second insulating layer 125a in the region in contact with the side surface of the EL layer included in the light-emitting device 130 is preferably 5 nm or more and 50 nm or less, more preferably 5 nm or more and 30 nm or less, more preferably 5 nm or more and 20 nm or less, and more preferably 5 nm or more and 10 nm or less. By setting the thickness of the second insulating layer 125a within the above range, a display device with a high aperture ratio and high reliability can be realized.

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

[0066] Note that in this specification, "oxynitride" refers to a material containing more oxygen than nitrogen in its composition, and "nitride oxide" refers to a material containing more nitrogen than oxygen in its composition. For example, "silicon oxynitride" refers to a material containing more oxygen than nitrogen in its composition, and "silicon nitride oxide" refers to a material containing more nitrogen than oxygen in its composition.

[0067] The first insulating layer 127 provided on the second insulating layer 125a can reduce the step in the formation surface of the second electrode 102 by filling the gap formed between adjacent light-emitting devices, and can suppress the occurrence of defects such as breakage by improving the coverage of the first insulating layer 127. As the first insulating layer 127, an insulating layer containing an organic material can be appropriately used. For example, as the first insulating layer 127, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene resin, phenolic resin and precursors of the above resins can be used. In addition, as the first insulating layer 127, a photosensitive resin can be used. The photosensitive resin can use a positive material or a negative material.

[0068] Figure 1BAs the light emitting device 130, a light emitting device 130R, a light emitting device 130G, and a light emitting device 130B are shown. The light emitting device 130R, the light emitting device 130G, and the light emitting device 130B emit light of different colors from each other. In addition, the wavelength of the light emitted by the light emitting device 130R is longer than the wavelength emitted by the light emitting device 130G. In addition, the wavelength of the light emitted by the light emitting device 130G is longer 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). In addition, the light emitting device 130R, the light emitting device 130G, or the light emitting device 130B can also emit other visible light or infrared light.

[0069] Note that in this specification, etc., the emission color of a light-emitting device can be determined based on the peak wavelength of the electroemission spectrum of the light-emitting device. For example, when the difference between the maximum peak wavelength in the visible light region of the electroemission spectrum of the first light-emitting device and the maximum peak wavelength in the visible light region of the electroemission 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] Note that in this specification, etc., the blue wavelength region refers to a wavelength region of 400 nm or more and less than 490 nm, and blue luminescence is luminescence having at least one emission spectrum peak in this region. In addition, the green wavelength region refers to a wavelength region of 490 nm or more and less than 580 nm, and green luminescence is luminescence having at least one emission spectrum peak in this region. In addition, the red wavelength region refers to a wavelength region of 580 nm or more and less than 780 nm, and red luminescence is luminescence having at least one emission spectrum peak in this region.

[0071] A display device according to one embodiment of the present invention may have a top emission structure that emits light in a direction opposite to a substrate on which a light-emitting device is formed. Note that one embodiment of the present invention is not limited to this, and may also be a double-sided emission (dual emission) type that extracts light emitted by a light-emitting device to both above and below a substrate on which a light-emitting device is formed.

[0072] The light-emitting device 130R includes a first electrode 101R (pixel electrode) composed 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. In addition, the light-emitting device 130R is located on the auxiliary electrode 106R and includes a protective layer 158R in a region where the auxiliary electrode 106R is not connected to the second electrode 102.

[0073] The light-emitting device 130G includes 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, and a second electrode 102 (common electrode) on the auxiliary electrode 106G. In the light-emitting device 130G, it can also be said that 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. In addition, the light-emitting device 130G is located on the auxiliary electrode 106G and includes a protective layer 158G in a region where the auxiliary electrode 106G is not in contact with the second electrode 102.

[0074] The light-emitting device 130B includes 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, an auxiliary electrode 106B on the EL layer 104B, and a second electrode 102 (common electrode) on the auxiliary electrode 106B. In the light-emitting device 130B, it can also be said that 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. In addition, the light-emitting device 130B is located on the auxiliary electrode 106B and includes a protective layer 158B in a region where the auxiliary electrode 106B is not in contact with the second electrode 102.

[0075] The EL layer 104R, the EL layer 104G, and the EL layer 104B are formed by depositing an EL film and processing the EL film by photolithography, so each or each luminescent color is independently formed into an island shape. Note that the EL layer 104R, the EL layer 104G, and the EL layer 104B preferably do not overlap with each other. By setting the EL layer in an island shape for each light-emitting device 130, the leakage current between adjacent light-emitting devices 130 can be suppressed even in a high-definition display device. As a result, crosstalk can be suppressed, and a light-emitting device with extremely high contrast can be realized. In particular, a display device with high current efficiency at low brightness can be realized. Note that in the following description of common matters between the EL layer 104R, the EL layer 104G, and the EL layer 104B, they are sometimes simply recorded as the EL layer 104.

[0076] Note that one of the pixel electrode (first electrode) and the common electrode (second electrode) included in the light-emitting device is used as an anode, and the other is used as a cathode. In this embodiment, unless otherwise specified, the description is sometimes made assuming that the pixel electrode is used as an anode and the common electrode is used 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 is used as a cathode, the auxiliary electrode is also used as a cathode, and when the common electrode is used as an anode, the auxiliary electrode is also used as an anode.

[0077] The auxiliary electrodes 106R, 106G, and 106B are formed by depositing a conductive film and processing the conductive film by photolithography, similarly to the EL layer 104R, 104G, and 104B, so they are each independently formed in an island shape in each luminescent color. By providing an island-shaped auxiliary electrode in each light-emitting device 130, the structure (thickness, material, etc.) of the auxiliary electrode can be changed for each light-emitting device 130, thereby making it possible to optically adjust each light-emitting device 130. The auxiliary electrodes 106R, 106G, and 106B can also be said to be used as optical adjustment layers. Note that in the following description of matters common to the auxiliary electrodes 106R, 106G, and 106B, they are sometimes simply referred to as the auxiliary electrodes 106.

[0078] As the second electrode 102 (common electrode), the auxiliary electrode 106R, the auxiliary electrode 106G, and the auxiliary electrode 106B, it is preferable to use a conductive film having light transmittance (a transparent conductive film, a semi-transmissive and semi-reflective conductive film, etc.). Note that in this specification, etc., visible light refers to light having a wavelength of 400 nm or more and less than 780 nm. In addition, in this specification, etc., light transmittance means that the transmittance of light of at least a portion of the wavelength in the visible light region is 5% or more. In addition, in this specification, etc., a conductive film refers to a film having a resistivity of 10×10 8Ωcm or less. Note that resistivity refers to the resistance value of the sample divided by the length of the sample and multiplied by the cross-sectional area of ​​the sample. This resistivity is different from the sheet resistance obtained by dividing the resistance value of the sample by the length of the sample and multiplying by the width of the sample.

[0079] A conductive film having a transmittance of 40% or more of light of at least a portion of the wavelength in the visible light region is 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. As specific examples of transparent conductive films, 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, indium tin oxide with silicon oxide added, etc. can be cited. In addition, a film of an organic substance with high conductivity or a mixed film of an organic substance and an inorganic substance can also be used as a transparent conductive film. As specific examples of organic substances with high conductivity, materials with electron transport properties, materials with hole transport properties, etc. can be cited. In addition, as specific examples of mixed films of organic and inorganic substances, a mixed film of a material with electron transport properties and Li, a mixture of a material with hole transport properties and MoO3 can be cited.

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

[0081] Note that in order to stably form the electrode and fully exert the function 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 further preferably 10 nm or more. When each light-emitting device adopts an optical microcavity resonator (microcavity) structure, by increasing the thickness of the auxiliary electrode, the emission spectrum can be narrowed and the color purity can be improved.

[0082] On the other hand, when the thickness of the auxiliary electrode 106 is too large, the absorption rate of visible light sometimes increases and the light extraction efficiency of the light-emitting device decreases. Therefore, in order to prevent the light extraction efficiency from decreasing, when a transparent conductive film is used for the auxiliary electrode 106, the upper limit of the thickness of the auxiliary electrode 106 is preferably 200 nm or less, more preferably 100 nm or less, further preferably 50 nm or less, and further preferably 30 nm or less. In addition, when a semi-transmissive and semi-reflective conductive film is used for the auxiliary electrode 106, the thickness is preferably 50 nm or less, more preferably 40 nm or less, further preferably 30 nm or less, and further preferably 20 nm or less. In addition, when a semi-transmissive and semi-reflective conductive film is used for both the second electrode 102 and the auxiliary electrode 106, the thickness of the stacked structure of the second electrode 102 and the auxiliary electrode 106 is preferably 50 nm or less, more preferably 40 nm or less, further preferably 30 nm or less, and further preferably 20 nm or less. By using the auxiliary electrode 106 having the above thickness, the auxiliary electrode 106 can improve the light extraction efficiency of the light emitting device by suppressing an increase in the absorption rate of visible light while ensuring the function as an optical adjustment layer.

[0083] Note that the absorption rate of visible light by a light-transmitting conductive film may differ depending on the wavelength of light. Figure 2A The light absorption rate of Ag:Mg films (thickness 15nm and 25nm) formed by co-evaporation on a quartz substrate in a volume ratio of Ag to Mg of 1:0.1 is shown. The measurement was performed using an ultraviolet visible spectrophotometer (manufactured by Hitachi, Ltd., U-4100). Note that Figure 2A The absorbance shown shows the ratio of the irradiation light intensity to the value obtained by subtracting the transmitted light intensity and the reflected light intensity from the irradiation light intensity. Figure 2A As shown in Figure 2, it can be seen that the absorption rate of the Ag:Mg film with a thickness of 25nm is greater than that of the Ag:Mg film with a thickness of 15nm. Figure 2A It is known that the Ag:Mg film has a greater light absorption rate at a short wavelength. When using materials having different absorption rates according to the wavelength of light for the auxiliary electrode 106R, the auxiliary electrode 106G, and the auxiliary electrode 106B, it is preferred to make the thickness of the auxiliary electrode 106R, the thickness of the auxiliary electrode 106G, and the thickness of the auxiliary electrode 106B different so as to have the thickness most suitable for each light-emitting device.

[0084] When a material with a higher absorption rate for short-wavelength light is used for the auxiliary electrodes 106R, 106G, and 106B, as in the case of the Ag:Mg film, and the light-emitting device 130R emits red light, the light-emitting device 130G emits green light, and the light-emitting device 130B emits blue light, Figure 1BAs shown, it is preferable to have a structure in which the thickness of the auxiliary electrode 106R is greater than the thickness of the auxiliary electrode 106G and the thickness of the auxiliary electrode 106G is greater than the thickness of the auxiliary electrode 106B. By adopting such a structure, the light extraction efficiency of each light emitting device can be improved.

[0085] in addition, Figure 2A It is shown that the absorption rate of the Ag:Mg film with a thickness of 15 nm is 6.49% and the absorption rate of the Ag:Mg film with a thickness of 25 nm is 9.56% at red light (wavelength of 700 nm), the absorption rate of the Ag:Mg film with a thickness of 15 nm is 6.97% and the absorption rate of the Ag:Mg film with a thickness of 25 nm is 13.14% at green light (wavelength of 546 nm), and the absorption rate of the Ag:Mg film with a thickness of 15 nm is 8.70% and the absorption rate of the Ag:Mg film with a thickness of 25 nm is 21.47% at blue light (wavelength of 436 nm). It can be seen that as the wavelength of the Ag:Mg film becomes shorter, the difference in absorption rate between the films with a thickness of 15 nm and 25 nm becomes larger. Therefore, it can be seen that as the wavelength becomes shorter, the effect of thinning the auxiliary electrode 106 becomes higher.

[0086] When a material having a higher absorption rate for short-wavelength light is used for the auxiliary electrode 106, such as the Ag:Mg film, the thickness of each auxiliary electrode is preferably controlled so that the absorption rate of the light emitting color of the light emitting device 130 of the auxiliary electrode 106 is less than 30%, preferably less than 10%, and more preferably less than 5%.

[0087] When a material having a higher absorption rate for short-wavelength light is used for both the second electrode 102 and the auxiliary electrode 106, as in the case of the Ag:Mg film, the thickness of each auxiliary electrode is preferably controlled in such a manner that the absorption rate of light of the luminous color of the light-emitting device of the stacked structure of the second electrode 102 and the auxiliary electrode 106 is less than 30%, preferably less than 10%, and more preferably less than 5%.

[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 50 nm or less, preferably 35 nm or less, and more preferably 20 nm or less, the thickness of the Ag:Mg film in the green light-emitting device is 45 nm or less, preferably 30 nm or less, and more preferably 15 nm or less, and the thickness of the Ag:Mg film in the blue light-emitting device is 35 nm or less, preferably 25 nm or less, and more preferably 15 nm or less. However, when the Ag:Mg film is used for both the second electrode 102 and the auxiliary electrode 106, the Ag:Mg film shows the thickness of the stacked structure of the second electrode 102 and the auxiliary electrode 106. By adopting this structure, the light extraction efficiency of each light-emitting device can be improved.

[0089] To illustrate the specific content, Figure 2B The following is shown: As a result of simulating the change in current efficiency caused by changing the thickness of the cathode (equivalent to the sum of the thickness of the second electrode 102 and the thickness of the auxiliary electrode 106 in one embodiment of the present invention) in the red light-emitting device, the green light-emitting device, and the blue light-emitting device, a relative comparison is shown when the current efficiency of the 25 nm thick cathode in each light-emitting device is 1. When it is assumed that Ag:Mg is used as the cathode, the simulation is performed using an organic EL-solar cell simulation (manufactured by Fluxim AG, setfos). Note that the following describes the efficiency of light emitted in a direction perpendicular to the light-emitting surface.

[0090] like Figure 2B As shown, the following results were obtained: in the red light-emitting device, the current efficiency when the cathode thickness is 25nm is higher than that when the cathode thickness is 15nm, in the green light-emitting device, the current efficiency when the cathode thickness is 15nm is higher than that when the cathode thickness is 25nm, and in the blue light-emitting device, the current efficiency when the cathode thickness is 15nm is significantly higher than that when the cathode thickness is 25nm. Because the absorptivity of red light by the Ag:Mg film is small, it can be said that the greater the cathode thickness of the red light-emitting device, the higher the current efficiency by utilizing the microcavity structure to improve the directivity in the direction perpendicular to the light-emitting surface. On the other hand, because the absorptivity of blue light by the Ag:Mg film is large, the smaller the cathode thickness of the blue light-emitting device, the more the light absorption caused by the cathode is suppressed, and the more the current efficiency is improved.

[0091] Thus, by changing the cathode thickness (or the thickness of the auxiliary electrode) of each color of the light-emitting device, the effect of each light-emitting device can be improved. Therefore, in a display device of one embodiment of the present invention, by separately manufacturing the auxiliary electrodes of each light-emitting device, the effect of each light-emitting device can be improved. Therefore, a low-power display device can be provided.

[0092] Figure 3A and Figure 3B as well as Figure 4A and Figure 4B Show Figure 1B A modified example of a cross-sectional view of a display device shown.

[0093] Figure 3A A display device according to one embodiment of the present invention is shown Figure 1BThe display device shown is different in that the light-emitting device 130B does not include the auxiliary electrode 106B. When the auxiliary electrode 106B is not included, in the light-emitting device 130B, the second electrode 102 (common electrode) is located on the EL layer 104B. In the light-emitting device 130B that does not include the auxiliary electrode 106B, it can be said that the EL layer 104B is located between the first electrode 101B and the second electrode 102, and it is in contact with the second electrode 102. Therefore, by adopting a structure in which the auxiliary electrode 106 is provided in a part of the light-emitting devices (here, the light-emitting device 130R and the light-emitting device 130G), and the auxiliary electrode 106 is not provided in other light-emitting devices (here, the light-emitting device 130B), the light extraction efficiency of each light-emitting device can also be improved. In this way, when a structure in which the auxiliary electrode 106B is not provided is adopted, the manufacturing process of the display device can be simplified, thereby reducing the manufacturing cost.

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

[0095] Note that Figure 1B and Figure 3A In each of the light-emitting devices 130 shown, the uppermost layer of the EL layer 104 is an electron injection layer or a charge generation layer, so that electrons can be easily injected from the second electrode 102 (common electrode) into the EL layer 104, thereby reducing the driving voltage of each light-emitting device 130. As materials for the electron injection layer or the charge generation layer, alkali metals such as lithium (Li) or compounds of the alkali metals, alkaline earth metals, and compounds of the alkaline earth metals having a small work function can be typically cited. Note that in the light-emitting device 130B without the auxiliary electrode 106B, when an alkali metal or a compound of the alkali metal is used as the uppermost layer of the EL layer 104B, when the EL layer 104B is formed by photolithography or when the sacrificial layer is peeled off, the film quality of the EL layer 104B may be degraded due to the influence of oxygen, water, or a chemical solution in the atmosphere, thereby increasing the driving voltage of the light-emitting device 130B or reducing the current efficiency.

[0096] Therefore, in Figure 3A In the display device shown, it is more preferable that an electron injection layer of an alkali metal or a compound not containing the alkali metal is used as the uppermost layer of the EL layer 104B. The electron injection layer of an alkali metal or a compound not containing the alkali metal will be described in the later embodiment.

[0097] Notice, Figure 3A Although the structure in which the auxiliary electrode is not provided in the light emitting device 130B is shown, one embodiment of the present invention is not limited to this, and a structure in which the auxiliary electrode is not provided in the light emitting device 130G may be adopted.

[0098] Figure 3B Show Figure 3A A modified example of a cross-sectional view of a display device shown. Figure 3B A display device according to one embodiment of the present invention is shown Figure 3A The display device shown differs in that a common layer 107 is included.

[0099] exist Figure 3B In the embodiment, the light emitting device 130R includes a first electrode 101R (pixel electrode) composed 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] In addition, Figure 3B In the embodiment, the light-emitting device 130G includes 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] In addition, Figure 3B In the embodiment, the light-emitting device 130B includes 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] Note that in the following description, when describing matters common to the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, they may be simply referred to as the conductive layer 151. In the following description, when describing matters common to the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B, they may be simply referred to as the conductive layer 152.

[0103] In addition, Figure 3B In the embodiment, the common layer 107 is preferably an electron injection layer. The common layer 107 is a layer formed after the sacrificial layer is removed by processing each EL layer using photolithography in the manufacturing process. Therefore, it is not easily affected by oxygen or water in the atmosphere, chemical solution, etc., so the range of material selection can be expanded. Since the common layer 107 is an electron injection layer, even if the uppermost layer of the EL layer 104B is not an electron injection layer, electrons can be easily injected from the second electrode 102 into the EL layer 104B through the common layer 107, thereby reducing the driving voltage of the light-emitting device 130B.

[0104] Note that the common layer 107 is located between the auxiliary electrode 106R and the second electrode 102 in the light-emitting device 130R, and is located between the auxiliary electrode 106B and the second electrode 102 in the light-emitting device 130B, and thus the common layer 107 is preferably configured in a manner that does not hinder the conduction between the auxiliary electrode 106 and the second electrode 102. For example, when the thickness of the common layer 107 is 10 nm or less, and more preferably 5 nm or less, it is preferred because it does not hinder the conduction between the auxiliary electrode 106 and the second electrode 102. Alternatively, it is preferred to use a material with high conductivity as the common layer 107.

[0105] In addition, the display device according to one embodiment of the present invention may not include the first insulating layer 127 . Figure 4A The display device shown is Figure 1B The difference is that the first insulating layer 127 is not provided. By not providing the first insulating layer 127, the manufacturing cost can be reduced.

[0106] Although in Figure 1A and Figure 1B , Figure 3A and Figure 3B as well as Figure 4A The example shows that the ends of the EL layer 104 and the auxiliary electrode 106 are located on the inner side of the ends of the conductive layers 151 and 152 of the first electrode, but one embodiment of the present invention is not limited to this. The ends of the EL layer 104 and the auxiliary electrode 106 can also be located on the outer side of the ends of the conductive layers 151 and 152. Figure 4BA display device having the following structure is shown: 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] in addition, Figure 4B The third insulating layer 125b is shown as an example, which is included on the first insulating layer 127. The third insulating layer 125b preferably has the same structure as the second insulating layer 125a. By providing the third insulating layer 125b on the first insulating layer 127 to separate the first insulating layer 127 from the second electrode 102, at least one of oxygen and moisture can be suppressed 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 electrode (101R, 101G, 101B) (pixel electrode) of the light-emitting device preferably has a stacked structure. Figure 1B In the illustrated example, 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, for example, 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 obtained by appropriately combining these metals can be used.

[0110] As the conductive layer 152, an oxide containing any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, it is preferable to use a conductive oxide containing any 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, 4.0 eV or more, so it can be preferably used as the conductive layer 152.

[0111] Each of the conductive layer 151 and the conductive layer 152 may have a stacked structure including a plurality of layers of different materials. In this case, the conductive layer 151 may include a layer using a material that can be used for the conductive layer 152 such as a conductive oxide, and the conductive layer 152 may include 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, the layer in contact with the conductive layer 152 may be a layer using a material that can be used for the conductive layer 152.

[0112] Note that the 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 less than 90°. In this case, the conductive layer 152 provided along the side of the conductive layer 151 also has a tapered shape. By making the side of the conductive layer 152 have a tapered shape, the coverage of the EL layer 104 provided along the side of the conductive layer 152 can be improved. Note that the end of the conductive layer 151 does not have a tapered shape and may be approximately perpendicular to the substrate surface. In this case, the interval between adjacent EL layers is narrowed, thereby providing a light-emitting device with a good aperture ratio.

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

[0114] Implementation Method 2 In this embodiment, refer to FIG. 5A to FIG. 10C An example of a method for manufacturing a display device according to one embodiment of the present invention is described below. FIG. 5A to FIG. 10C , using the equivalent of following Figure 1A The cross-sectional views along the dashed line A1 - A2 and the dashed line B1 - B2 in the figure illustrate an example of the manufacturing method.

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

[0116] In addition, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using wet deposition methods such as spin coating, dipping, spraying, inkjet, dispenser, screen printing, offset printing, doctor knife, slit coating, roll coating, curtain coating or doctor knife coating.

[0117] In addition, when processing a thin film constituting the display device, it is possible to perform processing using, for example, photolithography.

[0118] In the photolithography method, as the light used for exposure, for example, i-line (wavelength 365nm), g-line (wavelength 436nm), h-line (wavelength 405nm) or a mixture of these lights can be used. In addition, ultraviolet light, KrF laser or ArF laser, etc. can also be used. In addition, exposure can also be performed using liquid immersion exposure technology. In addition, as the light used for exposure, extreme ultraviolet (EUV: Extreme Ultra-violet) light or X-rays can also be used. In addition, instead of the light used for exposure, an electron beam can also be used.

[0119] For etching of the thin film, dry etching, wet etching, sand blasting, or the like can be used.

[0120] First, if Figure 5A As shown in the figure, 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] As the substrate, a substrate having heat resistance at least enough to withstand the subsequent heat treatment can be used. For example, a glass substrate; a quartz substrate; a sapphire substrate; a ceramic substrate; an organic resin substrate; or a semiconductor substrate such as a single crystal semiconductor substrate or a polycrystalline semiconductor substrate made of silicon or silicon carbide, a compound semiconductor substrate such as silicon germanium, an SOI substrate, etc. can be used.

[0122] Then, if Figure 5A As shown in FIG. 1 , openings reaching the conductive layer 172 are formed in the insulating layer 175, the insulating layer 174, and the insulating layer 173. Next, the plug 176 is formed so as to be embedded in the opening.

[0123] Then, if Figure 5A As shown in FIG. 1 , a conductive film 151f, which will later become the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, and the conductive layer 151C, is formed on the plug 176 and the insulating layer 175. As the conductive film 151f, for example, a metal material can be used.

[0124] Then, if Figure 5A As shown in FIG. 1 , a resist mask 191 is formed on the conductive film 151f. The resist mask 191 can be formed by applying a photosensitive material (photoresist), exposing it to light, and developing it.

[0125] Then, if Figure 5B As shown, for example, the conductive film 151f is removed in a region that does not overlap with the resist mask 191. Thus, the conductive layer 151 is formed.

[0126] Then, if Figure 5C As shown, the resist mask 191 is removed. The resist mask 191 can be removed by ashing using oxygen plasma, for example.

[0127] Then, if Figure 5D As shown, an insulating film 156f, which will later become the insulating layer 156R, the insulating layer 156G, the insulating layer 156B and the insulating layer 156C, is formed on the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, the conductive layer 151C and the insulating layer 175.

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

[0129] Then, if Figure 5E As shown, by processing the insulating film 156f, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B and the insulating layer 156C are formed.

[0130] Then, if Fig. 6A As shown, 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] As the conductive film 152f, for example, a conductive oxide can be used. The conductive film 152f can also have a stacked-layer structure.

[0132] Then, if Figure 6B As shown, 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] Next, 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. Figure 6C As shown, the organic compound film 103Rf is not formed on the conductive layer 152C.

[0134] Then, if Figure 6C As shown, the conductive film 106Rf, the protective film 158Rf, and the sacrificial film 159Rf are formed on the organic compound film 103Rf.

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

[0136] The protective film 158Rf is 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 large etching selectivity ratio with the organic compound film 103Rf and the conductive film 106Rf. The sacrificial film 159Rf is a film having a large etching selectivity ratio with the protective film 158Rf and the conductive film 106Rf.

[0137] In addition, the protective film 158Rf and the sacrificial film 159Rf are formed at a temperature lower than the heat resistance 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. to 200° C., preferably 100° C. to 150° C., and more preferably 100° C. to 120° C.

[0138] As the protective film 158Rf and the sacrificial film 159Rf, a film that can be removed by a wet etching method or a dry etching method is preferably used.

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

[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] As the protective film 158Rf and the sacrificial film 159Rf, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing the metal materials can be used. In particular, low melting point materials such as aluminum and silver are preferably used. By using a metal material that can shield ultraviolet rays as one or both of the protective film 158Rf and the sacrificial film 159Rf, it is possible to suppress ultraviolet rays from irradiating the organic compound film 103Rf during pattern exposure and suppress the degradation of the organic compound film 103Rf, which is preferred.

[0142] In addition, as 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) or indium tin oxide containing silicon can be used respectively.

[0143] Note that element M (M is one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten and magnesium) can also be used in the above-mentioned metal oxides instead of the above-mentioned gallium.

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

[0145] In addition, various inorganic insulating films can be used as the protective film 158Rf and the sacrificial film 159Rf. In particular, an oxide insulating film is preferred because its adhesion to the organic compound film 103Rf is higher than that of a nitride insulating film. A nitride insulating film is preferred because it is a dense film with high barrier properties. As the nitride insulating film, a silicon nitride film is particularly preferably used.

[0146] Then, if Figure 6C As shown, a resist mask 190R is formed. The resist mask 190R can be formed by applying a photosensitive resin (photoresist), exposing and developing the photosensitive resin.

[0147] Resist mask 190R is provided at a position overlapping conductive layer 152R. Resist mask 190R is preferably provided also at a position overlapping conductive layer 152C. This can prevent conductive layer 152C from being damaged during the manufacturing process of the display device.

[0148] Next, a portion 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. Next, a portion of the protective film 158Rf is removed using the sacrificial layer 159R as a mask (also referred to as a hard mask) to form a protective layer 158R.

[0149] By using the wet etching method, the damage to the organic compound film 103Rf during the 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 the wet etching method is used, for example, it is preferable to use a developer, an alkali aqueous solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, an acid aqueous solution such as a chemical solution of dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid thereof.

[0150] In addition, when dry etching is used in processing the protective film 158Rf, degradation 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 by the same method as the resist mask 191 .

[0152] Next, the conductive film 106Rf is processed to form the auxiliary electrode 106R. For example, the auxiliary electrode 106R is formed by removing a portion of the conductive film 106Rf using the sacrificial layer 159R and the protective layer 158R as a hard mask.

[0153] Next, the organic compound film 103Rf is processed to form the EL layer 103R. For example, the EL layer 103R is formed by removing a portion of the organic compound film 103Rf using the sacrificial layer 159R and the protective layer 158R as a hard mask.

[0154] Therefore, if Fig.6D As shown in FIG. 1 , a stacked 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. In addition, the conductive layer 152G and the conductive layer 152B are exposed.

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

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

[0157] In addition, an oxygen-containing gas may be used as the etching gas. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficient etching rate. Therefore, damage to the organic compound film 103Rf can be suppressed. In addition, defects such as adhesion of reaction products generated during etching can be suppressed.

[0158] When using the dry etching method, for example, it is preferred to use a gas containing one or more of the 18th group elements such as H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, He, Ar as the etching gas. Alternatively, it is preferred to use a gas containing one or more of the above gases and oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas.

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

[0160] The organic compound film 103Gf can be formed using the same method as that which can be used for forming the organic compound film 103Rf.

[0161] Then, if Fig. 7A As shown, a protective film 158Gf and a sacrificial film 159Gf are sequentially formed. 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 at a position overlapping with the conductive layer 152G.

[0163] Next, a portion 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. Next, the sacrificial layer 159G is used as a mask to remove a portion of the protective film 158Gf, thereby forming the protective layer 158G. Next, the organic compound film 103Gf is processed to form the EL layer 103G. Thus, as shown in FIG. Figure 7B As shown, a stacked 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. In addition, the sacrificial layer 159R and the conductive layer 152B are exposed.

[0164] Then, if Figure 7C As shown in FIG. 1 , an organic compound film 103Bf which will later become the EL layer 103B is formed.

[0165] The organic compound film 103Bf can be formed using the same method as that which can be used for forming the organic compound film 103Rf.

[0166] Then, if Figure 7CAs shown, a protective film 158Bf and a sacrificial film 159Bf are formed in sequence. 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 that can be used for the protective film 158Rf and the sacrificial film 159Rf. The materials and forming methods of the resist mask 190B are the same as those that can be used for the resist mask 190R.

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

[0168] Then, if Fig.7D As shown, a portion of the sacrificial film 159Bf is removed using the resist mask 190B, thereby forming the sacrificial layer 159B. The sacrificial layer 159B preferably remains on the conductive layer 152B. Then, the resist mask 190B is removed. Next, the sacrificial layer 159B is used as a mask to remove a portion of the protective film 158Bf to form the protective layer 158B. Next, the organic compound film 103Bf is processed to form the EL layer 103B. For example, the sacrificial layer 159B and the protective layer 158B are used as a hard mask to remove a portion of the organic compound film 103Bf to form the EL layer 103B.

[0169] Therefore, if Fig.7D As shown in FIG. 1 , a stacked structure of the EL layer 103B, the protective layer 158B, and the sacrificial layer 159B remains on the conductive layer 152B. In addition, the sacrificial layer 159R and the sacrificial layer 159G are exposed.

[0170] Note that the side surfaces of the EL layer 103R, the EL layer 103G, and the EL layer 103B are preferably perpendicular or substantially perpendicular to the surface on which they are formed. For example, the angle formed by the surface on which they are formed and these side surfaces is preferably not less than 60 degrees and not more than 90 degrees.

[0171] As described above, the distance between two adjacent EL layers among the EL layer 103R, the EL layer 103G, and the EL layer 103B formed by photolithography can be reduced 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 reduced to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. Here, for example, the distance can be specified based on the distance between the opposite ends of two adjacent EL layers among the EL layer 103R, the EL layer 103G, and the EL layer 103B. In this way, by reducing the distance between the island-shaped EL layers, a display device with high definition and a large aperture ratio can be provided. In addition, the distance between the first electrodes of adjacent light-emitting devices can be reduced, for example, the distance can be reduced 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 device for LSI, the distance can be reduced to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less.

[0172] Then, if Fig. 8A As shown, the sacrificial layer 159R, the sacrificial layer 159G and the sacrificial layer 159B are preferably removed.

[0173] The sacrificial layer removal step can be performed using the same method as the sacrificial film processing step. In particular, wet etching can reduce damage to the EL layer 103R, the EL layer 103G, and the EL layer 103B when removing the sacrificial layer, compared with dry etching.

[0174] Alternatively, the sacrificial layer may be removed by dissolving it in a polar solvent such as water or alcohol. Examples of the alcohol include ethanol, methanol, isopropyl alcohol (IPA), and glycerol.

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

[0176] Then, if Figure 8B As shown, an insulating film 125af which will later become a second insulating layer 125a is formed.

[0177] Then, if Figure 8C As shown in FIG. 1 , an insulating film 127 f which will later become a first insulating layer 127 is formed on the insulating film 125 af .

[0178] The insulating film 125af and the insulating film 127f are preferably deposited by a formation 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 deposited by a formation method that causes less damage to the EL layers than the insulating film 127f.

[0179] In addition, the insulating film 125af and the insulating film 127f are formed at a temperature lower than the heat resistance temperature of each EL layer. By increasing the substrate temperature when depositing the insulating film 125af, the insulating film 125af can be a film with a low impurity concentration and high barrier properties against at least one of water and oxygen even if it is thin.

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

[0181] As the insulating film 125af, it is preferred to form an insulating film with a thickness of 5 nm or 10 nm 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, deposition damage can be reduced, and a film with high coverage can be deposited, so it is preferred. In addition, as the insulating film 125af, it is preferred to form an aluminum oxide film by the ALD method. Alternatively, the insulating film 125af is preferably formed by the PEALD method. When the PEALD method is used, it is preferred because a film with high coverage can be deposited and a film with high barrier properties can be formed. As the insulating film 125af, for example, it is preferred to form a silicon nitride film by the PEALD method. Alternatively, as the insulating film 125af, after forming an aluminum oxide film by the ALD method, it is preferred to form a silicon-based insulating film by the PEALD method, and it is particularly preferred to form a silicon nitride film.

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

[0184] Next, exposure is performed to sensitize a portion of the insulating film 127f with visible light or ultraviolet light. The first insulating layer 127 is formed in a region sandwiched between any two of the conductive layer 152R, the conductive layer 152G, and the conductive layer 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 region in which the insulating film 127f is exposed. In this embodiment, the first insulating layer 127 is processed so that the first insulating layer 127 has a portion overlapping with the top surface of the conductive layer 151.

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

[0187] Then, if Fig.9A As shown, development is performed to remove the exposed region in the insulating film 127f, thereby forming a first insulating layer 127a.

[0188] Next, the entire substrate is preferably exposed to visible light or ultraviolet light to irradiate the first insulating layer 127a. The energy density of the exposure is preferably greater than 0 mJ / cm 2 And 800mJ / cm 2 Below, more preferably greater than 0 mJ / cm 2 And 500mJ / cm 2 By performing such exposure after development, the transparency of the first insulating layer 127 can be improved in some cases. In addition, the substrate temperature required for heat treatment in a later step for deforming the first insulating layer 127a into a tapered shape can be reduced in some cases.

[0189] Here, by providing an oxygen blocking insulating layer (for example, an aluminum oxide film, a silicon nitride film, etc.) as the protective layer 158R, the protective layer 158G, the protective layer 158B, and the insulating film 125af, diffusion of oxygen into the EL layer 103R, the EL layer 103G, and the EL layer 103B can be reduced.

[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 deformed into a first insulating layer 127 having a tapered side. 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, and more preferably 70°C to 130°C. The heating atmosphere can be either an air atmosphere or an inert gas atmosphere. In addition, the heating atmosphere can be either an air atmosphere or a reduced pressure atmosphere. Thus, the adhesion between the first insulating layer 127 and the second insulating layer 125a can be improved, and the corrosion resistance of the first insulating layer 127 can also be improved.

[0191] By providing the protective layers 158R, 158G, 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. Thus, the reliability of the light-emitting device can be improved.

[0192] Next, a photomask is formed on the first insulating layer 127, and etching is performed to remove a portion of the insulating film 125af. Thus, a second insulating layer 125a ( Fig. 9C ). Note that this etching process is sometimes referred to as a first etching process hereinafter.

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

[0194] When dry etching is performed, a chlorine-based gas is preferably used. As the chlorine-based gas, one gas selected from Cl2, BCl3, SiCl4, and CCl4, or a mixture of two or more of the above gases, can be used. In addition, one gas selected from oxygen gas, hydrogen gas, helium gas, and argon gas, or a mixture of two or more of the above gases can be appropriately added to the chlorine-based gas.

[0195] As a dry etching device, a dry etching device having a high-density plasma source can be used. As a dry etching device having a high-density plasma source, for example, an inductively coupled plasma (ICP: Inductively Coupled Plasma) etching device can be used. Alternatively, a capacitively coupled plasma (CCP: Capacitively Coupled Plasma) etching device including parallel plate electrodes can be used.

[0196] In addition, the first etching treatment is preferably performed by wet etching. By using the wet etching method, the damage to the EL layer 103R, the EL layer 103G, and the EL layer 103B can be reduced compared with the case of using the dry etching method. For example, an alkaline solution can be used for wet etching. For example, TMAH as an alkaline solution can be used in the wet etching of the aluminum oxide film. In addition, an acidic solution containing fluoride can also be used. In this case, wet etching can be performed by a puddle method.

[0197] As the first etching process, it is preferable to select an etching method that can ensure an etching selectivity ratio between the protective layer 158R, the protective layer 158G, and the protective layer 158B and the insulating film 125af.

[0198] Then, if Fig. 10AAs shown in FIG. 1 , etching is performed using the second insulating layer 125a and the first insulating layer 127 as masks to remove a portion of the protective layer 158R, the protective layer 158G, and the protective layer 158B. As a result, an opening is formed in each of the protective layer 158R, the protective layer 158G, and the protective layer 158B, and the top surfaces of the auxiliary electrodes 106R, the auxiliary electrodes 106G, the EL layer 103B, and the conductive layer 152C are exposed. Note that this etching process may be referred to as a second etching process hereinafter.

[0199] In addition, the second etching process is preferably performed by wet etching. By using the wet etching method, the damage to the auxiliary electrode 106R, the auxiliary electrode 106G and the EL layer 103B can be reduced compared with the case of using the dry etching method. For example, the wet etching can be performed using an alkaline solution or an acidic solution. In order to prevent the EL layer 103B from dissolving, it is preferable to use an aqueous solution.

[0200] Then, if Fig. 10B As shown, a common layer 107 and a second electrode 102 are formed over 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 sputtering or vacuum evaporation.

[0201] Then, if Fig. 10C As shown, a protective layer 131 is formed on the second electrode 102. The protective layer 131 can be formed by vacuum evaporation, sputtering, CVD, ALD, etc. In particular, by using the PEALD method, a film with high barrier properties can be formed at a low temperature.

[0202] Next, 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 a method for manufacturing a display device of 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 not formed using a high-precision metal mask, but are formed by processing after depositing a film on the entire surface, so that the island layer can be formed with a uniform thickness. In addition, a high-definition display device or a display device with a high aperture ratio can be realized. In addition, even if the clarity or aperture ratio is high and the distance between sub-pixels 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 sub-pixels. Therefore, leakage current between sub-pixels can be suppressed. Thus, crosstalk can be prevented to realize a display device with extremely high contrast. In addition, even a display device including a series-type light-emitting device manufactured by photolithography can provide a display device with good characteristics.

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

[0205] Implementation 3 In this embodiment, a structure of an organic EL element which is a light-emitting device including an EL layer is described with reference to FIG 11. The organic EL element is a light-emitting device including an EL layer including 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 is used as an anode, and the other is used as a cathode. FIG11 is an example of a case where the first electrode 101 is an 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). Specifically, examples include indium oxide-tin oxide (ITO: IndiumTinOxide), indium oxide-tin oxide containing silicon or silicon oxide (ITSO: IndiumTinSiliconOxide), indium oxide-zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), and the like. Although these conductive metal oxide films are usually formed by sputtering, they can also be formed by a sol-gel method. As an example of a formation method, a method of forming indium oxide-zinc oxide by sputtering using a target material having 1 wt% to 20 wt% of zinc oxide added to indium oxide can be cited. In addition, indium oxide (IWZO) containing tungsten oxide and zinc oxide can be formed by sputtering using a target material having 0.5 wt% to 5 wt% of tungsten oxide and 0.1 wt% to 1 wt% of zinc oxide added to indium oxide. In addition, as materials for the anode, 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) can be cited. In addition, the anode can also be a layer in which the above materials are stacked. For example, a film of Al, Ti, and ITSO stacked in sequence on Ti has high efficiency due to good reflectivity and can achieve a high resolution of thousands of ppi, so it is preferred. In addition, graphene can also be used as a material for the anode. In addition, by using a composite material that can constitute the hole injection layer 111 described later for a layer in contact with the anode (typically a hole injection layer), it is possible to select an electrode material without taking into account the work function.

[0208] The hole injection layer 111 is in contact with the anode and has a function of facilitating hole injection into the EL layer 103. The hole injection layer 111 can be formed using a phthalocyanine compound or complex such as phthalocyanine (abbreviated as H2Pc), copper phthalocyanine (abbreviated as CuPc), etc.; an aromatic amine compound such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTPD), etc.; or a polymer compound such as poly(3,4-ethylenedioxythiophene) / (polystyrenesulfonic acid) (abbreviated as PEDOT / PSS), etc.

[0209] In addition, the hole injection layer 111 may be composed of a substance having electron acceptor properties. As the substance having electron acceptor properties, an organic compound having an electron withdrawing group (halogen or cyano group) may be used, such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), 2-(7-dicyanomethylidene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile, and the like. In particular, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a fused aromatic ring having multiple heteroatoms are thermally stable and therefore are preferred. In addition, [3] axial ene derivatives including electron-withdrawing groups (especially halogen groups such as fluorine groups and cyano groups) are particularly preferred because their electron acceptability is very high. Specifically, examples thereof include: α, α', α"-1,2,3-cyclopropane tris(ylidene) tris[4-cyano-2,3,5,6-tetrafluorophenylacetonitrile], α, α', α"-1,2,3-cyclopropane tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenylacetonitrile], α, α', α"-1,2,3-cyclopropane tris[2,3,4,5,6-pentafluorophenylacetonitrile], etc. As a substance having electron acceptor properties, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used in addition to the above-mentioned organic compounds.

[0210] In addition, the hole injection layer 111 is preferably formed of a composite material including the above-mentioned material having electron accepting properties and an organic compound having hole transporting properties.

[0211] As the organic compound with hole transport property used in the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, high molecular weight compounds (oligomers, dendrimers, polymers, etc.) can be used. As the organic compound with hole transport property used in the composite material, it is preferred to use an organic compound with a hole mobility of 1×10 -6 cm 2 / Vs or more organic compound. The organic compound with hole transport properties used in the composite material is preferably a compound containing a fused aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the fused aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferred. In addition, as the π-electron-rich heteroaromatic ring, a fused aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton and a thiophene skeleton is preferred, and specifically a carbazole ring, a dibenzothiophene ring or a ring in which these rings are also fused with an aromatic ring or a heteroaromatic ring is preferred.

[0212] Such an organic compound having hole transport properties preferably has any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton and an anthracene skeleton. In particular, it can be an aromatic amine having a substituent including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine including a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine through an arylene group. Note that when these organic compounds having hole transport properties are substances including N, N-bis(4-biphenyl)amino groups, a light-emitting device with a long life can be manufactured, so it is preferred.

[0213] Specific examples of the organic compound having a hole transport property include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4"-phenyltriphenylamine (abbreviated as BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviated as BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1 ,2-d]furan-8-amine (abbreviated as BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviated as BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviated as DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-benzidine (abbreviated as ThBA1BP), 4-(2-naphthyl)-4',4"-diphenyltriphenylamine (abbreviated as BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4"-diphenyltriphenylamine (abbreviated as BBAβNBi), 4,4'- diphenyl-4"-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviated as: BBAαNβNB), 4,4'-diphenyl-4"-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviated as: BBAαNβNB-03), 4,4'-diphenyl-4"-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviated as: BBAPβNB-03), 4,4'-diphenyl-4"-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviated as: BBA(βN2)B), 4,4'-diphenyl-4"-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviated as: BBA(βN2)B-03), 4,4'-diphenyl-4"-(4;2'-binaphthyl- 1-yl) triphenylamine (abbreviated as: BBAβNαNB), 4,4'-diphenyl-4"-(5;2'-binaphthyl-1-yl) triphenylamine (abbreviated as: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4"-phenyltriphenylamine (abbreviated as: TPBiAβNB), 4-(3-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4"-phenyltriphenylamine (abbreviated as: mTPBiAβNBi), 4-(4-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4"-phenyltriphenylamine (abbreviated as: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviated as: 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)phenyl]tri(1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4"-phenyltriphenylamine (abbreviation: YGTBiβNB), 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 (abbreviated as: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviated as: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviated as: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)dibenzofuran-4-amine (abbreviated as: 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-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, etc.

[0214] In addition, as materials with hole transport properties, as other aromatic amine compounds, 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), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can also be used.

[0215] By forming the hole injection layer 111, hole injection properties can be improved, so that a light-emitting device with a low driving voltage can be obtained.

[0216] Furthermore, among substances having electron accepting properties, organic compounds having electron accepting properties can be easily formed by vapor deposition and are therefore easy-to-use materials.

[0217] The hole transport layer 112 is formed of an organic compound having a hole transport property. The organic compound having a hole transport property preferably has a 1×10 -6 cm 2 / Vs and above hole mobility.

[0218] Examples of the hole-transporting material include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as mBPAFLP), and 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBA1BP). , 4,4'-diphenyl-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBANB), 4,4'-di(1-naphthyl)-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluorene-2-amine (abbreviated as PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviated as PCBASF), etc.;1,3-Bis(N-carbazolyl)benzene (abbreviated as: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviated as: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as: CzTP), 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviated as: PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviated as: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H- 3,3'-bicarbazole (abbreviated as mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviated as βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviated as βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviated as 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':3',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'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3 , 3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviated as PCCzTp), 9,9'-bis(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenyl-2-yl)-9'-[1,1':3',1"-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]phenanthrene (abbreviated as PCPPn) and the like;Compounds having a thiophene skeleton, such as 4,4',4"-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluorene-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-fluorene-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among them, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferred because they have good reliability and high hole transport properties and contribute to lowering the driving voltage. Note that as the material constituting the hole transport layer 112, the substances listed as the materials having hole transport properties for the composite material used for the hole injection layer 111 can also be appropriately used. ;

[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. Note that the light-emitting layer 113 may also contain other materials. Alternatively, two layers having different compositions may be stacked.

[0220] The light-emitting substance may be a fluorescent substance, a phosphorescent substance, a substance exhibiting thermally activated delayed fluorescence (TADF), or other light-emitting substances.

[0221] In the light-emitting layer, materials that can be used as the fluorescent substance include, for example, the following substances. Note that other fluorescent substances can also be used.

[0222] Examples thereof include 5,6-bis[4-(10-phenyl-9-anthracenyl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthracenyl)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-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviated as: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthracenyl)triphenylamine (abbreviated as: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2- triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butyl perylene (abbreviation: TBP), 4-(10-phenyl-9-anthracenyl)-4'-(9-phenyl-9H-carbazole-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-carbazole-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-anthracenyl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthracenyl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthracenyl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthracenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-Bis(biphenyl-2-yl)-N-[4-(9H-carbazole-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-diphenylnaphthacene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-ylidene)malononitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizine-9- 1,2-diaminobenzene (abbreviated as: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)naphthocene-5,11-diamine (abbreviated as: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviated as: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviated as: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl -2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malononitrile (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)vinyl]-4H-pyran-4-ylidene}malononitrile (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-carbazole-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 represented by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 are preferred because they have high hole-trapping properties, high luminous efficiency, and high reliability. ,

[0223] In addition, 5,9-diphenyl-5,9-diaza-13b-borazinahpatho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-(diphenyl-3-yl)-N,N,5,11-tetraphenyl-5,9-dihydro-5,9-diaza-13b-borazinahpatho[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]benzazaboro[2,3,4-kl]phenazepine can be used as appropriate. Boron-7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetrakis(4-tert-butylphenyl)-5H,9H-[1,4]benzoazaboro[2,3,4-kl]benzoazaboro-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzoazaboro[2,3,4-kl]phenazineboro (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]benzazaboro[2,3,4-kl][1,4]benzazaboro[4',3',2':4,5][1,4]benzazaboro[3,2-b]phenazoneboro-7,13-diamine (abbreviation: ν-DABNA), 2-(4-tert-butylphenyl)benzo[5,6]indole[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), and especially compounds having a diaza-borazine-naphtho-anthracene skeleton, have narrow emission spectra and can produce blue light emission with good color purity, so they can be appropriately used.

[0224] In addition, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazole-9-yl]-2,5,15,18-tetra(1,1-dimethylethyl)indol[3,2,1-de]indol[3',2',1':8,1][1,4]benzazaboro[2,3,4-kl]phenazoneboro (abbreviation: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazole-9-yl]-2,5,15,18-tetra(1,1-dimethylethyl)indol[3',2',1'-de]indol[3',2',1':8,1][1,4]benzazaboro[2,3,4-kl]phenazoneboro (abbreviation: BBCz-Y), etc. can also be appropriately used.

[0225] When a phosphorescent substance is used as a light-emitting substance in the light-emitting layer, examples of usable materials include the following substances.

[0226] Examples include 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) (abbreviated as [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Mptz)3]), and the like. tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Prptz1-Me)3]) and the like; fac-tris[1-(2,6-diisopropyl)- phenyl)-2-phenyl-1H-imidazole]iridium (III) (abbreviated as [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium (III) (abbreviated as [Ir(dmpimpt-Me)3]), tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazole-2-yl-κ Organic metal 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) (abbreviated as [Ir(cb)3]), and organic metal complexes with a benzimidazole skeleton, such as bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 '] iridium (III) tetrakis (1-pyrazolyl) borate (abbreviated as: FIr6), bis [2- (4', 6'-difluorophenyl) pyridinium-N, C 2 '] iridium (III) picolinate (abbreviated as FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinium-N,C 2 '}iridium(III) picolinate (abbreviated as [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2 '] Iridium (III) acetylacetonate (abbreviated as FIracac) and other organic metal iridium complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands. The above substances are compounds that emit blue phosphorescence and have a luminescence peak in the wavelength region of 450nm to 520nm.

[0227] In addition, tris(4-methyl-6-phenylpyrimidinyl)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidinyl)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonate)bis(6-methyl-4-phenylpyrimidinyl)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonate)bis(6-tert-butyl-4-phenylpyrimidinyl)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonate)bis(6-tert-butyl-4-phenylpyrimidinyl)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonate)bis[6-(2-norbornyl)-4-phenylpyrimidinyl]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonate)bis[5-methyl -6-(2-methylphenyl)-4-phenylpyrimidinyl]iridium(III) (abbreviated as [Ir(mpmppm)2(acac)]), (acetylacetonate)bis(4,6-diphenylpyrimidinyl)iridium(III) (abbreviated as [Ir(dppm)2(acac)]) and the like organic metal iridium complexes having a pyrimidine skeleton; (acetylacetonate)bis(3,5-dimethyl-2-phenylpyrazinyl)iridium(III) (abbreviated as [Ir(mppr-Me)2(acac)]), (acetylacetonate)bis(5-isopropyl-3-methyl-2-phenylpyrazinyl)iridium(III) (abbreviated as [Ir(mppr-iPr)2(acac)]) and the like organic metal iridium complexes having a pyrazine skeleton; tris(2-phenylpyridinyl-N,C 2’ )iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinium-N,C 2’ )iridium(III)acetylacetonate (abbreviated as [Ir(ppy)2(acac)]), bis(benzo[h]quinoline)iridium(III)acetylacetonate (abbreviated as [Ir(bzq)2(acac)]), tris(benzo[h]quinoline)iridium(III) (abbreviated as [Ir(bzq)3]), tris(2-phenylquinoline-N,C 2’ )iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinoline-N,C 2’)iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mbfpypy-d3)]), [2-d3-methyl-(2-pyridyl -κN)benzofurano[2,3-b]pyridine-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy-d3)]), tris{2-[5-(methyl-d3)-4-phenyl-2-pyridyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d3)3]), [2-(4-d3-methyl-5-phenyl -2-pyridyl-κN2)phenyl-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mdppy-d3)]), [2-methyl-(2-pyridyl-κN)benzofurano[2,3-b]pyridine-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium (abbreviated as [Ir(ppy)2(mdppy)]) and other organic metal iridium complexes having a pyridine skeleton; and tris(acetylacetonato)(monophenanthroline)terbium (III) (abbreviated as [Tb(acac)3(Phen)] and other rare earth metal complexes. The above substances are mainly compounds that exhibit green phosphorescence and have a luminescence peak in the wavelength region of 500nm to 600nm. In addition, since the organic metal iridium complex having a pyrimidine skeleton has particularly excellent reliability and luminescence efficiency, it is particularly preferred.

[0228] In addition, organic gold metals having a pyrimidine skeleton include: (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinyl]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinyl](dipivaloylmethanone)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di(naphthalene-1-yl)pyrimidinyl](dipivaloylmethanone)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]) and the like. Iridium complexes; (acetylacetonato)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazine)(dipivaloylmethanone)iridium(III) (abbreviated as [Ir(tppr)2(dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxaline]iridium(III) (abbreviated as [Ir(Fdpq)2(acac)]) and other organometallic iridium complexes with pyrazine skeletons; tris(1-phenylisoquinoline-N,C 2’ )iridium(III) (abbreviated as [Ir(piq)3]), bis(1-phenylisoquinoline-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolyl-κN]phenyl-κC]iridium(III) and the like organic metal iridium complexes having a pyridine skeleton 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum (II) (abbreviated as PtOEP) and other platinum complexes; and tris (1,3-diphenyl-1,3-propanedione (propanedionato)) (monophenanthroline) europium (III) (abbreviated as [Eu (DBM) 3 (Phen)]), tris [1- (2-thenoyl) -3,3,3-trifluoroacetone] (monophenanthroline) europium (III) (abbreviated as [Eu (TTA) 3 (Phen)] and other rare earth metal complexes. The above substances are compounds that exhibit red phosphorescence and have a luminescence peak in the wavelength region of 600nm to 700nm. In addition, an organic metal iridium complex having a pyrazine skeleton can obtain red luminescence with good chromaticity.

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

[0230] As TADF materials, fullerene and its derivatives, acridine and its derivatives, and eosin derivatives can be used. In addition, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can also be mentioned. As the metal-containing porphyrin, for example, there can be mentioned 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)), protoporphyrin-tin fluoride complex (SnF2(Etio I)) and octaethylporphyrin-platinum chloride complex (PtCl2OEP) etc. represented by the following structural formula.

[0231] [Chemical formula 1]

[0232] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindol[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazine-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 9-[4-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5 -triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthene-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridinium)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracenes]-10'-one (abbreviation: ACRSA), etc., which have one or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring. The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and has high electron transport properties and hole transport properties, so it is preferred. Among them, in the skeleton with a π-electron-deficient heteroaromatic ring, the pyridine skeleton, the diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) and the triazine skeleton are stable and have good reliability, so they are preferred. In particular, the electron acceptor properties of the benzofuranopyrimidine skeleton, the benzothiophenopyrimidine skeleton, the benzofuranopyrazine skeleton, and the benzothiophenopyrazine skeleton are high and reliable, so they are preferred. In addition, in the skeleton with 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 stable and have good reliability, so it is preferred to have at least one of the above skeletons. In addition, as a furan skeleton, a dibenzofuran skeleton is preferably used, and as a thiophene skeleton, a dibenzothiophene skeleton is preferably used. As a pyrrole skeleton, an indole skeleton, a carbazole skeleton, an indolecarbazole skeleton, a bicarbazole skeleton, and a 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton are particularly preferably used. In a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded, 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 high, and the energy difference between the S1 energy level and the T1 energy level becomes small, so that thermally activated delayed fluorescence can be obtained efficiently, so it is particularly preferred. Note that an aromatic ring bonded with an electron-withdrawing group such as a cyano group can also be used instead of a π-electron-deficient heteroaromatic ring. In addition, as a π-electron-rich skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used.In addition, as the π-electron-deficient skeleton, 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 or heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanophenyl, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. can be used. In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used to replace at least one of the π-electron-deficient heteroaromatic ring and the π-electron-rich heteroaromatic ring.

[0233] [Chemical formula 2]

[0234] TADF materials refer to materials with a small difference between the S1 energy level and the T1 energy level and the function of converting triplet excitation energy into singlet excitation energy through anti-intersystem crossing. Therefore, it is possible to up-convert triplet excitation energy into singlet excitation energy (anti-intersystem crossing) through tiny thermal energy and efficiently generate singlet excited states. In addition, triplet excitation energy can be converted into luminescence.

[0235] The exciplex formed by two substances in an excited state has the function of a TADF material that can convert triplet excitation energy into singlet excitation energy because the difference between the S1 energy level and the T1 energy level is extremely small.

[0236] Note that as an indicator of the T1 level, a phosphorescence spectrum observed at a low temperature (e.g., 77 K to 10 K) can be used. With respect to the TADF material, when the wavelength energy of an extrapolated line obtained by cutting a line at the tail of the short wavelength side of the fluorescence spectrum is taken as the S1 level and the wavelength energy of an extrapolated line obtained by cutting a line at the tail of the short wavelength side of the phosphorescence spectrum is taken as the T1 level, it is preferred that the difference between the S1 level and the T1 level be 0.3 eV or less, more preferably 0.2 eV or less.

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

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

[0239] As the material having hole transport properties, it is preferred to use an organic compound having an amine skeleton, a π-electron-rich heteroaromatic ring skeleton, etc. As the π-electron-rich heteroaromatic ring, it is preferred to use a fused aromatic ring containing at least any one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton, and specifically preferably a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are further fused with an aromatic ring or a heteroaromatic ring.

[0240] Such an organic compound having hole transport properties preferably has any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton and an anthracene skeleton. In particular, it can be an aromatic amine having a substituent including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine including a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine through an arylene group. Note that when these organic compounds having hole transport properties are substances including N, N-bis(4-biphenyl)amino groups, a light-emitting device with a long life can be manufactured, so it is preferred.

[0241] Examples of such organic compounds include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as mBPAFLP), 4'-phenyl-4 ... -(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBA1BP), 4,4'-diphenyl-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBANB), 4,4'-di(1-naphthyl)-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviated as: PCBAF), N-phenyl -N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviated as PCBASF) and other compounds having an aromatic amine skeleton; 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviated as PCCP) and other compounds having a carbazole skeleton; 4,4',4"-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as DB T3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviated as: DBTFLP-III), 4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as: DBTFLP-IV) and other compounds having a thiophene skeleton; and 4,4',4"-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviated as: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as: mmDBFFLBi-II) and other compounds having a furan skeleton. Among them, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton have good reliability and high hole transport properties and help to reduce the driving voltage, so they are preferred. In addition, organic compounds listed as examples of materials with hole transport properties as hole transport layers can also be used.

[0242] As materials having electron transport properties, for example, metal complexes such as bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated as ZnPBO), bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as ZnBTZ) and organic compounds containing a π-electron-deficient heteroaromatic ring skeleton are preferably used. As organic compounds containing a π-electron-deficient heteroaromatic skeleton, for example, 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 can be cited.

[0243] Among them, organic compounds containing heteroaromatic rings having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing heteroaromatic rings having a pyridine skeleton, or organic compounds containing heteroaromatic rings having a triazine skeleton have good reliability, so they are preferred. In particular, organic compounds containing heteroaromatic rings having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings having a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage. In addition, benzofuranopyrimidine skeletons, benzothiophenopyrimidine skeletons, benzofuranopyrazine skeletons, and benzothiophenopyrazine skeletons have high electron acceptor properties and high reliability, so they are preferred.

[0244] Examples of organic compounds containing a π-electron-deficient heteroaromatic ring skeleton include: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole]-1,3,4-triazole (abbreviated as TAZ), Organic compounds having an azole skeleton such as oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), 2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), 4,4'-bis(5-methylbenzothiophene-2-yl)stilbene (abbreviated as BzOs); 3,5-bis[3-(9 H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproin (abbreviation: BCP), 2,9-bis(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 Organic compounds containing a heteroaromatic ring having a pyridine skeleton, such as 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthrenyl)-1-naphthyl]-1,10-phenanthroline (abbreviation: PnNPhen), and 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen);2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline ( Abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-Ⅲ), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-Ⅱ), 9-[(3'-dibenzothiophene-4-yl)biphenyl-3-yl]naphtho[1',2':4,5 ] furano[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthrene-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 (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-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[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]benzofurano[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d 13)、3,8-bis[3-(dibenzothiophene-4-yl)phenyl]benzofurano[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophene-4-yl)(biphenyl-3-yl)]naphtho[1',2':4,5]furano[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthyl)-6-yl]-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8(βN 2)-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]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthyl-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl] organic compounds having a dioxazine skeleton, such as 2-(biphenyl-4-yl)-6-(9H-carbazol-2-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-cgDBCzQz); 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluorene]-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), 2-{ 3-[3-(Benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviated as mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazine-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 (abbreviated as: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-phenylindole[2,3-a]carbazole (abbreviated as: BP-Icz(II)Tzn), 2-[3'- [(triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviated as PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1"-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviated as PCDBfTzn), mBP-TPDBfTzn) and the like. In addition, organic compounds containing heteroaromatic rings having diazine skeletons, organic compounds containing heteroaromatic rings having pyridine skeletons, or organic compounds containing heteroaromatic rings having triazine skeletons have good reliability and are therefore preferred. In particular, organic compounds containing heteroaromatic rings having diazine (pyrimidine or pyrazine) skeletons and organic compounds containing heteroaromatic rings having triazine skeletons have high electron transport properties, which contribute to lowering the driving voltage. ,

[0245] As a TADF material that can be used as a host material, the same material as the material cited above as a TADF material can be used. When a TADF material is used as a host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing and further energy is transferred to the luminescent material, thereby improving the luminous efficiency of the light-emitting device. At this time, the TADF material is used as an energy donor and the luminescent material is used as an energy acceptor.

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

[0247] In addition, it is preferable to use a TADF material that emits light at a wavelength overlapping with the absorption band on the lowest energy side of the fluorescent material. This is preferable because the excitation energy is smoothly transferred from the TADF material to the fluorescent material, and light emission can be obtained efficiently.

[0248] In order to efficiently generate singlet excitation energy from triplet excitation energy by anti-intersystem crossing, carrier recombination is preferably generated in TADF material. In addition, it is preferred that the triplet excitation energy generated in TADF material is not transferred to the triplet excitation energy of fluorescent material. For this reason, the fluorescent material preferably has a protecting group around the luminophore (the skeleton that becomes the cause of luminescence) possessed by the fluorescent material. As the protecting group, it is preferably a substituent without a π bond, preferably a saturated hydrocarbon, specifically, an alkyl group having a carbon number of more than 3 and less than 10, a substituted or unsubstituted cycloalkyl group having a carbon number of more than 3 and less than 10, and a trialkylsilyl group having a carbon number of more than 3 and less than 10, more preferably having a plurality of protecting groups. The substituent without a π bond has almost no function of transmitting carriers, so it has almost no effect on carrier transmission or carrier recombination, and the luminophore of the TADF material and the fluorescent material can be kept away from each other. Here, the luminophore refers to the atomic group (skeleton) that becomes the cause of luminescence in the fluorescent material. The luminophore preferably has a π-bond skeleton, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of such luminophores 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, In particular, the naphthalene skeleton, the anthracene skeleton, the fluorene skeleton, the Fluorescent substances having a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because they have high fluorescence quantum yields.

[0249] In the case where a fluorescent material is used as a light-emitting material, a material having an anthracene skeleton is preferably used as a host material. By using a substance having an anthracene skeleton as a host material of a fluorescent material, a light-emitting layer having high luminous efficiency and durability can be achieved. Among the substances having an anthracene skeleton used as a host material, substances having a diphenylanthracene skeleton (especially a 9,10-diphenylanthracene skeleton) are chemically stable, so they are preferred. In addition, when the host material has a carbazole skeleton, the injection / transport properties of holes are improved, so it is preferred, but when a benzocarbazole skeleton having a benzene ring also fused to a carbazole skeleton is used, the HOMO energy level is about 0.1eV shallower than that of a host material having a carbazole skeleton, and holes are easily injected, so it is more preferred. In particular, when the host material has a dibenzocarbazole skeleton, its HOMO energy level is about 0.1eV shallower than that of a host material having a carbazole skeleton, and not only holes are easily injected, but also hole transport and heat resistance are improved, so it is preferred. Therefore, a more preferred host material is one having a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Note that 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-anthracenyl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as CzPA), 7-[4-(10-phenyl-9-anthracenyl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthracenyl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviated as 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-9H-carbazole (abbreviated as PCPN), -biphenyl-4'-yl]-anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α, β-ADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)-benzo[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 because they exhibit very good properties.

[0250] In addition, the host material may also be a material mixed with multiple substances. When a mixed host material is used, it is preferred to mix a material having an electron transport property and a material having a hole transport property. By mixing a material having an electron transport property and a material having a hole transport property, it is easier to adjust the transport property of the light-emitting layer 113, and it is also easier to control the recombination area. The weight ratio of the content of the material having a hole transport property and the material having an electron transport property is 1:19 to 19:1.

[0251] Note that as part of the above mixed material, a phosphorescent substance may be used. When a fluorescent substance is used as a light-emitting substance, the phosphorescent substance may be used as an energy donor for supplying excitation energy to the fluorescent substance.

[0252] In addition, these mixed materials can also be used to form an exciplex. By selecting a mixed material in a manner to form an exciplex that emits light overlapping the wavelength of the absorption band on the lowest energy side of the luminescent substance, energy transfer can be smoothed, thereby efficiently obtaining luminescence, so it is preferred. In addition, by adopting this structure, the driving voltage can be reduced, so it is preferred.

[0253] Note that at least one of the materials forming the exciplex may be a phosphorescent substance. This allows efficient conversion of triplet excitation energy into singlet excitation energy via anti-intersystem crossing.

[0254] Regarding the combination of materials that efficiently form an exciplex, the HOMO energy level of the material having hole transport properties is preferably higher than the HOMO energy level of the material having electron transport properties. In addition, the LUMO energy level of the material having hole transport properties is preferably higher than the LUMO energy level of the material having electron transport properties. Note that the LUMO energy level and HOMO energy level of the material can be obtained from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0255] Note that the formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a material having hole transport properties, the emission spectra of a material having electron transport properties, and the emission spectra of a mixed film formed by mixing these materials. When the emission spectrum of the mixed film is observed to drift toward the long wavelength side compared to the emission spectrum of each material (or to have a new peak on the long wavelength side), it indicates that an exciplex has been formed. Alternatively, 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 formed by mixing these materials are compared. When the transient response is different, such as the ratio of the transient PL lifetime of the mixed film to the transient PL lifetime of each material having a long-life component or a delayed component becomes larger, it indicates that an exciplex has been formed. In addition, the above-mentioned transient PL can be referred to as transient electroluminescence (EL). In other words, the formation of an exciplex can 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 of 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. As the substance having an electron transport property, it is preferable to use a substance having an electron mobility of 1×10 -7 cm 2 / Vs or more, it is more preferable to use the material having an electron mobility of 1×10 -6 cm 2 / Vs or more. In addition, as long as the electron transport property is higher than the hole transport property, substances other than the above can also be used. In addition, the electron transport layer 114 is preferably an organic compound comprising a π-deficient heteroaromatic ring skeleton. As an organic compound comprising a π-deficient heteroaromatic skeleton, for example, an organic compound comprising a heteroaromatic ring having a polyazole skeleton, an organic compound comprising a heteroaromatic ring having a pyridine skeleton, an organic compound comprising a heteroaromatic ring having a diazine skeleton, and an organic compound comprising a heteroaromatic ring having a triazine skeleton. Among them, an organic compound comprising a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), an organic compound comprising a heteroaromatic ring having a pyridine skeleton, or an organic compound comprising a heteroaromatic ring having a triazine skeleton has good reliability, so it is preferred. In particular, an organic compound comprising a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound comprising a heteroaromatic ring having a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage. Furthermore, a benzofuranopyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuranopyrazine skeleton, and a benzothienopyrazine skeleton are preferred because they have high acceptor properties and high reliability.

[0257] Examples of such organic compounds include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)benzene (abbreviated as OXD-7), Organic compounds having an azole skeleton, such as 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviated as: BzOs); 3,5-bis[3-(9H-carbazole- 9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproin (abbreviation: BCP), 2,9-bis(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 Organic compounds containing a heteroaromatic ring having a pyridine skeleton, such as 2-phenyl-9-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviated as: mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (abbreviated as: Ph-TpPhen), 2-[4-(9-phenanthrenyl)-1-naphthyl]-1,10-phenanthroline (abbreviated as: PnNPhen), and 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviated as: pTpPPhen);2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTPDBq-II), 2-[3-(3'-dibenzothiophene-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mCzBPDBq), :2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 7mDBTPDBq-II) and 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 6mDBTPDBq-II), 9-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]naphtho[1',2':4, 5] furano[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthrene-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-carbazole-9-yl)phenyl] 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-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[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]benzofurano[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d 13)、3,8-bis[3-(dibenzothiophene-4-yl)phenyl]benzofurano[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophene-4-yl)(biphenyl-3-yl)]naphtho[1',2':4,5]furano[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthyl)-6-yl]-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8(βN 2)-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]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthyl-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl] organic compounds having a dioxazine skeleton, such as 2-(biphenyl-4-yl)-6-(9H-carbazol-2-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-cgDBCzQz); 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluorene]-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), 2-{ 3-[3-(Benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviated as mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviated as mINc(II)PTzn), 2-{3-[3-(dibenzothiophene-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as mDBtBPTzn), 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3 -yl)-1,3,5-triazine (abbreviated as: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviated as: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-phenylindole[2,3-a]carbazole (abbreviated as: BP-Icz(II)Tzn ), 2-[3'-(triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviated as PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1"-terphenyl)-4-yl]-1-dibenzofuranyl}- 1,3,5-triazine (abbreviation: mBP-TPDBfTzn) and other organic compounds containing heteroaromatic rings having a triazine skeleton. Among them, organic compounds that do not include fused aromatic rings consisting only of six-membered rings, or organic compounds that do not have a structure in which two or more six-membered aromatic hydrocarbon rings are fused in an adjacent manner, a structure in which two or more six-membered heteroaromatic rings are fused in an adjacent manner, and a structure in which one or more six-membered aromatic hydrocarbon rings and one six-membered heteroaromatic ring are fused in an adjacent manner are preferably used.

[0258] Among them, the organic compound comprising the heteroaromatic ring with diazine skeleton, the organic compound comprising the heteroaromatic ring with pyridine skeleton, the organic compound comprising the heteroaromatic ring with triazine skeleton have good reliability, so it is preferred. Especially, the organic compound comprising the heteroaromatic ring with diazine (pyrimidine or pyrazine) skeleton, the organic compound comprising the heteroaromatic ring with triazine skeleton have high electron transport, which helps to reduce the driving voltage. Especially the organic compound with phenanthroline skeleton such as mTpPPhen, PnNPhen and mPPhen2P is preferred, and the organic compound with phenanthroline dimer structure such as mPPhen2P has excellent stability, so it is more preferred.

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

[0260] As the electron injection layer 115, a layer containing lithium fluoride, 8-hydroxyquinoline-lithium (abbreviated as Liq), a compound or complex of an alkali metal or alkaline earth metal such as a mixed material of lithium fluoride and ytterbium, a mixture of these, or 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviated as hpp2Py) etc. can also be provided. As the electron injection layer 115, a layer containing the above-mentioned substances in a layer composed of a substance having electron transport properties can also be used.

[0261] Alternatively, the charge generation layer 116 may be provided instead of the electron injection layer 115 ( Fig. 11B ). The charge generation layer 116 is a layer that can inject holes into the layer in contact with the cathode side of the layer and inject electrons into the 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 above-mentioned composite material constituting the hole injection layer 111. In addition, the P-type layer 117 can also be formed by stacking a film containing the above-mentioned acceptor material and a film containing a hole transport material as a material constituting the composite material. By applying a potential to the P-type layer 117, electrons and holes are injected into the electron transport layer 114 and the cathode, respectively, so that the organic EL element works.

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

[0263] The electron relay layer 118 contains at least a substance with electron transport properties, and can prevent the interaction between the electron injection buffer layer 119 and the P-type layer 117, and smoothly transfer electrons. It is preferred to set the LUMO energy level of the substance with electron transport properties contained in the electron relay layer 118 between the LUMO energy level of the acceptor substance in the P-type layer 117 and the LUMO energy level of the substance contained in the layer in the electron transport layer 114 that contacts the charge generation layer 116. Specifically, the LUMO energy level of the substance with electron transport properties in the electron relay layer 118 is preferably above -5.0 eV, more preferably above -5.0 eV and below -3.0 eV. In addition, as a substance with electron transport properties in the electron relay layer 118, it is preferred to use phthalocyanine materials such as phthalocyanine (abbreviation: H2Pc), copper phthalocyanine (abbreviation: CuPc), zinc phthalocyanine (abbreviation: ZnPc) or metal complexes having metal-oxygen bonding and aromatic ligands.

[0264] The electron injection buffer layer 119 can use substances with high electron injection properties such as alkali metals, alkaline earth metals, rare earth metals and compounds of these substances (alkali metal compounds (including oxides such as lithium oxide, halides such as lithium fluoride, carbonates such as lithium carbonate or cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates) or rare earth metal compounds (including oxides, halides, carbonates)).

[0265] In addition, when the electron injection buffer layer 119 contains a substance having electron transport properties and a donor substance, as a donor substance, in addition to alkali metals, alkaline earth metals, rare earth metals and compounds of these substances (alkali metal compounds (including oxides such as lithium oxide, halides such as lithium fluoride, carbonates such as lithium carbonate or cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates) or rare earth metal compounds (including oxides, halides, carbonates)), tetrathianaphthacene (abbreviated as: TTN), nickelocene, decamethyl nickelocene and other organic compounds can also be used. In addition, as a substance having electron transport properties, the same material as the material for the electron transport layer 114 described above can be used.

[0266] As described in Embodiment Mode 1, by providing the auxiliary electrode between the electron injection layer 115 and the second electrode 102 or between the charge generation layer 116 and the second electrode 102 , optical adjustment can be performed, which is preferable.

[0267] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a stacked structure, in which case the layer in contact with the EL layer 103 is used as a cathode. As a material forming the cathode, a metal, an alloy, a conductive compound, and a mixture thereof with 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), or strontium (Sr), alloys containing them (Mg:Ag, Al:Li), compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), etc.), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing them. However, by providing an 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, etc. can be used as cathodes regardless of the size of the work function.

[0268] In the case where the second electrode 102 is formed of a material that is transparent to visible light, a light-emitting device that emits light from the second electrode 102 side can be formed.

[0269] These conductive materials can be formed by dry methods such as vacuum deposition and sputtering, inkjet, spin coating, etc. Alternatively, they can be formed by wet methods such as sol-gel or by wet methods using a paste of a metal material.

[0270] The EL layer 103 can be formed by any of a variety of methods, whether dry or wet. For example, vacuum deposition, gravure printing, offset printing, screen printing, inkjet, or spin coating can be used.

[0271] Furthermore, each electrode or each layer described above may also be formed by using a different film forming method.

[0272] Next, refer to Fig. 11C A method of describing a light-emitting device having a structure in which a plurality of light-emitting units are stacked (also referred to as a stacked element or a tandem element) is described. The organic EL element is an organic EL element having a plurality of light-emitting units between an anode and a cathode. One light-emitting unit has Fig.11A The EL layer 103 shown in FIG. 1 has a substantially similar structure. Fig. 11C The organic EL element shown is an organic EL element having a plurality of light-emitting units. Fig.11A or Fig. 11B The organic EL element shown is an organic EL element having one light-emitting unit.

[0273] exist Fig. 11CIn the embodiment, a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between the first electrode 501 and the 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 are respectively equivalent to Fig.11A The first electrode 101 and the second electrode 102 in the embodiment of the present invention can be applied to Fig.11A The materials described above are the same materials. In addition, 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 to the first electrode 501 and the second electrode 502. 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 preferably has Fig. 11B The charge generation layer 116 shown in FIG. 1 has the same structure as the charge generation layer 116 shown in FIG. Since the composite material of the organic compound and the metal oxide has good carrier injection and carrier transport properties, low voltage driving and low current driving can be achieved. Note that when the surface on the anode side of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can have the function of the hole injection layer of the light-emitting unit, so the light-emitting unit may not be provided with a hole injection layer.

[0276] When the electron injection buffer layer 119 is provided in the charge generation layer 513, since the electron injection buffer layer 119 has the function of an electron injection layer in the light emitting unit on the anode side, an electron injection layer is not necessarily provided in the light emitting unit on the anode side.

[0277] Although in Fig. 11C , an organic EL element having two light-emitting units is described, but an organic EL element having three or more light-emitting units stacked can be similarly applied. As in the organic EL element according to this embodiment, by separating and arranging a plurality of light-emitting units between a pair of electrodes using the charge generation layer 513, the element can achieve high-brightness light emission while maintaining a low current density, and can achieve an element with a long life. In addition, a display device capable of low voltage driving and low power consumption can be realized.

[0278] In addition, by making the emission colors of each light-emitting unit different, the desired color of light can be obtained in the entire organic EL element. For example, by obtaining red and green emission colors from the first light-emitting unit and blue emission color from the second light-emitting unit in an organic EL element having two light-emitting units, an organic EL element that emits white light in the entire organic EL element can be obtained.

[0279] In addition, the EL layer 103, the first light-emitting unit 511, the second light-emitting unit 512, the charge generation layer and other layers and electrodes can be formed by, for example, evaporation (including vacuum evaporation), droplet jetting (also known as inkjet), coating, gravure printing, etc. In addition, they can also include low molecular weight materials, medium molecular weight materials (including oligomers, dendrimers) or high molecular weight materials.

[0280] Fig.12 As shown in the following figure, two adjacent light-emitting devices (light-emitting device 130a, light-emitting device 130b) in a light-emitting device group composed of 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 in the light-emitting device, at least the first electrodes (101a, 101b), the EL layers (104a, 104b), the common layer 107 and the second electrode 102 overlap.

[0281] The light-emitting device 130a includes an EL layer 103a between a first electrode 101a on an insulating layer 175 and a second electrode 102 opposite to the first electrode 101a. The EL layer 103a shows a structure including 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 also be a layer having a different stacked structure. The EL layer 103a includes an independent EL layer 104a in each light-emitting device, and may also include a common layer 107 used in multiple light-emitting devices. Fig.12 In the embodiment, 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 instead of providing the common layer 107, a layer having the same function as the common layer may be independently provided in each light emitting device.

[0282] The light emitting device 130b includes an EL layer 103b between a first electrode 101b on an insulating layer 175 and a second electrode 102 opposite to the first electrode 101b. The EL layer 103b is shown to include 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 also be a layer having a different stacked structure. Fig.12 In the embodiment, the hole injection layer 111b, the hole transport layer 112b, the light emitting layer 113b, and the electron transport layer 114b are equivalent to the EL layer 104b. Note that the common layer 107 may be omitted by providing layers having the same function as the common layer in each light emitting device as separate structures.

[0283] Note that the second electrode 102 is preferably a continuous layer (common layer) shared by the light-emitting device 130a and the light-emitting device 130b. In addition, since the EL layer 103a and the EL layer 103b other than the common layer 107, that is, the EL layer 104a and the EL layer 104b are processed by photolithography after the electron transport layer 114a and the electron transport layer 114b are formed, they are independent of each other. Since the processing is performed by photolithography, the end (contour) of the EL layer 103a other than the common layer 107 is roughly aligned in the direction perpendicular to the substrate. Since the processing is performed by photolithography, the end (contour) of the EL layer 103b other than the common layer 107 is roughly aligned in the direction perpendicular to the substrate.

[0284] Furthermore, since the EL layer is processed by photolithography, the distance d between the first electrode 101 a and the first electrode 101 b can be smaller than that in the case of mask evaporation, and can be greater than or equal to 50 nm and less than or equal to 5 μm.

[0285] Note that the structure of this embodiment mode can be used in combination with the structures of other embodiment modes as appropriate.

[0286] Implementation 4 In this embodiment, a display device which is one embodiment of the present invention is described.

[0287] The display device of this embodiment can be a high-definition display device. Therefore, for example, the display device of this embodiment can be used as a display unit of information terminal devices (wearable devices) such as watch-type and bracelet-type devices, and a display unit of wearable devices that can be worn on the head such as VR devices such as head-mounted displays (HMDs) and glasses-type AR devices.

[0288] In addition, the display device of this embodiment can be a high-resolution display device or a large display device. Therefore, for example, the display device of this embodiment can be used as a display portion of the following devices: electronic devices with large screens such as television devices, desktop or notebook personal computers, displays for computers, etc., digital signage and large game machines such as pinball machines, etc.; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; portable information terminals; and sound reproduction devices.

[0289] [Display module] Fig.13A2 is 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 one of the display device 100B and the display device 100D to be described later.

[0290] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display portion 281. The display portion 281 is an image display region in the display module 280, and light from each pixel provided in a pixel portion 284 described below can be viewed.

[0291] Fig. 13B 2 is a perspective view of a structure on one side of a substrate 291. 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 stacked on the substrate 291. In addition, a terminal portion 285 for connecting to the FPC 290 is provided on a portion of the substrate 291 that is not overlapped by the pixel portion 284. The terminal portion 285 is electrically connected to the circuit portion 282 via a wiring portion 286 composed of a plurality of wirings.

[0292] The pixel portion 284 includes a plurality of pixels 284 a arranged periodically. Fig. 13B An enlarged view of one pixel 284a is shown on the right side of FIG. The pixel 284a can adopt the various structures described in the above embodiment. Fig. 13B Pixel 284a is shown having Figure 1A and Figure 1B An example of a case where the pixel 178 shown has the same structure.

[0293] The pixel circuit portion 283 includes a plurality of pixel circuits 283 a arranged periodically.

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

[0295] The circuit unit 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit unit 283. For example, it preferably includes one or both of a gate line driving circuit and a source line driving circuit. In addition, it may include at least one of a calculation circuit, a storage circuit, and a power supply circuit.

[0296] The FPC 290 is used as wiring for supplying video signals, power supply potential, and the like from the outside to the circuit portion 282. Alternatively, an IC may be mounted on the FPC 290.

[0297] The display module 280 may have a structure in which one or both of the pixel circuit portion 283 and the circuit portion 282 are stacked on the lower side of the pixel portion 284 , so that the display portion 281 may have an extremely high aperture ratio (effective display area ratio).

[0298] This high-definition display module 280 is suitable for use in VR devices such as HMD or glasses-type AR devices. For example, because the display module 280 has a very high-definition display unit 281, in a structure where the display unit of the display module 280 is viewed through a lens, even if the display unit is magnified by the lens, the user cannot see the pixels, thereby achieving a highly immersive display. In addition, the display module 280 can also be applied to electronic devices with a relatively small display unit.

[0299] [Display device 100A] Fig.14A The display device 100A shown 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] Substrate 301 is equivalent to Fig.13A and Fig. 13B The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, for example, a semiconductor substrate such as a single crystal silicon substrate can be used. The transistor 310 includes a portion of the substrate 301, a conductive layer 311, a low resistance region 312, an insulating layer 313 and an insulating layer 314. The conductive layer 311 is used as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and is used as a gate insulating layer. The low resistance region 312 is a region doped with impurities in the substrate 301 and is used as a source or a drain. The insulating layer 314 covers the side of the conductive layer 311.

[0301] Furthermore, 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 the capacitor 240 is provided over the insulating layer 261 .

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

[0304] The conductive layer 241 is provided on the insulating layer 261 and 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 through the plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided in a manner covering the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 via the insulating layer 243.

[0305] An insulating layer 255 is provided to cover 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. The light emitting devices 130R, 130G, and 130B are provided on the insulating layer 175. An insulator is provided in a region between adjacent light emitting devices.

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

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

[0308] In addition, a protective layer 131 is provided on the light emitting device 130R, the light emitting device 130G, and the light emitting device 130B. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. The details of the components of the light emitting device 130 to the substrate 120 can be referred to other embodiments. The substrate 120 is equivalent to Fig.13A substrate 292.

[0309] Fig. 14B Show Fig.14A A modified example of the display device 100A shown. Fig. 14B The display device shown includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B, and the light emitting device 130 has a region overlapping one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. Fig. 14B In the display device shown, the light emitting device 130 can emit white light, for example. In addition, for example, the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can transmit red light, green light, and blue light, respectively.

[0310] [Display device 100B] Fig.15 A perspective view showing a display device 100B is shown. Fig.16 A cross-sectional view of the display device 100B is shown.

[0311] The display device 100B has a structure in which a substrate 352 and a substrate 351 are bonded together. Fig.15In FIG. 3 , the substrate 352 is indicated by a dotted line.

[0312] The display device 100B includes a pixel portion 177 , a connection portion 140 , a circuit 356 , a wiring 355 , and the like. Fig.15 FIG. 1 shows an example in which the display device 100B is equipped with the IC 354 and the FPC 353. Fig.15 The structure shown is called a display module including the display device 100B, IC (integrated circuit) and FPC. Here, the substrate of the display device with a connector such as FPC mounted thereon or the substrate with IC mounted thereon is called a display module.

[0313] The connection part 140 is disposed outside the pixel part 177. There may be one or more connection parts 140. In the connection part 140, the common electrode of the light emitting device is electrically connected to the conductive layer, and power can be supplied to the common electrode.

[0314] As the circuit 356, for example, a scan line driver circuit can be used.

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

[0316] Fig.15 An example of providing IC354 on substrate 351 by COG (Chip On Glass) method or COF (Chip on Film) method is shown. As IC354, for example, an IC including a scanning line driving circuit or a signal line driving circuit can be used. Note that the display device 100B and the display module do not necessarily have to be provided with an IC. In addition, for example, the IC can also be mounted on an FPC by using a COF method.

[0317] Fig.16 An example of a cross section of 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 of the display device 100B is shown.

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

[0319] The details of the light emitting device 130R, the light emitting device 130G, and the light emitting device 130B may be referred to Embodiment 1 to Embodiment 3.

[0320] The light emitting device 130R includes a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. The light emitting device 130G includes a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. The light emitting device 130B includes a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B.

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

[0322] The conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in the light-emitting device 130G and the conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in the light-emitting device 130B are the same as the conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in the light-emitting device 130R, so detailed description is omitted.

[0323] Concave portions are formed in conductive layer 224R, conductive layer 224G, and conductive layer 224B so as to cover the openings provided in insulating layer 214. The concave portions are filled with layer 128.

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

[0325] Layer 128 may be an insulating layer or a conductive layer. Layer 128 may be formed of various inorganic insulating materials, organic insulating materials, and conductive materials as appropriate. In particular, layer 128 is preferably formed of an insulating material, and more preferably formed of an organic insulating material. Layer 128 may be formed of, for example, the organic insulating material that can be used for the first insulating layer 127.

[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 by an adhesive layer 142. The substrate 352 is provided with a light shielding layer 157. The sealing of the light emitting device 130 may adopt a solid sealing structure or a hollow sealing structure. Fig.16 In the embodiment, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, that is, a solid sealing structure is adopted. Alternatively, the space may be filled with an inert gas (nitrogen or argon, etc.), that is, a hollow sealing structure is adopted. In this case, the adhesive layer 142 may also be arranged in a manner that does not overlap with the light-emitting device. In addition, a resin different from the adhesive layer 142 arranged in a frame shape may be used to fill the space.

[0327] Fig.16 The following example is shown: the connection portion 140 includes a conductive layer 224C processed from the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive layer 151C processed from the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive layer 152C processed from the same conductive film as the conductive layers 152R, 152G, and 152B. In addition, Fig.16 An example is shown in which the insulating layer 156C is provided so as to include a region overlapping with the side surface of the conductive layer 151C.

[0328] The display device 100B is a top emission type display device. The light emitting device emits light to the substrate 352 side. The substrate 352 preferably uses a material with high transmittance to visible light. When the light emitting device emits infrared light or near-infrared light, it is preferably used a material with high transmittance to them. The pixel electrode includes a material that reflects visible light, and the counter electrode (common electrode 155) includes 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 sequentially provided on the substrate 351. A portion of the insulating layer 211 is used as a gate insulating layer of each transistor. A portion of the insulating layer 213 is used as a gate insulating layer of each transistor. The insulating layer 215 is provided in a manner covering the transistor. The insulating layer 214 is provided in a manner covering the transistor and is used as a planarization layer. In addition, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistor, and it can be one or more than two.

[0330] As the insulating layer 211 , the insulating layer 213 , and the insulating layer 215 , an inorganic insulating film is preferably used.

[0331] As the insulating layer 214 serving as a planarizing layer, an organic insulating layer is preferably used.

[0332] The transistor 201 and the transistor 205 include: a conductive layer 221 used as a gate; an insulating layer 211 used as a gate insulating layer; a conductive layer 222a and a conductive layer 222b used as a source and a drain; a semiconductor layer 231; an insulating layer 213 used as a gate insulating layer; and a conductive layer 223 used as a gate.

[0333] A connection portion 204 is provided in a region of the substrate 351 that is not overlapped by the substrate 352. In the connection portion 204, the source electrode or the drain electrode of the transistor 201 is electrically connected to the FPC 353 through the conductive layer 166 and the connection layer 242. The following example is shown: the conductive layer 166 has a laminated structure of a conductive film obtained by processing the same conductive film as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive film obtained by processing the same conductive film as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive film obtained by processing the same conductive film as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. The conductive layer 166 is exposed on the top surface of the connection portion 204. Therefore, the connection portion 204 can be electrically connected to the FPC 353 through the connection layer 242.

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

[0335] The substrate 351 and the substrate 352 can each adopt a material that can be used for the substrate 120 .

[0336] As the adhesive layer 142 , a material that can be used for the resin layer 122 can be used.

[0337] As the connection layer 242 , an anisotropic conductive film (ACF: Anisotropic Conductive Film), anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

[0338] [Display device 100D] Fig.17 The display device 100D shown is Fig.16 In the variation example of the display device 100B shown, the display device 100D is different from the display device 100B mainly in that the display device 100D includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B.

[0339] In the display device 100D, the light emitting device 130 has a region overlapping one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. The coloring layer 132R, the coloring layer 132G, and the coloring layer 132B may be provided on a surface of the substrate 352 on the substrate 351 side. An end portion of the coloring layer 132R, an end portion of the coloring layer 132G, and an end portion of the coloring layer 132B may overlap the light shielding layer 157.

[0340] In the display device 100D, the light emitting device 130 may emit white light, for example. In addition, for example, the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B may transmit red light, green light, and blue light, respectively. In addition, the display device 100D may also adopt a structure in which the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B are provided between the protective layer 131 and the adhesive layer 142.

[0341] Fig.16 and Fig.17 The example in which the top surface of the layer 128 has a flat portion is shown, 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 this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0343] Implementation method 5 In this embodiment, an electronic device which is one embodiment of the present invention is described.

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

[0345] Electronic devices include, for example, television sets, desktop or notebook personal computers, displays for computers, etc., digital signage, large-scale game consoles such as pinball machines, and other electronic devices with larger screens, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, sound reproduction devices, and the like.

[0346] In particular, since the display device of one embodiment of the present invention can improve the clarity, it can be appropriately used in electronic devices including a smaller display unit. Examples of such electronic devices include watch-type and bracelet-type information terminal devices (wearable devices), wearable devices that can be worn on the head, VR devices such as head-mounted displays, glasses-type AR devices, and MR devices.

[0347] The electronic device of this embodiment may also include a sensor (the sensor has the function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell or infrared).

[0348] Reference 18A to 18D An example of a wearable device that can be worn on the head is described.

[0349] Fig.18A The electronic device 700A shown and Fig.18B The electronic devices 700B shown include a pair of display panels 751, a pair of frames 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical components 753, 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, a highly reliable electronic device can be realized.

[0351] Both electronic devices 700A and 700B can project the image displayed by display panel 751 onto display region 756 in optical member 753. Since optical member 753 is light-transmissive, the user can see the image displayed on the display region superimposed on the transmitted image seen through optical member 753.

[0352] The electronic device 700A and the electronic device 700B may also be provided with a camera capable of photographing the front as an imaging unit. In addition, by providing an acceleration sensor such as a gyro sensor on the electronic device 700A and the electronic device 700B, the user's head orientation can be detected and an image corresponding to the direction can be displayed on the display area 756.

[0353] The communication unit includes a wireless communication device, through which, for example, a video signal can be supplied. In addition, the communication unit may include a connector to which a cable for supplying the video signal and the power supply potential can be connected, instead of or in addition to the wireless communication device.

[0354] Furthermore, electronic device 700A and electronic device 700B are provided with batteries, and can be charged wirelessly or by wire, or both.

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

[0356] As the touch sensor module, various touch sensors can be used. For example, various methods such as electrostatic capacitance, resistance film, infrared, electromagnetic induction, surface acoustic wave, and optical can be used. In particular, it is preferred to use electrostatic capacitance or optical sensors in the touch sensor module.

[0357] Fig.18C The electronic device 800A shown and Fig.18D The electronic devices 800B shown each include a pair of display portions 820 , a housing 821 , a communication portion 822 , a pair of mounting portions 823 , a control portion 824 , a pair of imaging portions 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. This makes it possible to realize an electronic device with high reliability.

[0359] The display unit 820 is provided at a position visible through the lens 832 inside the housing 821. In addition, by displaying different images on each of the pair of display units 820, three-dimensional display using parallax can be performed.

[0360] The electronic device 800A and the electronic device 800B preferably have a mechanism that can adjust the left and right positions of the lens 832 and the display unit 820 so that the lens 832 and the display unit 820 are located at the most appropriate positions according to the position of the user's eyes.

[0361] The user can wear the electronic device 800A or the electronic device 800B on the head using the mounting portion 823 .

[0362] The imaging unit 825 has a function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, a plurality of cameras can be provided to be able to correspond to various viewing angles such as telephoto and wide angle.

[0363] The electronic device 800A may also include a vibration mechanism for use as a bone conduction headset.

[0364] Electronic device 800A and electronic device 800B may both include input terminals. Cables for supplying video signals from a video output device or the like, power for charging a battery provided in the electronic device, and the like may be connected to the input terminals.

[0365] The electronic device according to one embodiment of the present invention may have a function of wirelessly communicating with the earphone 750 .

[0366] In addition, the electronic device may include an earphone unit. Fig.18BThe electronic device 700B shown includes an earphone unit 727. A part of the wiring connecting the earphone unit 727 and the control unit may be arranged inside the housing 721 or the mounting portion 723.

[0367] Likewise, Fig.18D The electronic device 800B shown includes an earphone unit 827. For example, a structure in which the earphone unit 827 and the control unit 824 are connected in a wired manner may be adopted.

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

[0369] Fig.19A The electronic device 6500 shown is a portable information terminal device 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, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0371] The display device of one embodiment of the present invention can be used as the display portion 6502. Thus, a highly reliable electronic device can be achieved.

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

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

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

[0375] In a region outside the display portion 6502, a portion of the display panel 6511 is folded back, and the folded back portion 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 panel 6511 can use a display device of one embodiment of the present invention. Thus, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a battery 6518 of a large capacitor can be installed while suppressing the thickness of the electronic device. In addition, by folding a portion of the display panel 6511 to provide a connection portion with the FPC 6515 on the back of the pixel portion, an electronic device with a narrow frame can be realized.

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

[0378] The display device of one embodiment of the present invention can be used as the display portion 7000. Thus, a highly reliable electronic device can be realized.

[0379] The operation can be performed by using the operation switch provided in the frame 7171 and the remote control operation machine 7151 provided separately. Fig.19C The operation of television device 7100 is shown.

[0380] Fig.19D 1 shows an example of a notebook personal computer. The notebook personal computer 7200 includes a housing 7211 , a keyboard 7212 , a pointing device 7213 , an external connection port 7214 , and the like. A display portion 7000 is incorporated in the housing 7211 .

[0381] The display device of one embodiment of the present invention can be used as the display portion 7000. Thus, a highly reliable electronic device can be realized.

[0382] Fig.19E and Fig.19F An example of digital signage is shown.

[0383] Fig.19E The digital signage 7300 shown includes a housing 7301, a display portion 7000, a speaker 7303, etc. In addition, an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, etc. may be included.

[0384] Fig.19F The digital signage 7400 is shown to be disposed on a cylindrical pillar 7401. The digital signage 7400 includes a display unit 7000 disposed along a curved surface of the pillar 7401.

[0385] exist Fig.19E and Fig.19F In the embodiment of the present invention, the display device according to one embodiment of the present invention can be used for the display portion 7000. Thus, a highly reliable electronic device can be achieved.

[0386] The larger the display unit 7000 is, the more information can be provided at one time. The larger the display unit 7000 is, the easier it is to attract people's attention, for example, the advertising effect can be improved.

[0387] like Fig.19E and Fig.19F As shown, the digital signage 7300 or the digital signage 7400 can preferably be linked with the information terminal device 7311 or the information terminal device 7411 such as a smart phone carried by the user through wireless communication.

[0388] FIG. 20A to FIG. 20G The electronic device shown includes a frame 9000, a display portion 9001, a speaker 9003, an operation key 9005 (including a power switch or an operation switch), a connecting terminal 9006, a sensor 9007 (the sensor has the function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell or infrared), a microphone 9008, etc.

[0389] FIG. 20A to FIG. 20G The electronic device shown has various functions. For example, it may have the following functions: a function of displaying various information (static images, dynamic images, or text images, etc.) on a display unit; a function of a touch panel; a function of displaying a calendar, date, or time, etc.; a function of being controlled and processed by various software (programs); a function of wireless communication; a function of reading out programs or data stored in a storage medium and processing them; etc.

[0390] Below, we explain in detail FIG. 20A to FIG. 20G Electronic equipment shown.

[0391] Fig. 20A 9171 is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used as a smart phone, for example. Note that a speaker 9003, a connection terminal 9006, a sensor 9007, and the like can also be provided in the portable information terminal 9171. In addition, as the portable information terminal 9171, text or image information can be displayed on multiple surfaces. Fig. 20A 9050. In addition, information 9051 indicated by a dotted rectangle may be displayed on another surface of the display unit 9001. Examples of information 9051 include information indicating that an email, SNS, or phone call has been received; a title of the email or SNS; a sender's name of the email or SNS; a date; a time; a remaining battery level; and radio wave strength. Alternatively, icon 9050 may be displayed at a location where information 9051 is displayed.

[0392] Fig. 20B 9172. The portable 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, when the portable information terminal 9172 is placed in a jacket pocket, the user can check the information 9053 displayed at a position viewed from above the portable information terminal 9172.

[0393] Fig. 20C 9173 is a perspective view showing a tablet terminal 9173. The tablet terminal 9173 can execute various application software such as mobile phone, reading and editing of e-mails and articles, playing music, network communication, computer games, etc. The tablet terminal 9173 includes a display portion 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the frame 9000, an operation key 9005 used as an operation button on the left side of the frame 9000, and a connection terminal 9006 on the bottom.

[0394] Fig.20D 9001 is a stereoscopic diagram showing a watch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smart watch (registered trademark). In addition, the display surface of the display unit 9001 is curved, and a display can be performed along its curved display surface. In addition, the portable information terminal 9200 can perform hands-free calls, for example, by communicating with a headset capable of wireless communication. In addition, by using the connection terminal 9006, the portable information terminal 9200 can perform data transmission or charging with other information terminals. Charging can also be performed by wireless power supply.

[0395] FIG. 20E to FIG. 20G 9201 is a perspective view showing a foldable portable information terminal. Fig.20E is a perspective view of the portable information terminal 9201 in an unfolded state. Figure 20G This is a three-dimensional diagram of the folded state. Fig.20F is from Fig.20E Status and Figure 20G The portable information terminal 9201 is easy to carry in the folded state, and has a large display area that is seamlessly spliced ​​in the unfolded state, so the display is easy to browse. The display unit 9001 included in the portable information terminal 9201 is supported by three frames 9000 connected by hinges 9055. The display unit 9001 can be bent within a range of a curvature radius of 0.1 mm or more and 150 mm or less, for example.

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

[0397] At least a part of the structural examples described in this embodiment mode and the drawings corresponding to the structural examples can be combined with other structural examples, drawings, and the like as appropriate.

[0398] At least a part of this embodiment mode can be implemented in combination with other embodiment modes described in this specification as appropriate. Example 1

[0399] In this embodiment, in order to explain a display device of one embodiment of the present invention, the following results are described: 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 manufactured and the luminous efficiencies of these light-emitting devices are compared. In addition, light-emitting devices 3R (red), 3G (green), and 3B (blue), which are light-emitting devices manufactured by forming an organic compound layer by photolithography in a manner to achieve a resolution of 3207 ppi, are manufactured and the results of evaluating the characteristics of these light-emitting devices are described.

[0400] First, a method for manufacturing the light-emitting device 1A, the light-emitting device 1B, the light-emitting device 2A, and the light-emitting device 2B will be described. The structural formula of the organic compound used for each light-emitting device is shown below.

[0401] [Chemical formula 3]

[0402] (Method of Manufacturing Light Emitting Device 1A) After stacking 50nm of titanium (Ti), 70nm of aluminum (Al), and 2nm of Ti on a glass substrate from one side of the substrate, it was baked at 300°C for 1 hour in the atmosphere. Thereafter, indium tin oxide (ITSO) containing silicon oxide was stacked with a thickness of 10nm as a transparent electrode by sputtering to form an anode. The electrode area is 4mm 2 (2mm×2mm).

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

[0404] Then, the substrate is placed inside the chamber and the pressure is reduced to 1×10 -4 Pa in a vacuum deposition apparatus, and perform heat treatment at 170° C. in a heating chamber in the vacuum deposition apparatus for 30 minutes, and then cool the substrate for about 30 minutes.

[0405] Next, the substrate was fixed to a bracket in a vacuum evaporation device with the surface having the anode facing downward, and N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: PCBBiF) and an electron acceptor material having a molecular weight of 672 and containing 4 or more fluorines (OCHD-003) were co-evaporated on the anode by a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) and a thickness of 10 nm to form a hole injection layer.

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

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

[0408] Next, 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]oxanthene]-4-yl-1,3,5-triazine (abbreviated as βNP-SFx(4)Tzn) was vapor-deposited in a thickness of 20 nm, and then 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P) was vapor-deposited in a thickness of 20 nm to form an electron transport layer.

[0409] After the electron transport layer was formed, lithium fluoride and ytterbium were co-evaporated at a volume ratio of 1:0.5 (=LiF:Yb) and a thickness of 1.5 nm 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) in a volume ratio of 1:0.1 and a thickness of 15 nm, thereby manufacturing the light-emitting device 1A.

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

[0412] (Method of Manufacturing Light Emitting Device 1B) The light-emitting device 1B is a red light-emitting device whose cathode thickness is different from that of the light-emitting device 1A. That is, in the light-emitting device 1B, the cathode is formed by co-evaporation on the electron injection layer in a volume ratio of 1:0.1 and a thickness of 25 nm. Other than that, it is manufactured in the same manner as the light-emitting device 1A.

[0413] (Method of Manufacturing Light Emitting Device 2A) The light-emitting device 2A is a blue light-emitting device having a hole transport layer structure, a light-emitting layer structure, and an electron transport layer thickness different from those of the light-emitting device 1A. The hole transport layer is formed by evaporating PCBBiF with a thickness of 105 nm on the hole injection layer and then evaporating N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviated as: DBfBB1TP) with a thickness of 10 nm. In addition, the light-emitting layer is formed by co-evaporating 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as: aN-bNPAnth) and 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as: 3,10PCA2Nbf(IV)-02) on the hole transport layer in a weight ratio of 1:0.015 (=aN-bNPAnth:3,10PCA2Nbf(IV)-02) and a thickness of 25 nm. In addition, the electron transport layer is formed by evaporating βNP-SFx(4)Tzn in a thickness of 15 nm and then evaporating mPPhen2P in a thickness of 20 nm.

[0414] (Method for Manufacturing Light Emitting Device 2B) The light-emitting device 2B is a blue light-emitting device whose cathode thickness is different from that of the light-emitting device 2A. That is, in the light-emitting device 2B, the cathode is formed by co-evaporation on the electron injection layer in a volume ratio of 1:0.1 and a thickness of 25 nm. Other than that, it is manufactured in the same manner as the light-emitting device 2A.

[0415] Table 1 shows the device structures of the light-emitting device 1A and the light-emitting device 1B.

[0416] [Table 1]

[0417] Table 2 shows the device structures of the light-emitting device 2A and the light-emitting device 2B.

[0418] [Table 2]

[0419] Next, a method for manufacturing light-emitting devices 3R, 3G, and 3B, which are light-emitting devices manufactured by forming an organic compound layer using a photolithography method in a manner to achieve a resolution of 3207 ppi, is described. Note that the light-emitting device 3R includes an organic compound layer having the same structure as the light-emitting device 1A and a cathode having the same thickness, except that the thickness of the hole transport layer is different. In addition, the light-emitting device 3B includes an organic compound layer having the same structure as the light-emitting device 2A and a cathode having the same thickness, except that the thickness of the hole transport layer is different. The structural formula of the organic compound used for each light-emitting device is shown below.

[0420] [Chemical formula 4]

[0421] (Method for Manufacturing Light-Emitting Device 3R, Light-Emitting Device 3G, and Light-Emitting Device 3B) First, 50nm of titanium (Ti), 70nm of aluminum (Al), and 2nm of Ti are stacked from one side of a silicon substrate provided with wiring, and then baked at 300°C in the atmosphere for 1 hour. Then, 10nm of indium tin oxide (ITSO) containing silicon oxide is stacked by sputtering, and then processed by photolithography in a manner to achieve a resolution of 3207ppi, thereby forming an anode. Then, SiON is deposited, and the sidewalls are formed by SiON in a manner covering the ends of the anode. The anode is formed in a manner that a total of 63001 pixels of 251×251 are arranged in a matrix within a range of 2mm×2mm. Note that this shape and configuration are equivalent to 3207ppi.

[0422] Next, as a pre-treatment for forming a light-emitting device on the substrate, the following treatment is performed: after heating the substrate at 120° C. for 120 seconds, 1,1,1,3,3,3-hexamethyldisilazane (abbreviated as: HMDS) is vaporized and the HMDS is sprayed on the substrate heated to 60° C. for 120 seconds. This can prevent the laminated film formed on the anode from being easily peeled off from the anode during the manufacturing process.

[0423] Then, the substrate is placed inside the chamber and the pressure is reduced to 1×10 -4 Pa in a vacuum deposition device, and vacuum bake at 170° C. for 60 minutes in a heating chamber in the vacuum deposition device, and then cool the substrate for about 60 minutes.

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

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

[0426] Next, after forming a light-emitting layer and an electron transport layer in the same manner as in the method for manufacturing the light-emitting device 2A which is a blue light-emitting device, the organic compound layer is processed by photolithography in a method described next.

[0427] <<Processing method using photolithography>> The substrate formed up to the electron transport layer was taken out from the vacuum deposition device and exposed to the atmosphere, and then aluminum oxide was deposited to a thickness of 30 nm by the ALD method using trimethylaluminum (TMA) as a precursor and water vapor as an oxidant, thereby forming a first sacrificial layer.

[0428] Next, tungsten (W) was deposited on the first sacrificial layer to a thickness of 54 nm by a sputtering method, thereby forming a second sacrificial layer.

[0429] A photoresist is applied on the second sacrificial layer, exposed and developed, and processed so that the end portion thereof is located inside the end face of the anode. Thus, the organic compound layer can be processed into a shape having an end portion inside the end face of the anode.

[0430] The second sacrificial layer is processed using an etching gas containing SF6 with the photoresist as a mask, and the first sacrificial layer is processed using an etching gas containing trifluoromethane (CHF3), helium (He), and methane (CH4) in a flow ratio of CHF3:He:CH4=16.5:118.5:15 (flow ratio). Then, the organic compound layer is processed using an etching gas containing oxygen (O2).

[0431] The above is a processing method using photolithography. By processing using photolithography, the hole injection layer, hole transport layer, light emitting layer and electron transport layer of the light emitting device 3B are formed. In addition, the anode in the portion where the light emitting device 3R and the light emitting device 3G are formed is exposed.

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

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

[0434] Next, a layer of 100% tantalum was deposited on the hole transport layer at a weight ratio of 0.5:0.5:0.1 (=8 mpTP-4 mDBtPBfpm-d 13:βNCCP:Ir(5m4dppy-d3)3) and co-deposited 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]benzofurano[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm-d 13 ), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as βNCCP) and tri{2-[5-(methyl-d3)-4-phenyl-2-pyridyl-κN]phenyl-κC}iridium(III) (abbreviated as Ir(5m4dppy-d3)3) as a green phosphorescent dopant, thereby forming a light-emitting layer.

[0435] Next, the electron transport layer is formed by vapor-depositing βNP-SFx(4)Tzn in a thickness of 10 nm, and then vapor-depositing mPPhen2P in a thickness of 15 nm. Then, the hole injection layer, hole transport layer, light-emitting layer and electron transport layer of the light-emitting device 3G are formed in the same manner as the processing method using the above-mentioned photolithography method. In addition, the anode in the portion forming the light-emitting device 3R is exposed.

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

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

[0438] Next, after forming the light-emitting layer and the electron transport layer in the same manner as the manufacturing method of the light-emitting device 1A of the red light-emitting device, the hole injection layer, the hole transport layer, the light-emitting layer and the electron transport layer of the light-emitting device 3R are formed in the same manner as the processing method using the above-mentioned photolithography method.

[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 is removed using etching gas containing SF6 to leave the first sacrificial layer. Then, aluminum oxide is deposited to a thickness of 15 nm using the ALD method to form a protective film.

[0440] Next, a photosensitive polymer material is formed on the protective film by photolithography so as not to overlap the anode. Then, after heating at 100°C for 1 hour in an atmospheric atmosphere, a mixed acid aqueous solution containing hydrofluoric acid (HF) is used to remove the unnecessary first sacrificial layer and protective film to expose the second electron transport layer. At this time, the photosensitive polymer material is used as an etching resist.

[0441] The substrate with the second electron transport layer exposed was placed inside the chamber and the pressure was reduced to 1×10 -4 In a vacuum deposition device of about 1.5 Å Pa, vacuum baking was performed at 100° C. for 90 minutes in a heating chamber in the vacuum deposition device.

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

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

[0444] [Table 3]

[0445] In a glove box with a nitrogen atmosphere, each manufactured light-emitting device was sealed using a glass substrate in such a way that the light-emitting device was not exposed to the atmosphere (UV-curing sealing material was applied around the element so that only the sealing material was irradiated with UV without irradiating the light-emitting device, and heat-treated at 80°C for 1 hour under atmospheric pressure), and then the initial characteristics of each light-emitting device were measured.

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

[0447] Note that the blue index (BI) refers to the value obtained by dividing the current efficiency (cd / A) by the chromaticity y, and is one of the indicators that represent the luminous characteristics of blue light. The smaller the chromaticity y is, the higher the color purity of blue light tends to be. Blue light with high color purity can present a wider range of blue even if the brightness component is small. When blue light with high color purity is used, the brightness required to present blue is reduced, so the effect of reducing power consumption can be achieved. Therefore, the BI of chromaticity y, which is one of the indicators of blue purity, is suitable for representing the efficiency of blue light. It can be said that the higher the BI of the light-emitting device, the better the efficiency of the light-emitting device when it is used as a blue light-emitting device for a display.

[0448] In addition, Table 4 shows the brightness of the light emitting device 1A and the light emitting device 1B, 1000 cd / m 2 Table 5 shows the brightness of the light emitting device 2A and the light emitting device 2B at 1000 cd / m 2 Note that the brightness, CIE chromaticity, and electric field emission spectrum were measured at room temperature using a spectroradiometer (manufactured by Topcon, SR-UL1R).

[0449] [Table 4]

[0450] [Table 5]

[0451] Fig.21 Table 4 shows that the current efficiency of the light emitting device 1B is higher than that of the light emitting device 1A. It can be seen that in the red light emitting device, the light emitting efficiency is improved when the cathode thickness is 25 nm.

[0452] Fig. 22 Table 5 shows that the blue index of the light emitting device 2A is higher than that of the light emitting device 2B. It can be seen that in the blue light emitting device, the light emitting efficiency is improved by using a cathode thickness of 15 nm.

[0453] like Figure 2B As shown, in the present embodiment 1, since the absorptivity of the Ag:Mg film to red light is small, it can be said that the greater the cathode thickness of the red light emitting device, the higher the current efficiency is by improving the directivity of light in the direction perpendicular to the light emitting surface by using the microcavity structure. On the other hand, since the absorptivity of the Ag:Mg film to blue light is large, it can be said that the smaller the cathode thickness of the blue light emitting device, the more light absorption caused by the cathode is suppressed, and the more the current efficiency is improved.

[0454] From the above results, we can see that Figure 1BAs shown, in a display device of one embodiment of the present invention, the thickness of the auxiliary electrode 106 is made different in each light-emitting device having different light-emitting colors. 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, the cathode thickness can be made different in each light-emitting device, thereby improving the light-emitting efficiency of each light-emitting device. Figure 3B As shown, it can be seen that in a display device of one embodiment of the present invention, by providing an auxiliary electrode 106R on the red light-emitting device 130R and not providing an auxiliary electrode on the blue light-emitting device 130B, the cathode thickness in each light-emitting device can be made different, thereby improving the light-emitting efficiency of each light-emitting device.

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

[0456] Notice, Figure 23 to Figure 26 The measurement results of a comparative light-emitting device (indicated as Ref. in the drawing) having the same structure as the light-emitting device 3R but not undergoing the process of forming an organic compound layer by photolithography are shown. Figures 27 to 30 The measurement results of a comparative light-emitting device (indicated as Ref. in the figure) having the same structure as the light-emitting device 3G but not undergoing the process of forming an organic compound layer by photolithography are shown. Figure 31 to Figure 34 The measurement results of a comparative light-emitting device (indicated as Ref. in the figure) having the same structure as the light-emitting device 3B but not undergoing the process of forming an organic compound layer by photolithography are shown. Note that the cap layer of each comparative light-emitting device was formed by evaporating PCBBiF to a thickness of 80 nm.

[0457] The above results show that a light-emitting device with good characteristics and little degradation in characteristics can be manufactured through the step of forming an organic compound layer by photolithography.

[0458] In addition, 50 mA / cm 2 It can be seen that the LT95 of the light emitting device 3B is 239 hours.

[0459] As described above, the light-emitting device 3R includes an organic compound layer having the same structure as the light-emitting device 1A and a cathode having the same thickness (15 nm), except that the thickness of the hole transport layer is different. Fig.21 As shown, based on the result that the current efficiency of the light-emitting device 1A with a cathode thickness of 15nm is lower than the current efficiency of the light-emitting device 1B with a cathode thickness of 25nm, it can be expected that in the light-emitting device 3R, the auxiliary electrode is arranged between the electron injection layer and the cathode and is manufactured in a manner such that the cathode thickness is 25nm, thereby improving the luminous efficiency.

[0460] In addition, the light-emitting device 3B includes an organic compound layer having the same structure as the light-emitting device 2A and a cathode having the same thickness (15 nm), except that the thickness of the hole transport layer is different. Fig. 22 As shown, based on the result that the blue index of the light-emitting device 2A with a cathode thickness of 15nm is higher than the blue index of the light-emitting device 2B with a cathode thickness of 25nm, it can be predicted that the light-emitting device 3B can maintain a higher luminous efficiency without providing an auxiliary electrode, so it is preferred. Example 2

[0461] In this embodiment, in order to explain a display device of one embodiment of the present invention, the following results are described: light emitting devices 4A and 4B, which are tandem red light emitting devices with different cathode thicknesses, light emitting devices 5A and 5B, which are tandem green light emitting devices with different cathode thicknesses, and light emitting devices 6A and 6B, which are tandem blue light emitting devices with different cathode thicknesses, are manufactured and the luminous efficiencies of these light emitting devices are compared. In addition, the following results are described: light emitting devices 7R (red), 7G (green), and 7B (blue), which are tandem light emitting devices manufactured by forming an organic compound layer by photolithography in a manner to achieve a resolution of 3207 ppi, are manufactured and the characteristics of these light emitting devices are evaluated.

[0462] First, a method for manufacturing the light emitting device 4A, the light emitting device 4B, the light emitting device 5A, the light emitting device 5B, the light emitting device 6A, and the light emitting device 6B will be described. The structural formula of the organic compound used for each light emitting device is shown below.

[0463] [Chemical formula 5]

[0464] [Chemical formula 6]

[0465] (Method of Manufacturing Light Emitting Device 4A) First, 50nm of titanium (Ti), 70nm of aluminum (Al), and 2nm of Ti were stacked on a glass substrate from one side of the substrate, and then baked at 300°C for 1 hour in the atmosphere. Thereafter, indium tin oxide (ITSO) containing silicon oxide was stacked with a thickness of 10nm as a transparent electrode by sputtering to form an anode. The electrode area is 4mm 2 (2mm×2mm).

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

[0467] Then, the substrate is placed inside the chamber and the pressure is reduced to 1×10 -4 Pa in a vacuum deposition apparatus, and perform heat treatment at 170° C. in a heating chamber in the vacuum deposition apparatus for 30 minutes, and then cool the substrate for about 30 minutes.

[0468] Next, the substrate was fixed to a holder in a vacuum evaporation device with the surface having the anode facing downward, and PCBBiF and OCHD-003 were co-evaporated on the anode by a evaporation method in a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) and a thickness of 10 nm, thereby forming a hole injection layer.

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

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

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

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

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

[0474] Furthermore, co-evaporation was performed so that the weight ratio of PCBBiF to OCHD-003 was 1:0.15 (=PCBBiF:OCHD-003) and the thickness was 10 nm, thereby forming a second layer of the intermediate layer.

[0475] Next, PCBBiF was deposited on the intermediate layer to a thickness of 65 nm, thereby forming a second hole transport layer.

[0476] Next, the second light-emitting layer was formed on the second hole transport layer in the same manner as the first light-emitting layer.

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

[0478] After the second electron transport layer was formed, lithium fluoride and ytterbium were co-evaporated at a volume ratio of 1:0.5 (=LiF:Yb) and a thickness of 1.5 nm 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) in a volume ratio of 1:0.1 and a thickness of 15 nm, thereby manufacturing the light-emitting device 4A.

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

[0481] (Method of Manufacturing Light Emitting Device 4B) The light emitting device 4B is a red light emitting device having a cathode thickness different from that of the light emitting device 4A. That is, in the light emitting device 4B, the cathode is formed by co-evaporation on the electron injection layer in a volume ratio of 1:0.1 and a thickness of 25 nm. Other than that, the light emitting device 4B is manufactured in the same manner as the light emitting device 4A.

[0482] (Method of Manufacturing Light Emitting Device 5A) The light-emitting device 5A is a green light-emitting device having different thicknesses of the first and second hole transport layers, structures of the first and second light-emitting layers, and thicknesses of the second electron transport layer from those of the light-emitting device 4A. PCBBiF is evaporated on the hole injection layer in a thickness of 32.5 nm, thereby forming a first hole transport layer. In addition, 8-(1,1':4',1"-terphenyl-3-yl)-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), βNCCP and [2-d3-methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)) are used. The first and second light-emitting layers were formed by co-evaporation in a weight ratio of 0.6:0.4:0.1 (=8mpTP-4mDBtPBfpm:βNCCP:Ir(5mppy-d3)2(mbfpypy-d3)) and a thickness of 40nm. In addition, PCBBiF was evaporated on the intermediate layer in a thickness of 55nm to form a second hole transport layer. In addition, after 2mPCCzPDBq was evaporated in a thickness of 10nm, mPPhen2P was evaporated in a thickness of 15nm to form a second electron transport layer.

[0483] (Method of Manufacturing Light Emitting Device 5B) Light-emitting device 5B is a green light-emitting device whose cathode thickness is different from that of light-emitting device 5A. That is, in light-emitting device 5B, silver (Ag) and magnesium (Mg) are co-evaporated on the electron injection layer in a volume ratio of 1:0.1 and a thickness of 25 nm to form a cathode. Other than that, it is manufactured in the same manner as light-emitting device 5A.

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

[0485] (Method of Manufacturing Light Emitting Device 6B) Light-emitting device 6B is a blue light-emitting device whose cathode thickness is different from that of light-emitting device 6A. That is, in light-emitting device 6B, silver (Ag) and magnesium (Mg) are co-evaporated on the electron injection layer in a volume ratio of 1:0.1 and a thickness of 25 nm to form a cathode. Other than that, it is manufactured in the same manner as light-emitting device 6A.

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

[0487] [Table 6]

[0488] Table 7 shows the device structures of the light-emitting device 5A and the light-emitting device 5B.

[0489] [Table 7]

[0490] Table 8 shows the device structures of the light-emitting device 6A and the light-emitting device 6B.

[0491] [Table 8]

[0492] Next, a method for manufacturing light-emitting devices 7R, 7G, and 7B, which are light-emitting devices manufactured by forming an organic compound layer using a photolithography method in a manner to achieve a clarity of 3207ppi, is described. Note that the light-emitting device 7R includes an organic compound layer having the same structure as the above-mentioned light-emitting device 4A and a cathode having the same thickness, except that the structures of the intermediate layer and the first electron transport layer are different. In addition, the structure of the organic compound layer of the light-emitting device 7G is different from that of the organic compound layer of the light-emitting device 5A, but it includes a green light-emitting device and a cathode having the same thickness as the light-emitting device 5A. In addition, the light-emitting device 7B includes an organic compound layer having the same structure as the above-mentioned light-emitting device 6A and a cathode having the same thickness, except that the structure of the intermediate layer is different, the thickness of the first hole transport layer is different, and the structure of the first electron transport layer is different. The structural formula of the organic compound used for each light-emitting device is shown below.

[0493] [Chemical formula 7]

[0494] (Method for Manufacturing Light-Emitting Device 7R, Light-Emitting Device 7G, and Light-Emitting Device 7B) First, 50nm of titanium (Ti), 70nm of aluminum (Al), and 2nm of Ti are stacked from one side of a silicon substrate provided with wiring, and then baked at 300°C in the atmosphere for 1 hour. Then, 10nm of indium tin oxide (ITSO) containing silicon oxide is stacked by sputtering, and then processed by photolithography in a manner to achieve a resolution of 3207ppi, thereby forming an anode. Then, SiON is deposited, and the sidewalls are formed by SiON in a manner covering the ends of the anode. The anode is formed in a manner that a total of 63001 pixels of 251×251 are arranged in a matrix within a range of 2mm×2mm. Note that this shape and configuration are equivalent to 3207ppi.

[0495] Next, as a pre-treatment for forming a light-emitting device on the substrate, the following treatment is performed: after heating the substrate at 120° C. for 120 seconds, 1,1,1,3,3,3-hexamethyldisilazane (abbreviated as: HMDS) is vaporized and the HMDS is sprayed on the substrate heated to 60° C. for 120 seconds. This can prevent the laminated film formed on the anode from being easily peeled off from the anode during the manufacturing process.

[0496] Then, the substrate is placed inside the chamber and the pressure is reduced to 1×10 -4 Pa in a vacuum deposition device, and vacuum bake at 170° C. for 60 minutes in a heating chamber in the vacuum deposition device, and then cool the substrate for about 60 minutes.

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

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

[0499] Next, after forming the first light-emitting layer in the same manner as in the method for manufacturing the light-emitting device 6A which is a blue light-emitting device, 2mPCCzPDBq was vapor-deposited to a thickness of 10 nm to form a first electron transport layer.

[0500] After forming the first electron transport layer, the first layer of the intermediate layer is formed by co-evaporation with a volume ratio of mPPhen2P and Li2O of 1:0.01 (=mPPhen2P:Li2O) and a thickness of 5nm, and then the third and second layers of the intermediate layer are formed in the same manner as the manufacturing method of the light-emitting device 4A.

[0501] Next, after forming the second hole transport layer, the second light emitting layer, and the second electron transport layer in the same manner as in the method for manufacturing the light emitting device 6A, the organic compound layer is processed by photolithography by the method described below.

[0502] <<Processing method using photolithography>> The substrate formed up to the second electron transport layer was taken out from the vacuum evaporation device and exposed to the atmosphere, and then aluminum oxide was deposited to a thickness of 30 nm by the ALD method using trimethylaluminum (TMA) as a precursor and water vapor as an oxidant, thereby forming a first sacrificial layer.

[0503] Then, tungsten (W) was deposited on the first sacrificial layer to a thickness of 54 nm by a sputtering method, thereby forming a second sacrificial layer.

[0504] A photoresist is applied on the second sacrificial layer, exposed and developed, and processed so that the end portion thereof is located inside the end face of the anode. Thus, the organic compound layer can be processed into a shape having an end portion inside the end face of the anode.

[0505] The second sacrificial layer is processed using an etching gas containing SF6 with the photoresist as a mask, and the first sacrificial layer is processed using an etching gas containing trifluoromethane (CHF3), helium (He), and methane (CH4) in a flow ratio of CHF3:He:CH4=16.5:118.5:15 (flow ratio). Then, the organic compound layer is processed using an etching gas containing oxygen (O2).

[0506] The above is a processing method using photolithography. Through processing using photolithography, 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 are formed. In addition, the anode in the portion where the light-emitting device 7R and the light-emitting device 7G are formed is exposed.

[0507] Next, a hole injection layer is formed on the second sacrificial layer and the anode in the same manner as in the method for manufacturing the light emitting device 4A.

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

[0509] 8mpTP-4mDBtPBfpm-d on the first hole transport layer 13 The weight ratio of βNCCP and Ir(5m4dppy-d3)3 is 0.5:0.5:0.1 (=8mpTP-4mDBtPBfpm-d 13 :βNCCP:Ir(5m4dppy-d3)3) was co-evaporated to a thickness of 40 nm to form a first light-emitting layer.

[0510] Next, the first electron transport layer, the first layer, the third layer, and the second layer of the intermediate layer are formed in the same manner as the method for manufacturing the light-emitting device 7B.

[0511] After forming a second hole transport layer by vapor-depositing PCBBiF to a thickness of 55 nm on the intermediate layer, a second light-emitting layer was formed in the same manner as the first light-emitting layer.

[0512] Next, a second electron transport layer is formed in the same manner as in the method for manufacturing the 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 are formed in the same manner as the processing method using the above-mentioned photolithography method. In addition, the anode in the portion where the light emitting device 7R is to be formed is exposed.

[0514] Next, a hole injection layer is formed on the second sacrificial layer and the anode in the same manner as in the method for manufacturing the light emitting device 4A.

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

[0516] Next, after forming the first light-emitting layer in the same manner as the manufacturing method of the light-emitting device 4A which is a red light-emitting device, the first electron transport layer, the first layer, the third layer, and the second layer of the intermediate layer are formed in the same manner as the manufacturing method of the light-emitting device 7B.

[0517] After forming a second hole transport layer by vapor-depositing PCBBiF to a thickness of 65 nm on the intermediate layer, a second light-emitting layer was formed in the same manner as the first light-emitting layer.

[0518] Next, after forming the second electron transport layer in the same manner as the manufacturing method of the light-emitting device 4A, 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 7R are formed in the same manner as the processing method using the above-mentioned photolithography method.

[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 is removed using an etching gas containing SF6, leaving the first sacrificial layer. Then, aluminum oxide is deposited in a thickness of 15 nm using an ALD method to form a protective film.

[0520] Next, a photosensitive polymer material is formed on the protective film by photolithography so as not to overlap the anode. After heating at 100°C for 1 hour in an atmospheric atmosphere, a mixed acid aqueous solution containing hydrofluoric acid (HF) is used to remove the unnecessary first sacrificial layer and protective film to expose the second electron transport layer. At this time, the photosensitive polymer material is used as an etching resist.

[0521] The substrate with the second electron transport layer exposed was placed inside the chamber and the pressure was reduced to 1×10 -4 In a vacuum deposition device of about 1.5 Å Pa, vacuum baking was performed at 100° C. for 90 minutes in a heating chamber in the vacuum deposition device.

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

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

[0524] [Table 9]

[0525] In a glove box with a nitrogen atmosphere, each manufactured light-emitting device was sealed using a glass substrate in such a way that the light-emitting device was not exposed to the atmosphere (UV-curing sealing material was applied around the element so that only the sealing material was irradiated with UV without irradiating the light-emitting device, and heat-treated at 80°C for 1 hour under atmospheric pressure), and then the initial characteristics of each light-emitting device were measured.

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

[0527] In addition, Table 10 shows the brightness of the light emitting device 4A and the light emitting device 4B, 1000 cd / m 2 Table 11 shows the brightness of the light emitting device 5A and the light emitting device 5B at 1000 cd / m 2 Table 12 shows the brightness of the light emitting device 6A and the light emitting device 6B at 1000 cd / m 2 Note that the brightness, CIE chromaticity, and electric field emission spectrum were measured at room temperature using a spectroradiometer (manufactured by Topcon, SR-UL1R).

[0528] [Table 10]

[0529] [Table 11]

[0530] [Table 12]

[0531] Fig.35 Table 10 shows that the current efficiency of the light emitting device 4B is higher than that of the light emitting device 4A. It can be seen that the luminous efficiency of the tandem red light emitting device is improved when the cathode thickness is 25 nm, as in the case of the single red light emitting device.

[0532] Fig.36 Table 11 shows that the current efficiency of the light emitting device 5A is higher than that of the light emitting device 5B. It can be seen that the luminous efficiency of the tandem green light emitting device is improved by using a cathode thickness of 15 nm.

[0533] in addition, Fig.37 Table 12 shows that the blue index of light emitting device 6A is higher than that of light emitting device 6B. It can be seen that the tandem blue light emitting device has improved luminous efficiency by adopting a cathode thickness of 15 nm, as in the case of the single blue light emitting device.

[0534] From the above results, we can see that Figure 1B As shown, in a display device of one embodiment of the present invention, the thickness of the auxiliary electrode 106 is made different in each light-emitting device having different light-emitting colors. More specifically, by making the thickness of the auxiliary electrode 106R of the red light-emitting device 130R larger 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, the cathode thickness can be made different in each light-emitting device, thereby improving the light-emitting efficiency of each light-emitting device. In addition, it can be seen that in a display device of one embodiment of the present invention, by providing the auxiliary electrode 106R on the red light-emitting device 130R and not providing the auxiliary electrode on the green light-emitting device 130G and the blue light-emitting device 130B, the cathode thickness can be made different in each light-emitting device, thereby improving the light-emitting efficiency of each light-emitting device.

[0535] then, Fig.38 shows the current density-voltage characteristics of the light emitting device 7R, Fig.39 The external quantum efficiency-current density characteristics are shown. In addition, Fig.40 : shows the current density-voltage characteristics of the light emitting device 7G, Fig.41 The external quantum efficiency-current density characteristics are shown. In addition, Fig.42 shows the current density-voltage characteristics of the light emitting device 7B, Fig.43 The external quantum efficiency-current density characteristics are shown.

[0536] Notice, Fig.38 and Fig.39 The measurement results of a comparative light-emitting device (indicated as Ref. in the drawing) having the same structure as the light-emitting device 7R but not undergoing the process of forming an organic compound layer by photolithography are shown. Fig.40 and Fig.41 The measurement results of a comparative light-emitting device (indicated as Ref. in the drawing) having the same structure as the light-emitting device 7G but not undergoing the process of forming an organic compound layer by photolithography are shown. Fig.42 and Fig.43 The measurement results of a comparative light-emitting device (indicated as Ref. in the drawing) which has the same structure as the light-emitting device 7B but is manufactured without going through the step of forming an organic compound layer by photolithography are shown.

[0537] in addition, Fig.44 The result of applying a current to the light emitting device 7R to perform constant current driving is shown. Fig.45 The result of applying a current to the light emitting device 7G to drive the light emitting device 7G with a constant current is shown. Fig.46 The result of applying a current to the light emitting device 7B to perform constant current driving is shown.

[0538] from Fig.44 It can be seen that when the current density is set to 63mA / cm 2 When , the LT95 of the light emitting device 7R is 590 hours. Fig.45 It can be seen that when the current density is set to 54 mA / cm 2 , the LT95 of the light emitting device 7G is 200 hours. Fig.46 It can be seen that when the current density is set to 50 mA / cm 2 , the LT95 of the light-emitting device 7B is 204 hours.

[0539] As described above, the light-emitting device 7R includes an organic compound layer having the same structure as that of the light-emitting device 4A, except that the structures of the intermediate layer and the first electron transport layer are different. Fig.35 As shown, based on the result that the current efficiency of the light-emitting device 4A with a cathode thickness of 15nm is lower than the current efficiency of the light-emitting device 4B with a cathode thickness of 25nm, it can be expected that in the light-emitting device 7R, the auxiliary electrode is arranged between the electron injection layer and the cathode and is manufactured in a manner such that the cathode thickness is 25nm, thereby improving the luminous efficiency.

[0540] In addition, like the above-mentioned light-emitting device 5A, the light-emitting device 7G is a green light-emitting device and includes a cathode having the same thickness (15 nm). Fig.36 As shown, based on the result that the current efficiency of the light-emitting device 5A with a cathode thickness of 15 nm is higher than the current efficiency of the light-emitting device 5B with a cathode thickness of 25 nm, it can be predicted that it is preferable to maintain a higher light-emitting efficiency when the light-emitting device 7G does not have an auxiliary electrode.

[0541] In addition, the light-emitting device 7B includes an organic compound layer having the same structure as the light-emitting device 6A and a cathode having the same thickness (15 nm), except that the structure of the intermediate layer is different, the thickness of the first hole transport layer is different, and the structure of the first electron transport layer is different. Fig.37 As shown, based on the result that the blue index of the light-emitting device 6A with a cathode thickness of 15nm is higher than the blue index of the light-emitting device 6B with a cathode thickness of 25nm, it can be predicted that it is preferable to maintain a higher luminous efficiency when the light-emitting device 7B does not have an auxiliary electrode.

Claims

1. A display device, comprising: a first light emitting device; as well as a second light emitting device, Wherein, the first light emitting device and the second light emitting device include a common electrode having light transmittance, The first light emitting device includes a first electrode, a first EL layer, and a first auxiliary electrode having light transmittance. The second light emitting device includes a second electrode, a second EL layer, and a second auxiliary electrode having light transmittance. 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. Furthermore, the thickness of the first auxiliary electrode is thicker than the thickness of the second auxiliary electrode.

2. A display device, comprising: a first light emitting device; as well as 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 includes a first electrode, a first EL layer, and a first auxiliary electrode having light transmittance. The second light emitting device includes 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 is in contact with the common electrode. Furthermore, the first auxiliary electrode is located between the first EL layer and the common electrode.

3. A display device, comprising: a first light emitting device; as well as a second light emitting device, The first light emitting device and the second light emitting device include a common electrode and a common layer having light transmittance. The common electrode is located on the common layer, The first light emitting device includes a first electrode, a first EL layer, and a first auxiliary electrode having light transmittance. The second light emitting device includes 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 is in contact with the common layer, Furthermore, the first auxiliary electrode is located between the first EL layer and the common layer.

4. The display device according to claim 3, The common layer comprises an alkali metal or an alkaline earth metal.

5. The display device according to any one of claims 1 to 4, The color of light emitted by the first light emitting device is different from the color of light emitted by the second light emitting device.

6. The display device according to any one of claims 1 to 4, The wavelength of light emitted by the first light emitting device is longer than the wavelength of light emitted by the second light emitting device.

7. The display device according to any one of claims 1 to 4, The first auxiliary electrode includes silver and magnesium.

8. The display device according to claim 7, The thickness of the first auxiliary electrode is greater than or equal to 1 nm and less than or equal to 50 nm.

9. The display device according to any one of claims 1 to 4, further comprising an insulating layer, The insulating layer is located between the first EL layer and the second EL layer.

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