Light emitting device

Abstract

Provided is a light-emitting device having high efficiency and good reliability. The light emitting device includes a light emitting layer, a first layer, and a second layer between an anode and a cathode. Specifically, the light emitting device includes a light emitting layer between an anode and a first layer and a second layer between the first layer and a cathode. The light-emitting layer contains a light-emitting substance. The first layer is a mixed layer containing a first organic compound and a second organic compound, the first organic compound having a strong basicity with a pKa of 8 or more, and the second organic compound having an electron-transporting property. The LUMO level of the first organic compound is higher than that of the second organic compound. The second layer contains a first hole-transporting organic compound and a first material that accepts the first hole-transporting organic compound.

Description

Technical Field

[0001] One aspect of the present invention relates to an organic compound, a light-emitting device, a light-emitting apparatus, a light-receiving apparatus, a display device, an electronic device, a lighting device, and an electronic component. Note that one aspect of the present invention is not limited to the above technical field. One aspect of the invention disclosed in this specification and the like relates to an object, a driving method, or a manufacturing method. In addition, one aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Thus, more specifically, as an example of the technical field of one aspect of the present invention disclosed in this specification, semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, power storage devices, storage devices, imaging devices, driving methods of these devices, or manufacturing methods of these devices can be cited. Background Art

[0002] The practical application of light-emitting devices (organic EL devices) using organic compounds and utilizing electroluminescence (EL) has been very active. In the basic structure of these light-emitting devices, an organic compound layer (EL layer) containing a light-emitting material is sandwiched between a pair of electrodes. By applying a voltage to this element, carriers are injected, and light emission from the light-emitting material can be obtained using the recombination energy of these carriers.

[0003] Since such a light-emitting device is a self-luminous type light-emitting device, when used for pixels of a display, it has advantages such as higher visibility and no need for a backlight compared to liquid crystals. Therefore, this light-emitting device is suitable for flat panel display elements. In addition, a display using such a light-emitting device can be manufactured to be thin and light, which is also a great advantage. Moreover, a very fast response speed is also one of its characteristics.

[0004] In addition, since the light-emitting layer of such a light-emitting device can be formed continuously in two dimensions, surface light emission can be obtained. Since this characteristic is difficult to obtain in point light sources typified by incandescent lamps and LEDs or line light sources typified by fluorescent lamps, it also has high utility value as a surface light source applicable to lighting and the like.

[0005] As described above, displays or lighting devices using light-emitting devices can be applied to various electronic devices. Therefore, research and development of light-emitting devices with better characteristics have been increasingly active.

[0006] As a method for manufacturing a light-emitting device, various methods are known. As one of the methods for manufacturing a high-definition light-emitting device, a method of forming a light-emitting layer without using a fine metal mask is known. As an example thereof, there is a method for manufacturing an organic EL display, including: a step of depositing a first light-emitting organic material containing a mixture of a host material and a dopant material over an electrode array including first and second pixel electrodes formed over an insulating substrate to form a first light-emitting layer as a continuous film provided over the entire display region including the electrode array; a step of irradiating ultraviolet light not to a portion of the first light-emitting layer located over the first pixel electrode but to a portion of the first light-emitting layer located over the second pixel electrode; a step of depositing a second light-emitting organic material containing a mixture of a host material and a dopant material and different from the first light-emitting organic material over the first light-emitting layer to form a second light-emitting layer as a continuous film provided over the entire display region; and a step of forming a counter electrode over the second light-emitting layer (Patent Document 1).

[0007] In addition, as one type of organic EL device, Non-Patent Document 1 discloses a method for manufacturing an organic optoelectronic device using a standard UV lithography method (Non-Patent Document 1).

[0008] [Prior Art Documents]

[0009] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-160473 Non-Patent Documents

[0011] [Non-Patent Documents]

[0012] [Non-Patent Document 1] B. Lamprecht et al., “Organic optoelectronic device fabrication using standard UV photolithography” phys.stat.sol.(RRL) 2, No. 1, p. 16-18 (2008) Summary of the Invention

[0013] Technical Problem to be Solved by the Invention

[0014] Generally, in the electron injection layer of a light-emitting device, an alkali metal such as lithium (Li) having a small work function or a compound of the alkali metal is used. And, by using the above alkali metal or its compound, good electron injection property can be ensured. In addition, due to the interaction between the above alkali metal or its compound and the electron transporting material, charge generation ability can be ensured and electrons can be injected into the electron transport layer. Therefore, by using the above alkali metal or its compound for the electron injection layer, low voltage operation of the light-emitting device can be achieved.

[0015] However, the above-mentioned alkali metal or its compound is a material that is easily oxidized and unstable. Therefore, if the above-mentioned alkali metal or its compound reacts with atmospheric components such as water or oxygen during the process of manufacturing a light-emitting device, there will be problems such as a significant increase in the driving voltage of the light-emitting device or a significant decrease in the luminous efficiency. Therefore, when manufacturing an organic EL device, it is necessary to manufacture it under vacuum or in an inert gas atmosphere such as nitrogen.

[0016] In recent years, as one of the methods for forming an organic compound layer into a specified shape, a vacuum evaporation method using a metal mask (mask evaporation) has been widely adopted. However, with the progress of high fineness, due to various reasons typified by problems such as position alignment accuracy and the configuration interval from the substrate, the further high fineness of mask evaporation is approaching the limit. On the other hand, by using lithography techniques (for example, X-ray lithography, electron beam lithography, multiphoton lithography, interference lithography, nanoimprint method, etc.) to process the shape of the organic compound film, a denser pattern can be formed. In this method, since it is also easy to increase the area, research on the processing of the organic compound film using lithography techniques has been carried out.

[0017] In addition, when manufacturing a light-emitting device using lithography techniques, the EL layer in the light-emitting device is exposed to the atmosphere, resist resin, water, or chemical solution, etc. during the processing step. In a device in which the N-type layer of the EL layer contains an alkali metal or a compound of the alkali metal, the N-type layer deteriorates due to this step, resulting in a significant decrease in characteristics. That is, due to the exposure of the layer of the alkali metal or the compound of the alkali metal in the EL layer to the photolithography process, there is a significant increase in the driving voltage and a significant decrease in the luminous efficiency.

[0018] One of the objects of one aspect of the present invention is to provide a novel light-emitting device. In addition, one of the objects of one aspect of the present invention is to provide a light-emitting device having good efficiency. In addition, one of the objects of one aspect of the present invention is to provide a light-emitting device having good reliability. In addition, one of the objects of one aspect of the present invention is to provide a light-emitting device having good reliability and efficiency.

[0019] One of the objects of one embodiment of the present invention is to provide a novel organic compound having excellent convenience, practicality, or reliability. One of the objects of one embodiment of the present invention is to provide a semiconductor device with a high degree of design freedom. Further, one of the objects of one embodiment of the present invention is to provide a light-emitting device with a high degree of design freedom in a manufacturing process. Further, one of the objects of another embodiment of the present invention is to provide a light-emitting device with high reliability. Further, one of the objects of one embodiment of the present invention is to provide a light-emitting device, a light-emitting device, an electronic device, a display device, or an electronic device with low power consumption. Further, one of the objects of one embodiment of the present invention is to provide a light-emitting device, a light-emitting device, an electronic device, a display device, or an electronic device with low power consumption and high reliability.

[0020] Note that the object of one embodiment of the present invention is not limited to the objects listed above. The objects listed above do not prevent the existence of other objects. In addition, other objects are objects that are not mentioned above and will be described in the following description. Those skilled in the art can derive and appropriately extract objects that are not mentioned above from the description of the specification or drawings, etc. Further, one embodiment of the present invention achieves at least one of the objects listed above and other objects without necessarily achieving all of the objects listed above and other objects.

[0021] Means for Solving Technical Problems (1)

[0023] One embodiment of the present invention is a light-emitting device that includes a light-emitting layer, a first layer, and a second layer between an anode and a cathode. Specifically, the light-emitting device includes a light-emitting layer between the anode and the first layer, and a second layer between the first layer and the cathode. Further, the light-emitting layer contains a light-emitting substance. The first layer is a mixed layer containing a first organic compound and a second organic compound. The first organic compound has a strong basicity with a pKa of 8 or more, and the second organic compound has electron-transporting properties. Further, the LUMO energy level of the first organic compound is higher than that of the second organic compound. The second layer contains a first hole-transporting organic compound and a first material having an acceptor property for the first hole-transporting organic compound. (2)

[0025] Further, one aspect of the present invention is a light-emitting device that includes a light-emitting layer, a first layer, a second layer, and a third layer between an anode and a cathode. Specifically, the light-emitting device includes the light-emitting layer between the anode and the first layer, the second layer between the first layer and the cathode, and the third layer between the first layer and the second layer. Further, the light-emitting layer contains a light-emitting substance. The first layer is a mixed layer containing a first organic compound and a second organic compound. The first organic compound has a strong basicity with a pKa of 8 or more, and the second organic compound has electron-transporting properties. Further, the LUMO energy level of the first organic compound is higher than that of the second organic compound. The second layer contains a first hole-transporting organic compound and a first material that is receptor-like to the first hole-transporting organic compound. The third layer contains a material having a LUMO energy level of -4.30 eV or more and -3.00 eV or less. (3)

[0027] Further, in the light-emitting device of (1) or (2) above, one aspect of the present invention may also adopt a structure in which the HOMO energy level of the first organic compound is higher than the HOMO energy level of the second organic compound. (4)

[0029] Further, in the light-emitting device of (1) or (2) above, one aspect of the present invention may also adopt a structure in which the second layer is a mixed layer of the first hole-transporting organic compound and the first material. (5)

[0031] Further, in the light-emitting device of (1) or (2) above, one aspect of the present invention may also adopt a structure in which the second layer is a laminate of a layer containing the first hole-transporting organic compound and a layer containing the first material. (6)

[0033] Further, in the light-emitting device of (5) above, one aspect of the present invention may also adopt a structure in which a layer containing the first hole-transporting organic compound is included between the layer containing the first material and the cathode. (7)

[0035] Further, in the light-emitting device of (1) or (2) above, one aspect of the present invention may also adopt a structure in which the second layer is in contact with the cathode. (8)

[0037] Further, in the light-emitting device of (1) or (2) above, one aspect of the present invention may also adopt a structure in which the second organic compound has a π-deficient heteroaromatic ring. (9)

[0039] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure including a fourth layer between the anode and the light-emitting layer. Particularly preferably, the fourth layer contains a second hole-transporting organic compound and a second material having an acceptor property for the second hole-transporting organic compound. (10)

[0041] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the LUMO energy level of the first organic compound is 0.05 eV or more higher than that of the second organic compound. (11)

[0043] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the LUMO energy level of the first organic compound is 0.05 eV or more higher than that of the second organic compound and the HOMO energy level of the first organic compound is 0.05 eV or more higher than that of the second organic compound. (12)

[0045] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less. (13)

[0047] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less and the HOMO energy level of the first organic compound is -5.7 eV or more and -4.8 eV or less. (14)

[0049] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less and the LUMO energy level of the second organic compound is -3.25 eV or more and -2.50 eV or less. (15)

[0051] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt the following structure: the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less, the LUMO energy level of the second organic compound is -3.25 eV or more and -2.50 eV or less, the HOMO energy level of the first organic compound is -5.7 eV or more and -4.8 eV or less, and the HOMO energy level of the second organic compound is -6.5 eV or more and -5.7 eV or less. (16)

[0053] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the second organic compound is a basic material having an acidity coefficient pKa of 4 or more and 8 or less. (17)

[0055] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the first organic compound does not have an electron-donating property to the second organic compound. (18)

[0057] In addition, in the light-emitting device of the above (1) or (2), one embodiment of the present invention may also adopt a structure in which the spin density of the mixed layer containing the first organic compound and the second organic compound measured by electron spin resonance method is 1×10 17 spins / cm 3 or less.

[0058] Advantages of the Invention

[0059] According to one embodiment of the present invention, a novel light-emitting device can be provided. In addition, according to another embodiment of the present invention, a light-emitting device having good efficiency can be provided. In addition, according to one embodiment of the present invention, a light-emitting device having good reliability can be provided. In addition, according to another embodiment of the present invention, a light-emitting device having good reliability and efficiency can be provided.

[0060] According to one embodiment of the present invention, a novel organic compound with excellent convenience, practicality or reliability can be provided. In addition, according to one embodiment of the present invention, a semiconductor device with a high degree of design freedom can be provided. In addition, according to one embodiment of the present invention, a light-emitting device with a high degree of design freedom in the manufacturing process can be provided. In addition, according to another embodiment of the present invention, a light-emitting device with high reliability can be provided. In addition, according to one embodiment of the present invention, a light-emitting device, a light-emitting device, an electronic device, a display device or an electronic device with low power consumption can be provided. In addition, according to one embodiment of the present invention, a light-emitting device, a light-emitting device, an electronic device, a display device, an electronic device or a lighting device with low power consumption and high reliability can be provided.

[0061] Note that the effects of one embodiment of the present invention are not limited to the above effects. The above-listed effects do not prevent the existence of other effects. In addition, other effects are the effects that are not mentioned above and will be described in the following description. Those skilled in the art can derive and appropriately extract the effects not mentioned above from the description of the specification or drawings, etc. In addition, one embodiment of the present invention has at least one of the above effects and other effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figures 1A to 1D is a diagram showing a structural example of a light-emitting device.

[0063] Figure 2A and Figure 2B is a band diagram explaining the driving mechanism of the light-emitting device of the present invention.

[0064] Figures 3A to 3C is a diagram showing a structural example of a light-emitting device.

[0065] Figure 4A and Figure 4B is a diagram showing a structural example of a light-emitting device.

[0066] Figure 5A and Figure 5B are a top view and a cross-sectional view of a structural example of a light-emitting device.

[0067] Figure 6 is a cross-sectional view of a structural example of a light-emitting device.

[0068] Figures 7A to 7D is a cross-sectional view showing a structural example of a light-emitting device.

[0069] Figures 8A to 8E is a cross-sectional view showing an example of a manufacturing method of a light-emitting device.

[0070] Figures 9A to 9E is a cross-sectional view showing an example of a manufacturing method of a light-emitting device.

[0071] Figures 10A to 10C is a cross-sectional view showing an example of a manufacturing method of a light-emitting device.

[0072] Figures 11A to 11C is a cross-sectional view showing an example of a manufacturing method of a light-emitting device.

[0073] Figures 12A to 12C is a cross-sectional view showing an example of a manufacturing method of a light-emitting device.

[0074] Figures 13A to 13C is a cross-sectional view showing an example of a manufacturing method of a light-emitting device.

[0075] Figures 14A to 14C is a cross-sectional view showing an example of a manufacturing method of a light-emitting device.

[0076] Figures 15A to 15G is a top view showing a structural example of a pixel.

[0077] Figures 16A to 16I is a top view showing a structural example of a pixel.

[0078] Figure 17A and Figure 17B is a perspective view showing a structural example of a display module.

[0079] Figure 18A and Figure 18B is a cross-sectional view showing a structural example of a light-emitting device.

[0080] Figure 19 is a perspective view showing a structural example of a light-emitting device.

[0081] Figure 20A is a cross-sectional view showing a structural example of a light-emitting device. Figure 20B and Figure 20C is a cross-sectional view showing a structural example of a transistor.

[0082] Figure 21 is a cross-sectional view showing a structural example of a light-emitting device.

[0083] Figures 22A to 22D is a cross-sectional view showing a structural example of a light-emitting device.

[0084] Figures 23A to 23D is a view showing an example of an electronic device.

[0085] Figures 24A to 24F is a view showing an example of an electronic device.

[0086] Figures 25A to 25D is a view showing an example of an electronic device.

[0087] Figures 26A to 26G is a view showing an example of an electronic device. Detailed Description of the Invention

[0088] The embodiments will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and it is easily understandable for those of ordinary skill in the art that the manner and details can be changed into various forms without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited only to the content described in the embodiments shown below.

[0089] Note that in the structure of the invention described below, the same reference numerals are used in different drawings to denote the same parts or parts having the same function, and repeated description is omitted. In addition, when denoting parts having the same function, the same hatching is sometimes used without particularly attaching reference numerals.

[0090] In addition, for ease of understanding, the positions, sizes, and ranges of the respective components shown in the drawings do not necessarily represent their actual positions, sizes, and ranges. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, and ranges disclosed in the drawings.

[0091] In this specification and the like, a light-emitting device (also referred to as a light-emitting element) includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer. In this specification and the like, a light-receiving device (also referred to as a light-receiving element) includes at least an active layer used as a photoelectric conversion layer between a pair of electrodes. In this specification and the like, sometimes one of the pair of electrodes is referred to as a pixel electrode and the other is referred to as a common electrode.

[0092] In addition, the light-emitting device in this specification includes an image display device using an organic EL device. In addition, the light-emitting device sometimes further includes the following modules: a module in which a connector (such as an anisotropic conductive film or a TCP (Tape Carrier Package)) is mounted on the organic EL device; a module in which a printed wiring board is provided at the end of the TCP; a module in which an IC (integrated circuit) is directly mounted on the organic EL device by a COG (Chip On Glass) method. Furthermore, a lighting device or the like sometimes includes the light-emitting device.

[0093] (Embodiment 1)

[0094] The light-emitting device includes an organic compound layer containing a light-emitting substance between electrodes (between an anode and a cathode), and emits light by using the energy generated by the recombination of carriers (holes and electrons) injected from the electrodes into the organic compound layer.

[0095] Figure 1A A light-emitting device 130 showing one aspect of the present invention is shown. The light-emitting device 130 includes an anode 101 and a cathode 102. In addition, the light-emitting device 130 includes an organic compound layer 103 between the anode 101 and the cathode 102. The organic compound layer 103 includes a light-emitting unit 501 having a light-emitting layer 113 and a layer 116. In particular, the layer 116 includes an electron injection buffer region 119 (hereinafter sometimes referred to as the first layer), an electron relay region 118 (hereinafter sometimes referred to as the third layer or the electron relay layer), and a charge generation region 117 (hereinafter sometimes referred to as the second layer or the P-type layer). In particular, the electron injection buffer region 119 is located between the light-emitting layer 113 and the electron relay region 118, the electron relay region 118 is located between the electron injection buffer region 119 and the charge generation region 117, and the charge generation region 117 is located between the electron relay region 118 and the cathode 102. In addition, the charge generation region 117 preferably contacts the cathode 102. Note that the light-emitting unit is sometimes referred to as an EL layer.

[0096] In particular, the electron relay region 118 is a functional layer for smoothly transferring electrons between the electron injection buffer region 119 and the charge generation region 117.

[0097] In addition, there is no particular limitation on the color gamut of the light emitted from the light-emitting layer in the light-emitting unit 501. In addition, the light-emitting layer may have a single-layer structure or a stacked structure. For example, the light-emitting unit 501 may also adopt a stacked structure including a light-emitting layer that emits light in the red region, a light-emitting layer that emits light in the green region, and a light-emitting layer that emits light in the blue region. In addition, by adopting this structure, white light emission can be obtained from the light-emitting unit 501.

[0098] In addition, in Figure 1A In the light-emitting device 130 shown, as an example, the light LGT generated in the light-emitting layer 113 is schematically shown to be emitted above the light-emitting device 130 through the cathode 102. Note that, at this time, when a transparent electrode is used as the cathode 102, the visible light transmittance (for example, with a wavelength of 400 nm or more and less than 750 nm) of the transparent electrode is preferably 40% or more. In addition, when a semi-transmissive and semi-reflective electrode is used as the cathode 102, the reflectance of the semi-transmissive and semi-reflective electrode is preferably 10% or more and 95% or less, more preferably 30% or more and 80% or less. Note that the light-emitting device 130 can emit light not only above the light-emitting device 130 through the cathode 102 but also below the light-emitting device 130 through the anode 101 (not shown). Note that, as an example, this light-emitting device can be included in a dual-sided emission type display device.

[0099] In addition, in a display device including a pixel circuit provided on a substrate and the light-emitting device 130 included in the pixel circuit, a structure in which the light generated in the light-emitting layer 113 of the light-emitting device 130 is not emitted through the substrate is sometimes referred to as a top emission type display device. In addition, a structure in which the light generated in the light-emitting layer 113 of the light-emitting device 130 is emitted through the substrate is sometimes referred to as a bottom emission type display device.

[0100] Here, it is preferable to use at least a mixed layer containing at least the following two organic compounds for at least the electron buffer region 119. One is a first organic compound having strong basicity (preferably an acidity coefficient pKa of 8 or more), and the other is a second organic compound whose lowest unoccupied molecular orbital energy level (LUMO energy level) is lower than that of the first organic compound. That is, the LUMO energy level of the first organic compound having strong basicity is preferably higher than the LUMO energy level of the second organic compound. By adopting this structure, the occurrence of problems caused by the alkali metal or the compound of the alkali metal used so far can be reduced.

[0101] In a light-emitting device according to one embodiment of the present invention, when a strongly basic organic compound having a large acidity coefficient pKa (preferably, pKa is 8 or more) is used for layer 116, holes injected from the anode 101 side are captured or blocked by the strongly basic organic compound after passing through the light-emitting unit 501, and then electrons are injected in the direction from the charge generation region 117 to the electron injection buffer region 119, whereby the light-emitting device is driven.

[0102] The strongly basic organic compound blocks holes because a material with a large pKa has a large electric dipole moment. Through the interaction between this electric dipole moment and the holes, the electron injection buffer region 119 can block holes.

[0103] In addition, the strongly basic organic compound has high nucleophilicity. That is, a material with high nucleophilicity sometimes reacts with a molecule that accepts a hole to become a cation radical to generate a new molecule or an intermediate state. Since this reaction consumes holes, this sometimes significantly reduces the hole transportability of the electron injection buffer region 119.

[0104] Note that the above-mentioned strongly basic organic compound preferably does not have an electron-transporting skeleton. When the above-mentioned strongly basic organic compound does not have an electron-transporting skeleton, the recombination of electrons injected into the electron injection buffer region 119 and holes captured by the strongly basic organic compound is suppressed, and electrons can be efficiently injected into the light-emitting unit 501.

[0105] In addition, when holes and electrons are respectively injected into the highest occupied molecular orbital energy level (HOMO energy level) and the LUMO energy level of the strongly basic organic compound, carriers recombine in the electron injection buffer region 119 and easily form an unstable excited state, whereby the reliability decreases, which results in a decrease in the characteristics of the light-emitting device.

[0106] In view of this, by mixing a second organic compound having electron-transporting properties into the electron injection buffer region 119 using the first strongly basic organic compound, the function of capturing or blocking holes possessed by the first organic compound and the function of allowing electrons to flow possessed by the second organic compound can be separated, thereby reducing the carrier recombination probability in the electron injection buffer region 119 to suppress the formation of an unstable excited state, and thus the reliability can be improved. That is, when the mixed layer (electron injection buffer region 119) used for layer 116 contains a first organic compound for capturing holes and a second organic compound for transporting electrons, the formation of an unstable excited state can be suppressed and the reliability can be improved.

[0107] Therefore, as the second organic compound having electron-transporting properties, an organic compound having a LUMO energy level lower than that of the first organic compound having strong basicity is preferably used. Further, as the second organic compound having electron-transporting properties, an organic compound having a HOMO energy level lower than that of the first organic compound having strong basicity is preferably used.

[0108] Note that the thicker the thickness of the electron injection buffer region 119, the farther the distance between the holes accumulated in the electron injection buffer region 119 and the electrons attracted from the charge generation region 117 sometimes becomes, and the electric field of the double layer is relaxed, which may lead to a higher voltage of the manufactured light-emitting device. Therefore, it is preferable to set the electron injection buffer region 119 to a thickness of 2 nm or more and 13 nm or less, and more preferably 5 nm or more and 10 nm or less.

[0109] Note that as the first organic compound, an organic compound having a LUMO energy level 0.05 eV or more higher than that of the second organic compound is preferably used. Alternatively, the first organic compound preferably has a LUMO energy level 0.1 eV or more, and more preferably 0.2 eV or more higher than that of the second organic compound. When such a LUMO energy level difference exists between the first organic compound and the second organic compound, the probability that the first organic compound receives electrons due to the influence of energy or an electric field at room temperature can be reduced.

[0110] In addition, as the first organic compound, an organic compound having a HOMO energy level 0.05 eV or more higher than that of the second organic compound is preferably used. Alternatively, the first organic compound preferably has a HOMO energy level 0.1 eV or more, and more preferably 0.2 eV or more higher than that of the second organic compound. When such a HOMO energy level difference exists between the first organic compound and the second organic compound, the probability that the second organic compound receives holes due to the influence of energy or an electric field at room temperature can be reduced.

[0111] <First organic compound>

[0112] The LUMO energy level of the first organic compound is preferably -2.50 eV or more and -1.00 eV or less. Further, the HOMO energy level of the first organic compound is preferably -5.7 eV or more and -4.8 eV or less.

[0113] In addition, the first organic compound preferably does not include a skeleton having electron-transporting properties. For example, as the first organic compound, there is an organic compound in which the aromatic ring does not contain a nitrogen atom (N).

[0114] In addition, the first organic compound is preferably an organic compound with strong basicity having an acidity coefficient pKa of 8 or more. By including an organic compound with strong basicity having a pKa of 8 or more, the first organic compound can block holes, and holes can accumulate in the first electron transport layer.

[0115] In addition, the first organic compound is preferably an organic compound having a pKa of 8 or more, preferably greater than 10. Furthermore, the first organic compound is more preferably an organic compound having an acidity coefficient pKa of 12 or more, preferably greater than 13.

[0116] As the acidity coefficient pKa of the basic skeleton, the value of an organic compound in which a part of the skeleton is replaced by hydrogen can be used. In addition, as the acidity index of an organic compound having a basic skeleton, the acidity coefficient pKa of the basic skeleton can be used. In addition, when an organic compound has a plurality of basic skeletons, the acidity coefficient pKa of the basic skeleton with the largest acidity coefficient pKa can be used as the acidity index of the organic compound.

[0117] Alternatively, the acidity coefficient pKa of an organic compound can also be calculated as follows.

[0118] First, the initial structure of the molecular structure of each molecule as the calculation model is the most stable structure (singlet ground state) obtained by first-principles calculation.

[0119] As the above first-principles calculation, use Jaguar, a quantum chemistry calculation software manufactured by Inc., to calculate the most stable structure in the singlet ground state through density functional theory (DFT: Density Functional Theory). Use 6-31G** as the basis function and B3LYP-D3 as the functional. As the structure for performing quantum chemistry calculations, use Maestro GUI manufactured by Inc., and perform conformational analysis with Mixed torsional / Low-mode sampling for sampling.

[0120] In the pKa calculation, one or more atoms in each molecule are designated as basic positions, Macro Model is used to explore the structure in which the protonated molecule is stable in water, and the conformational isomer with the lowest energy obtained by conformational exploration using the OPLS2005 force field is used. Use the pKa calculation module of Jaguar to optimize its structure with B3LYP / 6-31G*, then perform a single-point calculation with cc-pVTZ(+), and calculate the pKa value using the empirical correction for functional groups. In a molecule in which one or more atoms are designated as basic positions, the largest value in the obtained results is used as the pKa value.

[0121] Specific examples of the organic compound having a large acid dissociation constant pKa and usable as the first organic compound include organic compounds having a basic skeleton represented by the following structural formulas (120) to (123).

[0122] [Chemical formula 1]

[0123]

[0124] Specifically, the first organic compound is preferably an organic compound including a bicyclic structure having two or more nitrogens in the ring-forming elements and a heteroaromatic ring having 2 to 30 ring-forming carbon atoms or an aromatic ring having 6 to 30 ring-forming carbon atoms, and more specifically, an organic compound including a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton and a heteroaromatic ring having 2 to 30 ring-forming carbon atoms or an aromatic ring having 6 to 30 ring-forming carbon atoms. The first organic compound is more preferably an organic compound including a bicyclic structure having two or more nitrogens in the ring-forming elements and a heteroaromatic ring having 2 to 30 ring-forming carbon atoms, and more specifically, an organic compound including a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton and a heteroaromatic ring having 2 to 30 ring-forming carbon atoms. In addition, an organic compound having a guanidine skeleton is preferred.

[0125] More specifically, the organic compound is preferably an organic compound represented by the following general formula (G1).

[0126] [Chemical formula 2]

[0127]

[0128] In the organic compound represented by the above general formula (G1), X represents a group represented by the following general formula (G1-1), and Y represents a group represented by the following general formula (G1-2). In addition, R 1 and R 2 each independently represent hydrogen or deuterium, h represents an integer from 1 to 6, and Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring-forming carbon atoms or an aromatic ring having 6 to 30 ring-forming carbon atoms. In addition, Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring-forming carbon atoms.

[0129] [Chemical formula 3]

[0130]

[0131] In the above general formulas (G1-1) and (G1-2), R 3 to R 6Each independently represents hydrogen or deuterium, m represents an integer from 0 to 4, n represents an integer from 1 to 5, and m + 1 ≥ n. Note that when m or n is 2 or more, multiple Rs 3 can be the same as or different from each other, and the same applies to R 4 , R 5 and R 6 . Additionally, when m is 0, it is preferred that carbon (C) and nitrogen (N) are bonded in the above general formula (G1).

[0132] Furthermore, the organic compound represented by the above general formula (G1) is preferably any one of the following general formulas (G2-1) to (G2-6).

[0133] [Chemical formula 4]

[0134]

[0135] Note that in the organic compound, R 11 to R 26 each independently represent hydrogen or deuterium, h represents an integer from 1 to 6, and Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring-forming carbon atoms or an aromatic ring having 6 to 30 ring-forming carbon atoms. Additionally, Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 ring-forming carbon atoms.

[0136] Note that in the above general formula (G1) and general formulas (G2-1) to (G2-6), as the substituted or unsubstituted heteroaromatic ring having 2 to 30 ring-forming carbon atoms or aromatic ring having 6 to 30 ring-forming carbon atoms represented by Ar, specific examples include pyridine ring, bipyridine ring, pyrimidine ring, bipyrimidine ring, pyrazine ring, bipyrazine ring, triazine ring, quinoline ring, isoquinoline ring, benzoquinoline ring, phenanthroline ring, quinoxaline ring, benzoquinoxaline ring, dibenzoquinoxaline ring, azafluorene ring, diazafluorene ring, carbazole ring, benzocarbazole ring, dibenzocarbazole ring, dibenzofuran ring, benzonaphthofuran ring, dinaphthofuran ring, dibenzothiophene ring, benzonaphthothiophene ring, dinaphthothiophene ring, benzofuranopyridine ring, benzofuranopyrimidine ring, benzothiophenopyridine ring, benzothiophenopyrimidine ring, naphthofuranopyridine ring, naphthofuranopyrimidine ring, naphthothiophenopyridine ring, naphthothiophenopyrimidine ring, dibenzoquinoxaline ring, acridine ring, xanthene ring, phenothiazine ring, phenoxazine ring, phenazine ring, triazole ring, oxazole ring, oxadiazole ring, thiazole ring, thiadiazole ring, imidazole ring, benzimidazole ring, pyrazole ring, pyrrole ring, etc. Additionally, in the above general formula (G1) and general formulas (G2-1) to (G2-6), as the substituted or unsubstituted heteroaromatic ring having 6 to 30 ring-forming carbon atoms represented by Ar, specific examples include benzene ring, naphthalene ring, fluorene ring, dimethylfluorene ring, diphenylfluorene ring, spirofluorene ring, anthracene ring, phenanthrene ring, triphenylene ring, pyrene ring, tetracene ring Rings, benzo[a]anthracene rings, etc. Among them, those represented by any of the following structural formulas (Ar-1) to (Ar-27) are particularly preferred.

[0137] [Chemical Formula 5]

[0138]

[0139] In addition, preferably, the above-mentioned Ar contains nitrogen as a ring-forming element, and the Ar is bonded to the skeleton within the parentheses in the general formula (G1) by a bond of the nitrogen or a carbon adjacent to the nitrogen.

[0140] Specific examples of the organometallic compounds represented by the above general formula (G1) and general formulas (G2-1) to (G2-6) include 1,1'-(9,9'-spirobi[9H-fluorene]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2,7hpp2SF) (structural formula 108) and 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF) (structural formula 109), etc., which are organic compounds represented by the following structural formulas (101) to (117).

[0141] [Chemical Formula 6]

[0142]

[0143] Note that a substance with strong basicity having a pKa of 8 or more preferably does not have an electron transport skeleton in order to suppress the recombination of the injected electrons and the blocked holes on the substance with strong basicity having a pKa of 8 or more. As the substance with strong basicity having a pKa of 8 or more, organic compounds such as 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF), 2,9-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-yl)-1,10-phenanthroline (abbreviation: 2,9hpp2Phen), 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviation: Pyrrd-Phen), or 8,8'-pyridine-2,6-diyl-bis(5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidine) (abbreviation: 2,6tip2Py) can be specifically used.

[0144] In addition, in the case of manufacturing a light-emitting device by a process such as an atmospheric exposure process or a washing process using an aqueous solution, the solubility of the first organic compound is preferably low. For example, the solubility of the first organic compound depends on the number of hydrophilic groups such as 2H-pyrimido[1,2-a]pyrimidinyl (hpp group) in the first organic compound and the number of hydrophobic groups such as tert-butyl group. Therefore, the fewer the hydrophilic groups in the first organic compound, the better, and preferably it is 1. In addition, the number of hydrophobic groups in the first organic compound is preferably larger than the number of hydrophilic groups, specifically, preferably 2 or more.

[0145] Specifically, the solubility of the first organic compound in water is preferably lower than 0.77 mg / ml, preferably 0.065 mg / ml or less, preferably 0.0023 mg / ml or less, preferably 1×10 -5 mg / ml or less.

[0146] In addition, in the case of using a first organic compound with a high solubility, a good light-emitting device can also be provided by adjusting the concentration of the first organic compound in the electron injection buffer region 119. Specifically, when the concentration (wt%) of the first organic compound in the electron injection buffer region 119 is set to y and the solubility of the first organic compound in water (mg / ml) is set to x, it is preferably below the value of y = -8.735×ln(x) - 2.3154.

[0147] <Second Organic Compound>

[0148] On the other hand, the second organic compound is an organic compound having electron transporting properties. A substance with high electron transporting properties means a substance whose electron mobility is higher than its hole mobility. Specifically, the electron mobility when the square root of the electric field strength [V / cm] is 600 is preferably 1×10 -7 cm 2 / Vs or more, more preferably 1×10 -6 cm 2 / Vs or more.

[0149] As an organic compound with high electron transporting properties, for example, a heteroaromatic compound can be used. Note that a heteroaromatic compound is a cyclic compound in which the ring contains at least two different elements. Note that as the ring structure, it includes a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, etc., and particularly preferably a five-membered ring or a six-membered ring. As the elements contained in the heteroaromatic compound, in addition to carbon, any one or more of nitrogen, oxygen, and sulfur are preferably used. Particularly preferably, a heteroaromatic compound containing nitrogen (nitrogen-containing heteroaromatic compound) is used, and an electron transporting material with high electron transporting properties such as a nitrogen-containing heteroaromatic compound or an organic compound having a π-deficient heteroaromatic ring containing the nitrogen-containing heteroaromatic compound is preferably used.

[0150] In addition, the second organic compound preferably does not include a hole-transporting skeleton. For example, as the second organic compound, there is an organic compound that does not have an amine skeleton or a carbazole skeleton.

[0151] In addition, the LUMO energy level of the second organic compound is preferably -3.25 eV or more and -2.50 eV or less. In addition, the HOMO energy level of the second organic compound is preferably -6.5 eV or more and -5.7 eV or less.

[0152] In addition, preferably, the acidity coefficient pKa of the second organic compound is 3 or more and 8 or less, more preferably 4 or more and 6 or less. For example, the second organic compound may also have a basicity with an acidity coefficient pKa of 4 or more and 8 or less.

[0153] The second organic compound preferably includes a skeleton having electron-transporting properties. As materials having electron-transporting properties, for example, beryllium(II) bis(10-hydroxybenzo[h]quinoline) (abbreviation: BeBq2), aluminum(III) bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol) (abbreviation: BAlq), zinc(II) bis(8-hydroxyquinoline) (abbreviation: Znq), zinc(II) bis[2-(2-benzoxazolyl)phenol] (abbreviation: ZnPBO), or zinc(II) bis[2-(2-benzothiazolyl)phenol] (abbreviation: ZnBTZ) and other metal complexes or organic compounds having a π-deficient heteroaromatic ring can be cited. As organic compounds having a π-deficient heteroaromatic ring skeleton, for example, organic compounds containing a heteroaromatic ring having a triazole 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.

[0154] Among them, organic compounds containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing a heteroaromatic ring having a pyridine skeleton, or organic compounds containing a heteroaromatic ring having a triazine skeleton have good reliability, so they are preferred. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron-transporting properties, which helps to reduce the driving voltage. In addition, benzofuranopyrimidine skeletons, benzothiophenopyrimidine skeletons, benzofuranopyrazine skeletons, and benzothiophenopyrazine skeletons have good reliability, so they are preferred.

[0155] As the organic compound having a π-deficient heteroaromatic ring skeleton, the materials exemplified as the organic compound having electron transporting property in the first electron transporting layer described below can be used. In particular, an organic compound containing a heteroaromatic ring having a diazine skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, or an organic compound containing a heteroaromatic ring having a triazine skeleton has good reliability, and thus is preferred. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring having a triazine skeleton have high electron transporting property, which helps to reduce the driving voltage. Among them, it is preferred to use organic compounds having a phenanthroline skeleton such as 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: mpPPhen), 2-[4-(9-phenanthryl)-1-naphthyl]-1,10-phenanthroline (abbreviation: PnNPhen), etc. Organic compounds having a phenanthroline dimer structure such as mPPhen2P have high stability, and thus are more preferred. In addition, materials having a pyridine skeleton and a phenanthroline skeleton have a large pKa, and thus have high hole blocking property, and are particularly suitable as an electron transporting material used as the second organic compound in a light emitting device according to one embodiment of the present invention. In addition, the larger the number of pyridine skeletons or phenanthroline skeletons in the molecule, the higher the hole blocking property, and it is particularly suitable as an electron transporting material used as the second organic compound in a light emitting device according to one embodiment of the present invention.

[0156] In addition, by co-evaporating the organic compound described in the above <First Organic Compound> and the organic compound described in the <Second Organic Compound>, a mixed layer can be formed. By using this mixed layer as the electron injection buffer region 119 in the layer 116, the reliability of the light emitting device can be improved.

[0157] <Mechanism of Light Emitting Device>

[0158] Here, with reference to Figure 2A The mechanism of the light emitting device according to one embodiment of the present invention will be described in detail.

[0159] In a normal light emitting device, a Li compound used for the N-type layer acts as a donor, and charge separation occurs between the Li compound and the electron transporting material to generate carriers. However, the electron injection buffer region 119 (layer 1) according to one embodiment of the present invention is a charge-free layer in which charge separation does not occur and carriers are not generated.

[0160] On the other hand, in the charge generation region 117 (layer 2), even if the electron injection buffer region 119 (layer 1) does not generate charges, carriers (holes and electrons) are generated when a voltage is applied. However, generally, the difference in the LUMO levels (LUMO ETM ) between a material with electron-transporting properties and the LUMO level (LUMO AC ) of a material with acceptor properties is large. Therefore, the potential energy difference in the LUMO levels between the acceptor material in the charge generation region 117 and the electron-transporting material in the electron injection buffer region 119 is large, and it is difficult to inject the electrons generated in the charge generation region 117 into the electron injection buffer region 119( Figure 2A ).

[0161] Therefore, when electrons are generated in the charge generation region 117 and no charges are generated in the electron injection buffer region 119, it is also difficult for the electrons to be injected into the electron transport layer 114 of the light-emitting unit 501, and it is not easy to obtain light emission from the light-emitting layer 113 in the light-emitting unit 501.

[0162] However, although the electron injection buffer region 119 in the light-emitting device according to one embodiment of the present invention does not function as a charge generation layer, the light-emitting device functions as a light-emitting device. The reason can be explained with reference to the driving mechanism of the light-emitting device, such as the generation of an electric dipole due to charge accumulation and the vacuum level drift caused by the generation of the electric dipole.

[0163] First, in the light-emitting device according to one embodiment of the present invention, even when a voltage is applied as described above, no carriers are generated in the electron injection buffer region 119. On the other hand, holes injected from the anode 101 into the light-emitting unit 501 accumulate at the interface on the side of the electron transport layer 114 of the electron injection buffer region 119( Figure 2B holes 400 shown), because the electron transport layer blocks holes or has a low hole-transporting property. At this time, the electron injection buffer region 119 blocks holes or has a significantly low hole mobility, thereby preventing the escape of holes and enabling the light-emitting unit 501 to emit light efficiently, which is preferable.

[0164] Due to the application of voltage and the accumulation of holes, holes and electrons are induced in the charge generation region 117. As described above, since the difference in the LUMO levels between the acceptor material in the charge generation region 117 and the LUMO level of the second organic compound with electron-transporting properties in the electron injection buffer region 119 is large in the initial state, the electrons induced in the charge generation region 117 are not injected into the electron injection buffer region 119 but accumulate on the side of the electron injection buffer region 119 in the charge generation region 117( Figure 2Bas shown, electrons 401). The accumulated electrons and holes accumulated on the electron-transporting layer 114 side of the electron injection buffer region 119 form a double layer, thereby generating an electric dipole ( Figure 2B the electric dipole 402) as shown.

[0165] As a result, a vacuum level shift occurs ( Figure 2B the vacuum level 403) as shown, the LUMO level of the electron-accepting material in the charge generation region 117 approaches the LUMO level of the second organic compound with electron-transporting properties in the electron injection buffer region 119, and the electrons generated in the charge generation region 117 are injected into the electron injection buffer region 119 ( Figure 2B the electrons 404) as shown. Then, the electrons injected into the electron injection buffer region 119 are also injected into the light-emitting unit 501, and these electrons reach the light-emitting layer 113 and recombine, whereby light emission can be obtained in the light-emitting unit 501. Therefore, a light-emitting device according to one embodiment of the present invention can be used as a light-emitting device.

[0166] A light-emitting device using a layer 116 containing an alkali metal or alkaline earth metal such as Li oxide used as a donor or the above-mentioned unstable element or compound deteriorates due to exposure to the atmosphere. On the other hand, a light-emitting device using a layer that does not generate charges (electron injection buffer region 119) is not easily deteriorated due to exposure to the atmosphere. Therefore, even if the light-emitting device is processed through a lithography process using photolithography technology that involves exposure to the atmosphere during its manufacturing process, deterioration of the light-emitting device due to exposure to the atmosphere is not likely to occur, and a light-emitting device according to one embodiment of the present invention can have good characteristics.

[0167] Furthermore, the charge generation region 117 is located on the cathode side of the electron injection buffer region 119 and the electron relay region 118. The charge generation region 117 containing an electron-accepting material is stable against the atmosphere. For example, even if a cathode 102 is formed on the charge generation region 117 exposed to the atmosphere to manufacture a light-emitting device, the light-emitting device is not easily deteriorated due to exposure to the atmosphere. Thus, the light-emitting device using the layer 116 can be said to be a light-emitting device that is stable against the atmosphere.

[0168] A light-emitting device according to one embodiment of the present invention having the above structure can be a light-emitting device with high current efficiency, good reliability, and suppressed increase in driving voltage.

[0169] In addition, although a light-emitting device according to one embodiment of the present invention is particularly preferably used as a light-emitting device through a lithography process, even if it is used as a light-emitting device manufactured without a lithography process, it has high stability against the atmosphere. Therefore, the yield is increased, and strict atmosphere management is not required during the manufacturing process, which helps to reduce costs.

[0170] The following description includes specific structures other than the above-described structure of the light-emitting device 130 including the above organic compound.

[0171] The light-emitting unit 501 may include other functional layers in addition to the light-emitting layer. Figure 1A The structure in which the light-emitting unit 501 is provided with a hole injection layer 111 (hereinafter sometimes referred to as the fourth layer), a hole transport layer 112, and an electron transport layer 114 in addition to the light-emitting layer 113 is shown, but the structure of the organic compound layer 103 of the present invention is not limited thereto, and any one of the above layers may not be provided, or other layers may be provided. As other layers, typically there are a carrier blocking layer, an exciton blocking layer, and the like.

[0172] In addition, since the layer 116 includes the electron injection buffer region 119, the electron injection buffer region 119 is used as an electron injection layer in the light-emitting unit on the anode side. Therefore, an electron injection layer may be provided in the light-emitting unit 501 in Figure 1A as needed.

[0173] [Layer 116]

[0174] The following describes the structure of the layer 116 of the light-emitting device 130.

[0175] As described above, the electron injection buffer region 119 is a layer including a first organic compound having a basic skeleton and a second organic compound having an electron transporting property. Any one or more of a metal, a metal compound, and a metal complex may be mixed in this layer.

[0176] In addition, the first organic compound having a basic skeleton in the electron injection buffer region 119 preferably does not have an electron donating property. Further, the first organic compound having a basic property preferably does not have an electron donating property with respect to the second organic compound having an electron transporting property. When the first organic compound having a basic property has an electron donating property, it is more likely to react with atmospheric components such as water or oxygen, so the stability decreases. By including the first organic compound having a basic property and the second organic compound having an electron transporting property, the hole transporting property of the electron injection buffer region 119 can be significantly reduced, so that even if the first organic compound having a basic property does not have an electron donating property, it can be used as the layer 116. Thus, the layer 116 and the light-emitting device that are stable to atmospheric components such as water or oxygen can be manufactured. In addition, in the electron injection buffer region 119, preferably, the signal observed by the electron spin resonance (ESR: Electron Spin Resonance) method is small or no signal is observed. For example, the spin density due to the signal observed near the g value of 2.00 is preferably 1×10 17 spins / cm 3 Hereinafter, more preferably less than 1×10 16 spins / cm3 In particular, in the electron injection buffer region 119, the spin density of the mixed layer containing the first organic compound and the second organic compound measured by electron spin resonance is preferably 1×10 17 spins / cm 3 Hereinafter, it is more preferably less than 1×10 16 spins / cm 3 .

[0177] In addition, the charge generation region 117 of the charge generation layer preferably contacts the cathode 102, and is preferably formed using a composite material containing a first material having an acceptor property and a hole-transporting organic compound. In particular, by co-evaporating the first material having an acceptor property and the hole-transporting organic compound, a mixed layer can be formed. In other words, the mixed layer can be provided in the charge generation region 117. In addition, the charge generation region 117 may also include a stack of a layer containing the first material having an acceptor property and a layer containing a hole-transporting organic compound. For example, the layer containing the hole-transporting organic compound may also be located between the layer containing the first material having an acceptor property and the cathode 102.

[0178] Furthermore, the first material having an acceptor property in the charge generation region 117 preferably has an electron-accepting property. In addition, the first material having an acceptor property preferably has an electron-accepting property with respect to the hole-transporting organic compound. When the first material having an acceptor property has an electron-accepting property, charge separation occurs in the charge generation region 117 and it can be used as a charge generation layer. In addition, in the charge generation region 117, it is preferable to observe a signal in electron spin resonance. For example, the spin density due to the signal observed near the g value of 2.00 is more preferably 1×10 17 spins / cm 3 or more, more preferably 1×10 18 spins / cm 3 or more, and further preferably 1×10 19 spins / cm 3 or more.

[0179] As the hole-transporting organic compound for the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (for example, oligomers, dendrimers, polymers, etc.) can be used. As the hole-transporting organic compound for the composite material, it is preferable to use one having a hole mobility of 1×10 -6 cm 2Organic compounds above / Vs. The hole-transporting organic compounds for composite materials are preferably compounds containing a fused aromatic ring or a π-electron-rich heteroaromatic ring. As the fused aromatic ring, for example, an anthracene ring, a naphthalene ring, etc. are preferably used. 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 further fused with an aromatic ring or a heteroaromatic ring is preferred.

[0180] Such hole-transporting organic compounds more preferably have 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 9-fluorenyl is bonded to the nitrogen of the amine through an arylene group. Note that when these hole-transporting organic compounds are substances including N,N-bis(4-biphenyl)amino, a light-emitting device with a long lifetime can be manufactured, so they are preferred.

[0181] As the above hole-transporting organic compounds, specifically, N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophene-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthalen-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthalen-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthalen-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthalen-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthalen-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenyl)-4'[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenyl)-4'[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(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 (abbreviation: BBASF), N,N-bis[(biphenyl)-4-yl]-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-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-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-1-amine, etc.

[0182] In addition, as materials having hole transporting 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 be used.

[0183] As the first material having an acceptive property contained in the charge generation region 117, an organic compound having an electron-withdrawing group (such as a halogen group or a cyano group) can be used. Examples include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile, etc. In particular, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a fused aromatic ring having a plurality of heteroatoms are thermally stable and thus preferred. In addition, [3]axylene derivatives including an electron-withdrawing group (for example, especially a halogen group such as a fluorine group, a cyano group) have very high electron-accepting properties and are thus particularly preferred. Specifically, α,α',α''-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriyl tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriyl tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], etc. can be cited. As acceptive substances, in addition to the above organic compounds, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can also be used.

[0184] The electron relay region 118 contains a material having electron-transporting properties and has a function of preventing the interaction between the electron injection buffer region 119 and the charge generation region 117 to smoothly transfer electrons. It is preferable to set the LUMO level of the electron-transporting material contained in the electron relay region 118 between the LUMO level of the acceptor material in the charge generation region 117 and the LUMO level of the organic compound contained in the electron injection buffer region 119. Specifically, the LUMO level of the electron-transporting material for the electron relay region 118 is preferably -5.0 eV or more, more preferably -5.0 eV or more and -3.0 eV or less, further preferably -4.30 eV or more and -3.00 eV or less, and still more preferably -4.30 eV or more and -3.30 eV or less. Thus, it is easy to inject the electrons generated in the charge generation region 117 into the electron injection buffer region 119, and the rise of the driving voltage can be suppressed. In addition, as the electron-transporting material for the electron relay region 118, a phthalocyanine material or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

[0185] Specifically, diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA-F6), 3,4,9,10-perylenetetracarboxylic diimide (abbreviation: PTCDI), 3,4,9,10-perylenetetracarboxylic-bis-benzimidazole (abbreviation: PTCBI) and other perylene tetracarboxylic acid derivatives, (C60-Ih)[5,6]fullerene (abbreviation: C60), (C70-D5h)[5,6]fullerene (abbreviation: C70), phthalocyanine (abbreviation: H2Pc) can be used. In addition, copper phthalocyanine (abbreviation: CuPc), zinc phthalocyanine (abbreviation: ZnPc), cobalt phthalocyanine (abbreviation: CoPc), iron phthalocyanine (abbreviation: FePc), tin phthalocyanine (abbreviation: SnPc), tin oxide phthalocyanine (abbreviation: SnOPc), titanium oxide phthalocyanine (abbreviation: TiOPc), vanadium oxide phthalocyanine (abbreviation: VOPc) and other metal phthalocyanines and their derivatives containing copper, zinc, cobalt, iron, chromium, nickel, etc. can be used. In particular, phthalocyanine metal complexes such as copper phthalocyanine or zinc phthalocyanine or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine are preferably used. Among them, CuPc and ZnPc are inexpensive and have good characteristics, so they are preferred. And, ZnPc has a small diffusion coefficient for silicon, and the concern that the semiconductor characteristics are affected by the diffusion of the metal into the semiconductor is reduced. Therefore, it is particularly suitable for a display device using a silicon semiconductor.

[0186] In addition, the thickness of the electron relay region 118 is preferably 1 nm or more and 10 nm or less, more preferably 2 nm or more and 5 nm or less.

[0187] In such a light-emitting device including the layer 116, even when the organic compound layer 103 is processed using lithography technology, there is no significant increase in the driving voltage and no significant decrease in the luminous efficiency, so a light-emitting device with good characteristics can be realized.

[0188] Note that the light-emitting device according to one embodiment of the present invention is not limited to Figure 1A the structure of the light-emitting device 130. For example, in the light-emitting device according to one embodiment of the present invention, Figure 1A the light-emitting device 130 may not include the electron relay region 118. For example, as Figure 1B shown in the light-emitting device 130A, the charge generation region 117 may also be located on the electron injection buffer region 119.

[0189] [Electrode]

[0190] The structures of the anode 101 and the cathode 102 of the light-emitting device 130 will be described below.

[0191] The anode 101 may also have a stacked structure. In this case, the layer in contact with the organic compound layer 103 is used as the anode. The anode is preferably formed of a metal, an alloy, a conductive compound, and a mixture thereof having a large work function (specifically, 4.0 eV or more). Specifically, for example, indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, indium containing tungsten oxide and zinc oxide (IWZO), etc. can be cited. Although these conductive metal oxide films are usually deposited by sputtering, a sol-gel method or the like can also be applied to form them. As an example of the forming method, a method of forming indium zinc oxide by sputtering using a target in which 1 wt% or more and 20 wt% or less of zinc oxide is added to indium oxide can be cited. In addition, indium containing tungsten oxide and zinc oxide (IWZO) can be formed by sputtering using a target in which 0.5 wt% to 5 wt% of tungsten oxide and 0.1 wt% or more and 1 wt% or less of zinc oxide are added to indium oxide. In addition, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or a nitride of a metal material (for example, titanium nitride) can be cited. Alternatively, graphene can also be used as the material for the anode. In addition, by using the composite material constituting the charge generation region 117 of the layer 116 for the layer in contact with the anode (typically, the hole injection layer), there is no need to consider the work function when selecting the electrode material.

[0192] The cathode 102 may also have a laminated structure. In this case, the layer in contact with the organic compound layer 103 is used as the cathode. As the material for forming the cathode, metals, alloys, conductive compounds, and mixtures thereof having a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such cathode materials include elements belonging to Group 1 or Group 2 of the periodic table such as alkali metals (e.g., lithium (Li) or cesium (Cs)), alkaline earth metals (e.g., magnesium (Mg), calcium (Ca), or strontium (Sr)), and alloys containing them (e.g., MgAg, AlLi, etc.). In addition, specific examples of other cathode materials include rare earth metals (e.g., europium (Eu) or ytterbium (Yb)) and alloys containing them. However, by providing an electron injection layer between the cathode 102 and the electron transport layer, various conductive materials such as aluminum (Al), silver (Ag), indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide can be used for the cathode regardless of the work function size.

[0193] Note that in the case where the cathode 102 is made of a material having transparency to light LGT, a light-emitting device that emits light from the cathode 102 side can be formed.

[0194] These conductive materials can be deposited by dry methods such as vacuum evaporation or sputtering, inkjet methods, spin coating methods, etc. In addition, they can also be formed by wet methods such as sol-gel methods or wet methods using pastes of metal materials.

[0195] [Light-emitting unit]

[0196] The structure of the light-emitting unit 501 of the light-emitting device 130 will be described below.

[0197] The organic compound layer 103 has a laminated structure. Among them, a structure including a light-emitting unit 501 including a light-emitting layer 113 and a layer 116 is shown as the laminated structure. The light-emitting unit 501 also has a laminated structure. The light-emitting unit 501 is not limited to the structure shown in Figure 1A , and various functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier blocking layer (e.g., a hole blocking layer or an electron blocking layer), or an exciton blocking layer can be appropriately used. Figure 1A The structure shown can also be appropriately used with various functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier blocking layer (e.g., a hole blocking layer or an electron blocking layer), or an exciton blocking layer.

[0198] The hole injection layer 111 is provided in contact with the anode and has a function of easily injecting holes into the organic compound layer 103 (light-emitting unit 501). The hole injection layer 111 can be formed of a phthalocyanine compound or a complex compound (such as phthalocyanine (abbreviation: H2Pc), copper phthalocyanine (abbreviation: CuPc), etc.), an aromatic amine compound (such as 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), etc.), or a polymer such as poly(3,4-ethylenedioxythiophene) / (polystyrenesulfonic acid) (abbreviation: PEDOT / PSS), etc.).

[0199] In addition, the hole injection layer 111 as the fourth layer can also be formed of a substance having an electron-accepting property. As the substance having an accepting property, the substances exemplified as the acceptor substances of the composite material constituting the charge generation region 117 in the above layer 116 can be similarly used.

[0200] In addition, the hole injection layer 111 as the fourth layer can also be formed of the composite material constituting the charge generation region 117 in the above layer 116. For example, the hole injection layer 111 is preferably formed of a composite material containing a second material having an accepting property and a hole-transporting organic compound. In particular, a mixed layer can be formed by co-evaporating a second material having an accepting property and a hole-transporting organic compound. In other words, the mixed layer can be provided in the hole injection layer 111. In addition, the hole injection layer 111 can also include a laminate of a layer containing a second material having an accepting property and a layer containing a hole-transporting organic compound. For example, the layer containing the second material having an accepting property can also be located between the anode 101 and the layer containing the hole-transporting organic compound. Note that the second material can be a material usable for the above first material.

[0201] Note that in the hole injection layer 111, the hole-transporting organic compound for the composite material is more preferably a substance having a relatively low HOMO level with a HOMO level of -5.7 eV or more and -5.4 eV or less. When the hole-transporting organic compound for the composite material has a relatively low HOMO level, holes can be easily injected into the hole-transporting layer, and a light-emitting device with a long lifetime can be easily obtained. In addition, when the hole-transporting organic compound for the composite material is a substance having a relatively low HOMO level, the induction of holes is appropriately suppressed, so that a light-emitting device with an even longer lifetime can be realized.

[0202] By forming the hole injection layer 111, the hole injectability can be improved, and thus a light-emitting device with a lower driving voltage can be obtained.

[0203] In addition, among substances having acceptivity, organic compounds having acceptivity are easily vapor-deposited, and thus are materials that are easy to use.

[0204] Further, since the hole injection layer 111 can also use the composite material constituting the charge generation region 117, it can be said that the hole injection layer 111 is also stable to the atmosphere. Therefore, it can be said that the light-emitting device according to one embodiment of the present invention is a light-emitting device with less deterioration caused by exposure to the atmosphere (stable to the atmosphere), in which the anode is in contact with the hole injection layer 111 including the composite material constituting the charge generation region 117 and the cathode is in contact with the charge generation region 117.

[0205] The hole transport layer 112 is formed to contain a hole-transporting organic compound. The hole-transporting organic compound preferably has a hole mobility of 1×10 -6 cm 2 / Vs or more.

[0206] Examples of the hole-transporting material described above include compounds having an aromatic amine skeleton such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), etc.;1,3-Bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-Bis(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-Bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-Bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9'-Bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-Bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(Biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-Naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-Biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-Biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-Di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-Naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-Naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-Naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-Naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-Naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-Naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-Phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-Bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-Biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(Triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole and other compounds with a carbazole skeleton;Compounds with a thiophene skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV); and compounds with a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among them, compounds with an aromatic amine skeleton or a carbazole skeleton have good reliability and high hole transportability and help to reduce the driving voltage, so they are preferred. Note that substances listed as hole-transporting materials for use as composite materials for the hole injection layer 111 can also be appropriately used as materials for the hole transport layer 112.;

[0207] The light-emitting layer 113 preferably contains a light-emitting substance and a host material. Note that the light-emitting layer may also contain other materials. In addition, it may be a laminate of two layers with different compositions.

[0208] The light-emitting substance can be a fluorescent light-emitting substance, a phosphorescent light-emitting substance, a substance presenting thermally activated delayed fluorescence (TADF: Thermally Activated Delayed Fluorescence), or other light-emitting substances.

[0209] In the light-emitting layer, as materials that can be used as fluorescent light-emitting substances, for example, the following substances can be cited. Note that, in addition, other fluorescent light-emitting substances can also be used.

[0210] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation:

[0211] PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenyldistyrene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyl-di-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-benzenediamine) (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-benzenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p] (chrysene)-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), Rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N’-diphenyl-N,N’-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. In particular, fused aromatic diamine compounds represented by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 have high hole trapping properties, high luminous efficiency, and high reliability, so they are preferred.,

[0212] When a phosphorescent light-emitting material is used as a light-emitting substance in the light-emitting layer, examples of usable materials include the following substances.

[0213] Examples include: tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), etc., which are organometallic iridium complexes having a 4H-triazole skeleton; tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), etc., which are organometallic iridium complexes having a 1H-triazole skeleton; fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), etc., which are organometallic iridium complexes having an imidazole skeleton; and bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2' iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2Iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2'}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2' iridium(III) acetylacetonate (abbreviation: FIr(acac)), etc., which are organometallic iridium complexes with phenylpyridine derivatives having an electron-withdrawing group as ligands. The above substances are compounds that emit blue phosphorescence and are compounds having a luminescence peak in the wavelength region of 450 nm to 520 nm.

[0214] In addition, examples include: tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornanyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), etc., which are organometallic iridium complexes having a pyrimidine skeleton; (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), etc., which are organometallic iridium complexes having a pyrazine skeleton; tris(2-phenylpyridinato-N,C 2' )iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2' )iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2'Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinoline-N,C 2' ) iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridin-κN]benzofuro[2,3-b]pyridine-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridin-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridin-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridin-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridin-κN)phenyl-κC]bis[2-(2-pyridin-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mdppy)) and other organometallic iridium complexes having a pyridine skeleton; and rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline) terbium(III) (abbreviation: [Tb(acac)3(Phen)]). The above substances are mainly compounds that exhibit green phosphorescence and have a luminescence peak in the wavelength region of 500 nm to 600 nm. In addition, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they have particularly excellent reliability or luminescence efficiency.

[0215] In addition, examples include: (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](di-neopentanoylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](di-neopentanoylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]) and other organometallic iridium complexes having a pyrimidine skeleton; (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(di-neopentanoylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]) and other organometallic iridium complexes having a pyrazine skeleton; tris(1-phenylisoquinoline-N,C 2’ )iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinoline-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]) and other organometallic iridium complexes having a pyridine skeleton; 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) and other platinum complexes; and tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]), tris[1-(2-thienoyl)-3,3,3-trifluoroacetone](monophenanthroline)europium(III) (abbreviation: [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 600 nm to 700 nm. In addition, organometallic iridium complexes having a pyrazine skeleton can obtain red luminescence with good chromaticity.

[0216] In addition, in addition to the above phosphorescent compounds, known phosphorescent compounds can also be selected and used.

[0217] As TADF materials, fullerenes and their derivatives, acridine and its derivatives, eosin derivatives, etc. can be used. In addition, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd), etc. can also be cited. As such metal-containing porphyrins, for example, protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. represented by the following structural formulas can also be cited.

[0218] [Chemical formula 7]

[0219]

[0220] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc., which have one or both of a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring, can be used. Such a heterocyclic compound has a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring, and has high electron transportability and hole transportability, so it is preferred. Among them, in the skeleton having a π-deficient heteroaromatic ring, a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are stable and have good reliability, so they are preferred. In particular, a benzofuranopyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuranopyrazine skeleton, and a benzothienopyrazine skeleton have high acceptability and good reliability, so they are preferred. In addition, in the skeleton having a π-rich heteroaromatic ring, an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton are stable and have good reliability, so it is preferred to have at least one of the above skeletons. In addition, a dibenzofuran skeleton is preferably used as the furan skeleton, and a dibenzothiophene skeleton is preferably used as the thiophene skeleton. As the pyrrole skeleton, an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, and a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferably used. In a substance in which a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring are directly bonded, the electron donating property of the π-rich heteroaromatic ring and the electron accepting property of the π-deficient heteroaromatic ring are both high, and the energy difference between the S1 energy level and the T1 energy level becomes small, so 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 the π-deficient heteroaromatic ring. In addition, as the π-rich skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used.In addition, as the π-deficient electron type skeleton, an oxygen 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 and boranthrene, an aromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. can be used. Thus, at least one of the π-deficient electron type skeleton and the π-rich electron type skeleton can be used in place of the π-deficient electron type heteroaromatic ring and the π-rich electron type heteroaromatic ring.

[0221] [Chemical Formula 8]

[0222]

[0223] In addition, as the TADF material, a TADF material in which the singlet excited state and the triplet excited state are in a thermal equilibrium state can also be used. Since the emission lifetime (excitation lifetime) of this TADF material is short, a reduction in efficiency in the high-brightness region of the light-emitting device can be suppressed. Specifically, materials having the following molecular structure can be cited.

[0224] [Chemical Formula 9]

[0225]

[0226] The TADF material refers to a material in which the difference between the S1 energy level and the T1 energy level is small and which has a function of converting triplet excitation energy into singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be up-converted into singlet excitation energy (reverse intersystem crossing) by a small amount of thermal energy and singlet excited states can be efficiently generated. In addition, triplet excitation energy can be converted into light emission.

[0227] An exciplex formed by two substances in the 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.

[0228] Note that as an index of the T1 energy level, a phosphorescence spectrum observed at a low temperature (for example, 10 K to 77 K) can be used. Regarding the TADF material, when the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail on the short wavelength side of the fluorescence spectrum is defined as the S1 energy level and the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail on the short wavelength side of the phosphorescence spectrum is defined as the T1 energy level, the difference between S1 and T1 is preferably 0.3 eV or less, more preferably 0.2 eV or less.

[0229] In addition, when a TADF material is used as the 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.

[0230] As the host material of the light-emitting layer, one or both of an electron-transporting material and a hole-transporting material, and various charge-transporting materials such as the above-mentioned TADF materials can be used.

[0231] As a material having hole-transporting properties, an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton is preferably used. For example, the following can be cited: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF) and other compounds having an aromatic amine skeleton; 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP) and other compounds having a carbazole skeleton; 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenylfluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenylfluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) and other compounds having a thiophene skeleton; and 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenylfluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) and other compounds having a furan skeleton. Among them, the compounds having an aromatic amine skeleton and the compounds having a carbazole skeleton have good reliability and high hole-transporting properties and contribute to reducing the driving voltage, so they are preferred.In addition, an organic compound cited as an example of a material having hole-transporting properties that can be used as a hole-transporting layer can also be used.

[0232] As materials having electron-transporting properties, for example, the following are preferably used: metal complexes such as bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-hydroxyquinolinato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-hydroxyquinolinato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), etc., and organic compounds including π-deficient heteroaromatic rings. As organic compounds including π-deficient heteroaromatic rings, for example, the following can be cited: organic compounds having an oxazole skeleton such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), etc.; organic compounds containing heteroaromatic rings having a pyridine skeleton such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2,2'-biphenyl-4,4'-diylbis(1,10-phenanthroline) (abbreviation: Phen2BP), etc.; 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3-(3'-dibenzothiophen-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,[[]]END]]6-Diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3’-(Dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1’,2’:4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3’-(Dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1’,2’:4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-Bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-Bis[3-(4-dibenzothiophenyl)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-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-Bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-Bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3’-(Dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1’,2’:4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2’-Binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2’-(Pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2’-(Pyridine-2,6-diyl)bis{4-[4-(naphthalen-2-yl)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-naphthalen-1-ylphenyl)-4-[4-(pyridin-3-yl)phenyl]pyrimidine (abbreviation: 2,Organic compounds with a diazine backbone such as 4NP-6PyPPm, 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-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 (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 11-(4-biphenyl-4-yl-6-phenyl-1,3,5-triazin-2-yl)-11,12-dihydro-12-phenyl-indolo(2,3-a)carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-(triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-biphenyl-3-yl-4-phenyl-6-[8-(1,1':4',1''-terphenyl)-4-yl-1-dibenzofuranyl]-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), etc., organic compounds containing heteroaromatic rings having a triazine skeleton. Among them, organic compounds containing heteroaromatic rings having a diazine 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.,

[0233] As the TADF material that can be used as the host material, the same materials as those listed above as the TADF material can be used. When the TADF material is used as the host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing and further energy transferred to the luminescent material, whereby the luminous efficiency of the light-emitting device can be improved. At this time, the TADF material is used as the energy donor and the luminescent material is used as the energy acceptor.

[0234] This is very effective when the above 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.

[0235] In addition, it is preferable to use a TADF material that emits light overlapping the wavelength of the absorption band on the lowest energy side of the fluorescent luminescent material. Thereby, the excitation energy is smoothly transferred from the TADF material to the fluorescent luminescent material, and luminescence can be obtained efficiently, so it is preferred.

[0236] In order to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, it is preferable to generate carrier recombination in the TADF material. In addition, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent luminescent substance. For this purpose, the fluorescent luminescent substance preferably has a protecting group around the lumophore (the skeleton that causes luminescence) possessed by the fluorescent luminescent substance. As this protecting group, a substituent having no π bond is preferable, and a saturated hydrocarbon is preferable. Specifically, an alkyl group having 3 or more and 10 or less carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 or more and 12 or less carbon atoms, and a trialkylsilyl group having 3 or more and 10 or less carbon atoms can be cited. More preferably, it has a plurality of protecting groups. Since the substituent having no π bond has almost no function of transporting carriers, it has almost no influence on carrier transport or carrier recombination, and can keep the TADF material and the lumophore of the fluorescent luminescent substance away from each other. Here, the lumophore refers to the atomic group (skeleton) that causes luminescence in the fluorescent luminescent substance. The lumophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring. As the above lumophore, for example, a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, etc. can be cited. In particular, fluorescent luminescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton have a high fluorescence quantum yield, so they are preferable.

[0237] When a fluorescent luminescent substance is used as the luminescent substance, as the host material, a material having an anthracene skeleton is preferably used. By using a substance having an anthracene skeleton as the host material of the fluorescent luminescent substance, a luminescent layer with high luminous efficiency and durability can be achieved. Among the substances having an anthracene skeleton used as the host material, a substance having a diphenylanthracene skeleton (especially 9,10-diphenylanthracene skeleton) is chemically stable, so it is preferred. In addition, when the host material has a carbazole skeleton, the hole injection / transport property is improved, so it is preferred. In the case of having a benzocarbazole skeleton in which a benzene ring is fused to the carbazole skeleton, its HOMO is about 0.1 eV higher than that of the 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 is about 0.1 eV higher than that of the host material having a carbazole skeleton, and not only are holes easily injected, but also the hole transport property and heat resistance are improved, so it is preferred. Therefore, a substance further preferably used as the host material is a substance having a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Note that from the above viewpoint of hole injection / transport property, a benzofluorene skeleton or a dibenzofluorene skeleton can also be used instead of the carbazole skeleton. Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenz[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)-biphenyl-4'-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-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthryl)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-anthryl)phenyl]-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties, so they are preferred.

[0238] In addition, the host material may also be a material that mixes multiple substances. When using a mixed host material, it is preferable to mix a material with electron-transporting properties and a material with hole-transporting properties. By mixing a material with electron-transporting properties and a material with hole-transporting properties, it becomes easier to adjust the transport properties of the light-emitting layer 113, and it is also possible to more simply control the recombination region. The weight ratio of the content of the material with hole-transporting properties to the content of the material with electron-transporting properties may be from 1:19 to 19:1.

[0239] Note that, as part of the above-mentioned mixed materials, a phosphorescent light-emitting substance may be used. The phosphorescent light-emitting substance can be used as an energy donor that supplies excitation energy to the fluorescent light-emitting substance when the fluorescent light-emitting substance is used as the light-emitting substance.

[0240] In addition, an exciplex may be formed using these mixed materials. By selecting a combination that forms an exciplex that emits light with a wavelength overlapping the absorption band on the lowest energy side of the light-emitting substance, energy transfer can be made smooth, and thus light emission can be obtained efficiently, so it is preferable. In addition, by adopting this structure, the driving voltage can be reduced, so it is preferable.

[0241] Note that at least one of the materials forming the exciplex may also be a phosphorescent light-emitting substance. Thereby, triplet excitation energy can be efficiently converted into singlet excitation energy through reverse intersystem crossing.

[0242] As a combination of materials that efficiently form an exciplex, the HOMO level of the material with hole-transporting properties is preferably higher than the HOMO level of the material with electron-transporting properties. In addition, the LUMO level of the material with hole-transporting properties is preferably higher than the LUMO level of the material with electron-transporting properties. The LUMO level and HOMO level of the material can be obtained from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0243] Note that the formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, the emission spectra of an electron-transporting material, and the emission spectra of a mixed film formed by mixing these materials. When a phenomenon is observed in which the emission spectrum of the mixed film is shifted to the longer wavelength side (or has a new peak on the longer wavelength side) compared to the emission spectra of the respective materials, it indicates the formation of an exciplex. Alternatively, the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film formed by mixing these materials are compared. When a difference in transient response such as an increase in the ratio of a long-lived component or a delayed component in the transient PL lifetime of the mixed film compared to the transient PL lifetimes of the respective materials is observed, it indicates the formation of an exciplex. In addition, the above transient PL can be referred to as transient electroluminescence (EL). In other words, by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a mixed film of these materials and observing the difference in transient response, the formation of an exciplex can also be confirmed.

[0244] The electron transport layer 114 is a layer containing a material having electron-transporting properties. As the material having electron-transporting properties, a material having an electron mobility of 1×10 -7 cm 2 / Vs or more when the square root of the electric field strength [V / cm] is 600 is preferably used, and a material having an electron mobility of 1×10 -6 cm 2 / Vs or more is more preferably used. In addition, as long as the material has higher electron-transporting properties than hole-transporting properties, materials other than the above can be used. As the above organic compound, an organic compound including a π-deficient heteroaromatic ring is preferably used. As the organic compound including a π-deficient heteroaromatic ring, for example, an organic compound including a heteroaromatic ring having a triazole skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, an organic compound including a heteroaromatic ring having a diazine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton, any one or more of them are preferably used.

[0245] As the organic compound having electron-transporting properties that can be used for the above electron transport layer, the above material having electron-transporting properties and the organic compound that can be used as the organic compound having electron-transporting properties in the electron injection buffer region in layer 116 can be used. Among them, an organic compound including a heteroaromatic ring having a diazine skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, or an organic compound including a heteroaromatic ring having a triazine skeleton has good reliability, so it is preferred. In particular, an organic compound including a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound including a heteroaromatic ring having a triazine skeleton have high electron-transporting properties and contribute to reducing the driving voltage.

[0246] In addition, the electron mobility of the electron transport layer is preferably 1×10 -7 cm 2 / Vs or more and 5×10 -5 cm 2 / Vs or less when the square root of the electric field strength [V / cm] is 600. By reducing the electron transportability of electrons in the electron transport layer 114, the amount of electrons injected into the light-emitting layer can be controlled, thereby preventing the light-emitting layer from becoming a state with an excessive amount of electrons. When a composite material is used to form the hole injection layer, the HOMO energy level of the hole-transporting material in the composite material is a relatively low HOMO energy level of -5.7 eV or more and -5.4 eV or less, whereby a long lifetime can be obtained, so it is particularly preferred. Note that at this time, the HOMO energy level of the electron-transporting material is preferably -6.0 eV or more.

[0247] As the electron injection layer 115, in addition to the above-mentioned organic compound having a basic skeleton, a layer including lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-hydroxyquinoline-lithium (abbreviation: Liq), ytterbium (Yb), etc., an alkali metal, an alkaline earth metal, or a compound or complex thereof can also be used. The electron injection layer 115 can be a layer in which an alkali metal, an alkaline earth metal, or their compounds are included in a layer composed of an electron-transporting substance or an electride. As the electride, for example, a substance obtained by adding electrons to a mixed oxide of calcium and aluminum at a high concentration can be cited.

[0248] Note that as the electron injection layer 115, a layer in which the above-mentioned fluoride of an alkali metal or an alkaline earth metal is in a microcrystalline state at a concentration of 50 wt% or more with respect to an electron-transporting substance (preferably an organic compound having a bipyridine skeleton) can also be used. Since this layer has a low refractive index, a light-emitting device with better external quantum efficiency can be provided.

[0249] In addition, as a method for forming the organic compound layer 103, various methods can be used regardless of whether it is a dry method or a wet method. For example, a vacuum evaporation method, a gravure printing method, a photogravure printing method, a screen printing method, an inkjet method, a spin coating method, etc. can also be used.

[0250] In addition, the above-described respective electrodes or layers can also be formed by using different deposition methods.

[0251] Note that the structure of the light-emitting device included in the light-emitting device according to one embodiment of the present invention is not limited to Figure 1A the light-emitting device 130 and Figure 1B the light-emitting device 130A. The light-emitting device included in the light-emitting device according to one embodiment of the present invention can also adopt, for example, the following structure: as Figure 1CSimilar to the light-emitting device 130USD, a layer 116 is provided on the cathode 102, an organic compound layer 103 is provided on the layer 116, and an anode 101 is provided on the organic compound layer 103. Light LGT generated in the light-emitting layer 113 included in the organic compound layer 103 is emitted from the anode 101 side.

[0252] Similar to Figure 1A the layer 116 of the light-emitting device 130, in Figure 1C the light-emitting device 130USD, the layer 116 includes an electron injection buffer region 119, an electron relay region 118, and a charge generation region 117. Note that in the layer 116 of the light-emitting device 130USD, the charge generation region 117 is located on the cathode 102, the electron relay region 118 is located on the charge generation region 117, and the electron injection buffer region 119 is located on the electron relay region 118.

[0253] In addition, similar to Figure 1A the organic compound layer 103 of the light-emitting device 130, in Figure 1C the light-emitting device 130USD, the light-emitting unit 501 includes a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, and an electron transport layer 114. Note that in the organic compound layer 103 of the light-emitting device 130USD, the electron transport layer 114 is located on the electron injection buffer region 119 of the layer 116, the light-emitting layer 113 is located on the electron transport layer 114, the hole transport layer 112 is located on the light-emitting layer 113, and the hole injection layer 111 is located on the hole transport layer 112.

[0254] Furthermore, in the light-emitting device 130USD, as an example, light LGT generated in the light-emitting layer 113 is emitted above the light-emitting device 130USD through the cathode 102. Note that in this case, when a transparent electrode is used as the anode 101, the visible light (for example, with a wavelength of 400 nm or more and less than 750 nm) transmittance of the transparent electrode is preferably 40% or more. In addition, when a semi-transmissive and semi-reflective electrode is used as the anode 101, the reflectance of the semi-transmissive and semi-reflective electrode is preferably 10% or more and 95% or less, more preferably 30% or more and 80% or less. Note that the light-emitting device 130USD can not only emit light above the light-emitting device 130 through the anode 101, but also emit light below the light-emitting device through the cathode 102, that is, it can also be a double-sided emission type light-emitting device (not shown).

[0255] In addition, the light-emitting device included in a mode of the present invention can also adopt the following structure, for example: Similar to Figure 1D the light-emitting device 130USDA, in Figure 1C the light-emitting device 130USD, the electron relay region 118 is not provided.

[0256] In addition, for example, in the light-emitting device according to one embodiment of the present invention, various functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a carrier blocking layer (e.g., a hole blocking layer or an electron blocking layer), or an exciton blocking layer may be shared between adjacent light-emitting devices. For example, as an example thereof, Figure 3A FIG. showing two adjacent light-emitting devices (light-emitting device 130a and light-emitting device 130b) included in the light-emitting device according to one embodiment of the present invention.

[0257] The light-emitting device 130a includes an organic compound layer 103a between an anode 101a and a cathode 102 on an insulating layer 175. The organic compound layer 103a has a structure in which a light-emitting unit 501a and a layer 116a are stacked on each other. Note that, although Figure 3A an example in which one light-emitting device includes one light-emitting unit is shown, a structure in which one light-emitting device includes two or more stacked light-emitting units may also be employed. The light-emitting unit 501a includes a hole injection layer 111a, a hole transport layer 112a, a light-emitting layer 113a, and an electron transport layer 114a. The layer 116a includes a charge generation region 117a, an electron relay region 118a, and an electron injection buffer region 119a.

[0258] The light-emitting device 130b includes an organic compound layer 103b between an anode 101b and a cathode 102 on the insulating layer 175. The organic compound layer 103b has a structure in which a light-emitting unit 501b and a layer 116b are stacked on each other. Note that, although Figure 3A an example in which one light-emitting device includes one light-emitting unit is shown, a structure in which one light-emitting device includes two or more stacked light-emitting units may also be employed. The light-emitting unit 501b includes a hole injection layer 111b, a hole transport layer 112b, a light-emitting layer 113b, and an electron transport layer 114b. The layer 116b includes a charge generation region 117b, an electron relay region 118b, and an electron injection buffer region 119b. Note that the light-emitting device 130b may not be provided with the electron relay region 118b.

[0259] Note that the light-emitting device 130a may not be provided with the electron relay region 118a. Similarly, the light-emitting device 130b may not be provided with the electron relay region 118b. For example, a structure may also be employed in which, as in Figure 3B two adjacent light-emitting devices (light-emitting device 130aA and light-emitting device 130bA) shown, the layer 116a does not include the electron relay region 118a and the layer 116b does not include the electron relay region 118b.

[0260] In addition, in Figure 3AIn [the figure], the cathode 102 is preferably a continuous layer shared by the light-emitting device 130a and the light-emitting device 130b. Additionally, in Figure 3A [the figure], the layer 116a and the layer 116b can also be continuous layers shared by the light-emitting device 130a and the light-emitting device 130b. Specifically, as Figure 3C shown, the electron injection buffer region 119, the electron relay region 118, and the charge generation region 117 can also all be continuous layers shared by the light-emitting device 130a and the light-emitting device 130b. Note that in the layer 116, the continuous layer shared can include only the electron relay region 118 and the charge generation region 117, or can include only the charge generation region 117 (neither of the above cases is shown).

[0261] In Figure 3C the light-emitting device 130a and the light-emitting device 130b, the organic compound layer 103a and the organic compound layer 103b other than the electron injection layer 116 are respectively processed using lithography techniques after forming the electron transport layer 114a and the electron transport layer 114b, so they are independent of each other. Additionally, the end portions (contours) of the organic compound layer 103a other than the layer 116 are processed using lithography techniques, so they are aligned or substantially aligned in the direction perpendicular to the substrate. Additionally, the end portions (contours) of the organic compound layer 103b other than the layer 116 are processed using lithography techniques, so they are aligned or substantially aligned in the direction perpendicular to the substrate.

[0262] Additionally, since the organic compound layer is processed using lithography techniques, the distance d between the anode 101a and the anode 101b can be smaller than that during mask evaporation, and can be 2 μm or more and 5 μm or less. Additionally, an insulating layer can be provided between the anode 101a and the anode 101b, and this insulating layer is in contact with the cathode 102 or the layer 116.

[0263] Note that Figure 3A the light-emitting device 130a and the light-emitting device 130b can also be changed to the following structure: the anode 101a and the anode 101b are continuous layers shared, and the cathode 102 is formed in each light-emitting device. For example, the following structure can also be adopted: as Figure 4A shown in the light-emitting device 130aUSD, a cathode 102a is provided on the insulating layer 175, a layer 116a (charge generation region 117a, electron relay region 118a, electron injection buffer region 119a) is provided on the cathode 102a, a light-emitting unit 501a (electron transport layer 114a, light-emitting layer 113a, hole transport layer 112a, hole injection layer 111a) is provided on the layer 116a, and an anode 101 is provided on the organic compound layer 103a. Additionally, similarly, the following structure can also be adopted: as Figure 4AAs in the case of the light-emitting device 130bUSD shown, a cathode 102b is provided on an insulating layer 175, a layer 116b (charge generation region 117b, electron relay region 118b, electron injection buffer region 119b) is provided on the cathode 102b, a light-emitting unit 501b (electron transport layer 114b, light-emitting layer 113b, hole transport layer 112b, hole injection layer 111b) is provided on the layer 116b, and an anode 101 is provided on an organic compound layer 103b. That is to say, it can be said that Figure 4A the light-emitting devices 130aUSD and 130bUSD shown have Figure 3A a structure in which the stacking order of the respective functional layers of the light-emitting devices 130a and 130b shown is reversed.

[0264] In addition, in the same manner as described above, Figure 3B the light-emitting devices 130aA and 130bA can also adopt the following structure: the anodes 101a and 101b are continuous layers used in common, the cathode 102 is formed in each light-emitting device, and the stacking order of the respective functional layers is reversed. For example, the following structure can also be adopted: as in Figure 4B the light-emitting device 130aAUSD shown, a cathode 102a is provided on an insulating layer 175, a layer 116a (charge generation region 117a and electron injection buffer region 119a) is provided on the cathode 102a, a light-emitting unit 501a (electron transport layer 114a, light-emitting layer 113a, hole transport layer 112a, and hole injection layer 111a) is provided on the layer 116a, and an anode 101 is provided on an organic compound layer 103a. In addition, similarly, the following structure can also be adopted: as in Figure 4B the light-emitting device 130bAUSD shown, a cathode 102b is provided on an insulating layer 175, a layer 116b (charge generation region 117b and electron injection buffer region 119b) is provided on the cathode 102b, a light-emitting unit 501b (electron transport layer 114b, light-emitting layer 113b, hole transport layer 112b, and hole injection layer 111b) is provided on the layer 116b, and an anode 101 is provided on an organic compound layer 103b.

[0265] The structure of the present embodiment can be used in appropriate combination with other structures.

[0266] (Embodiment 2)

[0267] A plurality of the light-emitting devices 130 (the light-emitting devices 130A, 130USD, 130USDA, 130a, 130b, 130aA, 130bA, 130aUSD, 130bUSD, 130aAUSD, or 130bAUSD are collectively referred to as the light-emitting device 130 in addition to 130) described in the above embodiments are formed on the insulating layer 175 to constitute a light-emitting device. In the present embodiment, a light-emitting device according to one aspect of the present invention will be described in detail.

[0268] As Figure 5A and Figure 5B shown, the light-emitting device 1000 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.

[0269] In this specification and the like, the common content among the sub-pixels 110R, the sub-pixel 110G, and the sub-pixel 110B may sometimes be described as the sub-pixel 110. In addition, regarding the components distinguished by letters, the common content among the components may sometimes be described using symbols omitting the letters.

[0270] The sub-pixel 110R emits red light, the sub-pixel 110G emits green light, and the sub-pixel 110B emits blue light. Thus, an image that can be displayed in red, green, and blue can be displayed on the pixel portion 177. Note that in the present embodiment, the sub-pixels of three colors, red (R), green (G), and blue (B), are taken as an example for description, but the present invention is not limited to this structure. That is, sub-pixels of other colors may also be combined. For example, the number of sub-pixels is not limited to three and may be four or more. As four sub-pixels, for example, four-color sub-pixels of R, G, B, and white (W); four-color sub-pixels of R, G, B, and yellow (Y); and four sub-pixels of R, G, B, and infrared light (IR) can be cited; etc.

[0271] In this specification and the like, the row direction may sometimes be denoted as the X direction and the column direction may be denoted as the Y direction. The X direction intersects the Y direction, for example, perpendicularly or substantially perpendicularly.

[0272] Figure 5A An example in which sub-pixels of different colors are arranged and configured in the X direction and sub-pixels of the same color are arranged and configured in the Y direction is shown. Note that sub-pixels of different colors may also be arranged and configured in the Y direction and sub-pixels of the same color may be arranged and configured in the X direction.

[0273] A connection portion 140 and a region 141 may also be provided outside the pixel portion 177. For example, the region 141 is preferably provided between the pixel portion 177 and the connection portion 140. An organic compound layer 103 is provided in the region 141. In addition, a conductive layer 151C is provided in the connection portion 140.

[0274] Figure 5A An example is shown where 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 also be one or more.

[0275] Figure 5B along Figure 5A is an example of a cross-sectional view along the dash-dotted line A1 - A2 in Figure 5B As shown, the light-emitting device 1000 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and 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 preferably provided on a substrate (not shown). Openings reaching the conductive layer 172 are provided in the insulating layer 175, the insulating layer 174, and the insulating layer 173, and plugs 176 are provided in such a manner as to be embedded in the openings.

[0276] In the pixel portion 177, a light-emitting device 130 is provided on the insulating layer 175 and the plugs 176. In addition, a protective layer 131 is provided so as to cover the light-emitting device 130. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. In addition, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 may be provided between adjacent light-emitting devices 130.

[0277] Figure 5B A cross-section showing a plurality of inorganic insulating layers 125 and a plurality of insulating layers 127 is shown, but when looking down on the light-emitting device 1000, the inorganic insulating layer 125 and the insulating layer 127 are preferably formed as continuous single layers, respectively. That is, the insulating layer 127 is preferably an insulating layer having an opening portion on the anode.

[0278] Figure 5B The light-emitting devices 130R, 130G, and 130B are shown as the light-emitting device 130. The light-emitting devices 130R, 130G, and 130B emit light of mutually different colors. For example, the light-emitting device 130R may emit red light, the light-emitting device 130G may emit green light, and the light-emitting device 130B may emit blue light. In addition, the light-emitting device 130R, the light-emitting device 130G, or the light-emitting device 130B may also emit other visible light or infrared light.

[0279] The organic compound layer 103 includes at least a light-emitting layer, and may include other functional layers (such as a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer). In addition, the organic compound layer 103 and the common layer 104 may be combined to form the functional layers (such as a hole injection layer, a hole transport layer, a hole blocking layer, a light-emitting layer, an electron blocking layer, an electron transport layer, and an electron injection layer) included in the EL layer that exhibits light emission.

[0280] The light-emitting device according to one embodiment of the present invention may have, for example, a top emission structure that emits light in a direction opposite to the substrate on which the light-emitting device is formed. In addition, the light-emitting device according to one embodiment of the present invention may also have a bottom emission structure.

[0281] The light-emitting device 130 (130R, 130G, 130B) has the structure shown in Embodiment 1. It includes an anode (pixel electrode) composed of a conductive layer 151 (151R, 151G, 151B) and a conductive layer 152 (152R, 152G, 152B), an organic compound layer 103 (103R, 103G, 103B) on the anode, a common layer 104 on the organic compound layer 103 (103R, 103G, 103B), and a cathode (common electrode) 102 on the common layer.

[0282] Note that it is not necessarily required to provide the common layer 104. Specifically, for example, as Figure 6 shown, the light-emitting devices 130 (130R, 130G, 130B) are respectively provided with functional layers 104R, 104G, and 104B that replace the common layer 104. Note that, as an example, the organic compound layer and the functional layer are continuously deposited, and then the organic compound layer and the functional layer are patterned together by lithography, whereby the light-emitting devices 130 (130R, 130G, 130B) shown in Figure 6 can be formed.

[0283] As Figure 5B shown, by providing the common layer 104, the damage to the organic compound layer 103R caused by subsequent processes can be reduced. In addition, when the common layer 104 is provided, the common layer 104 can also be used as an electron injection region and a charge generation region. When the common layer 104 is used as an electron injection region and a charge generation region, the stacked structure of the organic compound layer 103R and the common layer 104 is equivalent to the organic compound layer 103 in Embodiment 1.

[0284] One of the pixel electrode and the common electrode included in the light-emitting device is used as the anode, and the other is used as the cathode. Hereinafter, unless otherwise specified, the case where the pixel electrode is used as the anode and the common electrode is used as the cathode will be described sometimes.

[0285] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are each formed in an island shape independently for each light-emitting color. By forming the organic compound layer 103 in an island shape for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can also be suppressed in the high-definition light-emitting device. Thereby, crosstalk can be prevented to realize a light-emitting device with extremely high contrast. In particular, a light-emitting device with high current efficiency at low brightness can be realized.

[0286] The organic compound layer 103 can also be provided so as to cover the top surface and the side surface of the anode (pixel electrode) of the light-emitting device 130. Thereby, it is easier to increase the aperture ratio of the light-emitting device 1000 than in the structure where the end portion of the organic compound layer 103 is located inside the end portion of the pixel electrode. In addition, by covering the side surface of the pixel electrode of the light-emitting device 130 with the organic compound layer 103, contact between the pixel electrode and the cathode 102 can be suppressed, and thus short circuit of the light-emitting device 130 can be suppressed. In addition, the distance between the light-emitting region of the organic compound layer 103 (that is, the region overlapping with the pixel electrode) and the end portion of the organic compound layer 103 can be increased. And, since the end portion of the organic compound layer 103 may be damaged by processing, by using the region far from the end portion of the organic compound layer 103 as the light-emitting region, the reliability of the light-emitting device 130 can be improved.

[0287] In addition, in the light-emitting device according to one aspect of the present invention, the anode (pixel electrode) of the light-emitting device may also have a stacked structure. For example, in Figure 5B the example shown, the anode of the light-emitting device 130 has a stacked structure of a conductive layer 151 and a conductive layer 152.

[0288] For example, when the light-emitting device 1000 has a top emission structure, in the pixel electrode of the light-emitting device 130, preferably, the conductive layer 151 is a layer with high visible light reflectivity, and the conductive layer 152 is a layer with visible light transmissivity and a large work function. The higher the visible light reflectivity of the pixel electrode, the higher the extraction efficiency of the light emitted by the organic compound layer 103 can be. In addition, when the pixel electrode is used as the anode, the larger the work function of the pixel electrode, the easier it is to inject holes into the organic compound layer 103. Therefore, by making the pixel electrode of the light-emitting device 130 have a stacked structure of a conductive layer 151 with high visible light reflectivity and a conductive layer 152 with a large work function, the light-emitting device 130 can be a light-emitting device with high light extraction efficiency and low driving voltage.

[0289] Specifically, the visible light reflectance of the conductive layer 151 is, for example, 40% or more and 100% or less, preferably 70% or more and 100% or less. Further, when the conductive layer 152 is an electrode having visible light transmissivity, its visible light transmittance is preferably 40% or more, for example.

[0290] In addition, when removing a film deposited after forming a pixel electrode having a laminated structure by a wet etching method or the like, the chemical solution used for etching sometimes infiltrates into the structure. When the infiltrated chemical solution comes into contact with the pixel electrode, galvanic corrosion or the like sometimes occurs between the multiple layers constituting the pixel electrode, resulting in deterioration of the pixel electrode.

[0291] In view of this, it is preferable to form the conductive layer 152 so as to cover the top surface and the side surface of the conductive layer 151. By covering the conductive layer 151 with the conductive layer 152, the infiltrated chemical solution does not come into contact with the conductive layer 151, and galvanic corrosion occurring in the pixel electrode can be suppressed. Therefore, the light-emitting device 1000 can be manufactured by a method with a high yield, and thus an inexpensive light-emitting device can be realized. In addition, the occurrence of defects in the light-emitting device 1000 can be suppressed, and thus the light-emitting device 1000 can be a highly reliable light-emitting device.

[0292] As the conductive layer 151, for example, a metal material can be used. 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), etc., and alloys obtained by appropriately combining them can also be used.

[0293] 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, the work function of indium tin oxide containing silicon is relatively large, and its work function is, for example, 4.0 eV or more, so it can be suitably used as the conductive layer 152.

[0294] In addition, each of the conductive layer 151 and the conductive layer 152 may also have a laminated structure including a plurality of layers containing different materials. In this case, the conductive layer 151 may also include a layer using a material such as a conductive oxide that can be used for the conductive layer 152, and the conductive layer 152 may also include a layer using a material such as a metal material that can be used for the conductive layer 151. For example, when the conductive layer 151 has a laminated structure of two or more layers, the layer in contact with the conductive layer 152 may be a layer containing the same material as the layer in contact with the conductive layer 151 in the conductive layer 152.

[0295] The end of the conductive layer 151 preferably has a tapered shape. Specifically, the end of the conductive layer 151 preferably has a tapered shape with a taper angle less than 90°. At this time, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By making the side surface of the conductive layer 152 have a tapered shape, the coverage of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be improved.

[0296] In addition, when the conductive layer 151 or the conductive layer 152 has a laminated structure, preferably, at least one of the laminated layers has a tapered shape. In addition, in the laminated structure constituting each conductive layer, different tapered shapes may be provided for each layer.

[0297] Figure 7A It is a diagram when the conductive layer 151 has a laminated structure including a plurality of layers containing different materials. As Figure 7A shown, the conductive layer 151 includes a conductive layer 151_1, a conductive layer 151_2 on the conductive layer 151_1, and a conductive layer 151_3 on the conductive layer 151_2. That is, Figure 7A the shown conductive layer 151 has a three-layer laminated structure. Thus, when the conductive layer 151 has a laminated structure of a plurality of layers, it is only necessary to make the visible light reflectance of at least one of the layers constituting the conductive layer 151 higher than the visible light reflectance of the conductive layer 152.

[0298] In Figure 7A the shown example, the conductive layer 151_2 is sandwiched between the conductive layer 151_1 and the conductive layer 151_3. The conductive layer 151_1 and the conductive layer 151_3 preferably use materials that are less likely to deteriorate compared to the conductive layer 151_2. For example, the conductive layer 151_1 may use a material that is less likely to undergo migration due to contact with the insulating layer 175 compared to the conductive layer 151_2. In addition, the conductive layer 151_3 may use a material that is less likely to be oxidized compared to the conductive layer 151_2; and the resistivity of its oxide is lower than that of the oxide of the material used for the conductive layer 151_2.

[0299] As described above, by adopting a structure in which the conductive layer 151_2 is sandwiched between the conductive layer 151_1 and the conductive layer 151_3, the range of material selection for the conductive layer 151_2 can be expanded. Thereby, for example, the conductive layer 151_2 can be made into a layer having a visible light reflectance higher than at least one of the conductive layer 151_1 and the conductive layer 151_3. For example, aluminum can be used as the conductive layer 151_2. In addition, an aluminum-containing alloy can also be used as the conductive layer 151_2. In addition, titanium can be used as the conductive layer 151_1. Although the visible light reflectance of titanium is lower than that of aluminum, even when in contact with the insulating layer 175, migration is less likely to occur compared to aluminum. And titanium can be used as the conductive layer 151_3. Although the visible light reflectance of titanium is lower than that of aluminum, it is less likely to be oxidized compared to aluminum and the resistivity of the oxide is lower than the resistivity of aluminum oxide.

[0300] In addition, silver or a silver-containing alloy can also be used as the conductive layer 151_3. Silver has the characteristic that its visible light reflectance is higher than that of titanium. Furthermore, silver is less likely to be oxidized compared to aluminum, and the resistivity of silver oxide is lower than the resistivity of aluminum oxide. Thereby, when silver or a silver-containing alloy is used as the conductive layer 151_3, while appropriately increasing the visible light reflectance of the conductive layer 151, an increase in the resistance of the pixel electrode due to the oxidation of the conductive layer 151_2 can be suppressed. Here, as the silver-containing alloy, for example, an alloy of silver, palladium, and copper (also denoted as Ag-Pd-Cu or APC) can be used. In addition, when silver or a silver-containing alloy is used as the conductive layer 151_3 and aluminum is used as the conductive layer 151_2, the visible light reflectance of the conductive layer 151_3 can be increased compared to the visible light reflectance of the conductive layer 151_2. Here, silver or a silver-containing alloy can also be used as the conductive layer 151_2. In addition, silver or a silver-containing alloy can also be used as the conductive layer 151_1.

[0301] On the other hand, the etch processability of a film using titanium is superior to that of a film using silver. Therefore, by using titanium as the conductive layer 151_3, the conductive layer 151_3 can be easily formed. In addition, the etch processability of a film using aluminum is also superior to that of a film using silver.

[0302] Thus, by making the conductive layer 151 have a stacked structure of multiple layers, the characteristics of the light-emitting device can be improved. For example, the light-emitting device 1000 can be made into a light-emitting device with high light extraction efficiency and high reliability.

[0303] Here, when the microcavity structure is adopted in the light-emitting device 130, by using silver or a silver-containing alloy, which is a material with high visible light reflectance, as the conductive layer 151_3, the light extraction efficiency of the light-emitting device 1000 can be appropriately increased.

[0304] In addition, as Figure 7AAs shown, depending on the material selection or processing method of the conductive layer 151, sometimes the side surface of the conductive layer 151_3 is located inside the side surfaces of the conductive layer 151_1 and the conductive layer 151_2, and the conductive layer 151_1 forms a protrusion. This results in a decrease in the coverage of the conductive layer 152 over the conductive layer 151, and there is a possibility of disconnection of the conductive layer 152.

[0305] In view of this, it is preferable to provide the insulating layer 156 as Figure 7A shown. Figure 7A An example is shown in which the insulating layer 156 is provided on the conductive layer 151 in such a way as to have an area overlapping with the side surface of the conductive layer 151_2. Thereby, disconnection or thinning of the conductive layer 152 due to the protrusion can be suppressed, and thus connection failure or an increase in driving voltage can be suppressed.

[0306] Note that although Figure 7A a structure is shown in which the entire side surface of the conductive layer 151_2 is covered with the insulating layer 156, a part of the side surface of the conductive layer 151_2 may not be covered with the insulating layer 156. The same applies to the pixel electrode having the structure shown below, and a part of the side surface of the conductive layer 151_2 may not be covered with the insulating layer 156.

[0307] In addition, as Figure 7A shown, the insulating layer 156 preferably has a curved surface. Thereby, for example, disconnection in the conductive layer 152 covering the insulating layer 156 can be suppressed as compared with the case where the side surface of the insulating layer 156 is perpendicular. Specifically, when the side surface of the insulating layer 156 has a conical shape with a cone angle less than 90°, for example, disconnection in the conductive layer 152 covering the insulating layer 156 can be suppressed as compared with the case where the side surface of the insulating layer 156 is perpendicular. Thereby, the light-emitting device 1000 can be manufactured by a method with a high yield. In addition, the occurrence of defects is suppressed, and the light-emitting device 1000 can be made into a highly reliable light-emitting device.

[0308] Note that one aspect of the present invention is not limited to this. For example, Figures 7B to 7D other structures of the anode 101 are shown.

[0309] Figure 7B It is a structure in which, in the Figure 1A anode 101, the insulating layer 156 covers the side surfaces of the conductive layer 151_1, the conductive layer 151_2, and the conductive layer 151_3 in addition to the side surface of the conductive layer 151_2.

[0310] Figure 7C It is a structure in which the insulating layer 156 is not provided in the Figure 1A anode 101.

[0311] Figure 7DIt has the following structure: in the anode 101 of FIG. 1, the conductive layer 151 does not have a laminated structure and the conductive layer 152 has a laminated structure.

[0312] The conductive layer 152_1 is a layer having, for example, a higher adhesion to the conductive layer 152_2 than the insulating layer 175. As the conductive layer 152_1, for example, 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 including any one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium titanium oxide, zinc titanate, aluminum zinc oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. Thereby, film peeling of the conductive layer 152_2 can be suppressed. In addition, the conductive layer 152_2 can be made not to contact the insulating layer 175.

[0313] The conductive layer 152_2 is a layer having a higher visible light reflectance (for example, reflectance of light having a wavelength in the range of 400 nm or more and less than 750 nm) than the conductive layer 151, the conductive layer 152_1, and the conductive layer 152_2. The visible light reflectance of the conductive layer 152_2 can be, for example, 70% or more and 100% or less, preferably 80% or more and 100% or less, more preferably 90% or more and 100% or less. In addition, for example, silver or a silver-containing alloy can be used as the conductive layer 152_2. As the silver-containing alloy, for example, an alloy of silver, palladium, and copper (APC) can be cited. Thereby, the light-emitting device 1000 can be made a light-emitting device with high light extraction efficiency. Note that a metal other than silver can also be used as the conductive layer 152_2.

[0314] When the conductive layer 151 and the conductive layer 152 are used as an anode, the conductive layer 152_1 is preferably a layer having a large work function. The conductive layer 152_3 is, for example, a layer having a larger work function than the conductive layer 152_2. As the conductive layer 152_3, for example, the same material as that which can be used for the conductive layer 152_1 can be used. For example, the same material can be used for the conductive layer 152_1 and the conductive layer 152_3.

[0315] Note that when the conductive layer 151 and the conductive layer 152 are used as a cathode, it is preferably a layer having a small work function. The conductive layer 152_3 is, for example, a layer having a smaller work function than the conductive layer 152_2.

[0316] In addition, the conductive layer 152_3 is preferably a layer with a high visible light transmittance (for example, the transmittance of light with wavelengths in the range of 400 nm or more and less than 750 nm). For example, the visible light transmittance of the conductive layer 152_3 is preferably higher than that of the conductive layer 151 and the conductive layer 152_2. For example, the visible light transmittance of the conductive layer 152_3 can be 60% or more and 100% or less, preferably 70% or more and 100% or less, and more preferably 80% or more and 100% or less. Thereby, the light emitted from the organic compound layer 103 and absorbed by the conductive layer 152_3 can be reduced. In addition, as described above, the conductive layer 152_2 under the conductive layer 152_3 can be a layer with a high visible light reflectance. Therefore, the light-emitting device 1000 can be made into a light-emitting device with high light extraction efficiency.

[0317] Next, an example of a manufacturing method of the light-emitting device 1000 having the structure shown in FIG. 5 will be described with reference to FIGS. 8 to 14.

[0318] [Example of manufacturing method]

[0319] The thin films (insulating films, semiconductor films, conductive films, etc.) constituting the light-emitting device can be formed, for example, by sputtering, chemical vapor deposition (CVD: Chemical Vapor Deposition), vacuum evaporation, pulsed laser deposition (PLD: Pulsed Laser Deposition), atomic layer deposition (ALD: Atomic Layer Deposition), etc. As the CVD method, for example, there are plasma enhanced chemical vapor deposition (PECVD: Plasma Enhanced CVD) method and thermal CVD method. In addition, as one of the thermal CVD methods, there is metal organic chemical vapor deposition (MOCVD: Metal Organic CVD) method.

[0320] In addition, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the light-emitting device can be formed by wet deposition methods such as spin coating, dipping, spraying, inkjet, dispenser method, screen printing, offset printing, doctor knife method, slot die coating method, roll coating method, curtain coating method, or blade coating method.

[0321] In particular, when manufacturing a light-emitting device, vacuum processes such as evaporation and solution processes such as spin coating and inkjet printing can be utilized. As the evaporation method, for example, physical vapor deposition (PVD) method, chemical vapor deposition (CVD) method, etc. can be cited. In addition, as the physical vapor deposition method, for example, sputtering method, ion plating method, ion beam evaporation method, molecular beam epitaxy method, vacuum evaporation method, etc. can be cited. In particular, methods such as evaporation method (such as vacuum evaporation method), coating method (such as dip coating method, dye coating method, bar coating method, spin coating method, spraying method), printing method (inkjet method, screen printing (stencil printing) method, offset printing (lithography) method, flexographic printing (such as letterpress printing) method, gravure printing method or microcontact printing method, etc.) can be used to form functional layers included in the organic compound layer (such as hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, and electron injection layer, etc.).

[0322] In addition, when processing the thin film constituting the light-emitting device, for example, photolithography technology can be utilized for processing. Or, the thin film can also be processed by nanoimprinting method, sandblasting method, lift-off method, etc. In addition, island-shaped thin films can also be directly formed by a deposition method using a masking mask such as a metal mask.

[0323] Typically, there are the following two methods for photolithography, which is one of the photolithography technologies. One is a method of forming a resist mask on the thin film to be processed, processing the thin film by etching, for example, and removing the resist mask. The other is a method of depositing a photosensitive thin film and then performing exposure and development to process the thin film into a desired shape.

[0324] In the etching of the thin film, dry etching method, wet etching method, sandblasting method, etc. can be utilized.

[0325] First, as Figure 8A shown, an insulating layer 171 is formed on a substrate (not shown). Next, 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. Next, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0326] As the substrate, a substrate having at least heat resistance capable of withstanding subsequent heat treatment can be used. When using an insulating substrate as the substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, etc. can be used. In addition, a single crystal semiconductor substrate or a polycrystalline semiconductor substrate made of silicon or silicon carbide, a compound semiconductor substrate (for example, a compound semiconductor substrate containing silicon germanium), an SOI substrate, etc. can also be used.

[0327] Next, as Figure 8A shown, 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 in such a manner as to embed in the openings.

[0328] Next, as Figure 8A shown, a conductive film 151f that 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. The conductive film 151f can be formed, for example, by a sputtering method or a vacuum evaporation method. In addition, a metal material can be used as the conductive film 151f, for example.

[0329] Next, as Figure 8A shown, for example, a resist mask 191 is formed on the conductive film 151f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0330] Next, as Figure 8B shown, for example, by an etching method, specifically, by a dry etching method, the conductive film 151f in a region that does not overlap with the resist mask 191 is removed. Note that, in the case where the conductive film 151f includes a layer using a conductive oxide such as indium tin oxide, the layer can also be removed by a wet etching method. Thus, the conductive layer 151 is formed. Note that, for example, when a part of the conductive film 151f is removed by a dry etching method, recesses (also referred to as depressions) sometimes form in the region of the insulating layer 175 that does not overlap with the conductive layer 151.

[0331] Next, as Figure 8C shown, the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma. Alternatively, oxygen gas and CF4, C4F8, SF6, CHF3, Cl2, H2O, or BCl3 can also be used. Alternatively, oxygen gas and a Group 18 element such as He can also be used. Alternatively, the resist mask 191 can be removed by wet etching.

[0332] Next, as Figure 8D shown, an insulating film 156f that 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. The insulating film 156f can be formed, for example, by a CVD method, an ALD method, a sputtering method, or a vacuum evaporation method.

[0333] The insulating film 156f can be made of an inorganic material. As the insulating film 156f, for example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitrogen oxide insulating film can be used. For example, as the insulating film 156f, an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitrogen oxide insulating film containing silicon can be used. For example, silicon oxynitride can be used as the insulating film 156f.

[0334] Next, as Figure 8E shown, the insulating film 156f is processed to form the insulating layers 156R, 156G, 156B, and 156C. For example, the top surface of the insulating film 156f is etched substantially uniformly, whereby the insulating layer 156 can be formed. The process of etching uniformly in this way for planarization is also called etch-back processing. In addition, the insulating layer 156 can also be formed by photolithography.

[0335] Next, as Figure 9A shown, a conductive film 152f that will later become the conductive layers 152R, 152G, 152B, and 152C is formed on the conductive layers 151R, 151G, 151B, 151C, the insulating layers 156R, 156G, 156B, 156C, and the insulating layer 175. Specifically, for example, the conductive film 152f is formed so as to cover the conductive layers 151R, 151G, 151B, 151C, the insulating layers 156R, 156G, 156B, and 156C.

[0336] The conductive film 152f can be formed, for example, by sputtering or vacuum evaporation. In addition, the conductive film 152f can be formed by ALD. In addition, for example, a conductive oxide can be used as the conductive film 152f. Alternatively, as the conductive film 152f, a laminated structure of a film using a metal material and a film using a conductive oxide on this film can be adopted. For example, as the conductive film 152f, a laminated structure of a film using titanium, silver, or a silver-containing alloy and a film using a conductive oxide on this film can be adopted.

[0337] Next, as Figure 9B shown, for example, the conductive film 152f is processed by photolithography, whereby the conductive layers 152R, 152G, 152B, and 152C are formed. Specifically, for example, after forming a resist mask, a part of the conductive film 152f is removed by etching. The conductive film 152f can be removed, for example, by wet etching. Note that the conductive film 152f can also be removed by dry etching. Thus, a pixel electrode including the conductive layer 151 and the conductive layer 152 is formed.

[0338] Next, it is preferable to hydrophobize the conductive layer 152. Through the hydrophobization treatment, the surface to be treated can be changed from hydrophilic to hydrophobic, or the hydrophobicity of the surface to be treated can be enhanced. By hydrophobizing the conductive layer 152, the adhesion between the conductive layer 152 and the organic compound layer 103 to be formed in the subsequent process can be improved to suppress film peeling. Note that the hydrophobization treatment may not be performed.

[0339] Next, as Figure 9C shown, an organic compound film 103Bf that will later become the organic compound layer 103B is formed on the conductive layer 152B, the conductive layer 152G, the conductive layer 152R, and the insulating layer 175.

[0340] In the present invention, the organic compound film 103Bf includes a plurality of organic compound layers each having at least one light-emitting layer. For specific details, reference can be made to the structure of the light-emitting device 130 described in Embodiment 1.

[0341] As Figure 9C shown, the organic compound film 103Bf is not formed on the conductive layer 152C. For example, by using a mask for defining the deposition range (in this specification, etc., sometimes referred to as a range mask or a coarse metal mask to distinguish it from a high-precision metal mask), the organic compound film 103Bf can be deposited only in a desired region. By adopting a deposition process using a range mask and a processing process using a resist mask, a light-emitting device can be manufactured with a relatively simple process.

[0342] The organic compound film 103Bf can be formed, for example, by an evaporation method, and specifically, by a vacuum evaporation method. In addition, the organic compound film 103Bf can also be formed by a transfer method, a printing method, an inkjet method, a coating method, or the like.

[0343] Next, as Figure 9D shown, a sacrificial film 158Bf that will later become the sacrificial layer 158B and a mask film 159Bf that will later become the mask layer 159B are sequentially formed on the organic compound film 103Bf.

[0344] The sacrificial film 158Bf and the mask film 159Bf can be formed, for example, by a sputtering method, an ALD method (such as a thermal ALD method, a PEALD method, etc.), a CVD method, or a vacuum evaporation method. In addition, they can also be formed by the above-mentioned wet deposition methods.

[0345] In addition, the sacrificial film 158Bf and the mask film 159Bf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Bf. The substrate temperature during the formation of the sacrificial film 158Bf and the mask film 159Bf is typically 200 °C or lower, preferably 150 °C or lower, more preferably 120 °C or lower, further preferably 100 °C or lower, and even more preferably 80 °C or lower.

[0346] Note that, in the present embodiment, an example in which the mask film is composed of a two-layer structure of the sacrificial film 158Bf and the mask film 159Bf is shown, but the mask film may have a single-layer structure or a stacked structure of three or more layers.

[0347] By providing a sacrificial layer on the organic compound film 103Bf, damage to the organic compound film 103Bf during the manufacturing process of the light-emitting device can be reduced, and the reliability of the light-emitting device can be improved.

[0348] As the sacrificial film 158Bf, a film with high resistance to the processing conditions of the organic compound film 103Bf is used, specifically, a film with a large etching selectivity ratio with respect to the organic compound film 103Bf. As the mask film 159Bf, a film with a large etching selectivity ratio with respect to the sacrificial film 158Bf is used.

[0349] As the sacrificial film 158Bf and the mask film 159Bf, a film that can be removed by wet etching is preferably used. By using wet etching, compared with the case of using dry etching, damage to the organic compound film 103Bf during the processing of the sacrificial film 158Bf and the mask film 159Bf can be reduced.

[0350] When using wet etching, an acidic chemical solution is particularly preferably used. As the acidic chemical solution, a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also referred to as a mixed acid) is preferably used.

[0351] As the sacrificial film 158Bf and the mask film 159Bf, 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.

[0352] In addition, by using a film containing a material having ultraviolet light-shielding properties as the sacrificial film 158Bf and the mask film 159Bf, for example, ultraviolet light can be prevented from irradiating the organic compound layer during the exposure process. By suppressing damage to the organic compound layer caused by ultraviolet light, the reliability of the light-emitting device can be improved.

[0353] Note that a film containing a material having ultraviolet light-shielding properties also exhibits the same effect when used as the material of the inorganic insulating film 125f described later.

[0354] As the sacrificial film 158Bf and the mask film 159Bf, 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 such metal materials can be used respectively. Low melting point materials such as aluminum or silver are particularly preferably used.

[0355] In addition, as the sacrificial film 158Bf and the mask film 159Bf, 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.

[0356] Note that an element M (where 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 be used instead of the above-mentioned gallium.

[0357] As the sacrificial film 158Bf and the mask film 159Bf, for example, semiconductor materials such as silicon or germanium are used. This has a high affinity with the semiconductor manufacturing process, so it is preferred. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, non-metal materials such as carbon or their compounds can be used. In addition, metals such as titanium, tantalum, tungsten, chromium, aluminum, or alloys containing one or more of them can be used. In addition, oxides of the above metals such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can be used.

[0358] In addition, as the sacrificial film 158Bf and the mask film 159Bf, various inorganic insulating films can be used respectively. In particular, the adhesion of the oxide insulating film to the organic compound film 103Bf is higher than that of the nitride insulating film to the organic compound film 103Bf, so it is preferred. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, or silicon oxide can be used for the sacrificial film 158Bf and the mask film 159Bf respectively. As the sacrificial film 158Bf and the mask film 159Bf, an aluminum oxide film can be formed by ALD method respectively. By using the ALD method, the damage to the substrate (especially to the organic compound layer) can be reduced, so it is preferred.

[0359] As one or both of the sacrificial film 158Bf and the mask film 159Bf, an organic material can also be used. For example, as the organic material, a material that can be dissolved in a solvent that is at least chemically stable to the film located at the uppermost part of the organic compound layer 103Bf can be used. In particular, a material that can be dissolved in water or alcohol can be appropriately used. When depositing the above material, preferably, the material is applied by the above wet deposition method in a state where the material is dissolved in a solvent such as water or alcohol, and then heat treatment for evaporating the solvent is performed. At this time, it is preferable to perform the heat treatment in a reduced-pressure atmosphere, whereby the solvent can be removed at a low temperature and in a short time, and the thermal damage to the organic compound film 103Bf can be reduced.

[0360] As the sacrificial film 158Bf and the mask film 159Bf, organic resins such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, a polyamide resin soluble in alcohol, or a fluororesin such as a perfluoropolymer can also be used.

[0361] For example, as the sacrificial film 158Bf, an organic film (e.g., a PVA film) formed by any one of the evaporation method and the above wet deposition method can be used, and as the mask film 159Bf, an inorganic film (e.g., a silicon nitride film) formed by the sputtering method can be used.

[0362] Next, as shown in Figure 9D a resist mask 190B is formed on the mask film 159Bf. The resist mask 190B can be formed by applying a photosensitive material (photoresist) and performing exposure and development.

[0363] The resist mask 190B can use a positive resist material or a negative resist material.

[0364] The resist mask 190B is provided at a position overlapping with the conductive layer 152B. The resist mask 190B is preferably also provided at a position overlapping with the conductive layer 152C. Thereby, damage to the conductive layer 152C during the manufacturing process of the light-emitting device can be suppressed. Note that the resist mask 190B may not be provided on the conductive layer 152C. In addition, as shown in the cross-sectional view along B1 - B2 in Figure 9C the resist mask 190B is preferably provided so as to cover the end of the organic compound film 103Bf to the end of the conductive layer 152C (the end on the organic compound film 103Bf side).

[0365] Next, as shown in Figure 9EAs shown, a part of the mask film 159Bf is removed using the resist mask 190B to form the mask layer 159B. The mask layer 159B remains on the conductive layer 152B and the conductive layer 152C. Then, the resist mask 190B is removed. Next, the mask layer 159B is used as a mask (also referred to as a hard mask) to remove a part of the sacrificial film 158Bf to form the sacrificial layer 158B.

[0366] The sacrificial film 158Bf and the mask film 159Bf can be processed by a wet etching method or a dry etching method, respectively. The processing of the sacrificial film 158Bf and the mask film 159Bf is preferably performed by wet etching.

[0367] By using the wet etching method, compared with the case of using the dry etching method, the damage to the organic compound film 103Bf during the processing of the sacrificial film 158Bf and the mask film 159Bf can be reduced. When using the wet etching method, for example, it is preferable to use a developing solution, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid of these chemical solutions.

[0368] Since the organic compound film 103Bf is not exposed during the processing of the mask film 159Bf, the range of selection of the processing method is wider compared with the case of processing the sacrificial film 158Bf. Specifically, when processing the mask film 159Bf, even if an oxygen-containing gas is used as the etching gas, the deterioration of the organic compound film 103Bf can be further suppressed.

[0369] When using the wet etching method, it is particularly preferable to use an acidic chemical solution. As the acidic chemical solution, it is preferable to use a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also referred to as a mixed acid).

[0370] In addition, when using the dry etching method in the processing of the sacrificial film 158Bf, the deterioration of the organic compound film 103Bf can be suppressed by not using an oxygen-containing gas as the etching gas. In the case of using the dry etching method, for example, it is preferable to use a gas containing CF4, C4F8, SF6, CHF3, Cl2, H2O, or BCl3 as the etching gas. In addition, for example, it is preferable to use a gas containing a Group 18 element such as He as the etching gas.

[0371] The resist mask 190B can be removed by the same method as the resist mask 191. At this time, since the sacrificial film 158Bf is located on the outermost surface and the organic compound film 103Bf is not exposed, damage to the organic compound film 103Bf during the removal process of the resist mask 190B can be suppressed. In addition, the range of selection of the removal method of the resist mask 190B can be expanded.

[0372] Next, as Figure 9EAs shown, an organic compound film 103Bf is processed to form an organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as hard masks to remove a part of the organic compound film 103Bf to form the organic compound layer 103B.

[0373] Thus, as Figure 9E shown, a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B. In addition, the conductive layer 152G and the conductive layer 152B are exposed.

[0374] The processing of the organic compound film 103Bf can use dry etching or wet etching. For example, when using the dry etching method for processing, an etching gas containing oxygen can be used. 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 103Bf can be suppressed. Also, defects such as the adhesion of reaction products generated during etching can be suppressed.

[0375] Alternatively, an etching gas not containing oxygen can also be used. For example, by using an etching gas not containing oxygen, deterioration of the organic compound film 103Bf can be suppressed.

[0376] As described above, in one aspect of the present invention, a mask layer 159B is formed by forming a resist mask 190B on the mask film 159Bf and removing a part of the mask film 159Bf using the resist mask 190B. Then, an organic compound layer 103B is formed by using the mask layer 159B as a mask to remove a part of the organic compound film 103Bf. Therefore, it can be said that the organic compound layer 103B is formed by processing the organic compound film 103Bf using photolithography. Alternatively, a part of the organic compound film 103Bf can be removed using the resist mask 190B. Then, the resist mask 190B can also be removed.

[0377] Here, a hydrophobization treatment of the conductive layer 152G can also be performed as needed. When processing the organic compound film 103Bf, for example, the surface state of the conductive layer 152G sometimes becomes hydrophilic. By performing the hydrophobization treatment of the conductive layer 152G, for example, the adhesion between the conductive layer 152G and the layer to be formed in a later process (here, the organic compound layer 103G) can be improved to suppress film peeling.

[0378] Next, as Figure 10A shown, an organic compound film 103Gf that will later become the organic compound layer 103G is formed on the conductive layer 152G, the conductive layer 152R, the mask layer 159B, and the insulating layer 175.

[0379] The organic compound film 103Gf can be formed in the same manner as the method that can be utilized when forming the organic compound film 103Bf. Additionally, the organic compound film 103Gf can have the same structure as the organic compound film 103Bf.

[0380] Next, as Figure 10B shown, a sacrificial film 158Gf that will later become the sacrificial layer 158G and a mask film 159Gf that will later become the mask layer 159G are sequentially formed on the organic compound film 103Gf and the mask layer 159B. Then, a resist mask 190G is formed. The materials and formation methods of the sacrificial film 158Gf and the mask film 159Gf are the same as the conditions that can be used for the sacrificial film 158Bf and the mask film 159Bf. The materials and formation methods of the resist mask 190G are the same as the conditions that can be used for the resist mask 190B.

[0381] The resist mask 190G is provided at a position overlapping with the conductive layer 152G.

[0382] Next, as Figure 10C shown, a part of the mask film 159Gf is removed using the resist mask 190G to form the mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Next, a part of the sacrificial film 158Gf is removed using the mask layer 159G as a mask to form the sacrificial layer 158G. Next, the organic compound film 103Gf is processed to form the organic compound layer 103G. For example, a part of the organic compound film 103Gf is removed using the mask layer 159G and the sacrificial layer 158G as a hard mask to form the organic compound layer 103G.

[0383] Thus, as Figure 10C shown, a stacked structure of the organic compound layer 103G, the sacrificial layer 158G, and the mask layer 159G remains on the conductive layer 152G. In addition, the mask layer 159B and the conductive layer 152R are exposed.

[0384] Additionally, for example, a hydrophobization treatment of the conductive layer 152R can also be performed.

[0385] Next, as Figure 11A shown, an organic compound film 103Rf that will later become the organic compound layer 103R is formed on the conductive layer 152R, the mask layer 159G, the mask layer 159B, and the insulating layer 175.

[0386] The organic compound film 103Rf can be formed in the same manner as the method that can be utilized when forming the organic compound film 103Gf. Additionally, the organic compound film 103Rf can have the same structure as the organic compound film 103Gf.

[0387] Next, as shown in Figure 11B and Figure 11C , a sacrificial layer 158 is formed from a sacrificial film 158Rf, a mask layer 159R is formed from a mask film 159Rf, or an organic compound layer 103R is formed from an organic compound film 103Rf. Regarding the formation methods of the resist mask 190R, the sacrificial layer 158R, the mask layer 159R, and the organic compound layer 103R, reference can be made to the description of the organic compound layer 103G.

[0388] Note that the sides of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R are each preferably perpendicular or substantially perpendicular to the formation surface. For example, the angle formed by the formation surface and these sides is preferably 60 degrees or more and 90 degrees or less.

[0389] As described above, the distance between two adjacent organic compound layers among the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R formed by lithography 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. Here, for example, this distance can be defined according to the distance between the opposite ends of two adjacent organic compound layers among the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. In this way, by reducing the distance between the island-shaped organic compound layers, a light-emitting device with high clarity and a large aperture ratio can be provided. In addition, the distance between the anodes of adjacent light-emitting devices can be reduced, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less. In addition, the distance between the anodes of adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0390] Next, as shown in Figure 12A , the mask layer 159B, the mask layer 159G, and the mask layer 159R are removed.

[0391] Note that although the case of removing the mask layer 159B, the mask layer 159G, and the mask layer 159R is described as an example in this embodiment, the mask layer 159B, the mask layer 159G, and the mask layer 159R may not be removed. For example, when the mask layer 159B, the mask layer 159G, and the mask layer 159R contain the above-mentioned material having ultraviolet light-shielding properties, by not removing the above mask layer and proceeding to the next process, the organic compound layer can be protected from light irradiation (including illumination light).

[0392] As the removal process of the mask layer, the same method as the processing process of the mask layer can be used. In particular, by using the wet etching method, compared with the case of using the dry etching method, the damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R during the removal of the mask layer can be reduced.

[0393] Alternatively, the mask layer can also be removed by dissolving it in a solvent such as water or alcohol. Examples of the alcohol include ethanol, methanol, isopropyl alcohol (IPA), or glycerin.

[0394] After removing the mask layer, a drying process can also be performed to remove the water contained in the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, as well as the water adsorbed on the surfaces of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. For example, heat treatment can be performed in an inert atmosphere or a reduced-pressure atmosphere. The heat treatment can be carried out at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. By using a reduced-pressure atmosphere, drying can be performed at a lower temperature, so it is preferred.

[0395] Next, as Figure 12B shown, an inorganic insulating film 125f that will later become the inorganic insulating layer 125 is formed so as to cover the organic compound layer 103B, the organic compound layer 103G, the organic compound layer 103R, the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R.

[0396] As described later, an insulating film that will later become the insulating layer 127 is formed in contact with the top surface of the inorganic insulating film 125f. Therefore, the top surface of the inorganic insulating film 125f preferably has a high affinity with the material of the insulating film that will become the insulating layer 127 (for example, a photosensitive resin composition containing an acrylic resin). To improve this affinity, the top surface of the inorganic insulating film 125f can be surface-treated. Specifically, it is preferred to hydrophobize (or increase its hydrophobicity) the top surface of the inorganic insulating film 125f. For example, treatment with a silylating agent such as hexamethyldisilazane (HMDS) is preferred. By hydrophobizing the top surface of the inorganic insulating film 125f in this way, the insulating film 127f can be formed with high adhesion.

[0397] Next, as Figure 12C shown, an insulating film 127f that will later become the insulating layer 127 is formed on the inorganic insulating film 125f.

[0398] The inorganic insulating film 125f and the insulating film 127f are preferably deposited by a formation method that causes less damage to the organic compound layers 103B, 103G, and 103R. In particular, since the inorganic insulating film 125f is formed in contact with the side surfaces of the organic compound layers 103B, 103G, and 103R, the inorganic insulating film 125f is preferably deposited by a formation method that causes less damage to the organic compound layers 103B, 103G, and 103R than when depositing the insulating film 127f.

[0399] In addition, the inorganic insulating film 125f and the insulating film 127f are each formed at a temperature lower than the heat-resistant temperature of the organic compound layers 103B, 103G, and 103R. By increasing the substrate temperature during deposition, an inorganic insulating film 125f with a low impurity concentration and high barrier properties against at least one of water and oxygen can be formed even if its thickness is thin.

[0400] The substrate temperature when forming the inorganic insulating film 125f 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.

[0401] As the inorganic insulating film 125f, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0402] The inorganic insulating film 125f 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 preferable. As the inorganic insulating film 125f, it is preferable to form an aluminum oxide film by the ALD method, for example.

[0403] In addition to this, the inorganic insulating film 125f can also be formed by a sputtering method, a CVD method, or a PECVD method with a deposition rate higher than that of the ALD method. Thereby, a light-emitting device with high reliability can be manufactured with high productivity.

[0404] The insulating film 127f is preferably formed by the above wet deposition method. The insulating film 127f is preferably formed by spin coating using a photosensitive material, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0405] For example, it is preferable to form the insulating film 127f using a resin composition containing a polymer, an acid generator, and a solvent. The polymer is formed using one or more monomers and has a structure in which one or more structural units (also referred to as constituent units) are repeated regularly or irregularly. As the acid generator, one or both of a compound that generates an acid upon irradiation with light and a compound that generates an acid upon heating can be used. The resin composition may further contain one or more of a photosensitizer, a sensitizer, a catalyst, an adhesion aid, a surfactant, and an antioxidant.

[0406] In addition, it is preferable to perform a heat treatment (also referred to as pre-baking) after forming the insulating film 127f. This heat treatment is performed at a temperature lower than the heat-resistant temperature of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. The substrate temperature during the heat treatment is preferably 50°C or higher and 200°C or lower, more preferably 60°C or higher and 150°C or lower, and still more preferably 70°C or higher and 120°C or lower. Thereby, the solvent in the insulating film 127f can be removed.

[0407] Next, exposure is performed to sensitize a part of the insulating film 127f with visible light or ultraviolet light. Here, when a positive photosensitive resin composition containing an acrylic resin is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will not be formed in a later process. The insulating layer 127 is formed in the region sandwiched by any two of the conductive layers 152B, 152G, and 152R and around the conductive layer 152C. Therefore, visible light or ultraviolet light is irradiated onto the conductive layers 152B, 152G, 152R, and 152C. Note that when a negative photosensitive material is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will be formed.

[0408] By means of the exposed region of the insulating film 127f, the width of the insulating layer 127 to be formed later can be controlled. In the present embodiment, processing is performed such that the insulating layer 127 has a portion overlapping with the top surface of the conductive layer 151.

[0409] Here, by providing an oxygen barrier insulating layer (such as an alumina film or the like) as one or both of the sacrificial layers 158 (sacrificial layer 158B, sacrificial layer 158G, and sacrificial layer 158R) and the inorganic insulating film 125f, oxygen diffusion into the organic compound layers 103B, 103G, and 103R can be suppressed. When light (visible light or ultraviolet light) is irradiated onto the organic compound layer, the organic compounds contained in the organic compound layer sometimes become excited states and promote reactions with oxygen in the atmosphere. Specifically, when light (visible light or ultraviolet light) is irradiated onto the organic compound layer in an oxygen-containing atmosphere, oxygen may bond to the organic compounds contained in the organic compound layer. By providing the sacrificial layer 158 and the inorganic insulating film 125f on the island-shaped organic compound layer, oxygen in the atmosphere bonding to the organic compounds contained in the organic compound layer can be reduced.

[0410] Next, as Figure 13A shown, development is performed to remove the exposed regions in the insulating film 127f to form the insulating layer 127a. The insulating layer 127a is formed in regions sandwiched by any two of the conductive layers 152B, 152G, and 152R and in a region surrounding the conductive layer 152C. Here, when an acrylic resin is used for the insulating film 127f, an alkaline solution such as TMAH can be used as the developer.

[0411] Next, as Figure 13B shown, an etching process is performed using the insulating layer 127a as a mask to remove a part of the inorganic insulating film 125f, thereby reducing the thickness of a part of the sacrificial layer 158B, sacrificial layer 158G, and sacrificial layer 158R. Thereby, an inorganic insulating layer 125 is formed under the insulating layer 127a. Hereinafter, the etching process of processing the inorganic insulating film 125f using the insulating layer 127a as a mask is sometimes referred to as the first etching process.

[0412] That is, in the first etching process, the sacrificial layer 158B, sacrificial layer 158G, and sacrificial layer 158R are not completely removed, and the etching process is stopped in a state where the thickness is reduced. Thus, by leaving the corresponding sacrificial layer 158B, sacrificial layer 158G, and sacrificial layer 158R on the organic compound layers 103B, 103G, and 103R, damage to the organic compound layers 103B, 103G, and 103R during subsequent processings can be prevented.

[0413] The first etching process can be performed by dry etching or wet etching. When depositing the inorganic insulating film 125f using the same material as the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R, it is preferable because the processing of the inorganic insulating film 125f and the thinning of the exposed sacrificial layer 158 can be performed at once by the first etching process.

[0414] By using the insulating layer 127a with a tapered side shape as a mask for etching, the side surfaces of the inorganic insulating layer 125 and the upper end portions of the side surfaces of the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R can be easily formed into a tapered shape.

[0415] For example, when performing the first etching process by dry etching, a chlorine-based gas can be 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. Additionally, 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 above chlorine-based gas. By using dry etching, regions with a small thickness of the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R can be formed with excellent in-plane uniformity.

[0416] Alternatively, for example, the first etching process can be performed by wet etching. By using the wet etching method, the damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R can be reduced compared to the case of using the dry etching method.

[0417] In wet etching, an acidic chemical solution is preferably used. As the acidic chemical solution, a chemical solution containing any one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid or a mixed chemical solution of two or more acids (also referred to as a mixed acid) is preferably used.

[0418] Alternatively, a basic solution can be used for wet etching. For example, TMAH as a basic solution can be used in the wet etching of an alumina film. In this case, wet etching can be performed in a coated-gel manner.

[0419] Next, a heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be deformed into the insulating layer 127 ( Figure 13C ) having a tapered side shape. This heat treatment is performed at a temperature lower than the heat-resistant temperature of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 130°C or lower. The heating atmosphere can be either an atmospheric atmosphere or an inert atmosphere. Additionally, the heating atmosphere can be either an atmospheric atmosphere or a reduced-pressure atmosphere. In the heat treatment of this process, it is preferable to increase the substrate temperature compared to the heat treatment (pre-baking) after forming the insulating film 127f.

[0420] Through heat treatment, the close contact between the insulating layer 127 and the inorganic insulating layer 125 can be improved, and the corrosion resistance of the insulating layer 127 can also be improved. In addition, by deforming the insulating layer 127a, a shape in which the end portion of the inorganic insulating layer 125 is covered with the insulating layer 127 can be achieved.

[0421] In the first etching process, by not completely removing the sacrificial layers 158B, 158G, and 158R and leaving the sacrificial layers 158B, 158G, and 158R in a state where their thicknesses are reduced, damage and deterioration of the organic compound layers 103B, 103G, and 103R during this heat treatment can be prevented. Thereby, the reliability of the light-emitting device can be improved.

[0422] Next, as Figure 14A shown, using the insulating layer 127 as a mask, an etching process is performed to remove a part of the sacrificial layers 158B, 158G, and 158R. Note that, at this time, sometimes a part of the inorganic insulating layer 125 is also removed. Through this etching process, openings are formed in the sacrificial layers 158B, 158G, and 158R, and the top surfaces of the organic compound layers 103B, 103G, 103R, and the conductive layer 152C are exposed from the openings. Hereinafter, the etching process of using the insulating layer 127 as a mask to expose the organic compound layers 103B, 103G, and 103R is sometimes referred to as the second etching process.

[0423] The second etching process is performed using wet etching. By using the wet etching method, the damage to the organic compound layers 103B, 103G, and 103R can be reduced as compared with the case of using the dry etching method. Similar to the first etching process, the wet etching can be performed using an acidic chemical solution or an alkaline solution.

[0424] In addition, heat treatment can also be performed after a part of the organic compound layers 103B, 103G, and 103R is exposed. Through this heat treatment, water contained in the organic compound layer and water adsorbed on the surface of the organic compound layer can be removed. In addition, the shape of the insulating layer 127 sometimes changes due to this heat treatment. Specifically, the insulating layer 127 sometimes expands in a manner that covers at least one of the end portion of the inorganic insulating layer 125, the end portions of the sacrificial layers 158B, 158G, and 158R, and the top surfaces of the organic compound layers 103B, 103G, and 103R.

[0425] In addition, Figure 14AAn example is shown in which a part of the end of the sacrificial layer 158G (specifically, a tapered portion formed by the first etching process) is covered by the insulating layer 127 and a tapered portion formed by the second etching process is exposed (see Figure 7A ).

[0426] In addition, the insulating layer 127 may also cover the entire end of the sacrificial layer 158G. For example, sometimes the end of the insulating layer 127 droops to cover the end of the sacrificial layer 158G. In addition, for example, sometimes the end of the insulating layer 127 contacts the top surface of at least one of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R.

[0427] Next, as Figure 14B shown, a common electrode 155 is formed on the organic compound layer 103B, the organic compound layer 103G, the organic compound layer 103R, the conductive layer 152C, and the insulating layer 127. The common electrode 155 can be formed by methods such as sputtering or vacuum evaporation. Alternatively, the common electrode 155 can also be formed by laminating a film formed by evaporation and a film formed by sputtering.

[0428] Next, as Figure 14C shown, a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed by methods such as vacuum evaporation, sputtering, CVD, or ALD.

[0429] Next, the substrate 120 is bonded to the protective layer 131 using the resin layer 122, whereby a light-emitting device can be manufactured. As described above, in the method for manufacturing a light-emitting device according to one embodiment of the present invention, the insulating layer 156 is provided so as to include a region overlapping the side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. Thereby, the yield of the light-emitting device can be improved, and the occurrence of defects can be suppressed.

[0430] As described above, in the method of manufacturing a light-emitting device according to one embodiment of the present invention, the island-shaped organic compound layer 103B, the island-shaped organic compound layer 103G, and the island-shaped organic compound layer 103R are not formed using a high-precision metal mask but are formed by processing after depositing a film on one surface. Therefore, the island-shaped layers can be formed with a uniform thickness. Moreover, a high-definition light-emitting device or a light-emitting device with a high aperture ratio can be realized. In addition, even when the definition or aperture ratio is high and the distance between sub-pixels is extremely short, contact between the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R in adjacent sub-pixels can be suppressed. Therefore, leakage current occurring between sub-pixels can be suppressed. Thereby, crosstalk can be suppressed, and a light-emitting device with an extremely high contrast can be realized. Further, even for a light-emitting device including a light-emitting element manufactured by photolithography, a light-emitting device with good characteristics can be provided.

[0431] The structure of the present embodiment can be used in appropriate combination with other structures.

[0432] (Embodiment 3)

[0433] In the present embodiment, with reference to Figures 15A to 15G and Figures 16A to 16I a light-emitting device according to one embodiment of the present invention will be described.

[0434] [Layout of pixels]

[0435] In the present embodiment, a pixel layout different from Figure 5A will be mainly described. The arrangement of sub-pixels is not particularly limited, and various arrangement methods can be adopted. As the arrangement of sub-pixels, for example, stripe arrangement, S-stripe arrangement, matrix arrangement, delta arrangement, Bayer arrangement, and Pentile arrangement can be cited.

[0436] In the present embodiment, the top surface shape of the sub-pixels shown in the drawings corresponds to the top surface shape of the light-emitting region.

[0437] In addition, as the top surface shape of the sub-pixels, for example, polygons such as triangles, quadrangles (including rectangles and squares), pentagons, etc., the above-mentioned polygonal shapes with rounded corners, ellipses, circles, etc. can be cited.

[0438] In addition, the circuit layout constituting the sub-pixels is not limited to the range of the sub-pixels shown in the drawings and can also be arranged outside thereof.

[0439] Figure 15A The pixel 178 shown adopts an S-stripe arrangement. Figure 15A The pixel 178 shown is composed of three sub-pixels, namely, a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0440] Figure 15B The pixel 178 shown includes a sub-pixel 110R having a top surface shape of an approximate trapezoid with rounded corners, a sub-pixel 110G having a top surface shape of an approximate triangle with rounded corners, and a sub-pixel 110B having a top surface shape of an approximate quadrilateral or approximate hexagon with rounded corners. In addition, the light-emitting area of the sub-pixel 110R is larger than that of the sub-pixel 110G. Thus, the shapes and sizes of the respective sub-pixels can be determined independently. For example, the size of a sub-pixel including a light-emitting device with high reliability can be smaller.

[0441] Figure 15C The pixels 124a and 124b shown adopt a Pentile arrangement. In Figure 15C the example shown, pixels 124a including sub-pixels 110R and sub-pixels 110G and pixels 124b including sub-pixels 110G and sub-pixels 110B are alternately arranged.

[0442] Figures 15D to 15F The pixels 124a and 124b shown adopt a Delta arrangement. Pixel 124a includes two sub-pixels (sub-pixel 110R and sub-pixel 110G) in the upper row (the first row) and one sub-pixel (sub-pixel 110B) in the lower row (the second row). Pixel 124b includes one sub-pixel (sub-pixel 110B) in the upper row (the first row) and two sub-pixels (sub-pixel 110R and sub-pixel 110G) in the lower row (the second row).

[0443] Figure 15D An example is shown in which each sub-pixel has a top surface shape of an approximate quadrilateral with rounded corners, Figure 15E an example is shown in which each sub-pixel has a circular top surface shape, Figure 15F an example is shown in which each sub-pixel has a top surface shape of an approximate hexagon with rounded corners.

[0444] In Figure 15F each sub-pixel is arranged inside a hexagonal region arranged in the closest packing. Each sub-pixel is arranged in such a way that when focusing on one sub-pixel, it is surrounded by six sub-pixels. In addition, it is arranged so that sub-pixels emitting light of the same color are not adjacent. For example, each sub-pixel is arranged in such a way that when focusing on the sub-pixel 110R, it is surrounded by three sub-pixels 110G and three sub-pixels 110B arranged alternately.

[0445] Figure 15G An example is shown in which sub-pixels of each color are arranged in a zigzag shape. Specifically, in a top view, the positions of the upper sides of two sub-pixels (for example, sub-pixel 110R and sub-pixel 110G or sub-pixel 110G and sub-pixel 110B) arranged in the row direction are offset.

[0446] In Figures 15A to 15GAmong the pixels shown, for example, it is preferable that the sub-pixel 110R is a sub-pixel R that emits red light, the sub-pixel 110G is a sub-pixel G that emits green light, and the sub-pixel 110B is a sub-pixel B that emits blue light. Note that the structure of the sub-pixels is not limited to this, and the colors presented by the sub-pixels and their arrangement order can be appropriately determined. For example, the sub-pixel 110G can be set as the sub-pixel R that emits red light, and the sub-pixel 110R can be set as the sub-pixel G that emits green light.

[0447] In photolithography, the finer the pattern to be processed, the more the influence of light diffraction cannot be ignored. Therefore, when transferring the pattern of the photomask through exposure, the fidelity deteriorates, and it is difficult to process the resist mask into the desired shape. Thus, even if the pattern of the photomask is rectangular, it is likely to form a pattern with rounded corners. Therefore, the top surface shape of the sub-pixels sometimes takes a polygonal shape with rounded corners, an oval shape, a circular shape, etc.

[0448] Moreover, in the manufacturing method of a light-emitting device according to one aspect of the present invention, the organic compound layer is processed into an island shape using a resist mask. The resist film formed on the organic compound layer needs to be cured at a temperature lower than the heat-resistant temperature of the organic compound layer. Therefore, depending on the heat-resistant temperature of the material of the organic compound layer and the curing temperature of the resist material, the curing of the resist film may sometimes be insufficient. An insufficiently cured resist film may sometimes take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the organic compound layer sometimes takes a polygonal shape with rounded corners, an oval shape, a circular shape, etc. For example, when forming a resist mask with a square top surface shape, a resist mask with a circular top surface shape may sometimes be formed, and the top surface shape of the organic compound layer is circular.

[0449] In order to make the top surface shape of the organic compound layer take the desired shape, a technique of pre-correcting the mask pattern so that the designed pattern and the transferred pattern are consistent (OPC (Optical Proximity Correction) technique) can also be used. Specifically, in the OPC technique, for example, correction patterns are added to the graphic corners on the mask pattern.

[0450] As Figures 16A to 16I shown, a pixel can include four types of sub-pixels.

[0451] Figures 16A to 16C The pixel 178 shown adopts a stripe arrangement.

[0452] Figure 16A An example is shown where each sub-pixel has a rectangular top surface shape, Figure 16B An example is shown where each sub-pixel has a top surface shape connecting two semi-circles and a rectangle, Figure 16C An example is shown where each sub-pixel has an oval top surface shape.

[0453] Figures 16D to 16F The pixel 178 shown is arranged in a matrix.

[0454] Figure 16D An example is shown in which each sub-pixel has a square top surface shape. Figure 16E An example is shown in which each sub-pixel has an approximately square top surface shape with rounded corners. Figure 16F An example is shown in which each sub-pixel has a circular top surface shape.

[0455] Figure 16G and Figure 16H An example is shown in which one pixel 178 is composed of two rows and three columns.

[0456] Figure 16G The pixel 178 shown includes three sub-pixels (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B) in the upper row (the first row) and one sub-pixel (sub-pixel 110W) in the lower row (the second row). In other words, the pixel 178 includes sub-pixel 110R in the left column (the first column), sub-pixel 110G in the central column (the second column), sub-pixel 110B in the right column (the third column), and sub-pixel 110W spanning these three columns.

[0457] Figure 16H The pixel 178 shown includes three sub-pixels (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B) in the upper row (the first row) and three sub-pixels 110W in the lower row (the second row). In other words, the pixel 178 includes sub-pixel 110R and sub-pixel 110W in the left column (the first column), sub-pixel 110G and sub-pixel 110W in the central column (the second column), and sub-pixel 110B and sub-pixel 110W in the right column (the third column). As Figure 16H shown, by making the configurations of the sub-pixels in the upper and lower rows consistent, for example, dust that may be generated in the manufacturing process can be efficiently removed. Thereby, a light-emitting device with high display quality can be provided.

[0458] In Figure 16G and Figure 16H In the pixel 178 shown, the sub-pixels 110R, 110G, and 110B are arranged in a stripe pattern, so the display quality can be improved.

[0459] Figure 16I An example is shown in which one pixel 178 is composed of three rows and two columns.

[0460] Figure 16IThe pixel 178 shown includes sub-pixel 110R in the upper row (the first row), sub-pixel 110G in the central row (the second row), sub-pixel 110B spanning the first row to the second row, and one sub-pixel (sub-pixel 110W) in the lower row (the third row). In other words, the pixel 178 includes sub-pixel 110R and sub-pixel 110G in the left column (the first column), sub-pixel 110B in the right column (the second column), and sub-pixel 110W spanning these two columns.

[0461] In Figure 16I In the pixel 178 shown, the layout of sub-pixel 110R, sub-pixel 110G, and sub-pixel 110B is a so-called S stripe arrangement, so the display quality can be improved.

[0462] Figures 16A to 16I The pixel 178 shown is composed of four sub-pixels: sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, and sub-pixel 110W. For example, sub-pixel 110R can be set as a sub-pixel that emits red light, sub-pixel 110G can be set as a sub-pixel that emits green light, sub-pixel 110B can be set as a sub-pixel that emits blue light, and sub-pixel 110W can be set as a sub-pixel that emits white light. In addition, at least one of sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, and sub-pixel 110W can be set as a sub-pixel that emits cyan light, magenta light, yellow light, or near-infrared light.

[0463] As described above, in the light-emitting device according to one aspect of the present invention, various layouts can be adopted for pixels composed of sub-pixels including light-emitting devices.

[0464] This embodiment can be appropriately combined with other embodiments. In addition, in this specification, when multiple structural examples are shown in one embodiment, the structural examples can be appropriately combined.

[0465] (Embodiment 4)

[0466] In this embodiment, a light-emitting device according to one aspect of the present invention will be described.

[0467] The light-emitting device of this embodiment can be a high-definition light-emitting device. Therefore, for example, the light-emitting device of this embodiment can be used for the display unit of a wearable device. As wearable devices, for example, information terminal devices such as watch-type and bracelet-type, VR (Virtual Reality) devices such as head-mounted displays (HMDs), and AR (Augmented Reality) devices such as glasses-type, which are electronic devices that can be worn on the head, can be cited.

[0468] In addition, the light-emitting device of the present embodiment can be a high-resolution light-emitting device or a large-sized light-emitting device. Therefore, for example, the light-emitting device of the present embodiment can be used for a relatively large display unit, such as a television device, a desktop or notebook personal computer, a display for a computer or the like, a digital signage, and a large-sized game machine such as a pachinko machine. In addition, the light-emitting device of the present embodiment can be used for a relatively small display unit, such as a digital camera, a digital video camera, a digital photo frame, a mobile phone, a portable game machine, a portable information terminal, and a sound reproduction device.

[0469] [Display module]

[0470] Figure 17A The perspective view which shows display module 280 is shown. Display module 280 includes light-emitting device 100A and FPC290. Note that the light-emitting device included in display module 280 is not limited to light-emitting device 100A, and it may be either light-emitting device 100B or light-emitting device 100C which will be described later.

[0471] Display module 280 includes substrate 291 and substrate 292. Display module 280 includes display unit 281. Display unit 281 is an image display area in display module 280, and light from each pixel provided in pixel unit 284 described below can be seen.

[0472] Figure 17B It is a perspective schematic view of the structure on the side of substrate 291. Circuit unit 282 is laminated on substrate 291, pixel circuit unit 283 on circuit unit 282, and pixel unit 284 on pixel circuit unit 283. In addition, terminal unit 285 for connecting to FPC290 is provided on the portion of substrate 291 that does not overlap with pixel unit 284. Terminal unit 285 and circuit unit 282 are electrically connected through wiring portion 286 composed of a plurality of wirings.

[0473] Pixel unit 284 includes a plurality of pixels 284a arranged periodically. Figure 17B The enlarged view of one pixel 284a is shown on the right side of. Pixel 284a can adopt various structures described in the above embodiment. Figure 17B The example which shows the case where pixel 284a has the same structure as pixel 178 shown in FIG. 5 is shown.

[0474] Pixel circuit unit 283 includes a plurality of pixel circuits 283a arranged periodically.

[0475] A pixel circuit 283a controls the driving of a plurality of elements included in a pixel 284a. Three circuits for controlling the light emission of a light-emitting device may be provided in a pixel circuit 283a. For example, the pixel circuit 283a may adopt a structure having at least one selection transistor, one current control transistor (driving transistor), and a capacitor for one light-emitting device. At this time, a gate signal is input to the gate of the selection transistor, and a video signal is input to the source or drain. Thereby, an active matrix light-emitting device is realized.

[0476] The circuit section 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit section 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 also have at least one of an arithmetic circuit, a storage circuit, and a power supply circuit.

[0477] The FPC 290 serves as a wiring for supplying a video signal or a power potential from the outside to the circuit section 282. In addition, an IC may be mounted on the FPC 290.

[0478] The display module 280 may adopt a structure in which one or both of the pixel circuit section 283 and the circuit section 282 are laminated on the lower side of the pixel section 284, so the display section 281 can have an extremely high aperture ratio (effective display area ratio). For example, the aperture ratio of the display section 281 may be 40% or more and less than 100%, preferably 50% or more and 95% or less, more preferably 60% or more and 95% or less. In addition, the pixels 284a can be arranged with extremely high density, whereby the display section 281 can have extremely high definition. For example, the display section 281 preferably arranges the pixels 284a with a definition of 2000 ppi or more, more preferably 3000 ppi or more, further preferably 5000 ppi or more, still more preferably 6000 ppi or more and 20000 ppi or less or 30000 ppi or less.

[0479] Such a display module 280 has extremely high definition, so it can be applied to VR devices such as HMDs or glasses-type AR devices. For example, because the display module 280 has a display section 281 with extremely high definition, in the structure of viewing the display section of the display module 280 through a lens, even if the display section is magnified by the lens, the user cannot see the pixels, whereby a display with a high sense of immersion can be realized. In addition, the display module 280 can also be applied to an electronic device having a relatively small display section. For example, it can be applied to the display section of a wearable electronic device such as a watch-type device.

[0480] [Light-emitting device 100A]

[0481] Figure 18AThe light-emitting 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.

[0482] The substrate 301 corresponds to Figure 17A and Figure 17B the substrate 291 in. 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 part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 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 in the substrate 301 doped with impurities and is used as a source or a drain. The insulating layer 314 covers the side surface of the conductive layer 311.

[0483] In addition, an element isolation layer 315 is provided in the substrate 301 in an embedded manner between two adjacent transistors 310.

[0484] In addition, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0485] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 serves as one electrode of the capacitor 240, the conductive layer 245 serves as the other electrode of the capacitor 240, and the insulating layer 243 serves as the dielectric of the capacitor 240.

[0486] The conductive layer 241 is provided on the insulating layer 261 and is embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 through a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0487] 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. A light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B are provided on the insulating layer 175. Figure 18A The light-emitting devices 130R, 130G, and 130B are shown to have Figure 5B an example of the stacked structure shown. An insulator is provided in the region between adjacent light-emitting devices. For example, in Figure 18A this, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided in this region.

[0488] An insulating layer 156R is provided in such a manner as to have a region overlapping with a side surface of the conductive layer 151R included in the light-emitting device 130R, an insulating layer 156G is provided in such a manner as to have a region overlapping with a side surface of the conductive layer 151G included in the light-emitting device 130G, and an insulating layer 156B is provided in such a manner as to have a region overlapping with a side surface of the conductive layer 151B included in the light-emitting device 130B. In addition, a conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is provided so as to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is provided so as to cover the conductive layer 151B and the insulating layer 156B. Furthermore, a sacrificial layer 158R is located on the organic compound layer 103R included in the light-emitting device 130R, a sacrificial layer 158G is located on the organic compound layer 103G included in the light-emitting device 130G, and a sacrificial layer 158B is located on the organic compound layer 103B included in the light-emitting device 130B.

[0489] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source and drain of the transistor 310 through plugs 256 embedded in the insulating layers 243, 255, 174, and 175, a conductive layer 241 embedded in the insulating layer 254, and plugs 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 175 is the same as or substantially the same as the height of the top surface of the plug 256. Various conductive materials can be used for the plugs.

[0490] In addition, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Details of the components from the light-emitting devices 130 to the substrate 120 can be referred to in Embodiment 2. The substrate 120 corresponds to Figure 17A the substrate 292.

[0491] Figure 18B Shows Figure 18A a modified example of the light-emitting device 100A shown. Figure 18B The shown light-emitting device includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B, and the light-emitting device 130 has a region overlapping with one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. In Figure 18B the shown light-emitting device, 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.

[0492] [Light-emitting device 100B]

[0493] Figure 19 A perspective view showing the light-emitting device 100B is presented. Figure 20A A cross-sectional view showing the light-emitting device 100B is presented.

[0494] The light-emitting device 100B has a structure in which the bonding substrate 352 and the substrate 351 are bonded. In Figure 19 the substrate 352 is shown by a dashed line.

[0495] The light-emitting device 100B includes a pixel portion 177, a connection portion 140, a circuit 356, and wirings 355. Figure 19 An example in which the IC 354 and the FPC 353 are mounted on the light-emitting device 100B is shown. Therefore, the structure shown can also be referred to as a display module including the light-emitting device 100B, an IC (integrated circuit), and an FPC. Here, the substrate of the light-emitting device on which a connector such as an FPC is mounted or the substrate on which an IC is mounted is referred to as a display module. Figure 19 The connection portion 140 is provided outside the pixel portion 177. The connection portion 140 can be provided along one or more sides of the pixel portion 177. The number of connection portions 140 can also be one or more.

[0496] An example in which the connection portion 140 is provided so as to surround four sides of the display portion is shown. In the connection portion 140, the common electrode of the light-emitting device is electrically connected to the conductive layer, and a potential can be supplied to the common electrode. Figure 19 As the circuit 356, for example, a scan line driving circuit can be used.

[0497] The wirings 355 have a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wirings 355 from the outside via the FPC 353 or from the IC 354 to the wirings 355.

[0498]

[0499] Figure 19 An example in which the IC 354 is provided on the substrate 351 by a COG (Chip On Glass) method or a COF (Chip On Film) method or the like is shown. As the IC 354, for example, an IC including a scan line driving circuit or a signal line driving circuit or the like can be used. Note that the light-emitting device 100B and the display module do not necessarily have to be provided with an IC. In addition, for example, the IC can be mounted on the FPC by a COF method.

[0500] Figure 20A An example of a cross-section of a part of the region including the FPC 353, a part of the circuit 356, a part of the pixel portion 177, a part of the connection portion 140, and a part of the region including the end portion of the light-emitting device 100B is shown.

[0501] Figure 20A The light-emitting 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, and a light-emitting device 130B between a substrate 351 and a substrate 352.

[0502] Except for the difference in the structure of the pixel electrode, the light-emitting devices 130R, 130G, and 130B all have Figure 5B the stacked structure shown. For the details of the light-emitting device, reference can be made to Embodiment 1 and Embodiment 2.

[0503] 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. Here, the conductive layer 224R, the conductive layer 151R, and the conductive layer 152R can be collectively referred to as the pixel electrode of the light-emitting device 130R, or the conductive layer 151R and the conductive layer 152R excluding the conductive layer 224R can be referred to as the pixel electrode of the light-emitting device 130R. Similarly, the conductive layer 224G, the conductive layer 151G, and the conductive layer 152G can be collectively referred to as the pixel electrode of the light-emitting device 130G, or the conductive layer 151G and the conductive layer 152G excluding the conductive layer 224G can be referred to as the pixel electrode of the light-emitting device 130G. In addition, the conductive layer 224B, the conductive layer 151B, and the conductive layer 152B can be collectively referred to as the pixel electrode of the light-emitting device 130B, or the conductive layer 151B and the conductive layer 152B excluding the conductive layer 224B can be referred to as the pixel electrode of the light-emitting device 130B.

[0504] 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. The end of the conductive layer 151R is located outside the end of the conductive layer 224R. An insulating layer 156R is provided in such a manner as to have a region in contact with the side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0505] The conductive layer 224G, the conductive layer 151G, the conductive layer 152G, the insulating layer 156G in the light-emitting device 130G, and the conductive layer 224B, the conductive layer 151B, the conductive layer 152B, the insulating layer 156B in the light-emitting device 130B are the same as the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, the insulating layer 156R in the light-emitting device 130R, so the detailed description is omitted.

[0506] The conductive layer 224R, the conductive layer 224G, and the conductive layer 224B are formed with recesses in such a way as to cover the openings provided in the insulating layer 214. The layer 128 is embedded in the recesses.

[0507] The layer 128 has a function of flattening the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B. A conductive layer 151R that is electrically connected to the conductive layer 224R is provided on the conductive layer 224R and the layer 128 embedded in the recess of the conductive layer 224R. In addition, a conductive layer 151G that is electrically connected to the conductive layer 224G is provided on the conductive layer 224G and the layer 128 embedded in the recess of the conductive layer 224G. In addition, a conductive layer 151B that is electrically connected to the conductive layer 224B is provided on the conductive layer 224B and the layer 128 embedded in the recess of the conductive layer 224B. Therefore, the regions on the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B that overlap with the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B can also be used as light-emitting regions, and the aperture ratio of the pixel can be increased.

[0508] The layer 128 can also be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be appropriately used for the layer 128. In particular, the layer 128 is preferably formed of an insulating material, and particularly preferably formed of an organic insulating material. For example, the organic insulating material that can be used for the insulating layer 127 described above can be used for the layer 128.

[0509] A protective layer 131 is provided on the light-emitting devices 130R, the light-emitting devices 130G, and the light-emitting devices 130B. The protective layer 131 and the substrate 352 are bonded by an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. The light-emitting device 130 can be sealed by a solid-sealing structure or a hollow-sealing structure, etc. In Figure 20A this case, 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 can be filled with an inert gas (such as nitrogen or argon) to adopt a hollow-sealing structure. At this time, the adhesive layer 142 can also be provided in such a way as not to overlap with the light-emitting device. In addition, the space can also be filled with a resin different from the adhesive layer 142 provided in a frame shape.

[0510] Figure 20A The following example is shown: The connection portion 140 includes a conductive layer 224C obtained by processing a conductive film the same as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive layer 151C obtained by processing a conductive film the same as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive layer 152C obtained by processing a conductive film the same as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. In addition, Figure 20AAn example in which the insulating layer 156C is provided so as to have a region overlapping with the side surface of the conductive layer 151C is shown.

[0511] The light-emitting device 100B is a top-emission type display device. The light-emitting element emits light toward the substrate 352 side. The substrate 352 is preferably made of a material having high visible light transmittance. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0512] Both the transistor 201 and the transistor 205 are formed on the substrate 351. These transistors can be formed using the same material and the same process.

[0513] 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 part of the insulating layer 211 serves as a gate insulating layer for each transistor. A part of the insulating layer 213 serves as a gate insulating layer for each transistor. The insulating layer 215 is provided so as to cover the transistors. The insulating layer 214 is provided so as to cover the transistors and serves 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 transistors, and they may be one or two or more.

[0514] Preferably, a material in which impurities such as water and hydrogen do not easily diffuse is used for at least one of the insulating layers covering the transistors. Thus, the insulating layer can be used as a barrier layer. By adopting such a structure, it is possible to effectively suppress the diffusion of impurities from the outside into the transistors, and thus the reliability of the light-emitting device can be improved.

[0515] An inorganic insulating film is preferably used as the insulating layer 211, the insulating layer 213, and the insulating layer 215. As the inorganic insulating film, for example, a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or an aluminum nitride film can be used. In addition, a hafnium oxide film, a yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, or a neodymium oxide film can also be used. In addition, two or more of the above insulating films can be laminated.

[0516] As the insulating layer 214 serving as a planarization layer, an organic insulating layer is preferably used. As materials that can be used for the organic insulating layer, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimide amide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins can be cited. In addition, the insulating layer 214 may have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 is preferably used as an etching protection layer. Thereby, when processing the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, etc., formation of recesses in the insulating layer 214 can be suppressed. Alternatively, recesses may be provided in the insulating layer 214 when processing the conductive layer 224R, the conductive layer 151R, or the conductive layer 152R.

[0517] The transistors 201 and 205 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; conductive layers 222a and 222b serving as source and drain; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate. Here, multiple layers obtained by processing the same conductive film are shown with the same hatching. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0518] There is no particular limitation on the transistor structure included in the light-emitting device of the present embodiment. For example, a planar transistor, a staggered transistor, or an anti-staggered transistor can be employed. In addition, the transistors can all have a top-gate structure or a bottom-gate structure. Alternatively, gates may be provided above and below the semiconductor layer where the channel is formed.

[0519] As the transistors 201 and 205, a structure in which a semiconductor layer forming a channel is clamped by two gates is adopted. In addition, the two gates may be connected, and the transistors may be driven by supplying the same signal to the two gates. Alternatively, by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other, the threshold voltage of the transistor can also be controlled.

[0520] There is also no particular limitation on the crystallinity of the semiconductor material used for the transistors, and amorphous semiconductors, semiconductors having crystallinity (microcrystalline semiconductors, polycrystalline semiconductors, single-crystalline semiconductors, or semiconductors having a crystalline region in a part thereof) can be used. When using a semiconductor having crystallinity, deterioration of the transistor characteristics can be suppressed, so it is preferred.

[0521] The semiconductor layer of the transistor is preferably a metal oxide. That is, the light-emitting device of the present embodiment preferably uses a transistor (hereinafter, an OS transistor) including a metal oxide in the channel formation region.

[0522] As a crystalline oxide semiconductor, CAAC (c-axis-aligned crystalline)-OS, nc (nanocrystalline)-OS, etc. can be cited.

[0523] Alternatively, a transistor (Si transistor) using silicon for a channel formation region can also be used. As the silicon, single crystal silicon, polycrystalline silicon, or amorphous silicon can be cited. In particular, a transistor in which a semiconductor layer contains low-temperature polycrystalline silicon (LTPS: Low Temperature Poly Silicon) (hereinafter, also referred to as an LTPS transistor) can be used. The LTPS transistor has a high field-effect mobility and good frequency characteristics.

[0524] By using an Si transistor such as an LTPS transistor, a circuit (for example, a source driver circuit) that needs to be driven at a high frequency and a display unit can be formed on the same substrate. Therefore, an external circuit mounted on a light-emitting device can be simplified, and component costs and mounting costs can be reduced.

[0525] The field-effect mobility of an OS transistor is much higher than that of a transistor using amorphous silicon. In addition, the leakage current between the source and the drain in the off state of the OS transistor (hereinafter, also referred to as the off-state current) is extremely low, and the charge accumulated in a capacitor connected in series with the transistor can be maintained for a long period. In addition, by using an OS transistor, power consumption of the light-emitting device can be reduced.

[0526] In addition, when increasing the light emission luminance of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. For this purpose, it is necessary to increase the source-drain voltage of the driving transistor included in the pixel circuit. Since the breakdown voltage between the source and the drain of the OS transistor is higher than that of the Si transistor, a high voltage can be applied between the source and the drain of the OS transistor. Thus, by using an OS transistor as the driving transistor included in the pixel circuit, the amount of current flowing through the light-emitting device can be increased to increase the light emission luminance of the light-emitting device.

[0527] In addition, when the transistor operates in the saturation region, compared with the Si transistor, the OS transistor can make the change in the source-drain current with respect to the change in the gate-source voltage small. Therefore, by using an OS transistor as the driving transistor included in the pixel circuit, the current flowing through the source and the drain can be determined in detail according to the change in the gate-source voltage, so that the amount of current flowing through the light-emitting device can be controlled. Thus, the gradation displayed by the pixel circuit can be increased.

[0528] In addition, regarding the saturation characteristics of the current flowing when the transistor operates in the saturation region, compared with Si transistors, OS transistors can cause a stable current (saturation current) to flow even when gradually increasing the source-drain voltage. Therefore, by using OS transistors as driving transistors, even if, for example, the current-voltage characteristics of the light-emitting device are uneven, a stable current can flow through the light-emitting device. That is, when an OS transistor operates in the saturation region, even if the source-drain voltage is increased, the source-drain current hardly changes, so the emission brightness of the light-emitting device can be stabilized.

[0529] As described above, by using OS transistors as the driving transistors included in the pixel circuit, "suppression of black impurity", "increase in emission brightness", "multi-gray scale", "suppression of unevenness of the light-emitting device", etc. can be achieved.

[0530] For example, the semiconductor layer preferably contains indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium). In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0531] In particular, as the semiconductor layer, an oxide containing indium (In), gallium (Ga), and zinc (also denoted as IGZO) is preferably used. Alternatively, an oxide containing indium, tin, and zinc is preferably used. Alternatively, an oxide containing indium, gallium, tin, and zinc is preferably used. Alternatively, an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also called IAZO) is preferably used. Alternatively, an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also called IAGZO) is preferably used.

[0532] When using In-M-Zn oxide in a semiconductor layer, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. As the atomic ratios of the metal elements in such In-M-Zn oxide, there can be mentioned compositions such as In:M:Zn = 1:1:1 or in the vicinity thereof, In:M:Zn = 1:1:1.2 or in the vicinity thereof, In:M:Zn = 2:1:3 or in the vicinity thereof, In:M:Zn = 3:1:2 or in the vicinity thereof, In:M:Zn = 4:2:3 or in the vicinity thereof, In:M:Zn = 4:2:4.1 or in the vicinity thereof, In:M:Zn = 5:1:3 or in the vicinity thereof, In:M:Zn = 5:1:6 or in the vicinity thereof, In:M:Zn = 5:1:7 or in the vicinity thereof, In:M:Zn = 5:1:8 or in the vicinity thereof, In:M:Zn = 6:1:6 or in the vicinity thereof, In:M:Zn = 5:2:5 or in the vicinity thereof, etc. In addition, the vicinity of the composition includes a range of ±30% of the desired atomic ratio.

[0533] For example, when it is described that the composition has an atomic ratio of In:Ga:Zn = 4:2:3 or in the vicinity thereof, it includes the following cases: when the atomic ratio of In is 4, the atomic ratio of Ga is 1 or more and 3 or less, and the atomic ratio of Zn is 2 or more and 4 or less. In addition, when it is described that the composition has an atomic ratio of In:Ga:Zn = 5:1:6 or in the vicinity thereof, it includes the following cases: when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. In addition, when it is described that the composition has an atomic ratio of In:Ga:Zn = 1:1:1 or in the vicinity thereof, it includes the following cases: when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0534] The transistors included in circuit 356 and the transistors included in pixel section 177 may have the same structure or may have different structures. The multiple transistors included in circuit 356 may have the same structure or may have two or more different structures. Similarly, the multiple transistors included in pixel section 177 may have the same structure or may have two or more different structures.

[0535] All of the transistors included in pixel section 177 may be OS transistors, all of the transistors included in pixel section 177 may be Si transistors, or some of the transistors included in pixel section 177 may be OS transistors and the remaining transistors may be Si transistors.

[0536] For example, by using both LTPS transistors and OS transistors in the pixel portion 177, a light-emitting device having low power consumption and high driving ability can be realized. In addition, a structure combining LTPS transistors and OS transistors is sometimes referred to as LTPO. Further, for example, it is preferable that an OS transistor is used as a transistor serving as a switch for switching between an on state and an off state of a control wiring, and an LTPS transistor is used as a transistor for controlling current.

[0537] For example, one of the transistors included in the pixel portion 177 that is used as a transistor for controlling the current flowing through the light-emitting device may be referred to as a driving transistor. One of the source and drain of the driving transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor for the driving transistor. Thereby, the current flowing through the light-emitting device in the pixel circuit can be increased.

[0538] On the other hand, another one of the transistors included in the pixel portion 177 that is used as a switch for controlling selection and non-selection of a pixel may also be referred to as a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a source line (signal line). It is preferable to use an OS transistor for the selection transistor. Thereby, since the gray level of the pixel can be maintained even when the frame frequency is extremely small (for example, 1 fps or less), power consumption can be reduced by stopping the driver when displaying a static image.

[0539] In this way, the light-emitting device according to one embodiment of the present invention can have both a high aperture ratio, high definition, high display quality, and low power consumption.

[0540] Note that a light-emitting device according to one embodiment of the present invention employs a structure including an OS transistor and a light-emitting device having an MML (Metal MaskLess) structure. By adopting this structure, the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices (sometimes referred to as lateral leakage current, horizontal leakage current, or transverse leakage current) can be made extremely low. In addition, by adopting the above structure, when an image is displayed on the light-emitting device, a viewer can observe any one or more of the sharpness of the image, the sharpness of the image, high color saturation, and high contrast. In addition, by adopting a structure in which the leakage current that can flow through the transistor and the horizontal leakage current between the light-emitting devices are extremely low, display with extremely little light leakage (so-called black impurity) that can occur when displaying black can be performed.

[0541] In particular, when the above-described SBS structure is adopted in a light-emitting device having an MML structure, the layer provided between the light-emitting devices (for example, also referred to as an organic layer or a common layer shared by the light-emitting devices) is disconnected, whereby side leakage can be eliminated or made extremely small.

[0542] Figure 20B andFigure 20C Shows other structural examples of transistors.

[0543] The transistor 209 and the transistor 210 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n; a conductive layer 222a connected to one of the pair of low-resistance regions 231n; a conductive layer 222b connected to the other of the pair of low-resistance regions 231n; an insulating layer 225 serving as a gate insulating layer; a conductive layer 223 serving as a gate; and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is at least located between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0544] In Figure 20B In the example shown, in the transistor 209, the insulating layer 225 covers the top surface and the side surface of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215. One of the conductive layer 222a and the conductive layer 222b is used as a source electrode, and the other is used as a drain electrode.

[0545] On the other hand, in Figure 20C In the transistor 210 shown, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 and does not overlap with the low-resistance region 231n. For example, by processing the insulating layer 225 using the conductive layer 223 as a mask, the structure shown in Figure 20C can be formed. In Figure 20C , the insulating layer 215 covers the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are respectively connected to the low-resistance region 231n through openings in the insulating layer 215.

[0546] A connection portion 204 is provided in a region of the substrate 351 that does not overlap with the substrate 352. In the connection portion 204, a wiring 355 is electrically connected to the FPC 353 through the conductive layer 166 and the connection layer 242. The conductive layer 166 shows an example of a structure: a laminated film obtained by processing a conductive film identical to the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a laminated film obtained by processing a conductive film identical to the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a laminated film obtained by processing a conductive film identical to 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.

[0547] Preferably, a light-shielding layer 157 is provided on the surface of the substrate 351 on the side of the substrate 352. The light-shielding layer 157 can be provided in the regions between adjacent light-emitting devices (regions overlapping with the insulating layer 127), the connection portion 140, and the circuit 356. In addition, various optical members can be arranged outside the substrate 352.

[0548] The substrate 351 and the substrate 352 can use the materials that can be used for the substrate 120.

[0549] As the adhesive layer 142, the materials that can be used for the resin layer 122 can be used.

[0550] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film) or an anisotropic conductive paste (ACP: Anisotropic Conductive Paste) can be used.

[0551] [Light-emitting device 100H]

[0552] Figure 21 The main difference between the shown light-emitting device 100H and the light-emitting device 100A shown in FIG. 20 is that the former is a light-emitting device adopting a bottom-emission structure.

[0553] The light emitted by the light-emitting device is emitted to the side of the substrate 351. The substrate 351 preferably uses a material with high visible light transmittance. On the other hand, there is no limitation on the light transmittance of the material used for the substrate 352.

[0554] Preferably, a light-shielding layer 157 is formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 21 An example is shown in which a light-shielding layer 157 is provided on the substrate 351, an insulating layer 153 is provided on the light-shielding layer 157, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0555] The light-emitting device 130R includes a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0556] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0557] As the conductive layer 112R, the conductive layer 112B, the conductive layer 126R, the conductive layer 126B, the conductive layer 129R, and the conductive layer 129B, materials with high visible light transmittance are each used. As the common electrode 155, a material that reflects visible light is preferably used.

[0558] Note that although Figure 21 the light-emitting device 130G is not illustrated in

[0559] it is still provided. Figure 21 In addition, although

[0560] [Light-emitting device 100C]

[0561] Figure 22A The illustrated light-emitting device 100C is Figure 20A a modified example of the illustrated light-emitting device 100B, and the difference between the light-emitting device 100C and the light-emitting device 100B is that the former includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B.

[0562] In the light-emitting device 100C, 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 can be provided on the surface of the substrate 351 on the side of the substrate 352. The ends of the coloring layer 132R, the ends of the coloring layer 132G, and the ends of the coloring layer 132B can overlap the light-shielding layer 157.

[0563] In the light-emitting device 100C, 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. In addition, the light-emitting device 100C can 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.

[0564] Although Figure 20A , Figure 21 and Figure 22A illustrate examples in which the top surface of the layer 128 has a flat portion, there is no particular limitation on the shape of the layer 128. Figures 22B to 22D illustrates a modified example of the layer 128.

[0565] As Figure 22B and Figure 22D shown, the top surface of the layer 128 can have a shape that is concave in the center and its vicinity in cross-section, that is, a shape having a concave curved surface.

[0566] In addition, as Figure 22C shown, the top surface of the layer 128 can have a shape that is convex in the center and its vicinity in cross-section, that is, a shape having a convex curved surface.

[0567] In addition, the top surface of layer 128 may have one or both of a convex surface and a concave surface. In addition, there is no limit to the number of convex and concave surfaces on the top surface of layer 128, and it may be one or more.

[0568] In addition, the height of the top surface of layer 128 may be the same as or substantially the same as the height of the top surface of conductive layer 224R, or may be different. For example, the height of the top surface of layer 128 may be lower than or higher than the height of the top surface of conductive layer 224R.

[0569] Figure 22B This can also be said to be an example where layer 128 is received inside the concave portion formed in conductive layer 224R. On the other hand, as Figure 22D shown, layer 128 may also be formed in such a way that it exists outside the concave portion formed in conductive layer 224R, that is, formed in such a way that its top surface width is greater than that of the concave portion.

[0570] This embodiment can be appropriately combined with other embodiments. In addition, in this specification, when multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0571] (Embodiment 5)

[0572] In this embodiment, an electronic device of one aspect of the present invention will be described.

[0573] The electronic device of this embodiment includes a light-emitting device of one aspect of the present invention in a display unit. The light-emitting device of one aspect of the present invention has high reliability and is easily capable of high definition and high resolution. Therefore, it can be used for the display units of various electronic devices.

[0574] As electronic devices, for example, in addition to electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, large game machines such as pachinko machines, etc., digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, sound reproduction devices, etc. can also be cited.

[0575] In particular, since the light-emitting device of one aspect of the present invention can improve clarity, it can be appropriately used for electronic devices including relatively small display units. Examples of such electronic devices include watch-type and bracelet-type information terminal devices (wearable devices), wearable devices that can be worn on the head such as VR devices like head-mounted displays, glasses-type AR devices, and MR (Mixed Reality) devices.

[0576] One embodiment of the light-emitting device of the present invention preferably has an extremely high resolution such as HD (number of pixels: 1280×720), FHD (number of pixels: 1920×1080), WQHD (number of pixels: 2560×1440), WQXGA (number of pixels: 2560×1600), 4K (number of pixels: 3840×2160), 8K (number of pixels: 7680×4320), etc. In particular, it is preferably set to a resolution of 4K, 8K or higher. In addition, the pixel density (clarity) of the light-emitting device of one embodiment of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, further preferably 1000 ppi or more, still further preferably 2000 ppi or more, still further preferably 3000 ppi or more, yet further preferably 5000 ppi or more, and further preferably 7000 ppi or more. By using the above light-emitting device having one or both of high resolution and high clarity, the sense of reality and depth can be further enhanced in personal-use electronic devices such as portable or household devices. In addition, there is no particular limitation on the screen ratio (aspect ratio) of the light-emitting device of one embodiment of the present invention. For example, the light-emitting device can adapt to various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0577] The electronic device of this embodiment may also include a sensor (for example, the sensor has a function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light (including infrared rays), liquid, magnetism, temperature, chemical substances (including odor), sound, time, hardness, electric field, current, voltage, electric power, radiation, flow rate, humidity, inclination or vibration. Or, the sensor has a function of detecting or measuring odor or light, for example).

[0578] The electronic device of this embodiment can have various functions. For example, it can have the following functions: a function of displaying various information (for example, still images, moving images or text images) on the display unit; a function of a touch panel; a function of displaying a calendar, date or time, etc.; a function of executing various software (programs); a function of performing wireless communication; a function of reading out programs or data stored in a storage medium.

[0579] [Wearable device]

[0580] Use Figures 23A to 23DDescribe an example of a wearable device that can be worn on the head. These wearable devices have at least one of the functions of displaying AR content, displaying VR content, displaying SR (Substitutional Reality) content, and displaying MR content. When an electronic device has the function of displaying at least one of AR, VR, SR, and MR content, the immersion of the user can be enhanced.

[0581] Figure 23A The illustrated electronic device 700A and Figure 23B The illustrated electronic device 700B both include a pair of display panels 751, a pair of frames 721, a communication unit (not shown), a pair of mounting portions 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a bezel 757, and a pair of nose pads 758.

[0582] The display panel 751 can apply the light-emitting device of one aspect of the present invention. Thereby, an electronic device with high reliability can be realized.

[0583] Both the electronic device 700A and the electronic device 700B can project the image displayed by the display panel 751 onto the display area 756 in the optical member 753. Since the optical member 753 has translucency, the user can see the image displayed in the display area overlapping with the transmitted image seen through the optical member 753. Therefore, both the electronic device 700A and the electronic device 700B are electronic devices capable of performing AR display.

[0584] A camera capable of photographing the front can also be provided as the imaging unit on the electronic device 700A and the electronic device 700B. In addition, by providing an acceleration sensor such as a gyro sensor in the electronic device 700A and the electronic device 700B, the head orientation of the user can be detected and the image corresponding to the direction can be displayed on the display area 756.

[0585] The communication unit has a wireless communication device, and an image signal can be supplied through this wireless communication device, for example. In addition, instead of the wireless communication device or in addition to the wireless communication device, a connector capable of connecting a cable for supplying an image signal and a power potential can also be included.

[0586] In addition, the electronic device 700A and the electronic device 700B are provided with a battery, and can be charged in one or both of a wireless manner and a wired manner.

[0587] The housing 721 may also be provided with a touch sensor module. The touch sensor module has a function of detecting whether the outer surface of the housing 721 is touched. Through the touch sensor module, various processes can be executed by detecting a tap operation or a swipe operation of the user. For example, through a tap operation, processes such as temporary stop or reproduction of a moving image can be executed, and through a swipe operation, processes such as fast forward and rewind can be executed, etc. In addition, by providing a touch sensor module in each of the two housings 721, the operation range can be expanded.

[0588] As the touch sensor module, various touch sensors can be used. For example, various methods such as a capacitive method, a resistive film method, an infrared method, an electromagnetic induction method, a surface acoustic wave method, and an optical method can be adopted. In particular, it is preferable to apply a capacitive method or an optical method sensor to the touch sensor module.

[0589] When using an optical touch sensor, a photoelectric conversion device (also referred to as a photoelectric conversion element) can be used as a light receiving element. One or both of an inorganic semiconductor and an organic semiconductor can be used in the active layer of the photoelectric conversion device.

[0590] Figure 23C The illustrated electronic device 800A includes a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832 (not shown). In addition, similar to the electronic device 800A, Figure 23D The illustrated electronic device 800B includes a pair of display units 820 (not shown), a housing 821, a communication unit 822 (not shown), a pair of mounting units 823, a pair of imaging units 825 (not shown), and a pair of lenses 832.

[0591] The display unit 820 can apply a light emitting device according to one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0592] The display unit 820 is disposed at a position inside the housing 821 where it can be seen through the lens 832. In addition, by displaying different images on each of the pair of display units 820, three-dimensional display using parallax can be performed.

[0593] Both the electronic device 800A and the electronic device 800B can be referred to as VR-oriented electronic devices. A user wearing the electronic device 800A or the electronic device 800B can see the image displayed on the display unit 820 through the lens 832.

[0594] The electronic device 800A and the electronic device 800B preferably have a mechanism in which the left - right positions of the lens 832 and the display unit 820 can be adjusted so that the lens 832 and the display unit 820 are located at the most suitable positions according to the position of the user's eyes. In addition, it preferably has a mechanism in which the focus is adjusted by changing the distance between the lens 832 and the display unit 820.

[0595] The user can mount the electronic device 800A or the electronic device 800B on the head using the mounting part 823. Note that, for example, in Figure 23C the mounting part 823 has a shape like the temple of glasses (also called hinges or temple wires), but is not limited thereto. As long as the user can mount it, the mounting part 823 can have, for example, a helmet - type or band - type shape.

[0596] 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, multiple cameras can also be provided to be able to correspond to various perspectives such as telephoto and wide - angle.

[0597] Note that an example including the imaging unit 825 is shown here, and a distance measuring sensor (hereinafter, also called a detection unit) capable of measuring the distance to an object may be provided. In other words, the imaging unit 825 is one form of the detection unit. As the detection unit, for example, a distance image sensor such as an image sensor or a lidar (Light Detection and Ranging) can be used. By using the image acquired by the camera and the image acquired by the distance image sensor, more information can be obtained, and more accurate attitude operations can be achieved.

[0598] The electronic device 800A may also include a vibration mechanism used as a bone - conduction headphone. For example, any one or more of the display unit 820, the housing 821, and the mounting part 823 may adopt a structure including this vibration mechanism. Thereby, there is no need to separately provide audio devices such as over - the - ear headphones, earphones, or speakers, and only by mounting the electronic device 800A, the user can enjoy images and sounds.

[0599] The electronic device 800A and the electronic device 800B may also both include input terminals. For example, a cable for supplying video signals from a video output device, etc., and power for charging a battery provided in the electronic device can be connected to the input terminals.

[0600] The electronic device according to one aspect of the present invention may also have a function of wirelessly communicating with the headphone 750. The headphone 750 includes a communication unit (not shown) and has a wireless communication function. The headphone 750 can receive information (such as audio data) from the electronic device through the wireless communication function. For example,Figure 23A The illustrated electronic device 700A has a function of sending information to the earphone 750 through a wireless communication function. Additionally, for example Figure 23C The illustrated electronic device 800A has a function of sending information to the earphone 750 through a wireless communication function.

[0601] Additionally, the electronic device may also include an earphone unit. Figure 23B The illustrated electronic device 700B includes an earphone unit 727. For example, a structure in which the earphone unit 727 and the control unit are connected in a wired manner may be adopted. A part of the wiring connecting the earphone unit 727 and the control unit may also be disposed inside the housing 721 or the mounting portion 723.

[0602] Similarly, Figure 23D The illustrated electronic device 800B 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. A part of the wiring connecting the earphone unit 827 and the control unit 824 may also be disposed inside the housing 821 or the mounting portion 823. Additionally, the earphone unit 827 and the mounting portion 823 may also include magnets. Thus, the earphone unit 827 can be fixed to the mounting portion 823 by magnetic force, making storage easier, so it is preferable.

[0603] The electronic device may also include a sound output terminal capable of connecting to an earphone or a headset. Additionally, the electronic device may also include one or both of a sound input terminal and a sound input mechanism. As the sound input mechanism, for example, a sound collection device such as a microphone may be used. By providing the sound input mechanism to the electronic device, the electronic device can have the function of a so-called headset.

[0604] In this way, as the electronic device according to one aspect of the present invention, both the glasses type (electronic devices 700A and 700B) and the goggles type (electronic devices 800A and 800B) are preferable.

[0605] Additionally, the electronic device according to one aspect of the present invention can send information to the earphone in a wired or wireless manner.

[0606] [Portable Information Terminal]

[0607] Figure 24A The illustrated electronic device 6500 is a portable information terminal that can be used as a smartphone.

[0608] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508. The display unit 6502 has a touch panel function.

[0609] The display unit 6502 can use the light-emitting device of one aspect of the present invention. Thereby, an electronic device with high reliability can be realized.

[0610] Figure 24B It is a schematic cross-sectional view of one end of the microphone 6506 side including the housing 6501.

[0611] On the display surface side of the housing 6501, a protective member 6510 with light-transmitting properties is provided, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, and a battery 6518 are provided in the space surrounded by the housing 6501 and the protective member 6510.

[0612] 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).

[0613] In the area outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on the printed circuit board 6517.

[0614] The display panel 6511 can use the flexible display of one aspect of the present invention. Thereby, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, by folding a part of the display panel 6511 to provide a connection portion with the FPC 6515 on the back surface of the pixel portion, a narrow-bezel electronic device can be realized.

[0615] [Television device]

[0616] Figure 24C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a housing 7171. A structure in which the housing 7171 is supported by a bracket 7173 is shown here.

[0617] The display unit 7000 can use the light-emitting device of one aspect of the present invention. Thereby, an electronic device with high reliability can be realized.

[0618] It can be performed by using the operation switches provided in the housing 7171 and a separately provided remote controller 7151 Figure 24COperation of the television apparatus 7100 shown. Alternatively, a touch sensor may be provided in the display unit 7000, and the television apparatus 7100 may be operated by touching the display unit 7000 with a finger or the like. Further, a display unit for displaying data output from the remote controller 7151 may be provided in the remote controller 7151. By using the operation keys or the touch panel provided in the remote controller 7151, channel and volume operations can be performed, and operations on the image displayed on the display unit 7000 can be performed.

[0619] In addition, the television apparatus 7100 includes a receiver and a modem. General television broadcasts can be received by using the receiver. Further, by connecting to a communication network in a wired or wireless manner through the modem, one-way (from the sender to the receiver) or two-way (between the sender and the receiver or between the receivers) information communication can be performed.

[0620] [Personal computer]

[0621] Figure 24D An example of a notebook personal computer is shown. The notebook personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214. The display unit 7000 is assembled in the housing 7211.

[0622] The display unit 7000 may use a light-emitting device according to one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0623] [Digital signage]

[0624] Figure 24E and Figure 24F An example of digital signage is shown.

[0625] Figure 24E The digital signage 7300 shown includes a housing 7301, a display unit 7000, and a speaker 7303. In addition, it may include LED lights, operation keys (including a power switch or an operation switch), connection terminals, various sensors, and a microphone.

[0626] Figure 24F The digital signage 7400 provided on the cylindrical column 7401 is shown. The digital signage 7400 includes a display unit 7000 provided along the curved surface of the column 7401.

[0627] In Figure 24E and Figure 24F a light-emitting device according to one aspect of the present invention can be used for the display unit 7000. Thereby, a highly reliable electronic device can be realized.

[0628] The larger the display unit 7000 is, the more information can be provided at one time. The larger the display unit 7000 is, the more likely it is to attract people's attention. For example, it can improve the advertising effect.

[0629] By using the touch panel for the display unit 7000, not only can static images or dynamic images be displayed on the display unit 7000, but also the user can operate intuitively, so it is preferable. In addition, when used for providing information such as route information or traffic information, the usability can be improved through intuitive operations.

[0630] As Figure 24E and Figure 24F shown, the digital signage 7300 or the digital signage 7400 is preferably capable of being linked with an information terminal device 7311 such as a smartphone carried by the user or the information terminal device 7411 through wireless communication. For example, the advertisement information displayed on the display unit 7000 can be displayed on the screen of the information terminal device 7311 or the information terminal device 7411. In addition, by operating the information terminal device 7311 or the information terminal device 7411, the display of the display unit 7000 can be switched.

[0631] In addition, games can be executed on the digital signage 7300 or the digital signage 7400 with the screen of the information terminal device 7311 or the information terminal device 7411 as the operation unit (controller). Thus, an unspecified number of users can participate in the game simultaneously and enjoy the fun of the game.

[0632] [Wristwatch-type terminal]

[0633] Figure 25A is a diagram showing the appearance of a wristwatch-type information terminal 5900 which is an example of a wearable terminal. The information terminal 5900 includes a housing 5901, a display unit 5902, operation buttons 5903, a crown 5904, and a watch band 5905.

[0634] The display unit 5902 can apply the light-emitting device described in the above embodiment. Thus, functions such as a watch, a stopwatch, and a timer can be visually displayed on the display unit 5902.

[0635] In addition, the information terminal 5900 can be used as, for example, Figure 24A shown, an auxiliary tool for an electronic device 6500 such as a smartphone. For example, by enabling wireless communication between the information terminal 5900 and the electronic device 6500, emails received by the smartphone, notifications of SNS, etc. can also be displayed on the information terminal 5900.

[0636] [Camera]

[0637] Figure 25BThis is an external view of a camera 8000 equipped with a viewfinder 8100. The camera 8000 includes a housing 8001, a display unit 8002, operation buttons 8003, and a shutter button 8004. In addition, the camera 8000 is equipped with a detachable lens 8006. The viewfinder 8100 includes a housing 8101, a display unit 8102, and a button 8103.

[0638] In the camera 8000, the lens 8006 and the housing may also be formed integrally.

[0639] The camera 8000 can take pictures by pressing the shutter button 8004 or touching the display unit 80...

Claims

1. A light-emitting device including a light-emitting layer, a first layer, and a second layer between an anode and a cathode, Among them, wherein the light-emitting layer is included between the anode and the first layer, the second layer is included between the first layer and the cathode, the light-emitting layer contains a light-emitting substance, the first layer is a mixed layer containing a first organic compound and a second organic compound, the first organic compound has a strong basicity with a pKa of 8 or more, the second organic compound has electron-transporting properties, the LUMO energy level of the first organic compound is higher than that of the second organic compound, and the second layer contains a first hole-transporting organic compound and a first material having an acceptor property with respect to the first hole-transporting organic compound.

2. A light-emitting device including a light-emitting layer, a first layer, a second layer, and a third layer between an anode and a cathode, Among them, wherein the light-emitting layer is included between the anode and the first layer, the second layer is included between the first layer and the cathode, the third layer is included between the first layer and the second layer, the light-emitting layer contains a light-emitting substance, the first layer is a mixed layer containing a first organic compound and a second organic compound, the first organic compound has a strong basicity with a pKa of 8 or more, the second organic compound has electron-transporting properties, the LUMO energy level of the first organic compound is higher than that of the second organic compound, the second layer contains a first hole-transporting organic compound and a first material having an acceptor property with respect to the first hole-transporting organic compound, and the third layer contains a material having a LUMO energy level of -4.30 eV or more and -3.00 eV or less.

3. The light-emitting device according to claim 1 or 2, wherein the HOMO energy level of the first organic compound is higher than that of the second organic compound.

4. The light-emitting device according to claim 1 or 2, wherein the second layer is a mixed layer of the first hole-transporting organic compound and the first material.

5. The light-emitting device according to claim 1 or 2, wherein the second layer is a laminate of a layer containing the first hole-transporting organic compound and a layer containing the first material.

6. The light-emitting device according to claim 5, wherein a layer containing the first material and the cathode include a layer containing the first hole-transporting organic compound therebetween.

7. The light-emitting device according to claim 1 or 2, wherein the second layer is in contact with the cathode.

8. The light-emitting device according to claim 1 or 2, wherein the second organic compound has a π-deficient heteroaromatic ring.

9. The light-emitting device according to claim 1 or 2, wherein a fourth layer is included between the anode and the light-emitting layer, and the fourth layer contains a second hole-transporting organic compound and a second material having an acceptor property with respect to the second hole-transporting organic compound.

10. The light-emitting device according to claim 1 or 2, wherein the LUMO energy level of the first organic compound is 0.05 eV or more higher than that of the second organic compound.

11. The light-emitting device according to claim 1 or 2, The LUMO energy level of the first organic compound is 0.05 eV or more higher than that of the second organic compound, and the HOMO energy level of the first organic compound is 0.05 eV or more higher than that of the second organic compound.

12. The light-emitting device according to claim 1 or 2, wherein the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less.

13. The light-emitting device according to claim 1 or 2, wherein the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less, and the HOMO energy level of the first organic compound is -5.7 eV or more and -4.8 eV or less.

14. The light-emitting device according to claim 1 or 2, wherein the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less, and the LUMO energy level of the second organic compound is -3.25 eV or more and -2.50 eV or less.

15. The light-emitting device according to claim 1 or 2, wherein the LUMO energy level of the first organic compound is -2.50 eV or more and -1.00 eV or less, the LUMO energy level of the second organic compound is -3.25 eV or more and -2.50 eV or less, the HOMO energy level of the first organic compound is -5.7 eV or more and -4.8 eV or less, and the HOMO energy level of the second organic compound is -6.5 eV or more and -5.7 eV or less.

16. The light-emitting device according to claim 1 or 2, wherein the second organic compound is a basic material having an acidity coefficient pKa of 4 or more and 8 or less.

17. The light-emitting device according to claim 1 or 2, wherein the first organic compound does not have an electron-donating property to the second organic compound.

18. The light-emitting device according to claim 1 or 2, wherein the spin density of the mixed layer containing the first organic compound and the second organic compound is measured by electron spin resonance method to be 1×10 17 spins / cm 3 as follows.

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