Light emitting device, light emitting device, electronic device, and lighting device

Abstract

To provide a new light emitting device having excellent convenience, usefulness, or reliability.SOLUTION: A light emitting device includes a second electrode on a first electrode with an EL layer interposed therebetween, and the EL layer includes at least a light emitting layer, an electron transport layer, and an electron injection layer, and further includes the electron transport layer on the light emitting layer, an insulating layer in contact with the side surfaces of the light emitting layer and the electron transport layer, and an electron injection layer on the electron transport layer, and the electron injection layer is in contact with the electron transport layer and the insulating layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to a light-emitting device, a light-emitting apparatus, an electronic device, and a lighting apparatus.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. The technical field of one aspect of the invention disclosed herein relates to a product, method, or method of manufacture. Alternatively, one aspect of the present invention relates to a process, machine, manufacture, or composition of matter. More specifically, examples of the technical field of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, methods for driving them, or methods for manufacturing them. [Background technology]

[0003] A method for manufacturing an organic EL display that enables the formation of an emissive layer without using a fine metal mask is known. One example of such a method includes the steps of: depositing a first luminescent organic material containing a mixture of a host material and a dopant material on top of an electrode array including first and second pixel electrodes formed on top of an insulating substrate to form a first emissive layer as a continuous film extending over a display area including the electrode array; irradiating the portion of the first emissive layer located above the second pixel electrode with ultraviolet light without irradiating the portion of the first emissive layer located above the first pixel electrode with ultraviolet light; depositing a second luminescent organic material containing a mixture of a host material and a dopant material and different from the first luminescent organic material on top of the first emissive layer to form a second emissive layer as a continuous film extending over a display area; and forming a counter electrode on top of the second emissive layer (Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2012-160473 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] One aspect of the present invention aims to provide a novel light-emitting device that is superior in convenience, usefulness, or reliability. Another aspect of the present invention aims to provide a novel light-emitting apparatus that is superior in convenience, usefulness, or reliability. Another aspect of the present invention aims to provide a novel electronic device that is superior in convenience, usefulness, or reliability. Another aspect of the present invention aims to provide a novel lighting apparatus that is superior in convenience, usefulness, or reliability.

[0006] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other problems from the description in the specification, drawings, and claims. [Means for solving the problem]

[0007] One aspect of the present invention is a light-emitting device having a second electrode sandwiched between a first electrode and an EL layer, wherein the EL layer comprises at least a light-emitting layer, an electron transport layer, and an electron injection layer, the electron transport layer is on the light-emitting layer, an insulating layer is in contact with the sides of the light-emitting layer and the electron transport layer, and the electron injection layer is on the electron transport layer, the electron injection layer is in contact with the electron transport layer and the insulating layer.

[0008] Alternatively, one aspect of the present invention is a light-emitting device having a second electrode with an EL layer interposed therebetween on a first electrode, the EL layer having at least a hole injection layer, a light-emitting layer, an electron transport layer, and an electron injection layer, having a hole injection layer on the first electrode, having a light-emitting layer on the hole injection layer, having an electron transport layer on the light-emitting layer, having an insulating layer in contact with side surfaces of the hole injection layer, the light-emitting layer, and the electron transport layer, having an electron injection layer on the electron transport layer, and the electron injection layer being in contact with the electron transport layer and the insulating layer.

[0009] Also, in the light-emitting device having each of the above-described configurations, the electron injection layer may contain a composite material formed by mixing an organic compound and an electron donor, or a composite material formed by mixing an organic compound and any one of an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Group 5, Group 7, Group 9, Group 11, or Group 13 in the periodic table.

[0010] Also, one aspect of the present invention is a light-emitting device having the light-emitting device having each of the above-described configurations, a transistor, or a substrate.

[0011] Also, one aspect of the present invention is a light-emitting device having an adjacent first light-emitting device and a second light-emitting device, the first light-emitting device having a second electrode with a first EL layer interposed therebetween on a first electrode, the first EL layer having at least a first light-emitting layer, a first electron transport layer, and an electron injection layer, having a first electron transport layer on the first light-emitting layer, having a first insulating layer in contact with side surfaces of the first light-emitting layer and the first electron transport layer, having an electron injection layer on the first electron transport layer, the second light-emitting device having a second electrode with a second EL layer interposed therebetween on a third electrode, the second EL layer having at least a second light-emitting layer, a second electron transport layer, and an electron injection layer, having a second electron transport layer on the second light-emitting layer, having a second insulating layer in contact with side surfaces of the second light-emitting layer and the second electron transport layer, having an electron injection layer on the first electron transport layer and the second electron transport layer, and the electron injection layer being in contact with the first electron transport layer, the second electron transport layer, the first insulating layer, and the second insulating layer.

[0012] Furthermore, one aspect of the present invention comprises an adjacent first light-emitting device and a second light-emitting device, wherein the first light-emitting device has a second electrode sandwiching a first EL layer on a first electrode, the first EL layer comprises at least a first hole injection layer, a first light-emitting layer, a first electron transport layer, and an electron injection layer, the first electrode has a first hole injection layer, the first hole injection layer has a first light-emitting layer, the first light-emitting layer has a first electron transport layer, the first hole injection layer has a first insulating layer in contact with the sides of the first hole injection layer, the first light-emitting layer, and the first electron transport layer, and the first electron transport layer has an electron injection layer, the second light-emitting device comprises a third The light-emitting device has a second electrode sandwiched between two EL layers on an electrode, the second EL layer comprising at least a second hole injection layer, a second light-emitting layer, a second electron transport layer, and an electron injection layer, the third electrode having a second hole injection layer, the second light-emitting layer on the second hole injection layer, the second electron transport layer on the second light-emitting layer, a second insulating layer in contact with the sides of the second hole injection layer, the second light-emitting layer, and the second electron transport layer, and an electron injection layer on the first electron transport layer and the second electron transport layer, the electron injection layer in contact with the first electron transport layer, the second electron transport layer, the first insulating layer, and the second insulating layer.

[0013] In the light-emitting device with the above configuration, the second electrode may be located on the side surface of the first light-emitting layer and the second light-emitting layer via an electron injection layer.

[0014] Furthermore, in the light-emitting devices of the above configurations, the second electrode may be located on the side surfaces of the first electron transport layer and the second electron transport layer, and the first light-emitting layer and the second light-emitting layer, via an electron injection layer.

[0015] Furthermore, in the light-emitting devices of the above configurations, the electron injection layer may include a composite material made by mixing an organic compound with an electron donor, or a composite material made by mixing an organic compound with an alkali metal, alkaline earth metal, rare earth metal, or a metal belonging to Group 5, Group 7, Group 9, Group 11, or Group 13 of the periodic table.

[0016] Furthermore, one aspect of the present invention is an electronic device having the above-described light-emitting device, a sensor, an operation button, a speaker, or a microphone.

[0017] Furthermore, one aspect of the present invention is a lighting device having the above-described light-emitting device and a housing.

[0018] In the drawings attached to this specification, components are classified by function and shown as independent blocks in block diagrams. However, in reality, it is difficult to completely separate components by function, and a single component may be involved in multiple functions.

[0019] In this specification, the terms "source" and "drain" of a transistor are interchangeable depending on the transistor's polarity and the potential applied to each terminal. Generally, in an n-channel transistor, the terminal to which a low potential is applied is called the source, and the terminal to which a high potential is applied is called the drain. Similarly, in a p-channel transistor, the terminal to which a low potential is applied is called the drain, and the terminal to which a high potential is applied is called the source. For convenience, this specification sometimes describes the connection relationships of a transistor assuming that the source and drain are fixed, but in reality, the terms "source" and "drain" are interchangeable according to the potential relationship described above.

[0020] In this specification, the source of a transistor refers to the source region, which is part of the semiconductor film that functions as the active layer, or the source electrode connected to the semiconductor film. Similarly, the drain of a transistor refers to the drain region, which is part of the semiconductor film, or the drain electrode connected to the semiconductor film. The gate refers to the gate electrode.

[0021] In this specification, a state in which transistors are connected in series means, for example, a state in which only one source or drain of the first transistor is connected to only one source or drain of the second transistor. A state in which transistors are connected in parallel means a state in which one source or drain of the first transistor is connected to one source or drain of the second transistor, and the other source or drain of the first transistor is connected to the other source or drain of the second transistor.

[0022] In this specification, "connection" means an electrical connection, corresponding to a state in which current, voltage, or potential can be supplied or transmitted. Therefore, a connected state does not necessarily refer to a direct connection, but also includes a state indirectly connected through circuit elements such as wiring, resistors, diodes, and transistors, so that current, voltage, or potential can be supplied or transmitted.

[0023] In this specification, even when components that appear independent in a circuit diagram are connected, in reality, a single conductive film may combine the functions of multiple components, for example, when a portion of the wiring functions as an electrode. In this specification, "connection" includes such cases where a single conductive film combines the functions of multiple components.

[0024] Furthermore, in this specification, one of the first or second electrodes of the transistor refers to the source electrode, and the other refers to the drain electrode. [Effects of the Invention]

[0025] According to one aspect of the present invention, a novel light-emitting device with superior convenience, usefulness, or reliability can be provided. Furthermore, according to one aspect of the present invention, a novel light-emitting apparatus with superior convenience, usefulness, or reliability can be provided. Furthermore, according to one aspect of the present invention, a novel electronic device with superior convenience, usefulness, or reliability can be provided. Furthermore, according to one aspect of the present invention, a novel lighting apparatus with superior convenience, usefulness, or reliability can be provided.

[0026] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other effects from the description in the specification, drawings, and claims. [Brief explanation of the drawing]

[0027] [Figure 1] Figures 1(A) to 1(C) illustrate the configuration of a light-emitting device according to an embodiment. [Figure 2] Figures 2(A) to 2(E) illustrate the configuration of a light-emitting device according to an embodiment. [Figure 3] Figures 3(A) and 3(B) illustrate the configuration of a light-emitting device according to an embodiment. [Figure 4] Figures 4(A) and 4(B) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 5] Figures 5(A) to 5(C) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 6] Figures 6(A) to 6(C) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 7] Figures 7(A) and 7(B) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 8] Figure 8 is a diagram illustrating a light-emitting device according to an embodiment. [Figure 9]Figures 9(A) and 9(B) illustrate the light-emitting apparatus and light-emitting device according to the embodiment. [Figure 10] Figure 10 is a diagram illustrating a light-emitting device according to an embodiment. [Figure 11] Figures 11(A) to 11(C) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 12] Figures 12(A) and 12(B) illustrate a method for manufacturing a light-emitting device according to an embodiment. [Figure 13] Figure 13 is a diagram illustrating a light-emitting device according to an embodiment. [Figure 14] Figures 14(A) and 14(B) illustrate a light-emitting device according to an embodiment. [Figure 15] Figures 15(A) and 15(B) illustrate a light-emitting device according to an embodiment. [Figure 16] Figures 16(A) and 16(B) illustrate a light-emitting device according to an embodiment. [Figure 17] Figures 17(A) and 17(B) illustrate a light-emitting device according to an embodiment. [Figure 18] Figures 18(A) to 18(E) illustrate the electronic equipment according to the embodiment. [Figure 19] Figures 19(A) to 19(E) illustrate an electronic device according to an embodiment. [Figure 20] Figures 20(A) and 20(B) illustrate the electronic device according to the embodiment. [Figure 21] Figures 21(A) and 21(B) illustrate the electronic device according to the embodiment. [Figure 22] Figure 22 is a diagram illustrating an electronic device according to an embodiment. [Figure 23] Figure 23 shows the structure of the light-emitting devices used in Examples 1 to 4. [Figure 24]Figure 24 shows the luminance-current density characteristics of light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. [Figure 25] Figure 25 shows the luminance-voltage characteristics of light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. [Figure 26] Figure 26 shows the current efficiency-luminance characteristics of light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. [Figure 27] Figure 27 shows the current density-voltage characteristics of light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. [Figure 28] Figure 28 shows the blue index-luminance characteristics of light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. [Figure 29] Figure 29 shows the emission spectra of light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. [Figure 30] Figure 30 shows the reliability of light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. [Figure 31] Figure 31 shows the luminance-current density characteristics of light-emitting device 5 and reference light-emitting device 6. [Figure 32] Figure 32 shows the luminance-voltage characteristics of light-emitting device 5 and reference light-emitting device 6. [Figure 33] Figure 33 shows the current efficiency-luminance characteristics of light-emitting device 5 and reference light-emitting device 6. [Figure 34] Figure 34 shows the current density-voltage characteristics of light-emitting device 5 and reference light-emitting device 6. [Figure 35] Figure 35 shows the blue index-luminance characteristics of light-emitting device 5 and reference light-emitting device 6. [Figure 36] Figure 36 shows the emission spectra of light-emitting device 5 and reference light-emitting device 6. [Figure 37]Figure 37 shows the reliability of light-emitting device 5 and reference light-emitting device 6. [Figure 38] Figure 38 shows the luminance-current density characteristics of light-emitting device 7 and reference light-emitting device 8. [Figure 39] Figure 39 shows the luminance-voltage characteristics of light-emitting device 7 and reference light-emitting device 8. [Figure 40] Figure 40 shows the current efficiency-luminance characteristics of light-emitting device 7 and reference light-emitting device 8. [Figure 41] Figure 41 shows the current density-voltage characteristics of light-emitting device 7 and reference light-emitting device 8. [Figure 42] Figure 42 shows the emission spectra of light-emitting device 7 and reference light-emitting device 8. [Figure 43] Figure 43 shows the reliability of light-emitting device 7 and reference light-emitting device 8. [Figure 44] Figure 44 shows the luminance-current density characteristics of light-emitting device 9 and reference light-emitting device 10. [Figure 45] Figure 45 shows the luminance-voltage characteristics of light-emitting device 9 and reference light-emitting device 10. [Figure 46] Figure 46 shows the current efficiency-luminance characteristics of light-emitting device 9 and reference light-emitting device 10. [Figure 47] Figure 47 shows the current density-voltage characteristics of light-emitting device 9 and reference light-emitting device 10. [Figure 48] Figure 48 shows the emission spectra of light-emitting device 9 and reference light-emitting device 10. [Figure 49] Figure 49 shows the reliability of the light-emitting device 9 and the reference light-emitting device 10. [Figure 50] Figure 50 shows the luminance-current density characteristics of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Figure 51] Figure 51 shows the luminance-voltage characteristics of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Figure 52]Figure 52 shows the current efficiency-luminance characteristics of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Figure 53] Figure 53 shows the current density-voltage characteristics of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Figure 54] Figure 54 shows the power efficiency-luminance characteristics of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Figure 55] Figure 55 shows the external quantum efficiency-luminance characteristics of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Figure 56] Figure 56 shows the emission spectra of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Figure 57] Figure 57 shows the reliability of light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. [Modes for carrying out the invention]

[0028] Embodiments will be described in detail with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be interpreted as being limited to the contents of the embodiments shown below. In the configuration of the invention described below, the same reference numerals are used in common across different drawings for the same parts or parts having similar functions, and repeated descriptions are omitted.

[0029] (Embodiment 1) In this embodiment, the configuration of a light-emitting device and a display panel according to one aspect of the present invention will be described with reference to Figures 1 and 2.

[0030] Figures 1(A) to 1(C) are cross-sectional views illustrating a light-emitting device 100 according to one embodiment of the present invention.

[0031] As shown in Figures 1(A) to 1(C), the light-emitting device 100 includes a first electrode 101, a second electrode 102, and an EL layer 103. The first electrode 101 has a region that overlaps with the second electrode 102, and the EL layer 103 has a region sandwiched between the first electrode 101 and the second electrode 102. The EL layer 103 has a structure in which a hole injection / transport layer 104, a light-emitting layer 113, an electron transport layer 108, and an electron injection layer 109 are sequentially stacked on the first electrode 101.

[0032] The electron injection layer 109 is a layer for increasing the efficiency of electron injection from the second electrode 102. When comparing the work function value of the material used for the second electrode 102 with the LUMO level value of the material used for the electron injection layer 109, it is preferable to use a material in which the difference is small (0.5 eV or less). Therefore, the electron injection layer 109 can be made of lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), lithium oxide (LiO x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Rare earth metal compounds such as erbium fluoride (ErF3) can also be used. An electride may also be used in the electron injection layer 109. Examples of electrides include substances obtained by adding electrons to a mixed oxide of calcium and aluminum at a high concentration.

[0033] Furthermore, a composite material obtained by mixing an organic compound and an electron donor may be used in the electron injection layer 109. Such a composite material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent in transporting the generated electrons, and specifically, for example, an electron transport material (metal complex and heteroaromatic compound, etc.) used in the electron transport layer described later can be used. As the electron donor, any substance that exhibits electron-donating properties to the organic compound is acceptable. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides and alkaline earth metal oxides are also preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Furthermore, organic compounds such as tetrathiafulvalene (abbreviated as TTF) can also be used.

[0034] In addition, a composite material made by mixing an organic compound and a metal may be used for the electron injection layer 109. Preferably, the organic compound used has a LUMO (Lowest Unoccupied Molecular Orbital) level of -3.6 eV or higher and -2.3 eV or lower. Furthermore, a material having lone pairs of electrons is preferred.

[0035] Therefore, as the above organic compounds, materials having lone pairs of electrons, such as heterocyclic compounds having a pyridine skeleton, a diazine skeleton (pyrimidine, pyrazine, etc.), or a triazine skeleton, are preferred. Details of heterocyclic compounds having a pyridine skeleton, heterocyclic compounds having a diazine skeleton, and heterocyclic compounds having a triazine skeleton will be described later in this embodiment.

[0036] In composite materials formed by mixing organic compounds and metals, it is preferable to use transition metals belonging to Group 5, Group 7, Group 9, or Group 11 of the periodic table, and materials belonging to Group 13, such as Ag, Cu, Al, or In. In this case, the organic compound forms a partially occupied molecular orbital (SOMO) with the metal.

[0037] Furthermore, the electron injection layer 109 may have a multilayer structure. The multilayer structure may consist of multiple layers, some of which are different from each other, or it may consist of multiple layers, all of which are different from each other.

[0038] Details of the materials that can be used for the electron injection layer 109 will be described later in this embodiment.

[0039] Furthermore, materials that can be used as the first electrode 101, the second electrode 102, the hole injection / transport layer 104, the light-emitting layer 113, and the electron transport layer 108 will be described later in this embodiment. The electron transport layer 108 may have a laminated structure, and may also have a hole-blocking layer to block holes moving from the first electrode 101 side through the light-emitting layer 113 to the second electrode 102 side. As for the material forming the hole injection / transport layer 104, materials described later in this embodiment can be used as the hole injection layer and the hole transport layer. The hole injection / transport layer 104 may be formed as a single layer or as multiple layers. The hole injection layer and the hole transport layer may also be formed separately. Furthermore, the hole injection / transport layer 104 may consist of only one of the hole injection layer and the hole transport layer.

[0040] The electron injection layer 109 is part of the EL layer 103, but it may have a different shape from the other layers of the EL layer 103 (hole injection / transport layer 104, light-emitting layer 113, and electron transport layer 108). Normally, when some layers of the EL layer have a different shape from the other layers, the other layers may be exposed to the atmosphere during the manufacturing process, which may reduce the reliability and brightness of the light-emitting device. However, when the electron injection layer 109 has a different shape from the other layers, the possibility of exposure to the atmosphere during the manufacturing process arises after the electron transport layer 108 is formed on the upper surface of the light-emitting layer 113. Therefore, the hole injection / transport layer 104 and the light-emitting layer 113 are prevented from being exposed to the atmosphere, and the reduction in the reliability and brightness of the light-emitting device 100 can be suppressed. Accordingly, in the light-emitting device 100, the electron injection layer 109 can have a different shape from the other layers of the EL layer 103 (hole injection / transport layer 104, light-emitting layer 113, and electron transport layer 108).

[0041] Furthermore, if the electron transport layer 108 has multiple layers, even if the possibility of exposure to the atmosphere, etc., arises after some layers of the electron transport layer 108 have been formed but before the other layers of the electron transport layer 108 have been formed, it may be possible to suppress a decrease in the reliability and brightness of the light-emitting device 100.

[0042] Figures 1(B) and 1(C) show examples of light-emitting devices 100 in which the electron injection layer 109 has a different shape from the other layers of the EL layer 103 (hole injection / transport layer 104, light-emitting layer 113, and electron transport layer 108).

[0043] As shown in Figure 1(B), the electron injection layer 109 and the second electrode 102 can have different shapes from the hole injection / transport layer 104, the light-emitting layer 113, and the electron transport layer 108. Since the electron injection layer 109 and the second electrode 102 can be layers common to multiple light-emitting devices, the manufacturing process of the light-emitting device 100 can be simplified and throughput can be improved.

[0044] Furthermore, as shown in Figure 1(B), the light-emitting device 100 may have an insulating layer 107. The insulating layer 107 is in contact with a portion of the first electrode 101, the side surface of the hole injection / transport layer 104, the side surface of the light-emitting layer 113, and the side surface of the electron transport layer 108. The electron injection layer 109 is located on the side surface of the first electrode 101, the side surface of the hole injection / transport layer 104, the side surface of the light-emitting layer 113, and the side surface of the electron transport layer 108 via the insulating layer 107, and is also in contact with the upper surface of the electron transport layer 108 without the insulating layer 107. The second electrode 102 is located on the side of the hole injection / transport layer 104, the side of the light-emitting layer 113, and the side of the electron transport layer 108 via the insulating layer 107 and the electron injection layer 109, on the side of the first electrode 101 via the electron injection layer 109, and on the upper surface of the electron transport layer 108 via the electron injection layer 109. It can also be said that the insulating layer 107 is located between the side of the light-emitting layer 113 and the electron injection layer 109.

[0045] By configuring the second electrode 102 to be located on the side of the first electrode 101, the side of the hole injection / transport layer 104, the side of the light-emitting layer 113, and the side of the electron transport layer 108 via the insulating layer 107 and the electron injection layer 109, it is possible to prevent conductivity between the second electrode 102 and the hole injection / transport layer 104, and between the second electrode 102 and the first electrode 101.

[0046] While the insulating layer 107 is not strictly necessary to achieve the above effects, having the insulating layer 107 is preferable because it can protect the sides (or edges) of the hole injection / transport layer 104, the sides of the light-emitting layer 113, and the sides of the electron transport layer 108.

[0047] Furthermore, having an insulating layer 107 is preferable because it can further prevent conductivity between the second electrode 102 and the hole injection / transport layer 104, and between the second electrode 102 and the first electrode 101.

[0048] Therefore, various structures can be applied to the light-emitting device 100. For example, when arranging multiple light-emitting devices 100 in a row, the electron injection layers 109 and second electrodes 102 of adjacent light-emitting devices 100 can be connected to each other.

[0049] The materials that can be used as the insulating layer 107 will be described later in a subsequent embodiment.

[0050] Alternatively, as shown in Figure 1(C), the hole injection / transport layer 104 may be patterned first (even if only the hole injection layer is patterned), and then the light-emitting layer 113 and the electron transport layer 108 may be sequentially stacked to create a shape in which the hole injection / transport layer 104 is surrounded by the light-emitting layer 113. In this case, since the light-emitting layer 113 is in contact with the top and side surfaces of the hole injection / transport layer 104, the electron injection layer 109 is not in contact with the side surfaces of the hole injection / transport layer 104, but is in contact with the side surfaces of the first electrode 101, the side surfaces of the light-emitting layer 113, and the side surfaces of the electron transport layer 108. The second electrode 102 is located on the side surfaces of the light-emitting layer 113 and the side and top surfaces of the electron transport layer 108 via the electron injection layer 109.

[0051] By shaping the end of the hole injection / transport layer 104 so that it is surrounded by the light-emitting layer 113, electrical conductivity between the second electrode 102 and the hole injection / transport layer 104 can be prevented without providing an insulating layer 107.

[0052] Furthermore, one aspect of the present invention is not limited to the configurations shown in Figures 1(B) and 1(C). For example, if an insulating layer is provided between adjacent light-emitting devices, and the second electrode 102 and electron injection layer 109 are formed on the insulating layer, the second electrode 102 and electron injection layer 109 may not be located on some or all of the sides of the first electrode 101, the side of the hole injection / transport layer 104, the side of the light-emitting layer 113, and the side of the electron transport layer 108.

[0053] Note that the configuration of the light-emitting device according to one aspect of the present invention is not limited to the configuration shown in Figure 1. The basic structure of the light-emitting device will be explained using Figure 2.

[0054] ≪Basic Structure of Light-Emitting Devices≫ The basic structure of a light-emitting device will be described. Figure 2(A) shows a light-emitting device having an EL layer containing a light-emitting layer between a pair of electrodes. Specifically, it has a structure in which an EL layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0055] Furthermore, Figure 2(B) shows a light-emitting device with a stacked structure (tandem structure) having multiple (two layers in Figure 2(B)) EL layers (103a, 103b) between a pair of electrodes, and a charge generation layer 106 between the EL layers. Light-emitting devices with a tandem structure have low current stress and can realize highly reliable light-emitting devices.

[0056] The charge generation layer 106 has the function of injecting electrons into one EL layer (103a or 103b) and holes into the other EL layer (103b or 103a) when a potential difference is created between the first electrode 101 and the second electrode 102. Therefore, in Figure 2(B), when a voltage is applied to the first electrode 101 such that the potential is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into EL layer 103a and holes are injected into EL layer 103b.

[0057] Furthermore, from the viewpoint of light extraction efficiency, it is preferable that the charge generation layer 106 is transparent to visible light (specifically, the transmittance of visible light to the charge generation layer 106 is 40% or more). In addition, the charge generation layer 106 can function even if its conductivity is lower than that of the first electrode 101 and the second electrode 102.

[0058] Figure 2(C) shows the laminated structure of the EL layer 103 of a light-emitting device according to one embodiment of the present invention. In this case, the first electrode 101 functions as an anode and the second electrode 102 functions as a cathode. The EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially laminated on the first electrode 101. The light-emitting layer 113 may be a configuration in which multiple light-emitting layers of different emission colors are laminated. For example, a light-emitting layer containing a red light-emitting material, a light-emitting layer containing a green light-emitting material, and a light-emitting layer containing a blue light-emitting material may be laminated, or laminated via a layer having a carrier transport material. Alternatively, a combination of a light-emitting layer containing a yellow light-emitting material and a light-emitting layer containing a blue light-emitting material may be used. However, the laminated structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may be a structure in which multiple light-emitting layers of the same emission color are stacked. For example, a first light-emitting layer containing a blue light-emitting material and a second light-emitting layer containing a blue light-emitting material may be stacked, or a structure in which they are stacked via a layer having a carrier transport material. In the case of a structure in which multiple light-emitting layers of the same emission color are stacked, reliability can be increased compared to a single-layer structure. Also, even when there are multiple EL layers as in the tandem structure shown in Figure 2(B), each EL layer is stacked sequentially from the anode side as described above. Furthermore, if the first electrode 101 is the cathode and the second electrode 102 is the anode, the stacking order of the EL layer 103 is reversed. Specifically, on the first electrode 101, which is the cathode, 111 is an electron injection layer, 112 is an electron transport layer, 113 is a light-emitting layer, 114 is a hole transport layer, and 115 is a hole injection layer.

[0059] The light-emitting layers 113 contained in the EL layers (103, 103a, 103b) each contain a combination of light-emitting material and multiple materials as appropriate, and can be configured to produce fluorescence or phosphorescence that exhibits a desired emission color. Alternatively, the light-emitting layers 113 may be arranged in a laminated structure with different emission colors. In this case, the light-emitting material and other materials used in each laminated light-emitting layer may be different materials. Alternatively, a configuration may be used in which different emission colors can be obtained from multiple EL layers (103a, 103b) as shown in Figure 2(B). In this case as well, the light-emitting material and other materials used in each light-emitting layer may be different materials.

[0060] Furthermore, in a light-emitting device according to one aspect of the present invention, for example, by using a reflective electrode as the first electrode 101 shown in Figure 2(C) and a semi-transparent / semi-reflective electrode as the second electrode 102, and by using a micro-cavity structure, the light emitted from the light-emitting layer 113 contained in the EL layer 103 can be made to resonate between the two electrodes, thereby strengthening the light emitted from the second electrode 102.

[0061] Furthermore, if the first electrode 101 of the light-emitting device is a reflective electrode consisting of a laminated structure of a reflective conductive material and a translucent conductive material (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the optical distance (product of film thickness and refractive index) between the first electrode 101 and the second electrode 102 to be mλ / 2 (where m is an integer of 1 or more) or close to it, with respect to the wavelength λ of light obtained from the light-emitting layer 113.

[0062] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region of the light-emitting layer 113 where the desired light is obtained (light-emitting region), and the optical distance from the second electrode 102 to the region of the light-emitting layer 113 where the desired light is obtained (light-emitting region), so that they are (2m'+1)λ / 4 (where m' is an integer of 1 or more) or near that value. The light-emitting region referred to here is the region in the light-emitting layer 113 where holes and electrons recombine.

[0063] By performing such optical adjustments, the spectrum of specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, resulting in emission with good color purity.

[0064] However, in the above case, the optical distance between the first electrode 101 and the second electrode 102 can be precisely defined as the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. However, since it is difficult to precisely determine the reflective regions of the first electrode 101 and the second electrode 102, the above effects can be sufficiently obtained by assuming that any position on the first electrode 101 and the second electrode 102 is the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which the desired light is obtained can be precisely defined as the optical distance between the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which the desired light is obtained. However, since it is difficult to precisely determine the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which the desired light is obtained, the above effects can be sufficiently obtained by assuming that any position on the first electrode 101 is the reflective region and any position on the light-emitting layer from which the desired light is obtained is the light-emitting region.

[0065] The light-emitting device shown in Figure 2(D) is a light-emitting device having a tandem structure and a microcavity structure, which allows for the extraction of light of different wavelengths (monochromatic light) from each EL layer (103a, 103b). Therefore, color separation (e.g., RGB) to obtain different emission colors is unnecessary. Consequently, high resolution can be easily achieved. It can also be combined with a colored layer (color filter). Furthermore, it is possible to strengthen the emission intensity in the front direction at a specific wavelength, thereby reducing power consumption.

[0066] The light-emitting device shown in Figure 2(E) is an example of a tandem-structured light-emitting device shown in Figure 2(B). As shown in the figure, it has a structure in which three EL layers (103a, 103b, 103c) are stacked with charge generation layers (106a, 106b) in between. Each of the three EL layers (103a, 103b, 103c) has a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of each light-emitting layer can be freely combined. For example, light-emitting layer 113a can be blue, light-emitting layer 113b can be one or more of red, green, and yellow, and light-emitting layer 113c can be blue. Alternatively, light-emitting layer 113a can be red, light-emitting layer 113b can be one or more of blue, green, and yellow, and light-emitting layer 113c can be red.

[0067] In the light-emitting device according to one aspect of the present invention described above, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transparent / semi-reflective electrode). If the light-transmitting electrode is a transparent electrode, the transmittance of visible light of the transparent electrode shall be 40% or more. If it is a semi-transparent / semi-reflective electrode, the reflectance of visible light of the semi-transparent / semi-reflective electrode shall be 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, the resistivity of these electrodes shall be 1 × 10⁻⁶. -2 It is preferable to keep it below Ωcm.

[0068] Furthermore, in the light-emitting device according to one aspect of the present invention described above, if one of the first electrode 101 and the second electrode 102 is a reflective electrode (reflective electrode), the visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, the resistivity of this electrode is 1 × 10⁻⁶. -2 It is preferable to keep it below Ωcm.

[0069] ≪Specific structure of a light-emitting device≫ Next, a specific structure of a light-emitting device according to one aspect of the present invention will be described using Figure 2. Here, we will use Figure 2(D), which has a tandem structure, for the explanation. The same applies to the EL layer configuration for the light-emitting devices in Figures 2(A) and 2(C), which have a single structure. Furthermore, if the light-emitting device shown in Figure 2(D) has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transparent / semi-reflective electrode. Therefore, one or more desired electrode materials can be used and formed in a single layer or in a stacked configuration. The second electrode 102 is formed after the EL layer 103b is formed, by selecting a material in the same manner as described above.

[0070] <First electrode and second electrode> As materials for forming the first electrode 101 and the second electrode 102, any combination of the following materials can be used as long as the functions of both electrodes described above are met. For example, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, these include In-Sn oxide (also called ITO), In-Si-Sn oxide (also called ITSO), In-Zn oxide, and In-W-Zn oxide. In addition, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys containing these in appropriate combinations can also be used. In addition, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (for example, lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing these in appropriate combinations, as well as graphene and other materials can be used.

[0071] In the light-emitting device shown in Figure 2(D), when the first electrode 101 is the anode, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially laminated on the first electrode 101 by vacuum deposition. After the EL layer 103a and the charge generation layer 106 are formed, the hole injection layer 111b and the hole transport layer 112b of the EL layer 103b are similarly sequentially laminated on the charge generation layer 106.

[0072] <Hole injection layer> The hole injection layers (111, 111a, 111b) are layers that inject holes from the first electrode 101, which is the anode, and the charge generation layers (106, 106a, 106b) into the EL layers (103, 103a, 103b), and are layers that contain either or both an organic acceptor material and / or a material with high hole injection potential.

[0073] Organic acceptor materials are materials that can generate holes in an organic compound by separating its charge from other organic compounds whose LUMO level and HOMO level are close. Therefore, compounds having electron-withdrawing groups (e.g., halogen groups or cyano groups), such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives, can be used as organic acceptor materials. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile, etc. can be used. Furthermore, among organic acceptor materials, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple heteroatoms, such as HAT-CN, are particularly suitable because they have high acceptor properties and the film quality is stable with respect to heat. In addition, radialene derivatives having an electron-withdrawing group (especially a halogen group such as a fluoro group or a cyano group) [3] are also preferred because they have very high electron-accepting properties. Specifically, α,α',α''-1,2,3-cyclopropanetriylidenates[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenates[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenates[2,3,4,5,6-pentafluorobenzeneacetonitrile] can be used.

[0074] Furthermore, as materials with high hole injection potential, oxides of metals belonging to groups 4 through 8 of the periodic table (such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, and other transition metal oxides) can be used. Specifically, examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. In addition, phthalocyanine compounds such as phthalocyanine (abbreviated as H2Pc) or copper phthalocyanine (abbreviated as CuPc) can be used.

[0075] In addition to the above materials, the low molecular weight compounds 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), 1,3,5- Aromatic amine compounds such as tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

[0076] Furthermore, polymer compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can be used. Alternatively, polymer compounds to which acids such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviated as PAni / PSS) can be added can also be used.

[0077] Furthermore, as a material with high hole injection capabilities, a composite material containing a hole transport material and the aforementioned organic acceptor material (electron-accepting material) can also be used. In this case, electrons are extracted from the hole transport material by the organic acceptor material, generating holes in the hole injection layer 111, and these holes are injected into the light-emitting layer 113 via the hole transport layer 112. The hole injection layer 111 may be formed as a single layer of a composite material containing a hole transport material and an organic acceptor material (electron-accepting material), or it may be formed by laminating the hole transport material and the organic acceptor material (electron-accepting material) in separate layers.

[0078] Furthermore, for hole-transporting materials, the hole mobility at which the square root of the electric field strength [V / cm] is 600 is 1 × 10⁻⁶. -6 cm 2 A material having a hole mobility of / Vs or higher is preferred. However, any material that has higher hole transport than electron transport can be used.

[0079] As hole-transporting materials, materials with high hole-transporting properties such as π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, furan derivatives, or thiophene derivatives) and aromatic amines (compounds having an aromatic amine skeleton) are preferred.

[0080] Examples of the above-mentioned carbazole derivatives (compounds having a carbazole skeleton) include bicarbazole derivatives (e.g., 3,3'-bicarbazole derivatives) and aromatic amines having a carbazolyl group.

[0081] Furthermore, specific examples of the above-mentioned bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives) include 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP), 9,9'-bis(1,1'-biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviated as BisBPCz), 9,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviated as BismBPCz), 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviated as mBPCCBP), and 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as βNCCP).

[0082] Furthermore, examples of aromatic amines having the above-mentioned carbazolyl group include 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole-3-amine (abbreviated as PCBiF), and N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3- [9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl) Diphenylamine (abbreviation: PCBNBB), 4-phenyldiphenyl-(9-phenyl-9H-carbazole-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N,N',N''-tris(9-phenylcarbazole-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 9 ,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-Bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 3,[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-Bis[N-(4-diphenylaminophenyl)-N-(1 Examples include -naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N-[4-(9H-carbazole-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), and 4,4',4''-tris(carbazole-9-yl)triphenylamine (abbreviation: TCTA).

[0083] In addition to the above, other examples of carbazole derivatives include 3-[4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPPn), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviated as CzPA).

[0084] Furthermore, specific examples of the above-mentioned furan derivatives (compounds having a furan skeleton) include 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II).

[0085] Furthermore, specific examples of the above-mentioned thiophene derivatives (compounds having a thiophene skeleton) include 1,3,5-tri(dibenzothiophen-4-yl)-benzene (abbreviated as DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV).

[0086] Furthermore, the above aromatic amines specifically include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BPAFLP), and 4-phenyl-3 '-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9 ,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'-bifluorene (abbreviation: DPA2SF), 4,4',4''-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: m-MTDATA), N, N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 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-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenyl Min (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)na Phthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4' '-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris(1, 1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi(9H-fluorene)-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-bi Phenyl]-4-yl)-9,9'-spirobio[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis([1,1'-biphenyl]-4-yl)-9,9'-spirobio[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobio(9H-fluorene)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), N,N-bis(9,9-dimethyl-9H-fluoren-2- Examples include N,N-bis(9,9-dimethyl-9H-fluoren-4-amine), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-1-amine, etc.

[0087] In addition, polymer compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can be used as hole transport materials. Alternatively, polymer compounds to which acids such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (abbreviated as PAni / PSS) can be added can also be used.

[0088] However, the hole transport material is not limited to the above, and various known materials may be used as a hole transport material by combining one or more of them.

[0089] The hole injection layers (111, 111a, 111b) can be formed using various known film deposition methods, for example, by vacuum deposition.

[0090] <Hole transport layer> The hole transport layers (112, 112a, 112b) are layers that transport holes injected from the first electrode 101 by the hole injection layers (111, 111a, 111b) to the light-emitting layers (113, 113a, 113b, 113c). The hole transport layers (112, 112a, 112b) are layers containing a hole-transporting material. Therefore, the hole transport layers (112, 112a, 112b) can use the same hole-transporting material that can be used in the hole injection layers (111, 111a, 111b).

[0091] In one embodiment of the present invention, the same organic compound used in the hole transport layer (112, 112a, 112b) can be used in the light-emitting layer (113, 113a, 113b, 113c). Using the same organic compound in both the hole transport layer (112, 112a, 112b) and the light-emitting layer (113, 113a, 113b, 113c) is preferable because it allows for more efficient transport of holes from the hole transport layer (112, 112a, 112b) to the light-emitting layer (113, 113a, 113b, 113c).

[0092] <Luminous layer> The light-emitting layers (113, 113a, 113b, 113c) are layers containing a light-emitting material. The light-emitting material that can be used in the light-emitting layers (113, 113a, 113b, 113c) can be any material that exhibits a light-emitting color such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red. Furthermore, if there are multiple light-emitting layers, a configuration exhibiting different light-emitting colors can be achieved by using different light-emitting materials in each layer (for example, white light emission obtained by combining complementary light-emitting colors). Additionally, a laminated structure in which each light-emitting layer contains a different light-emitting material is also possible.

[0093] Furthermore, the light-emitting layers (113, 113a, 113b, 113c) may contain one or more types of organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0094] Furthermore, when multiple host materials are used in the light-emitting layer (113, 113a, 113b, 113c), it is preferable to use a material with a larger energy gap than the energy gaps of the existing guest material and the first host material as the newly added second host material. It is also preferable that the lowest singlet excitation energy level (S1 level) of the second host material is higher than the S1 level of the first host material, and that the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the guest material. Furthermore, it is preferable that the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the first host material. With this configuration, an excitation complex can be formed using two types of host materials. In order to efficiently form the excitation complex, it is particularly preferable to combine a compound that readily accepts holes (hole transport material) with a compound that readily accepts electrons (electron transport material). This configuration also enables the simultaneous achievement of high efficiency, low voltage, and long lifespan.

[0095] The organic compounds used as the host material (including the first and second host materials) can be hole-transporting materials that can be used in the aforementioned hole-transporting layers (112, 112a, 112b), or electron-transporting materials that can be used in the electron-transporting layers (114, 114a, 114b) described later, as long as they satisfy the conditions for being a host material used in the light-emitting layer. An excited complex composed of multiple types of organic compounds (the first and second host materials) may also be used. An excited complex (also called an exciplex) that forms an excited state with multiple types of organic compounds has an extremely small difference between the S1 and T1 levels and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy. Furthermore, as a combination of multiple types of organic compounds that form an excited complex, for example, it is preferable that one has a π-electron-deficient heteroaromatic ring and the other has a π-electron-rich heteroaromatic ring. Furthermore, as a combination for forming the excitation complex, one of the components may be a phosphorescent material such as an iridium, rhodium, or platinum-based organometallic complex, or a metal complex.

[0096] There are no particular limitations on the luminescent material that can be used in the luminescent layers (113, 113a, 113b, 113c). A luminescent material that converts singlet excitation energy into visible light emission, or a luminescent material that converts triplet excitation energy into visible light emission, can be used.

[0097] <<Luminescent material that converts singlet excitation energy into light emission>> Examples of luminescent materials that can be used in the light-emitting layers (113, 113a, 113b, 113c) to convert singlet excitation energy into light include the following fluorescent materials (fluorescent materials). For example, pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives are examples. Pyrene derivatives are particularly preferred because they have a high luminescence quantum yield. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6FrAPrn), N,N'-bis(dibenzothiophen-2-yl)-N, Examples include N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-02), and N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03).

[0098] Also, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-antryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole (9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'- (9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-phenyl-9-antryl)phenyl]-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPBA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenyl) Nilen)bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviated as DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviated as 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as 2DPAPPA), etc. can be used.

[0099] Also, N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl- 2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl DCM1)propanedinitrile, 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluorantene-3,10-diamine (p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-Bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), 1,6BnfAP Examples include rn-03, 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, pyrenediamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0100] <<Luminescent material that converts triplet excitation energy into light emission>> Next, examples of light-emitting materials that can be used in the light-emitting layer 113 to convert triplet excitation energy into light include phosphorescent materials (phosphorescent materials) or thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0101] A phosphorescent material is a compound that exhibits phosphorescence and does not fluoresce at any temperature range above low temperatures (e.g., 77K) and below room temperature (i.e., between 77K and 313K). The phosphorescent material preferably contains a metal element with strong spin-orbit interaction, and examples include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. Specifically, transition metal elements are preferred, and particularly platinum group elements (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) are preferred. The presence of iridium is especially preferable because it increases the transition probability involved in the direct transition between the singlet ground state and the triplet excited state.

[0102] ≪Phosphorescent materials (450nm to 570nm: blue or green)≫ Examples of phosphorescent materials that exhibit blue or green light and have a peak wavelength of emission spectrum between 450 nm and 570 nm include the following:

[0103] For example, Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazole-3-yl-κN 2Phenyl-κC iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPr5btz)3]), organometallic complexes having a 4H-triazole skeleton, tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), organometallic complexes having a 1H-triazole skeleton such as tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3]), organometallic complexes having an imidazole skeleton such as tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ Iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3’,5’-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’Examples include organometallic complexes that use phenylpyridine derivatives having electron-withdrawing groups as ligands, such as iridium(III) acetylacetonate (abbreviated as Fir(acac)).

[0104] ≪Phosphorescent materials (495nm to 590nm: green or yellow)≫ Examples of phosphorescent materials that exhibit a green or yellow color and have a peak wavelength of emission spectrum between 495 nm and 590 nm include the following:

[0105] For example, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert- (Ir(tBuppm)2(acac)) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) Organometallic iridium(III) with a pyrimidine skeleton, such as (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviation: [Ir(dmppm-dmp)2(acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]). iridium complexes having a pyrazine skeleton, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), and tris(2-phenylpyridinato-N,C) 2’ Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinate-N,C) 2’Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinate)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinate)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinate-N,C) 2’ Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C) 2’ iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-phenyl-2-pyridinyl-κN)phenyl-κC], iridium(III) (abbreviation: [Ir(ppy)2(4dppy)]), organometallic iridium complexes having a pyridine skeleton such as bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC], and bis(2,4-diphenyl-1,3-oxazolato-N,C 2’ Iridium(III) acetylacetonate (abbreviation: [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridinate-N,C 2’ Iridium(III) acetylacetonate (abbreviation: [Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolat-N,C) 2’ Examples include organometallic complexes such as iridium(III) acetylacetonate (abbreviated as [Ir(bt)2(acac)]), as well as rare earth metal complexes such as tris(acetylacetonate)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0106] ≪Phosphorescent materials (570nm to 750nm: yellow or red)≫ Examples of phosphorescent materials that exhibit a yellow or red color and have a peak wavelength of emission spectrum between 570 nm and 750 nm include the following:

[0107] For example, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), (dipivaloylmethanato)bis[4,6-di(naphthalene-1-yl)pyrimidinato]iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]), and other pyramidal compounds. Organometallic complexes having a limidine skeleton: (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ 2 O,O') Iridium(III) (abbreviation: [Ir(dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyradinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedionato-κ 2 O,O') Iridium(III) (abbreviation: [Ir(dmdppr-dmCP)2(dpm)]), bis[2-(5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN)-4,6-dimethylphenyl-κC](2,2',6,6'-tetramethyl-3,5-heptanedionato-κ 2 O,O') Iridium(III) (abbreviation: [Ir(dmdppr-dmp)2(dpm)]), (acetylacetonato)bis[2-methyl-3-phenylquinoxalinato-N,C 2’ Iridium(III) (abbreviation: [Ir(mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C) 2’Organometallic complexes with a pyrazine skeleton, such as iridium(III) (abbreviation: [Ir(dpq)2(acac)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), and tris(1-phenylisoquinolinato-N,C) 2’ Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C) 2’ Iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedionato-κ 2 Examples include organometallic complexes with a pyridine skeleton, such as O,O')iridium(III) (abbreviation: [Ir(dmpqn)2(acac)]), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: [PtOEP]), and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]) and tris[1-(2-tenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]).

[0108] ≪TADF material≫ Furthermore, the following materials can be used as TADF materials. A TADF material is a material in which the difference between the S1 level and the T1 level is small (preferably 0.2 eV or less), the triplet excited state can be upconverted to the singlet excited state with a small amount of thermal energy (reverse intersystem crossing), and the emission (fluorescence) from the singlet excited state is efficiently exhibited. Furthermore, conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited energy level and the singlet excited energy level being 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less. In addition, delayed fluorescence in TADF materials refers to emission that has a spectrum similar to normal fluorescence but with a remarkably long lifetime. Its lifetime is 1 × 10⁻⁶ -6 For more than a second, preferably 1 × 10⁻⁶ seconds. -3 It is more than a second.

[0109] Examples of TADF materials include fullerenes and their derivatives, acridine derivatives such as proflavin, and eosin. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) are also included. Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complexes (abbreviated as SnF2(Proto IX)), mesoporphyrin-tin fluoride complexes (abbreviated as SnF2(Meso IX)), hematoporphyrin-tin fluoride complexes (abbreviated as SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complexes (abbreviated as SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complexes (abbreviated as SnF2(OEP)), etioporphyrin-tin fluoride complexes (abbreviated as SnF2(Etio I)), and octaethylporphyrin-platinum chloride complexes (abbreviated as PtCl2OEP).

[0110] [ka]

[0111] Other examples include 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), and 2-[4-(10H-phenyl Noxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviation: ACRXTN), bis[4 -(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazole-9-yl)benzoflo[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl Heterocyclic compounds having π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings, such as -3,3'-bi-9H-carbazole-9-yl)phenyl]benzofl[3,2-d]pyrimidine (abbreviation: 4PCCzPBfpm) and 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), may also be used.

[0112] Furthermore, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferable because both the donor properties of the π-electron-rich heteroaromatic ring and the acceptor properties of the π-electron-deficient heteroaromatic ring become stronger, and the energy difference between the singlet excited state and the triplet excited state becomes smaller.

[0113] [ka]

[0114] In addition to the above, other materials that have the function of converting triplet excitation energy into light emission include nanostructures of transition metal compounds having a perovskite structure. Nanostructures of metal halogen perovskites are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0115] In the light-emitting layers (113, 113a, 113b, 113c), the organic compounds (host materials, etc.) used in combination with the light-emitting material (guest material) described above may be one or more materials having an energy gap larger than the energy gap of the light-emitting material (guest material).

[0116] ≪Host materials for fluorescence emission≫ When the light-emitting material used in the light-emitting layer (113, 113a, 113b, 113c) is a fluorescent light-emitting material, it is preferable to use an organic compound (host material) that has a large singlet excited state energy level and a small triplet excited state energy level, or an organic compound with a high fluorescence quantum yield. Therefore, any organic compound that satisfies these conditions can be used, such as the hole transport material (described above) and electron transport material (described below) shown in this embodiment.

[0117] Although some of these overlap with the specific examples mentioned above, from the perspective of preferred combinations with luminescent substances (fluorescent substances), examples of organic compounds (host materials) include condensed polycyclic aromatic compounds such as anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives.

[0118] Specific examples of organic compounds (host materials) that are preferable to use in combination with fluorescent luminescent substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviated as DPCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9,10-diphenylanthracene (abbreviated as DPAnth), and N,N-diphenyl-9-[ 4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), 6,12-dimethoxy-5, 11-Diphenylchrysene, N,N,N',N',N'',N'',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation) Name: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}anthracene (abbreviation: FLPPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,9'-biantryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviation: DPNS), 9,Examples include 9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviation: TPB3), 5,12-diphenyltetracene, and 5,12-bis(biphenyl-2-yl)tetracene.

[0119] ≪Host materials for phosphorescence≫ Furthermore, when the luminescent material used in the luminescent layers (113, 113a, 113b, 113c) is a phosphorescent material, it is sufficient to select an organic compound (host material) to combine with it that has a triplet excitation energy greater than the triplet excitation energy of the luminescent material (the energy difference between the ground state and the triplet excited state). When using multiple organic compounds (for example, a first host material and a second host material (or assist material), etc.) in combination with the luminescent material to form an excited complex, it is preferable to mix these multiple organic compounds with the phosphorescent material.

[0120] This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excited complex to the luminescent material. The combination of organic compounds should ideally be one that readily forms an excited complex, and a combination of a compound that readily accepts holes (hole transport material) and a compound that readily accepts electrons (electron transport material) is particularly preferable.

[0121] Although some of these overlap with the specific examples mentioned above, from the perspective of preferred combinations with luminescent substances (phosphorescent substances), examples of organic compounds (host materials, assist materials) include aromatic amines, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, zinc and aluminum-based metal complexes, oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, and the like.

[0122] Furthermore, among the above-mentioned organic compounds, specific examples of aromatic amines and carbazole derivatives, which are organic compounds with high hole transport properties, are the same as the specific examples of hole transport materials described above, and all of these are preferred as host materials.

[0123] Furthermore, among the above organic compounds, specific examples of dibenzothiophene derivatives and dibenzofuran derivatives, which are organic compounds with high hole transport properties, include 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), DBT3P-II, and 2,8-diphenyl Examples include nyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and 4-[3-(triphenylene-2-yl)phenyl]dibenzothiophene (abbreviated as mDBTPTp-II), all of which are preferred as host materials.

[0124] Furthermore, among the above, specific examples of metal complexes that are organic compounds (electron-transporting materials) with high electron transport properties include zinc-based or aluminum-based metal complexes such as tris(8-quinolinolato)aluminum(III) (abbreviated as Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviated as Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), as well as metal complexes having a quinoline skeleton or a benzoquinoline skeleton, all of which are preferred as host materials.

[0125] Other preferred host materials include metal complexes having oxazole-based or thiazole ligands such as bis[2-(2-benzoxazolyl)phenolate]zinc(II) (abbreviated as ZnPBO) and bis[2-(2-benzothiazolyl)phenolate]zinc(II) (abbreviated as ZnBTZ).

[0126] Furthermore, among the above organic compounds, specific examples of organic compounds with high electron transport properties (electron transport materials), such as oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, and phenanthroline derivatives, include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation: OXD-7), 9 -[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 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-methylbenzoxazole-2-yl)stilbene (abbreviation: BzOS), vasophenanthroline (abbreviation: Bphen), vasocuproin (abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: mPPhen2P), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTP) DBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,Examples include [h]quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), all of which are preferred as host materials.

[0127] Furthermore, among the above, specific examples of organic compounds with high electron transport properties (electron transport materials), such as heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a triazine skeleton, and heterocyclic compounds having a pyridine skeleton, include 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), and 2-{4-[3-(N-phenyl-9H- Examples include rubazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviated as mPCCzPTzn-02), 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviated as 35DCzPPy), and 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviated as TmPyPB), all of which are preferred as host materials.

[0128] Other polymer compounds such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) are also preferred as host materials.

[0129] Furthermore, bipolar 9-phenyl-9'-(4-phenyl-2-quinazolinyl)-3,3'-bi-9H-carbazol (abbreviated as PCCzQz), which is an organic compound with high hole transport and electron transport properties, can also be used as a host material.

[0130] <Electron transport layer> The electron transport layers (114, 114a, 114b) are layers that transport electrons injected from the second electrode 102 and the charge generation layers (106, 106a, 106b) by the electron injection layers (115, 115a, 115b), described later, to the light-emitting layers (113, 113a, 113b, 113c). The electron transport layers (114, 114a, 114b) are layers containing an electron-transporting material. The electron-transporting material used in the electron transport layers (114, 114a, 114b) has an electron mobility of 1 × 10⁻¹⁰ at an electric field strength [V / cm] square root of 600. -6 cm 2 Materials with an electron mobility of / Vs or higher are preferred. However, other materials can be used as long as they have higher electron transport capabilities than holes. In addition, although the electron transport layers (114, 114a, 114b) can function as single layers, device characteristics can be improved by creating a stacked structure of two or more layers as needed.

[0131] ≪Electron transport material≫ As electron transport materials that can be used in the electron transport layers (114, 114a, 114b), you can use materials with high electron transport properties (electron transport materials) such as organic compounds having a structure in which an aromatic ring is condensed on a furan ring of a phlodiazine skeleton, metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, etc., as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0132] Specific examples of electron transport materials include 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), and 2-{3-[3-(dibenzothiophen- 4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalene-2-yl)-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzoflo[2,3-b]pyrazine (abbreviation: 3,8mDBtP2B fpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 8-[3'-(dibenzothiophen-4-yl)(1,1'-biphenyl-3-yl)]naphtho To[1',2':4,5]flo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthalene)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,Examples include metal complexes having a quinoline or benzoquinoline skeleton, such as [2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), tris(8-quinolinolato)aluminum(III) (abbreviation: Alq3), Almq3, BeBq2, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq); and metal complexes having an oxazole or thiazole skeleton, such as bis[2-(2-benzoxazollyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0133] In addition to metal complexes, other derivatives include oxadiazole derivatives such as PBD, OXD-7, and CO11; triazole derivatives such as TAZ and p-EtTAZ; imidazole derivatives (including benzimidazole derivatives) such as TPBI and mDBTBIm-II; oxazole derivatives such as BzOS; phenanthroline derivatives such as Bphen, BCP, NBphen, and mPPhen2P; and 2mDBTPDBq-II, 2mDBTBPDBq-II, and 2mCzBPD. Quinoxaline derivatives or dibenzoquinoxaline derivatives such as Bq, 2CzPDBq-III, 7mDBTPDBq-II, and 6mDBTPDBq-II, pyridine derivatives such as 35DCzPPy and TmPyPB, pyrimidine derivatives such as 4,6mPnP2Pm, 4,6mDBTP2Pm-II, and 4,6mCzP2Pm, and triazine derivatives such as PCCzPTzn and mPCCzPTzn-02 can be used as electron transport materials.

[0134] Furthermore, polymer compounds such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) can also be used as electron transport materials.

[0135] Furthermore, the electron transport layers (114, 114a, 114b) may be not only single layers, but also have a structure in which two or more layers made of the above material are stacked.

[0136] <Electron injection layer> The electron injection layers (115, 115a, 115b) are layers containing a material with high electron injection capabilities. Furthermore, the electron injection layers (115, 115a, 115b) are layers for increasing the electron injection efficiency from the second electrode 102, and it is preferable to use a material in which the difference between the work function value of the material used for the second electrode 102 and the LUMO level value of the material used for the electron injection layers (115, 115a, 115b) is small (0.5 eV or less). Therefore, the electron injection layers (115, 115a, 115b) contain lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), and lithium oxide (LiO x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. Rare earth metal compounds such as erbium fluoride (ErF3) can also be used. Electrides may also be used in the electron injection layers (115, 115a, 115b). Examples of electrides include substances obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum. The materials that constitute the electron transport layers (114, 114a, 114b) described above can also be used.

[0137] Furthermore, a composite material obtained by mixing an organic compound with an electron donor may be used in the electron injection layers (115, 115a, 115b). Such a composite material exhibits excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material with excellent electron transport properties, and specifically, for example, electron transport materials (metal complexes and heteroaromatic compounds, etc.) used in the electron transport layers (114, 114a, 114b) described above can be used. The electron donor can be any substance that exhibits electron-donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides and alkaline earth metal oxides are also preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Furthermore, organic compounds such as tetrathiafulvalene (abbreviated as TTF) can also be used.

[0138] In addition, composite materials made by mixing an organic compound and a metal may be used for the electron injection layers (115, 115a, 115b). The organic compound used here preferably has a LUMO (Lowest Unoccupied Molecular Orbital) level of -3.6 eV or higher and -2.3 eV or lower. Furthermore, materials having lone pairs of electrons are preferred.

[0139] Therefore, as the above organic compounds, materials having lone pairs of electrons, such as heterocyclic compounds having a pyridine skeleton, a diazine skeleton (pyrimidine, pyrazine, etc.), or a triazine skeleton, are preferred.

[0140] Examples of heterocyclic compounds containing a pyridine skeleton include 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), vasocuproin (abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: mPPhen2P), and vasophenanthroline (abbreviation: Bphen).

[0141] Furthermore, heterocyclic compounds having a diazine skeleton include 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), and 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f, Examples include [h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), and 4-{3-[3'-(9H-carbazole-9-yl)]biphenyl-3-yl}benzoflo[3,2-d]pyrimidine (abbreviation: 4mCzBPBfpm).

[0142] Furthermore, examples of heterocyclic compounds having a triazine skeleton include 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz).

[0143] Furthermore, it is preferable to use transition metals belonging to Group 5, Group 7, Group 9, or Group 11 of the periodic table, and materials belonging to Group 13, such as Ag, Cu, Al, or In. In this case, the organic compound forms a half-occupied orbital (SOMO) with the transition metal.

[0144] For example, when amplifying the light obtained from the light-emitting layer 113b, it is preferable to form the optical distance between the second electrode 102 and the light-emitting layer 113b to be less than 1 / 4 of the wavelength λ of the light emitted by the light-emitting layer 113b. In this case, this can be adjusted by changing the film thickness of the electron transport layer 114b or the electron injection layer 115b.

[0145] Furthermore, as shown in the light-emitting device in Figure 2(D), by providing a charge generation layer 106 between two EL layers (103a, 103b), a structure in which multiple EL layers are stacked between a pair of electrodes (also called a tandem structure) can be created.

[0146] <Charge generation layer> The charge generation layer 106 has the function of injecting electrons into the EL layer 103a and holes into the EL layer 103b when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102. The charge generation layer 106 may be a configuration in which electron acceptors are added to a hole transport material (also called a P-type layer), or a configuration in which electron donors are added to an electron transport material (also called an electron injection buffer layer). Furthermore, both of these configurations may be stacked. In addition, an electron relay layer may be provided between the P-type layer and the electron injection buffer layer. By forming the charge generation layer 106 using the materials described above, it is possible to suppress the increase in driving voltage when the EL layers are stacked.

[0147] In the charge generation layer 106, when an electron acceptor is added to a hole-transporting material which is an organic compound (P-type layer), the material shown in this embodiment can be used as the hole-transporting material. Examples of electron acceptors include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, etc. Other examples include oxides of metals belonging to groups 4 to 8 of the periodic table. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The acceptor material mentioned above may also be used. Furthermore, the P-type layer may be used as a mixed film formed by mixing the hole-transporting material and the electron acceptor, or as a laminated film consisting of a single film containing the hole-transporting material and a single film containing the electron acceptor.

[0148] Furthermore, in the charge generation layer 106, if an electron donor is added to the electron transport material (electron injection buffer layer), the materials shown in this embodiment can be used as the electron transport material. As the electron donor, alkali metals, alkaline earth metals, rare earth metals, or metals belonging to groups 2 and 13 of the periodic table, as well as their oxides and carbonates, can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (Li2O), cesium carbonate, etc., are preferred. Organic compounds such as tetrathianaphthalene may also be used as electron donors.

[0149] In the charge generation layer 106, when an electron relay layer is provided between the P-type layer and the electron injection buffer layer, the electron relay layer contains at least an electron-transporting material and has the function of preventing interaction between the electron injection buffer layer and the P-type layer and smoothly transferring electrons. Preferably, the LUMO level of the electron-transporting material included in the electron relay layer is between the LUMO level of the acceptor material in the P-type layer and the LUMO level of the electron-transporting material included in the electron transport layer in contact with the charge generation layer 106. The specific energy level of the LUMO level of the electron-transporting material used in the electron relay layer is preferably -5.0 eV or higher, preferably -5.0 eV or higher and -3.0 eV or lower. Preferably, as the electron-transporting material used in the electron relay layer, a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand is used.

[0150] Although Figure 2(D) shows a configuration in which two EL layers 103 are stacked, a stacked structure of three or more EL layers may be used by providing a charge generation layer between different EL layers.

[0151] <Circuit board> The light-emitting device shown in this embodiment can be formed on various substrates. The type of substrate is not limited to any particular type. Examples of substrates include semiconductor substrates (e.g., single crystal substrates or silicon substrates), SOI substrates, glass substrates, quartz substrates, plastic substrates, metal substrates, stainless steel substrates, substrates with stainless steel foil, tungsten substrates, substrates with tungsten foil, flexible substrates, laminated films, paper containing fibrous materials, or base films.

[0152] Examples of glass substrates include barium borosilicate glass, aluminobrosilicate glass, or soda-lime glass. Examples of flexible substrates, laminated films, and base films include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), synthetic resins such as acrylic, polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride, polyamide, polyimide, aramid, epoxy, inorganic vapor-deposited films, or paper.

[0153] In this embodiment, the light-emitting device can be fabricated using vacuum processes such as vapor deposition, spin coating, and solution processes such as inkjet. When using vapor deposition, physical vapor deposition methods (PVD) such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, as well as chemical vapor deposition (CVD), can be used. In particular, the functional layers included in the EL layer of light-emitting devices (hole injection layers (111, 111a, 111b), hole transport layers (112, 112a, 112b), light-emitting layers (113, 113a, 113b, 113c), electron transport layers (114, 114a, 114b), electron injection layers (115, 115a, 115b)), and charge generation layers (106, 106a, 106b) can be formed by methods such as vapor deposition (vacuum deposition, etc.), coating (dip coating, die coating, bar coating, spin coating, spray coating, etc.), and printing (inkjet, screen printing, offset printing, flexographic printing, gravure, microcontact, etc.).

[0154] Furthermore, when applying the above-mentioned coating method, printing method, or other film formation method, polymer compounds (oligomers, dendrimers, polymers, etc.), medium-molecular-weight compounds (compounds in the intermediate region between low-molecular-weight and high-molecular-weight compounds: molecular weight 400 to 4000), inorganic compounds (quantum dot materials, etc.) can be used. As for quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core-type quantum dot materials, etc., can be used.

[0155] The functional layers (hole injection layers (111, 111a, 111b), hole transport layers (112, 112a, 112b), light-emitting layers (113, 113a, 113b, 113c), electron transport layers (114, 114a, 114b), electron injection layers (115, 115a, 115b)) and charge generation layers (106, 106a, 106b) that constitute the EL layer (103, 103a, 103b) of the light-emitting device shown in this embodiment are not limited to the materials shown in this embodiment, and other materials can be used in combination as long as they can satisfy the function of each layer.

[0156] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0157] (Embodiment 2) This embodiment describes a specific configuration example and manufacturing method of a light-emitting device (also called a display panel) which is one aspect of the present invention.

[0158] <Example of configuration of light-emitting device 700 1> The light-emitting device 700 shown in Figure 3(A) includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes a drive circuit GD composed of multiple transistors, a drive circuit SD, a pixel circuit, and wiring to electrically connect them. These drive circuits are electrically connected to the light-emitting devices 550B, 550G, and 550R, respectively, and can drive them. The light-emitting device 700 also includes an insulating layer 705 on the functional layer 520 and each light-emitting device, and the insulating layer 705 has the function of bonding the second substrate 770 to the functional layer 520. The drive circuits GD and SD will be described later in Embodiment 3.

[0159] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 1. In particular, Figure 2(A) shows a case where the EL layer 103 in the structure shown differs for each light-emitting device.

[0160] The light-emitting device 550B includes an electrode 551B, an electrode 552, an EL layer 103B, and an insulating layer 107B. The specific configuration of each layer is as shown in Embodiment 1. The EL layer 103B has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 3(A), only the hole injection / transport layer 104B, the light-emitting layer 113B, the electron transport layer 108B, and the electron injection layer 109 among the layers included in the EL layer 103B are shown, but the present invention is not limited to these. The hole injection / transport layer 104B refers to a layer having the functions of the hole injection layer and hole transport layer as shown in Embodiment 1, and may have a laminated structure. In this specification, the hole injection / transport layer can be interpreted in this way in any light-emitting device. The electron transport layer 108B may also have a laminated structure, and may have a hole blocking layer in contact with the light-emitting layer 113B for blocking holes moving from the anode side through the light-emitting layer to the cathode side. Furthermore, the electron injection layer 109 may also have a laminated structure formed using some or all different materials.

[0161] Furthermore, as shown in Figure 3(A), the insulating layer 107B is formed on the electrode 551B while leaving the resist formed on a portion of the EL layer 103B (in this embodiment, up to the electron transport layer 108B on the light-emitting layer 113B). Therefore, the insulating layer 107B is formed in contact with the side surface (or edge) of a portion of the EL layer 103B (as described above). This suppresses the penetration of oxygen, moisture, or their constituent elements into the interior from the side surface of the EL layer 103B. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulating layer 107B. Sputtering, CVD, MBE, PLD, ALD, etc. can be used to form the insulating layer 107B, but the ALD method, which has good coverage, is more preferable.

[0162] Furthermore, an electron injection layer 109 is formed covering a portion of the EL layer 103B (up to the electron transport layer 108B on the light-emitting layer 113B) and the insulating layer 107B. Preferably, the electron injection layer 109 has a laminated structure of two or more layers with different electrical resistances. For example, a first layer in contact with the electron transport layer 108B may be formed solely of an electron-transporting material, and a second layer made of an electron-transporting material containing a metal material may be laminated on top of it, or a third layer made of an electron-transporting material containing a metal material may be further laid between the first layer and the electron transport layer 108B.

[0163] Electrode 552 is formed on the electron injection layer 109. Electrode 551B and electrode 552 have overlapping regions. Furthermore, an EL layer 103B is present between electrode 551B and electrode 552. Therefore, the electron injection layer 109 is located on the side (or edge) of a portion of the EL layer 103B via the insulating layer 107B, or electrode 552 is located on the side (or edge) of a portion of the EL layer 103B via the electron injection layer 109 and the insulating layer 107B. This prevents electrical short circuits between the EL layer 103B and electrode 552, more specifically, between the hole injection / transport layer 104B of the EL layer 103B and electrode 552.

[0164] The EL layer 103B shown in Figure 3(A) has the same configuration as the EL layers 103, 103a, 103b, and 103c described in Embodiment 1. Furthermore, the EL layer 103B can emit, for example, blue light.

[0165] The light-emitting device 550G includes an electrode 551G, an electrode 552, an EL layer 103G, and an insulating layer 107G. The specific configuration of each layer is as shown in Embodiment 1. The EL layer 103G has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 3(A), only the hole injection / transport layer 104G, the light-emitting layer 113G, the electron transport layer 108G, and the electron injection layer 109 among the layers included in the EL layer 103G are shown, but the present invention is not limited to these. The hole injection / transport layer 104G refers to a layer having the functions of a hole injection layer and a hole transport layer as shown in Embodiment 1, and may have a laminated structure.

[0166] Furthermore, the electron transport layer 108G may have a multilayer structure, and may also have a hole-blocking layer in contact with the light-emitting layer 113G to block holes moving from the anode side through the light-emitting layer 113G to the cathode side. In addition, the electron injection layer 109 may also have a multilayer structure formed using some or all different materials.

[0167] Furthermore, as shown in Figure 3(A), the insulating layer 107G is formed on the electrode 551G while leaving the resist formed on a portion of the EL layer 103G (in this embodiment, up to the electron transport layer 108G on the light-emitting layer 113G). Therefore, the insulating layer 107G is formed in contact with the side surface (or edge) of a portion of the EL layer 103G (as described above). This suppresses the penetration of oxygen, moisture, or their constituent elements into the interior from the side surface of the EL layer 103G. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulating layer 107G. Sputtering, CVD, MBE, PLD, ALD, etc. can be used to form the insulating layer 107G, but the ALD method, which has good coverage, is more preferable.

[0168] Furthermore, an electron injection layer 109 is formed covering a portion of the EL layer 103G (up to the electron transport layer 108G on the light-emitting layer 113G) and the insulating layer 107G. Preferably, the electron injection layer 109 has a laminated structure of two or more layers with different electrical resistances. For example, a first layer in contact with the electron transport layer 108G may be formed solely of an electron-transporting material, and a second layer made of an electron-transporting material containing a metallic material may be laminated on top of it, or a third layer made of an electron-transporting material containing a metallic material may be further laid between the first layer and the electron transport layer 108G.

[0169] Furthermore, electrode 552 is formed on the electron injection layer 109. Electrode 551G and electrode 552 have overlapping regions. Additionally, an EL layer 103G is present between electrode 551G and electrode 552. Therefore, the electron injection layer 109 is located on the side (or edge) of a portion of the EL layer 103G via the insulating layer 107G, or electrode 552 is located on the side (or edge) of a portion of the EL layer 103G via the electron injection layer 109 and the insulating layer 107G. This prevents electrical short circuits between the EL layer 103G and electrode 552, or more specifically, between the hole injection / transport layer 104G of the EL layer 103G and electrode 552.

[0170] The EL layer 103G shown in Figure 3(A) has the same configuration as the EL layers 103, 103a, 103b, and 103c described in Embodiment 1. Furthermore, the EL layer 103G can emit, for example, green light.

[0171] The light-emitting device 550R includes an electrode 551R, an electrode 552, an EL layer 103R, and an insulating layer 107R. The specific configuration of each layer is as shown in Embodiment 1. The EL layer 103R has a laminated structure consisting of multiple layers with different functions, including the light-emitting layer. In Figure 3(A), only the hole injection / transport layer 104R, the light-emitting layer 113R, the electron transport layer 108R, and the electron injection layer 109 among the layers included in the EL layer 103R are shown, but the present invention is not limited to these. The hole injection / transport layer 104R refers to a layer having the functions of a hole injection layer and a hole transport layer as shown in Embodiment 1, and may have a laminated structure. In this specification, the hole injection / transport layer can be interpreted in this way in any light-emitting device. The electron transport layer 108R may also have a laminated structure, and may have a hole blocking layer in contact with the light-emitting layer to block holes moving from the anode side through the light-emitting layer to the cathode side. Furthermore, the electron injection layer 109 may also have a laminated structure formed using some or all different materials.

[0172] Furthermore, as shown in Figure 3(A), the insulating layer 107R is formed on the electrode 551R while leaving the resist formed on a portion of the EL layer 103R (in this embodiment, up to the electron transport layer 108R on the light-emitting layer 113R). Therefore, the insulating layer 107R is formed in contact with the side surface (or edge) of a portion of the EL layer 103R (as described above). This suppresses the penetration of oxygen, moisture, or their constituent elements into the interior from the side surface of the EL layer 103R. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulating layer 107R. Sputtering, CVD, MBE, PLD, ALD, etc. can be used to form the insulating layer 107R, but the ALD method, which has good coverage, is more preferable.

[0173] Furthermore, an electron injection layer 109 is formed covering a portion of the EL layer 103R (up to the electron transport layer 108R on the light-emitting layer 113R) and the insulating layer 107R. It is preferable that the electron injection layer 109 has a laminated structure of two or more layers with different electrical resistances. For example, a first layer in contact with the electron transport layer 108R may be formed solely of an electron-transporting material, and a second layer made of an electron-transporting material containing a metal material may be laminated on top of it. Alternatively, a third layer made of an electron-transporting material containing a metal material may be further laid between the first layer and the electron transport layer 108R.

[0174] Electrode 552 is formed on the electron injection layer 109. Electrode 551R and electrode 552 have overlapping regions. Furthermore, an EL layer 103R is present between electrode 551R and electrode 552. Therefore, the electron injection layer 109 is located on the side (or edge) of a portion of the EL layer 103R via the insulating layer 107R, or electrode 552 is located on the side (or edge) of a portion of the EL layer 103R via the electron injection layer 109 and the insulating layer 107R. This prevents electrical short circuits between the EL layer 103R and electrode 552, more specifically, between the hole injection / transport layer 104R of the EL layer 103R and electrode 552.

[0175] The EL layer 103R shown in Figure 3(A) has the same configuration as the EL layers 103, 103a, 103b, and 103c described in Embodiment 1. Furthermore, the EL layer 103R can emit, for example, red light.

[0176] A gap 580 is provided between each of the EL layers 103B, 103G, and 103R. In each EL layer, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Accordingly, by providing a gap 580 between each EL layer as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0177] In a high-resolution light-emitting device (display panel) with a resolution exceeding 1000 ppi, if electrical conductivity is detected between the EL layer 103B, EL layer 103G, and EL layer 103R, crosstalk occurs, narrowing the color gamut that the light-emitting device can display. By providing a gap 580 in a high-resolution display panel exceeding 1000 ppi, preferably a high-resolution display panel exceeding 2000 ppi, and more preferably an ultra-high-resolution display panel exceeding 5000 ppi, a display panel capable of displaying vivid colors can be provided.

[0178] Figure 3(B) is a top view in the XY direction of the light-emitting device shown in Figure 3(A), and the cross-sectional view at Y1-Y2 corresponds to Figure 3(A). As shown in Figure 3(B), the partition wall 528 has openings 528B, 528G, and 528R. As shown in Figure 3(A), opening 528B overlaps with electrode 551B, opening 528G overlaps with electrode 551G, and opening 528R overlaps with electrode 551R.

[0179] Furthermore, since the separation process of these EL layers (EL layer 103B, EL layer 103G, and EL layer 103R) is performed using photolithography to form patterns, a high-definition light-emitting device (display panel) can be manufactured. In addition, the edges (sides) of the EL layers (hole injection / transport layer, light-emitting layer, and electron transport layer) processed by pattern formation using photolithography have a shape that is substantially the same surface (or substantially located on the same plane). At this time, the gap 580 provided between each EL layer is preferably 5 μm or less, and more preferably 1 μm or less.

[0180] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using a pattern formation method with photolithography, as shown in this example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0181] <Example 1 of a manufacturing method for a light-emitting device> As shown in Figure 4(A), electrodes 551B, 551G, and 551R are formed. For example, a conductive film is formed on a functional layer 520 formed on the first substrate 510, and then processed into a predetermined shape using photolithography.

[0182] Conductive films can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD). CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0183] In addition to the photolithography method described above, conductive films may also be processed using nanoimprint lithography, sandblasting, lift-off lithography, or other methods. Furthermore, island-shaped thin films may be directly formed using a film deposition method that utilizes a shielding mask such as a metal mask.

[0184] There are two main processing methods using photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means to remove the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0185] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other options include ultraviolet light, KrF laser light, or ArF laser light. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of light for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0186] For etching thin films using a resist mask, methods such as dry etching, wet etching, and sandblasting can be used.

[0187] Next, as shown in Figure 4(B), partition walls 528 are formed between electrodes 551B, 551G, and 551R. For example, these can be formed by creating an insulating film covering electrodes 551B, 551G, and 551R, creating an opening using photolithography, and exposing a portion of electrodes 551B, 551G, and 551R. Materials that can be used for the partition walls 528 include inorganic materials, organic materials, or composite materials of inorganic and organic materials. Specifically, inorganic oxide films, inorganic nitride films, or inorganic oxidoxide-nitride films, or laminated materials made by laminating a plurality of these selected materials, or more specifically, silicon oxide films, films containing acrylic, or films containing polyimide, or laminated materials made by laminating a plurality of these selected materials can be used.

[0188] Next, as shown in Figure 5(A), a hole injection / transport layer 104B, an emissive layer 113B, and an electron transport layer 108B are formed on electrodes 551B, 551G, 551R, and the partition wall 528. For example, a vacuum deposition method is used to form the hole injection / transport layer 104B, the emissive layer 113B, and the electron transport layer 108B on electrodes 551B, 551G, 551R, and the partition wall 528, covering them.

[0189] Next, as shown in Figure 5(B), the hole injection / transport layer 104B, light-emitting layer 113B, and electron transport layer 108B on electrode 551B are processed into a predetermined shape. For example, a resist is formed using photolithography, and the hole injection / transport layer 104B, light-emitting layer 113B, and electron transport layer 108B on electrode 551G and the hole injection / transport layer 104B, light-emitting layer 113B, and electron transport layer 108B on electrode 551R are removed by etching to create a shape with sides (or with exposed sides), in other words, a strip shape extending in the direction intersecting the plane of the paper (X-axis direction). Specifically, dry etching is performed using the resist REG formed on the hole injection / transport layer 104B, light-emitting layer 113B, and electron transport layer 108B that overlap with electrode 551B (see Figure 5(B)). The partition wall 528 can be used as an etching stopper.

[0190] Next, as shown in Figure 5(C), with the resist REG formed, the hole injection / transport layer 104G, the light-emitting layer 113G, and the electron transport layer 108G are formed on the resist REG, electrode 551G, electrode 551R, and partition wall 528. For example, using a vacuum deposition method, the hole injection / transport layer 104G, the light-emitting layer 113G, and the electron transport layer 108G are formed on the electrode 551G, electrode 551R, and partition wall 528 so as to cover them.

[0191] Next, as shown in Figure 6(A), the hole injection / transport layer 104G, light-emitting layer 113G, and electron transport layer 108G on electrode 551G are processed into a predetermined shape. For example, a resist is formed on the hole injection / transport layer 104G, light-emitting layer 113G, and electron transport layer 108G on electrode 551G using photolithography, and the hole injection / transport layer 104G, light-emitting layer 113G, and electron transport layer 108G on electrode 551B and on electrode 551R are removed by etching to create a shape with sides (or with exposed sides), in other words, a strip shape extending in the direction intersecting the plane of the paper (X-axis direction). Specifically, dry etching is performed using the resist REG formed on the hole injection / transport layer 104G, light-emitting layer 113G, and electron transport layer 108G that overlap with electrode 551G. Furthermore, bulkhead 528 can be used as an etching stopper.

[0192] Next, as shown in Figure 6(B), with the resist REG formed on electrodes 551B and 551G, the hole injection / transport layer 104R, the light-emitting layer 113R, and the electron transport layer 108R are formed on the resist REG, electrode 551R, and partition wall 528. For example, using a vacuum deposition method, the hole injection / transport layer 104R, the light-emitting layer 113R, and the electron transport layer 108R are formed on electrode 551R, resist REG, and partition wall 528 so as to cover them.

[0193] Next, as shown in Figure 6(C), the hole injection / transport layer 104R, light-emitting layer 113R, and electron transport layer 108R on electrode 551R are processed into a predetermined shape. For example, a resist is formed on the hole injection / transport layer 104R, light-emitting layer 113R, and electron transport layer 108R on electrode 551R using photolithography, and the hole injection / transport layer 104R, light-emitting layer 113R, and electron transport layer 108R on electrode 551B and on electrode 551G are removed by etching to process them into a shape with sides (or with exposed sides), in other words, a strip shape extending in the direction intersecting the plane of the paper (X-axis direction). Specifically, dry etching is performed using the resist REG formed on the hole injection / transport layer 104R, light-emitting layer 113R, and electron transport layer 108R that overlap with electrode 551R. Furthermore, bulkhead 528 can be used as an etching stopper.

[0194] As shown in Figures 5(A), 5(B), 5(C), 6(A), 6(B), and 6(C), it is preferable to first form the hole injection / transport layer 104B, the light-emitting layer 113B, and the electron transport layer 108B on electrode 551B, then form the hole injection / transport layer 104G, the light-emitting layer 113G, and the electron transport layer 108G on electrode 551G, and finally form the hole injection / transport layer 104R, the light-emitting layer 113R, and the electron transport layer 108R on electrode 551R.

[0195] In the process described above, when the hole injection / transport layer 104B, light-emitting layer 113B, and electron transport layer 108B on electrode 551G and the hole injection / transport layer 104B, light-emitting layer 113B, and electron transport layer 108B on electrode 551R are removed by etching, the surfaces of electrodes 551G and 551R are exposed to etching gas. Also, when the hole injection / transport layer 104G, light-emitting layer 113G, and electron transport layer 108G on electrode 551R are removed by etching, the surface of electrode 551R is exposed to etching gas. Therefore, the surface of electrode 551B is not exposed to etching gas, but the surface of electrode 551G is exposed to etching gas once, and the surface of electrode 551R is exposed to etching gas twice.

[0196] Exposure of the electrode surface to etching gas can cause damage to the electrode surface. Furthermore, using electrodes with damaged surfaces to form a light-emitting device can degrade the characteristics of the device. The degree to which the electrode surface condition affects the characteristics of the light-emitting device depends on the structure of the device and the materials used. Comparing light-emitting devices 550B, 550G, and 550R, the electrode surface condition is most susceptible to damage in the case of light-emitting device 550B.

[0197] In this case, by first forming the hole injection / transport layer 104B, the light-emitting layer 113B, and the electron transport layer 108B on the electrode 551B, it is possible to prevent the surface of the electrode 551B from being exposed to etching gas and to prevent deterioration of the characteristics of the light-emitting device 550B, which is most susceptible to the effects of the electrode surface condition.

[0198] Next, an insulating layer 107 is formed on the resist REG, hole injection / transport layer 104B, light-emitting layer 113B, electron transport layer 108B, hole injection / transport layer 104G, light-emitting layer 113G, electron transport layer 108G, hole injection / transport layer 104R, light-emitting layer 113R, electron transport layer 108R, and partition wall 528. For example, using the ALD method, an insulating layer 107 is formed on the resist REG, hole injection / transport layer 104B, light-emitting layer 113B, electron transport layer 108B, hole injection / transport layer 104G, light-emitting layer 113G, electron transport layer 108G, hole injection / transport layer 104R, light-emitting layer 113R, electron transport layer 108R, and partition wall 528 so as to cover them. In this case, the insulating layer 107 is formed in contact with the sides of the hole injection / transport layer 104B, the light-emitting layer 113B, the electron transport layer 108B, the hole injection / transport layer 104G, the light-emitting layer 113G, the electron transport layer 108G, the hole injection / transport layer 104R, the light-emitting layer 113R, and the electron transport layer 108R, as shown in Figure 6(C). This prevents the intrusion of oxygen, moisture, or their constituent elements into the interior from the sides of the hole injection / transport layer 104B, the light-emitting layer 113B, the electron transport layer 108B, the hole injection / transport layer 104G, the light-emitting layer 113G, the electron transport layer 108G, the hole injection / transport layer 104R, the light-emitting layer 113R, and the electron transport layer 108R. As for the material used for the insulating layer 107, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used.

[0199] Next, as shown in Figure 7(A), the resist REG is removed to form an electron injection layer 109 on the insulating layer (107B, 107G, 107R) and the electron transport layer (108B, 108G, 108R). The electron injection layer 109 is formed, for example, by vacuum deposition. The electron injection layer 109 has a structure in which it is located on the side of some of the layers of each EL layer (103B, 103G, 103R) via the insulating layer (107B, 107G, 107R) (however, this includes the hole injection / transport layer (104R, 104G, 104B), the light-emitting layer (113B, 113G, 113R), and the electron transport layer (108B, 108G, 108R)).

[0200] Next, as shown in Figure 7(B), electrodes 552 are formed. Electrodes 552 are formed, for example, using a vacuum deposition method. The electrodes 552 are formed on the electron injection layer 109. The electrodes 552 have a structure located on the side (or edge) of some of the layers of each EL layer (103B, 103G, 103R) (including hole injection / transport layers (104R, 104G, 104B), light-emitting layers (113B, 113G, 113R), and electron transport layers (108B, 108G, 108R)) via the electron injection layer 109 and insulating layers (107B, 107G, 107R). This prevents electrical short circuits between each EL layer (103B, 103G, 103R) and the electrode 552, or more specifically, between the hole injection / transport layers (104B, 104G, 104R) of each EL layer (103B, 103G, 103R) and the electrode 552.

[0201] Through the above process, the EL layers 103B, 103G, and 103R of the light-emitting devices 550B, 550G, and 550R can be separated.

[0202] Furthermore, since the separation process of these EL layers (EL layer 103B, EL layer 103G, and EL layer 103R) is performed using photolithography to form patterns, high-resolution light-emitting devices (display panels) can be manufactured. In addition, the edges (sides) of the EL layers (hole injection / transport layer, light-emitting layer, and electron transport layer) processed by pattern formation using photolithography have a shape that is substantially the same surface (or is substantially located on the same plane).

[0203] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using a pattern formation method with photolithography, as shown in this example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0204] <Example 2 of the configuration of the light-emitting device 700> The light-emitting device 700 shown in Figure 8 includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes drive circuits GD and SD, each composed of multiple transistors, as well as wiring to electrically connect them. These drive circuits are electrically connected to the light-emitting devices 550B, 550G, and 550R, respectively, and can drive them.

[0205] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 1. In particular, Figure 2(A) shows a case where the EL layer 103 in the structure shown differs for each light-emitting device.

[0206] The specific configurations of each light-emitting device shown in Figure 8 are the same as those of light-emitting devices 550B, 550G, and 550R described in Figure 3.

[0207] As shown in Figure 8, the hole injection / transport layers (104B, 104G, 104R) of the EL layers (103B, 103G, 103R) of each light-emitting device (550B, 550G, 550R) are smaller than the other functional layers that make up the EL layer (103B, 103G, 103R) and have a structure covered by the stacked functional layers.

[0208] In this configuration, the hole injection and transport layers (104B, 104G, 104R) in each EL layer are completely isolated by being covered with other functional layers. Therefore, the insulating layer 107 shown in Configuration Example 1 (see Figure 3(A)) is unnecessary to prevent short circuits with the electrode 552.

[0209] Furthermore, since each EL layer in this configuration (EL layer 103B, EL layer 103G, and EL layer 103R) is patterned using photolithography during the separation process, the edges (sides) of the processed EL layers (light-emitting layer and electron transport layer) have a shape in which they are substantially the same surface (or are located substantially on the same plane).

[0210] In EL layers, the hole injection layer, particularly the hole transport region located between the anode and the light-emitting layer, often has high conductivity. Therefore, if it is formed as a common layer for adjacent light-emitting devices, it can cause crosstalk. Consequently, by separating the EL layer using a pattern formation method with photolithography, as shown in this example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0211] In this specification, devices fabricated using a metal mask or an FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or an FMM may be referred to as MML (Metal Maskless) structured devices.

[0212] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (for example, a color filter) to realize a full-color display device.

[0213] Furthermore, light-emitting devices can be broadly classified into single-structure and tandem-structure devices. In a single-structure device, it is preferable that there is one EL layer between a pair of electrodes, and that this EL layer includes one or more light-emitting layers. To obtain white light emission, it is sufficient to select light-emitting layers such that the light emitted from each of the two or more layers is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary, a configuration that emits white light as a whole can be obtained. The same applies to light-emitting devices having three or more light-emitting layers.

[0214] A tandem device preferably has two or more EL layers between a pair of electrodes, and each EL layer preferably includes one or more light-emitting layers. To obtain white light emission, the device should be configured such that the light from the light-emitting layers of the multiple EL layers is combined to produce white light emission. The configuration for obtaining white light emission is the same as that for a single structure. In a tandem device, it is preferable to provide intermediate layers, such as charge-generating layers, between the multiple EL layers.

[0215] Furthermore, when comparing the aforementioned white light-emitting devices (single or tandem structure) with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. If you want to keep power consumption low, it is preferable to use SBS structure light-emitting devices. On the other hand, white light-emitting devices are preferable because their manufacturing process is simpler than that of SBS structure light-emitting devices, which can lead to lower manufacturing costs or higher manufacturing yields.

[0216] <Example 3 of the configuration of the light-emitting device 700> The light-emitting device 700 shown in Figure 9(A) includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes drive circuits GD and SD, each composed of multiple transistors, as well as wiring to electrically connect them. These drive circuits are electrically connected to the light-emitting devices 550B, 550G, and 550R, respectively, and can drive them.

[0217] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 1. In particular, the case in which each light-emitting device has in common an EL layer 103 having the structure shown in Figure 2(B), a so-called tandem structure.

[0218] The light-emitting device 550B has an electrode 551B, an electrode 552, EL layers (103P, 103Q), a charge generation layer 106B, and an insulating layer 107, and has the laminated structure shown in Figure 9(A). The specific configuration of each layer is as shown in Embodiment 1. Also, electrodes 551B and 552 overlap. Furthermore, EL layers 103P and 103Q are laminated with the charge generation layer 106B in between, and EL layers 103P, 103Q, and 106B are located between electrodes 551B and 552. Note that EL layers 103P and 103Q have a laminated structure consisting of multiple layers with different functions, including a light-emitting layer, similar to EL layers 103, 103a, 103b, and 103c described in Embodiment 1. Furthermore, the EL layer 103P can emit blue light, for example, and the EL layer 103Q can emit yellow light, for example.

[0219] In Figure 9(A), only the hole injection / transport layer 104P is shown among the layers included in the EL layer 103P, and only the hole injection / transport layer 104Q, light-emitting layer 113Q, electron transport layer 108Q, and electron injection layer 109 are shown among the layers included in the EL layer 103Q, but the present invention is not limited to this. Hereafter, if it is possible to explain including the layers included in each EL layer, the EL layer (EL layer 103P, EL layer 103Q) may be used for convenience. Furthermore, the electron transport layer may have a laminated structure, and may also have a hole-blocking layer for blocking holes that move from the anode side through the light-emitting layer to the cathode side. Furthermore, the electron injection layer 109 may also have a laminated structure formed using some or all different materials.

[0220] Furthermore, as shown in Figure 9(A), the insulating layer 107 is formed on the electrode 551B while leaving the resist formed on a portion of the EL layer 103Q (in this embodiment, up to the electron transport layer 108Q on the light-emitting layer 113Q). Therefore, the insulating layer 107 is formed in contact with a portion of the EL layer 103Q (as described above), the EL layer 103P, and the side surface (or edge) of the charge generation layer 106B. This suppresses the penetration of oxygen, moisture, or their constituent elements into the interior from the side surfaces of the EL layer 103P, EL layer 103Q, and charge generation layer 106B. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulating layer 107. Sputtering, CVD, MBE, PLD, and ALD methods can be used to form the insulating layer 107, but the ALD method, which has good coverage, is more preferable.

[0221] Furthermore, an electron injection layer 109 is formed covering a portion of the EL layer 103Q (up to the electron transport layer 108Q on the light-emitting layer 113Q) and the insulating layer 107. It is preferable that the electron injection layer 109 has a laminated structure of two or more layers with different electrical resistances. For example, a first layer in contact with the electron transport layer 108Q may be formed solely of an electron-transporting material, and a second layer made of an electron-transporting material containing a metal material may be laminated on top of it. Alternatively, a third layer made of an electron-transporting material containing a metal material may be further laid between the first layer and the electron transport layer 108Q.

[0222] Furthermore, electrode 552 is formed on the electron injection layer 109. Electrode 551B and electrode 552 have overlapping regions. Additionally, EL layer 103P, EL layer 103Q, and charge generation layer 106B are located between electrode 551B and electrode 552. Therefore, the electron injection layer 109 is located on the side (or edge) of EL layer 103Q, EL layer 103P, and charge generation layer 106B via the insulating layer 107, or electrode 552 is located on the side (or edge) of EL layer 103Q, EL layer 103P, and charge generation layer 106B via the electron injection layer 109 and the insulating layer 107. This prevents electrical short circuits between EL layer 103P and electrode 552, more specifically, between the hole injection / transport layer 104P of EL layer 103P and electrode 552. Furthermore, it is possible to prevent electrical short circuits between the EL layer 103Q and the electrode 552, and more specifically, between the hole injection / transport layer 104Q of the EL layer 103Q and the electrode 552. Also, it is possible to prevent electrical short circuits between the charge generation layer 106B and the electrode 552.

[0223] The light-emitting device 550G has an electrode 551G, an electrode 552, EL layers (103P, 103Q), a charge generation layer 106G, and an insulating layer 107, and has the laminated structure shown in Figure 9(A). The specific configuration of each layer is as shown in Embodiment 1. Also, electrodes 551G and 552 overlap. Furthermore, EL layers 103P and 103Q are laminated with the charge generation layer 106G in between, and EL layers 103P, 103Q, and 106G are located between electrodes 551G and 552.

[0224] Furthermore, as shown in Figure 9(A), the insulating layer 107 is formed on the electrode 551G while leaving the resist formed on a portion of the EL layer 103Q (in this embodiment, up to the electron transport layer 108Q on the light-emitting layer 113Q). Therefore, the insulating layer 107 is formed in contact with a portion of the EL layer 103Q (as described above), the EL layer 103P, and the side surface (or edge) of the charge generation layer 106G. This suppresses the penetration of oxygen, moisture, or their constituent elements into the interior from the side surfaces of the EL layer 103P, EL layer 103Q, and charge generation layer 106G. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulating layer 107. Sputtering, CVD, MBE, PLD, ALD, etc. can be used to form the insulating layer 107, but the ALD method, which has good coverage, is more preferable.

[0225] Furthermore, an electron injection layer 109 is formed covering a portion of the EL layer 103Q (up to the electron transport layer 108Q on the light-emitting layer 113Q) and the insulating layer 107. Preferably, the electron injection layer 109 has a laminated structure of two or more layers with different electrical resistances. For example, a first layer in contact with the electron transport layer 108Q may be formed solely of an electron-transporting material, and a second layer made of an electron-transporting material containing a metal material may be laminated on top of it, or a third layer made of an electron-transporting material containing a metal material may be further laid between the first layer and the electron transport layer 108Q.

[0226] Further, the electrode 552 is formed on the electron injection layer 109. The electrode 551G and the electrode 552 have an overlapping region with each other. Also, between the electrode 551G and the electrode 552, there are an EL layer 103P, an EL layer 103Q, and a charge generation layer 106G. Therefore, the electron injection layer 109 is located on the side surface (or end portion) of the EL layer 103Q, the EL layer 103P, and the charge generation layer 106G via the insulating layer 107, or the electrode 552 is located on the side surface (or end portion) of the EL layer 103Q, the EL layer 103P, and the charge generation layer 106G via the electron injection layer 109 and the insulating layer 107. Thereby, it is possible to prevent the EL layer 103P and the electrode 552, more specifically, the hole injection / transport layer 104P included in the EL layer 103P and the electrode 552 from being electrically short-circuited. Also, it is possible to prevent the EL layer 103Q and the electrode 552, more specifically, the hole injection / transport layer 104Q included in the EL layer 103Q and the electrode 552 from being electrically short-circuited. Also, it is possible to prevent the charge generation layer 106G and the electrode 552 from being electrically short-circuited.

[0227] The light-emitting device 550R has an electrode 551R, an electrode 552, EL layers (103P, 103Q), a charge generation layer 106R, and an insulating layer 107, and has a stacked structure shown in FIG. 9(A). The specific configuration of each layer is as shown in Embodiment 1. Also, the electrode 551R and the electrode 552 overlap. Also, the EL layer 103P and the EL layer 103Q are stacked with the charge generation layer 106R interposed therebetween, and between the electrode 551R and the electrode 552, there are an EL layer 103P, an EL layer 103Q, and a charge generation layer 106R.

[0228] Also, as shown in Fig. 9(A), the insulating layer 107 is formed while leaving a resist formed on a part of the EL layer 103Q (in this embodiment, up to the electron transport layer 108Q on the light-emitting layer 113Q) on the electrode 551R. Therefore, the insulating layer 107 is formed in contact with a part of the EL layer 103Q (as described above), the EL layer 103P, and the side surface (or end portion) of the charge generation layer 106R. Thereby, it is possible to suppress the intrusion of oxygen, moisture, or these constituent elements from the side surfaces of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R into the interior. Note that, for the insulating layer 107, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, silicon oxynitride, or the like can be used. For the formation of the insulating layer 107, a sputtering method, a CVD method, an MBE method, a PLD method, an ALD method, or the like can be used, but the ALD method with good coating properties is more preferable.

[0229] Further, an electron injection layer 109 is formed to cover a part of the EL layer 103Q (formed up to the electron transport layer 108Q on the light-emitting layer 113Q) and the insulating layer 107. Note that the electron injection layer 109 preferably has a laminated structure of two or more layers having different electrical resistances in the layer. For example, a structure in which a first layer in contact with the electron transport layer 108Q is formed only of an electron transport material and a second layer formed of an electron transport material containing a metal material is laminated thereon, or a structure having a third layer formed of an electron transport material containing a metal material between the first layer and the electron transport layer 108Q may also be used.

[0230] Furthermore, electrode 552 is formed on the electron injection layer 109. Note that electrode 551R and electrode 552 have overlapping regions. Also, between electrode 551R and electrode 552 are EL layer 103P, EL layer 103Q, and charge generation layer 106R. Therefore, the electron injection layer 109 is located on the side (or edge) of EL layer 103Q, EL layer 103P, and charge generation layer 106R via the insulating layer 107, or electrode 552 is located on the side (or edge) of EL layer 103Q, EL layer 103P, and charge generation layer 106R via the electron injection layer 109 and the insulating layer 107. This prevents electrical short circuits between EL layer 103P and electrode 552, more specifically between the hole injection / transport layer 104P of EL layer 103P and electrode 552. Furthermore, it is possible to prevent electrical short circuits between the EL layer 103Q and the electrode 552, and more specifically, between the hole injection / transport layer 104Q of the EL layer 103Q and the electrode 552. Also, it is possible to prevent electrical short circuits between the charge generation layer 106R and the electrode 552.

[0231] Furthermore, when separating and processing the EL layers (103P, 103Q) and charge generation layers (106B, 106G, 106R) of each light-emitting device, a pattern is formed using photolithography. As a result, the edges (sides) of the processed EL layers (EL layer 103P, hole injection / transport layer 104Q, light-emitting layer 113Q, and electron transport layer 108Q) and charge generation layer 106 have substantially the same surface (or are located substantially on the same plane).

[0232] Each light-emitting device has an EL layer (103P, 103Q) and a charge generation layer (106B, 106G, 106R), each with a gap 580 between them and adjacent light-emitting devices. The hole injection layer and charge generation layer (106B, 106G, 106R) included in the hole transport region of the EL layer (103P, 103Q) often have high conductivity, and if they are formed as layers common to adjacent light-emitting devices, they may cause crosstalk. Therefore, by providing a gap 580 as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0233] In a high-resolution light-emitting device (display panel) with a resolution exceeding 1000 ppi, if electrical conductivity is detected between the EL layer 103B, EL layer 103G, and EL layer 103R, crosstalk occurs, narrowing the color gamut that the light-emitting device can display. By providing a gap 580 in a high-resolution display panel exceeding 1000 ppi, preferably a high-resolution display panel exceeding 2000 ppi, and more preferably an ultra-high-resolution display panel exceeding 5000 ppi, a display panel capable of displaying vivid colors can be provided.

[0234] In this configuration example, the light-emitting devices 550B, 550G, and 550R all emit white light. Therefore, the second substrate 770 has a colored layer CFB, a colored layer CFG, and a colored layer CFR. These colored layers may be partially overlapped, as shown in Figure 9(A). By partially overlapping them, the overlapped portion can function as a light-shielding film. In this configuration example, for example, the colored layer CFB uses a material that preferentially transmits blue light (B), the colored layer CFG uses a material that preferentially transmits green light (G), and the colored layer CFR uses a material that preferentially transmits red light (R).

[0235] Figure 9(B) shows the configuration of light-emitting device 550B when light-emitting devices 550B, 550G, and 550R are light-emitting devices that emit white light. EL layers 103P and 103Q are laminated on electrode 551B with a charge generation layer 106B in between. EL layer 103P has a light-emitting layer 113B that emits blue light EL(1), and EL layer 103Q has a light-emitting layer 113G that emits green light EL(2) and a light-emitting layer 113R that emits red light EL(3).

[0236] Alternatively, a color conversion layer can be used instead of the colored layer described above. For example, nanoparticles, quantum dots, etc., can be used as the color conversion layer.

[0237] For example, instead of the colored layer CFG, a color conversion layer that converts blue light to green light can be used. This allows the blue light emitted by the light-emitting device 550G to be converted to green light. Alternatively, instead of the colored layer CFR, a color conversion layer that converts blue light to red light can be used. This allows the blue light emitted by the light-emitting device 550R to be converted to red light.

[0238] <Example of configuration of light-emitting device 700 4> The light-emitting device (display panel) 700 shown in Figure 10 includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes drive circuits GD and SD, each composed of multiple transistors, as well as wiring to electrically connect them. These drive circuits are electrically connected to the light-emitting devices 550B, 550G, and 550R, enabling them to be driven.

[0239] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 1. This is particularly suitable when each light-emitting device has in common an EL layer 103 having the structure shown in Figure 2(B), a so-called tandem structure.

[0240] The specific configurations of each light-emitting device shown in Figure 10 are the same as those of light-emitting devices 550B, 550G, and 550R described in Figure 9(A), and all of them emit white light.

[0241] Note that the light-emitting device shown in this example differs from the configuration of the light-emitting device shown in Figure 9(A) in that it has a colored layer CFB, a colored layer CFG, and a colored layer CFR formed on each light-emitting device formed on the first substrate 510.

[0242] Specifically, each light-emitting device formed on the first substrate 510 has an insulating layer 573 on its electrode 552, and a colored layer CFB, a colored layer CFG, and a colored layer CFR on the insulating layer 573.

[0243] Furthermore, the substrate has an insulating layer 705 on the colored layers CFB, CFG, and CFR. The insulating layer 705 has a region sandwiched between the first substrate 510 and the second substrate 770 on the colored layer (CFB, CFG, CFR) side of the first substrate 510, which has a functional layer 520, each light-emitting device (550B, 550G, 550R), and the colored layers CFB, CFG, and CFR, and has the function of bonding the first substrate 510 and the second substrate 770.

[0244] Furthermore, the insulating layer 573 and the insulating layer 705 can be made of inorganic materials, organic materials, or composite materials of inorganic and organic materials.

[0245] Furthermore, as the inorganic material, an inorganic oxide film, an inorganic nitride film, or an inorganic oxidnitride film, or a laminated material made by laminating a plurality of these selected can be used. For example, a film containing a silicon oxide film, a silicon nitride film, a silicon oxidnitride film, an aluminum oxide film, or a laminated material made by laminating a plurality of these selected can be used. Note that silicon nitride films are dense films and have excellent function in suppressing the diffusion of impurities. Alternatively, as an oxide semiconductor (for example, an IGZO film), a laminated structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used.

[0246] Furthermore, as organic materials, polyester, polyolefin, polyamide, polyimide, polycarbonate, polysiloxane, or acrylic, or laminated or composite materials of multiple resins selected from these, can be used. Alternatively, organic materials such as reaction-curing adhesives, photocuring adhesives, thermosetting adhesives, and / or anaerobic adhesives can be used.

[0247] <Example 2 of a manufacturing method for a light-emitting device> Next, the method for fabricating the light-emitting device shown in Figure 10 will be explained using Figures 11 and 12.

[0248] As shown in Figure 11(A), on the electrodes (551B, 551G, 551R) and partition wall 528 (see Figure 4(B)) formed on the first substrate 510, an EL layer 103P (including a hole injection / transport layer 104P), a charge generation layer 106 which becomes a charge generation layer (106B, 106G, 106R), a hole injection / transport layer 104Q, a light-emitting layer 113Q, and an electron transport layer 108Q are formed so as to cover them.

[0249] Next, as shown in FIG. 11(B), the EL layer 103P (including the hole injection / transport layer 104P), the charge generation layer 106, the hole injection / transport layer 104Q, the light-emitting layer 113Q, and the electron transport layer 108Q on the electrodes (551B, 551G, 551R) are processed into a predetermined shape. For example, using photolithography, a resist REG is formed on the hole injection / transport layer 104Q, the light-emitting layer 113Q, and the electron transport layer 108Q on the electrodes (551G, 551B, 551R), and by etching, the portion where the resist REG is not formed on the upper part is removed to form a shape having a side surface (or the side surface is exposed), in other words, a strip-shaped shape extending in the direction (X-axis direction) intersecting the paper surface. Specifically, dry etching is performed using the resist REG formed on the electron transport layer 108Q (see FIG. 11(C)). Note that the partition wall 528 can be used as an etching stopper.

[0250] Next, an insulating layer 107 is formed on the resist REG, the EL layer 103P, the charge generation layers (106B, 106G, 106R), the hole injection / transport layer 104Q, the light-emitting layer 113Q, the electron transport layer 108Q, and the partition wall 528. For example, using the ALD method, an insulating layer 107 is formed to cover the resist REG, the EL layer 103P, the charge generation layers (106B, 106G, 106R), the hole injection / transport layer 104Q, the light-emitting layer 113Q, the electron transport layer 108Q, and the partition wall 528. In this case, as shown in Figure 11(C), the insulating layer 107 is formed in contact with the side surfaces of the EL layer 103P, the charge generation layers (106B, 106G, 106R), the hole injection / transport layer 104Q, the light-emitting layer 113Q, and the electron transport layer 108Q. Thereby, the intrusion of oxygen, moisture, or these constituent elements from the side surfaces of the EL layer 103P, the charge generation layers (106B, 106G, 106R), the hole injection / transport layer 104Q, the light-emitting layer 113Q, and the electron transport layer 108Q into the interior can be suppressed. Note that as the material used for the insulating layer 107, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon oxynitride can be used.

[0251] Next, as shown in Figure 12(A), the resist REG is removed to form an electron injection layer 109 on the insulating layer 107, the electron transport layer 108Q, and the partition wall 528. The electron injection layer 109 is formed, for example, by vacuum deposition. The electron injection layer 109 has a structure that is located on the sides of some layers of the EL layers 103P and 103Q (hole injection / transport layer 104Q, light-emitting layer 113Q, and electron transport layer 108Q) and on the sides of the charge generation layers (106B, 106G, 106R) via the insulating layer 107.

[0252] Next, electrodes 552 are formed on the electron injection layer 109. The electrodes 552 are formed, for example, using a vacuum deposition method. The electrodes 552 have a structure that is located on the side (or edge) of the EL layer 103P, a part of the EL layer 103Q (hole injection / transport layer 104Q, light-emitting layer 113Q, and electron transport layer 108Q), and the charge generation layers (106B, 106G, 106R) via the electron injection layer 109 and the insulating layer 107. This prevents electrical short circuits between each EL layer (103P, 103Q) and the electrodes 552, or more specifically, between the hole injection / transport layers (104P, 104Q) of each EL layer (103P, 103Q) and the electrodes 552.

[0253] As described above, the EL layer 103P (including the hole injection / transport layer 104P), charge generation layers (106B, 106G, 106R), and some layers of the EL layer 103Q (including the hole injection / transport layer 104Q, the light-emitting layer 113Q, and the electron transport layer 108Q) of the light-emitting devices 550B, 550G, and 550R can be formed separately in a single photolithography pattern formation.

[0254] As the material used for the electron injection layer 109, the hole transport material described in Embodiment 1 can be used.

[0255] Furthermore, the electron injection layer 109 is also formed on the exposed sides when the EL layer 103P (including the hole injection / transport layer 104P), the charge generation layers (106B, 106G, 106R), and the EL layer 103Q (including the hole injection / transport layer 104Q and the electron transport layer 108Q) are etched.

[0256] Furthermore, the electrode 552 is formed on the electron injection layer 109. The electrode 552 has a structure in which it is located on the side of the EL layer 103P (including the hole injection / transport layer 104P), the charge generation layers (106B, 106G, 106R), and some layers of the EL layer 103Q (including the hole injection / transport layer 104Q, the light-emitting layer 113Q, and the electron transport layer 108Q) via the insulating layer 107. This prevents electrical short circuits between the EL layer 103P and the electrode 552, more specifically between the hole injection / transport layer 104P of the EL layer 103P and the electrode 552. It also prevents electrical short circuits between the EL layer 103Q and the electrode 552, more specifically between the hole injection / transport layer 104Q of the EL layer 103Q and the electrode 552. Furthermore, it is possible to prevent electrical short circuits between the charge generation layers (106B, 106G, 106R) and the electrode 552.

[0257] Next, an insulating layer 573, a colored layer CFB, a colored layer CFG, a colored layer CFR, and an insulating layer 705 are formed (see Figure 12(B)).

[0258] For example, an insulating layer 573 is formed by laminating a flat film and a dense film. Specifically, a flat film is formed using a coating method, and a dense film is laminated on top of the flat film using chemical vapor deposition or atomic layer deposition (ALD). This makes it possible to form a high-quality insulating layer 573 with few defects.

[0259] For example, a color resist is used to form colored layers CFB, CFG, and CFR in predetermined shapes. The colored layers CFR and CFB are processed so that they overlap on the partition wall 528. This suppresses the phenomenon of light from adjacent light-emitting devices bending around the material.

[0260] The insulating layer 705 can be made of an inorganic material, an organic material, or a composite material of an inorganic material and an organic material.

[0261] Furthermore, when separating and processing the EL layer (103P, 103Q) and charge generation layer (106B, 106G, 106R) of each light-emitting device, a pattern is formed using photolithography, enabling the creation of high-resolution light-emitting devices (display panels). In addition, the edges (sides) of the EL layer processed by pattern formation using photolithography have a shape that is approximately the same surface (or is located on approximately the same plane).

[0262] Furthermore, the hole injection layer and charge generation layer (106B, 106G, 106R) included in the hole transport region of the EL layer (103P, 103Q) often have high conductivity. Therefore, if they are formed as layers common to adjacent light-emitting devices, they may cause crosstalk. Accordingly, by separating the EL layer using pattern formation with photolithography, as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0263] <Example of configuration of light-emitting device 700 5> The light-emitting device (display panel) 700 shown in Figure 13 includes light-emitting devices 550B, 550G, 550R, and a partition wall 528. The light-emitting devices 550B, 550G, 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes drive circuits GD and SD, composed of multiple transistors, as well as wiring to electrically connect them. These drive circuits are electrically connected to the light-emitting devices 550B, 550G, and 550R, enabling them to be driven.

[0264] Furthermore, the light-emitting devices 550B, 550G, and 550R have the device structure shown in Embodiment 1. This is particularly suitable when each light-emitting device has in common an EL layer 103 having the structure shown in Figure 2(B), a so-called tandem structure.

[0265] As shown in Figure 13, there is a gap 580 between each light-emitting device, for example, between light-emitting device 550B and light-emitting device 550G. Therefore, the configuration includes forming an insulating layer 540 in this gap 580.

[0266] For example, by pattern formation using photolithography, the EL layer 103P (including the hole injection / transport layer 104P), the charge generation layers (106B, 106G, 106R), and the EL layer 103Q (including the hole injection / transport layer 104Q) can be separated and formed, and then an insulating layer 540 can be formed in the gap 580 on the partition wall 528 using photolithography. Furthermore, electrodes 552 can be formed on the EL layer 103Q (including the hole injection / transport layer 104Q) and the insulating layer 540.

[0267] In this configuration, since each EL layer is completely separated by the insulating layer 540, the insulating layer 107 shown in Configuration Example 3 (see Figure 9(A)) is unnecessary.

[0268] Furthermore, when separating and processing the EL layer (103P, 103Q) and charge generation layer (106B, 106G, 106R) of each light-emitting device, a pattern is formed using photolithography, enabling the creation of high-resolution light-emitting devices (display panels). In addition, the edges (sides) of the EL layer processed by pattern formation using photolithography have a shape that is approximately the same surface (or is located on approximately the same plane).

[0269] Furthermore, the hole injection layer and charge generation layer (106B, 106G, 106R) included in the hole transport region of the EL layer (103P, 103Q) often have high conductivity. Therefore, if they are formed as layers common to adjacent light-emitting devices, they may cause crosstalk. Accordingly, by separating the EL layer using pattern formation with photolithography, as shown in this example configuration, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0270] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0271] (Embodiment 3) In this embodiment, a light-emitting device, which is one aspect of the present invention, will be described using Figures 14(A) to 16(B). The light-emitting device 700 shown in Figures 14(A) to 16(B) has the light-emitting device shown in Embodiment 1. Furthermore, since the light-emitting device 700 described in this embodiment can be applied to the display section of electronic devices and the like, it can also be called a display panel.

[0272] As shown in Figure 14(A), the light-emitting device 700 described in this embodiment includes a display area 231, the display area 231 having a pair of pixels 703(i,j). Also, as shown in Figure 14(B), there is a pair of pixels 703(i+1,j) adjacent to the pair of pixels 703(i,j).

[0273] Note that pixel 703(i,j) can contain multiple pixels. For example, multiple pixels displaying colors with different hues can be used. Each of these multiple pixels can be referred to as a subpixel. Alternatively, multiple subpixels can be grouped together and referred to as a single pixel.

[0274] This allows for additive or subtractive color mixing of the colors displayed by the multiple pixels. Alternatively, it enables the display of hues that cannot be displayed by individual pixels.

[0275] Specifically, the pixel 702B(i,j) that displays blue, the pixel 702G(i,j) that displays green, and the pixel 702R(i,j) that displays red can be used as the pixel 703(i,j). In addition, pixels 702B(i,j), 702G(i,j), and 702R(i,j) can each be referred to as subpixels.

[0276] Additionally, a pixel displaying white or the like may be used as pixel 703(i,j) in addition to the above pair. Furthermore, a pixel displaying cyan, a pixel displaying magenta, and a pixel displaying yellow may each be used as a sub-pixel in pixel 703(i,j).

[0277] In addition to the above pair, a pixel that emits infrared light may be used for pixel 703(i,j). Specifically, a pixel that emits light including light with a wavelength of 650 nm to 1000 nm can be used for pixel 703(i,j).

[0278] The display area 231 shown in Figure 14(A) is surrounded by a drive circuit GD and a drive circuit SD. It also has terminals 519 that are electrically connected to the drive circuits GD and SD. Terminals 519 can be electrically connected, for example, to a flexible printed circuit FPC1 (see Figure 16).

[0279] The drive circuit GD has the function of supplying a first selection signal and a second selection signal. For example, the drive circuit GD is electrically connected to the conductive film G1(i), which will be described later, and supplies the first selection signal, and is electrically connected to the conductive film G2(i), which will be described later, and supplies the second selection signal. The drive circuit SD also has the function of supplying an image signal and a control signal, and the control signal includes a first level and a second level. For example, the drive circuit SD is electrically connected to the conductive film S1g(j), which will be described later, and supplies the image signal, and is electrically connected to the conductive film S2g(j), which will be described later, and supplies the control signal.

[0280] Furthermore, as shown in Figure 16(A), the light-emitting device 700 has a functional layer 520 between the first substrate 510 and the second substrate 770. The functional layer 520 includes the aforementioned drive circuit GD, drive circuit SD, and wiring that electrically connects them. In Figure 16(A), the functional layer 520 is shown to include a pixel circuit 530B(i,j) and a pixel circuit 530G(i,j) and a drive circuit GD, but is not limited to this configuration.

[0281] Furthermore, each pixel circuit of the functional layer 520 (for example, pixel circuits 530B(i,j) and 530G(i,j) shown in Figure 16(A)) is electrically connected to each light-emitting device formed on the functional layer 520 (for example, light-emitting device 550B(i,j) and light-emitting device 550G(i,j) shown in Figure 16(A)). In addition, an insulating layer 705 is provided on the functional layer 520 and each light-emitting device, and the insulating layer 705 has the function of bonding the second substrate 770 and the functional layer 520.

[0282] Furthermore, the second substrate 770 can be a substrate equipped with touch sensors in a matrix. For example, a substrate equipped with a capacitive touch sensor or an optical touch sensor can be used as the second substrate 770. This allows the light-emitting device according to one embodiment of the present invention to be used as a touch panel.

[0283] Furthermore, the specific configuration of the pixel circuit 530G(i,j) is shown in Figure 15(A).

[0284] As shown in Figure 15(A), the pixel circuit 530G(i,j) has switch SW21, switch SW22, transistor M21, capacitor C21, and node N21. The pixel circuit 530G(i,j) also has node N22, capacitor C22, and switch SW23.

[0285] Transistor M21 has a gate electrode electrically connected to node N21, a first electrode electrically connected to light-emitting device 550G(i,j), and a second electrode electrically connected to conductive film ANO.

[0286] Switch SW21 has a first terminal electrically connected to node N21 and a second terminal electrically connected to conductive film S1g(j), and has the function of controlling a conduction state or a non-conduction state based on the potential of conductive film G1(i).

[0287] The switch SW22 has a first terminal electrically connected to the conductive film S2g(j), and has the function of controlling the conduction state or non-conduction state based on the potential of the conductive film G2(i).

[0288] Capacitor C21 has a conductive film electrically connected to node N21 and a conductive film electrically connected to the second electrode of switch SW22.

[0289] This allows the image signal to be stored in node N21. Alternatively, the potential of node N21 can be changed using switch SW22. Or, the intensity of the light emitted by the light-emitting device 550G(i,j) can be controlled using the potential of node N21.

[0290] Next, Figure 15(B) shows an example of the specific structure of transistor M21, as explained in Figure 15(A). Note that, as appropriate, a bottom-gate transistor or a top-gate transistor can be used as transistor M21.

[0291] The transistor shown in Figure 15(B) has a semiconductor film 508, a conductive film 504, an insulating film 506, a conductive film 512A, and a conductive film 512B. The transistor is formed, for example, on an insulating film 501C.

[0292] The semiconductor film 508 has a region 508A that is electrically connected to the conductive film 512A, and a region 508B that is electrically connected to the conductive film 512B. The semiconductor film 508 has a region 508C between regions 508A and 508B.

[0293] The conductive film 504 has a region that overlaps with region 508C, and the conductive film 504 has the function of a gate electrode.

[0294] The insulating film 506 has a region sandwiched between the semiconductor film 508 and the conductive film 504. The insulating film 506 functions as a gate insulating film.

[0295] The conductive film 512A has either the function of a source electrode or the function of a drain electrode, and the conductive film 512B has either the function of a source electrode or the function of a drain electrode.

[0296] Furthermore, the conductive film 524 can be used in a transistor. The conductive film 524 has a region in which the semiconductor film 508 is sandwiched between it and the conductive film 504. The conductive film 524 functions as a second gate electrode. The insulating film 501D is sandwiched between the semiconductor film 508 and the conductive film 524 and functions as a second gate insulating film.

[0297] Furthermore, in the process of forming the semiconductor film used for the transistors in the pixel circuit, the semiconductor film used for the transistors in the drive circuit can also be formed. For example, a semiconductor film with the same composition as the semiconductor film used for the transistors in the pixel circuit can be used in the drive circuit.

[0298] Furthermore, the semiconductor film 508 can be made of a semiconductor containing elements of Group 14. Specifically, a semiconductor containing silicon can be used for the semiconductor film 508.

[0299] Furthermore, hydrogenated amorphous silicon can be used for the semiconductor film 508. Alternatively, microcrystalline silicon or the like can be used for the semiconductor film 508. This makes it possible to provide a light-emitting device (or display panel) with less display unevenness than, for example, a light-emitting device (or display panel) that uses polysilicon for the semiconductor film 508. Alternatively, it is easier to scale up the light-emitting device.

[0300] Furthermore, polysilicon can be used for the semiconductor film 508. This allows for a higher field-effect mobility of the transistor compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508. It also allows for improved driving capability compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508. Alternatively, it allows for an improved aperture ratio of the pixels compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508.

[0301] Alternatively, for example, the reliability of the transistor can be improved compared to a transistor using hydrogenated amorphous silicon as the semiconductor film 508.

[0302] Alternatively, the temperature required for transistor fabrication can be lowered compared to, for example, transistors using single-crystal silicon.

[0303] Alternatively, the semiconductor film used for the transistors in the drive circuit can be formed using the same process as the semiconductor film used for the transistors in the pixel circuit. Alternatively, the drive circuit can be formed on the same substrate as the substrate on which the pixel circuit is formed. Alternatively, the number of components constituting the electronic device can be reduced.

[0304] Furthermore, single-crystal silicon can be used for the semiconductor film 508. This allows for higher resolution than, for example, a light-emitting device (or display panel) that uses hydrogenated amorphous silicon for the semiconductor film 508. Alternatively, it is possible to provide a light-emitting device with less display unevenness than a light-emitting device that uses polysilicon for the semiconductor film 508. Alternatively, for example, smart glasses or a head-mounted display can be provided.

[0305] Furthermore, a metal oxide can be used for the semiconductor film 508. This allows the pixel circuit to hold the image signal for a longer time compared to a pixel circuit using a transistor with a hydrogenated amorphous silicon semiconductor film. Specifically, the selection signal can be supplied at a frequency of less than 30 Hz, preferably less than 1 Hz, and more preferably less than once per minute, while suppressing the occurrence of flicker. As a result, fatigue accumulated in the user of the electronic device can be reduced. In addition, power consumption associated with operation can be reduced.

[0306] Furthermore, an oxide semiconductor can be used for the semiconductor film 508. Specifically, an oxide semiconductor containing indium, an oxide semiconductor containing indium, gallium, and zinc, or an oxide semiconductor containing indium, gallium, zinc, and tin can be used for the semiconductor film 508.

[0307] Furthermore, by using an oxide semiconductor as the semiconductor film, it is possible to obtain a transistor with a smaller leakage current in the off state than a transistor using hydrogenated amorphous silicon as the semiconductor film. Therefore, it is preferable to use a transistor using an oxide semiconductor as the semiconductor film for switches and the like. Moreover, a circuit using a transistor with an oxide semiconductor as the semiconductor film as a switch can maintain the potential of the floating node for a longer time than a circuit using a transistor with hydrogenated amorphous silicon as the semiconductor film as a switch.

[0308] Figure 16(A) shows a light-emitting device with a structure that extracts light from the second substrate 770 side (top emission type), but as shown in Figure 16(B), a light-emitting device with a structure that extracts light from the first substrate 510 side (bottom emission type) may also be used. In the case of a bottom emission type light-emitting device, the first electrode 101 is formed to function as a semi-transparent / semi-reflective electrode, and the second electrode 102 is formed to function as a reflective electrode.

[0309] Furthermore, although Figures 16(A) and 16(B) describe an active matrix type light-emitting device, the configuration of the light-emitting device shown in Embodiment 1 may also be applied to the passive matrix type light-emitting device shown in Figures 17(A) and 17(B).

[0310] Figure 17(A) is a perspective view showing a passive matrix type light-emitting device, and Figure 17(B) is a cross-sectional view of Figure 17(A) cut along the X and Y axes. In Figure 17, an EL layer 955 is provided on the substrate 951 between electrodes 952 and 956. The ends of electrodes 952 are covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The side walls of the partition layer 954 have a slope such that the distance between one side wall and the other side wall narrows as it approaches the substrate surface. In other words, the cross-section of the partition layer 954 in the short axis direction is trapezoidal, with the lower base (the side in contact with the insulating layer 953) being shorter than the upper base. By providing the partition layer 954 in this way, defects in the light-emitting device caused by static electricity and the like can be prevented.

[0311] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0312] (Embodiment 4) In this embodiment, the configuration of an electronic device according to one aspect of the present invention will be explained with reference to Figures 18(A) to 20(B).

[0313] Figures 18(A) to 20(B) illustrate the configuration of an electronic device according to one embodiment of the present invention. Figure 18(A) is a block diagram of the electronic device, and Figures 18(B) to 18(E) are perspective views illustrating the configuration of the electronic device. Figures 19(A) to 19(E) are perspective views illustrating the configuration of the electronic device, and Figures 20(A) and 20(B) are perspective views illustrating the configuration of the electronic device.

[0314] The electronic device 5200B described in this embodiment includes a computing device 5210 and an input / output device 5220 (see Figure 18(A)).

[0315] The arithmetic unit 5210 has a function to receive operation information and a function to supply image information based on the operation information.

[0316] The input / output device 5220 includes a display unit 5230, an input unit 5240, a detection unit 5250, a communication unit 5290, a function for supplying operation information, and a function for supplying image information. Furthermore, the input / output device 5220 also includes a function for supplying detection information, a function for supplying communication information, and a function for receiving communication information.

[0317] The input unit 5240 has the function of supplying operation information. For example, the input unit 5240 supplies operation information based on the operation of the user of the electronic device 5200B.

[0318] Specifically, the input unit 5240 can use a keyboard, hardware buttons, pointing device, touch sensor, illuminance sensor, imaging device, voice input device, eye-tracking device, posture detection device, etc.

[0319] The display unit 5230 has the function of displaying a display panel and image information. For example, the display panel described in Embodiment 2 can be used in the display unit 5230.

[0320] The detection unit 5250 has the function of supplying detection information. For example, it has the function of detecting the surrounding environment in which electronic equipment is being used and supplying it as detection information.

[0321] Specifically, illuminance sensors, imaging devices, posture detection devices, pressure sensors, and human presence sensors can be used in the detection unit 5250.

[0322] The communication unit 5290 has functions for receiving and supplying communication information. For example, it has functions for connecting with other electronic devices or communication networks via wireless or wired communication. Specifically, it has functions such as wireless local area communication, telephone communication, and short-range wireless communication.

[0323] Figure 18(B) shows an electronic device having an external shape that follows a cylindrical column or the like. One example is digital signage. A display panel, which is one aspect of the present invention, can be applied to the display unit 5230. It may also have a function to change the display method according to the illumination of the usage environment. It may also have a function to change the display content when a person is detected. This allows it to be installed, for example, on a building column, or to display advertisements or information.

[0324] Figure 18(C) shows an electronic device that has the function of generating image information based on the trajectory of a pointer used by the user. Examples include electronic whiteboards, electronic bulletin boards, and electronic signboards. Specifically, a display panel with a diagonal length of 20 inches or more, preferably 40 inches or more, and more preferably 55 inches or more can be used. Alternatively, multiple display panels can be arranged to form a single display area. Alternatively, multiple display panels can be arranged to form a multi-screen.

[0325] Figure 18(D) shows an electronic device that can receive information from other devices and display it on the display unit 5230. One example is a wearable electronic device. Specifically, it can display several options, or the user can select several options and send them back to the information sender. Alternatively, it can have a function to change the display method according to the illumination of the usage environment. This can reduce the power consumption of the wearable electronic device, for example. Alternatively, it can display images on the wearable electronic device so that it can be used suitably even in environments with strong ambient light, such as outdoors on a sunny day.

[0326] Figure 18(E) shows an electronic device having a display unit 5230 with a curved surface that gently curves along the side of the housing. One example is a mobile phone. The display unit 5230 includes a display panel, which has the function of displaying on, for example, the front, side, top, and back. This allows information to be displayed not only on the front of the mobile phone, but also on the sides, top, and back.

[0327] Figure 19(A) shows an electronic device that can receive information from the internet and display it on the display unit 5230. One example is a smartphone. For example, a message that has been created can be viewed on the display unit 5230. Alternatively, a message that has been created can be sent to another device. Alternatively, for example, it has a function to change the display method according to the illumination of the usage environment. This can reduce the power consumption of the smartphone. Alternatively, for example, an image can be displayed on the display unit 5230 so that it can be used suitably even in environments with strong ambient light, such as outdoors on a sunny day.

[0328] Figure 19(B) shows an electronic device that can use a remote controller as an input unit 5240. One example is a television system. For example, it can receive information from a broadcasting station or the internet and display it on the display unit 5230. Alternatively, it can photograph the user using the detection unit 5250. Alternatively, it can transmit the user's video. Alternatively, it can acquire the user's viewing history and provide it to a cloud service. Alternatively, it can acquire recommendation information from a cloud service and display it on the display unit 5230. Alternatively, it can display a program or video based on the recommendation information. Alternatively, for example, it has a function to change the display method according to the illumination of the usage environment. This allows the video to be displayed on the display unit 5230 so that it can be used effectively even when strong sunlight shines into the room on a sunny day.

[0329] Figure 19(C) shows an electronic device that can receive educational materials from the internet and display them on the display unit 5230. An example of such a device is a tablet computer. Using the input unit 5240, reports can be entered and sent to the internet. Alternatively, the correction results or evaluations of reports can be obtained from a cloud service and displayed on the display unit 5230. Or, based on the evaluation, suitable educational materials can be selected and displayed.

[0330] For example, it can receive image signals from other electronic devices and display them on the display unit 5230. Alternatively, it can be propped up on a stand or the like and used as a sub-display. For example, it can display images on the display unit 5230 so that it can be used effectively even in environments with strong ambient light, such as outdoors on a sunny day.

[0331] Figure 19(D) shows an electronic device having multiple display units 5230. One example is a digital camera. For example, the detection unit 5250 can capture images while displaying them on the display unit 5230. Alternatively, captured images can be displayed on the display unit 5230. Alternatively, the input unit 5240 can be used to add embellishments to captured images. Alternatively, messages can be attached to captured images. Alternatively, images can be transmitted to the internet. Alternatively, the device has a function to change the shooting conditions according to the illumination of the environment in which they are used. This allows the subject to be displayed on the display unit 5230 in a way that allows for suitable viewing even in environments with strong ambient light, such as outdoors on a sunny day.

[0332] Figure 19(E) shows an electronic device that can control other electronic devices by using the electronic device of this embodiment as a master and using other electronic devices as slaves. One example is a portable personal computer. For example, part of the image information can be displayed on the display unit 5230 and the other part of the image information can be displayed on the display unit of the other electronic device. Alternatively, an image signal can be supplied. Alternatively, information to be written can be obtained from the input unit of the other electronic device using the communication unit 5290. This allows, for example, a portable personal computer to utilize a wide display area.

[0333] Figure 20(A) shows an electronic device having a detection unit 5250 that detects acceleration or direction. An example is a goggle-type electronic device. The detection unit 5250 can supply information relating to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information for the right eye and image information for the left eye based on the user's position or the direction the user is facing. Alternatively, the display unit 5230 has a display area for the right eye and a display area for the left eye. This allows, for example, the display unit 5230 to display images of an immersive virtual reality space.

[0334] Figure 20(B) shows an electronic device having an imaging device and a detection unit 5250 that detects acceleration or direction. An example is a glasses-type electronic device. The detection unit 5250 can supply information relating to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information based on the user's position or the direction the user is facing. This allows, for example, information to be attached to and displayed on a real-world landscape. Alternatively, images of an augmented reality space can be displayed on the glasses-type electronic device.

[0335] This embodiment can be appropriately combined with other embodiments shown in this specification.

[0336] (Embodiment 5) In this embodiment, a configuration in which the light-emitting device described in Embodiment 2 is used as an illumination device will be explained with reference to Figure 21. Figure 21(A) is a cross-sectional view of ef in the top view of the illumination device shown in Figure 21(B).

[0337] In this embodiment, the lighting device has a first electrode 401 formed on a translucent substrate 400 which serves as a support. The first electrode 401 corresponds to the first electrode 101 in Embodiment 1. When light is extracted from the first electrode 401 side, the first electrode 401 is formed from a translucent material.

[0338] A pad 412 for supplying voltage to the second electrode 404 is formed on the substrate 400.

[0339] An EL layer 403 is formed on the first electrode 401. The EL layer 403 corresponds to the configuration of the EL layer 103 in Embodiment 1, or a configuration combining EL layers 103a, 103b, 103c and charge generation layer 106 (106a, 106b). For details on these configurations, please refer to the relevant description.

[0340] A second electrode 404 is formed by covering the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in Embodiment 1. When light emission is extracted from the first electrode 401 side, the second electrode 404 is formed of a material with high reflectivity. Voltage is supplied to the second electrode 404 by connecting it to the pad 412.

[0341] As described above, the lighting device shown in this embodiment has a light-emitting device having a first electrode 401, an EL layer 403, and a second electrode 404. Since this light-emitting device is a light-emitting device with high luminous efficiency, the lighting device in this embodiment can be a lighting device with low power consumption.

[0342] The lighting device is completed by fixing and sealing the substrate 400, on which the light-emitting device having the above configuration is formed, and the sealing substrate 407 using sealing materials 405 and 406. Either sealing material 405 or 406 may be used. In addition, a desiccant can be mixed into the inner sealing material 406 (not shown in Figure 21(B)), which allows for the adsorption of moisture and leads to improved reliability.

[0343] Furthermore, by extending the pad 412 and a portion of the first electrode 401 outside the sealing materials 405 and 406, it can be used as an external input terminal. Alternatively, an IC chip 420 with a converter or the like may be placed on top of it.

[0344] (Embodiment 6) In this embodiment, an example of an application of a lighting device manufactured by applying a light-emitting device, or a light-emitting device which is a part thereof, according to one aspect of the present invention, will be explained with reference to Figure 22.

[0345] As an indoor lighting device, it can be used as a ceiling light 8001. The ceiling light 8001 is available in both surface-mounted and recessed ceiling types. Such lighting devices are constructed by combining a light-emitting device with a housing or cover. It can also be used as a cord pendant type (suspended from the ceiling by a cord).

[0346] Furthermore, the 8002 footlight illuminates the floor surface, enhancing safety underfoot. For example, it is effective for use in bedrooms, stairwells, and corridors. In such cases, the size and shape can be appropriately changed according to the size and structure of the room. It is also possible to create a freestanding lighting device consisting of a light-emitting device and a support base.

[0347] Furthermore, the sheet-type lighting 8003 is a thin, sheet-shaped lighting device. Because it is attached to a wall surface, it does not take up much space and can be used in a wide range of applications. In addition, it can be easily made to cover a large area. It can also be used on curved walls and enclosures.

[0348] Alternatively, a lighting device 8004 can be used in which the light from the light source is controlled to flow only in a desired direction.

[0349] Furthermore, the desk lamp 8005 has a light source 8006, and as the light source 8006, a light-emitting device that is a part of the present invention or a light-emitting device that is a part thereof can be applied.

[0350] In addition to the above, by applying a light-emitting device, or a light-emitting device that is a part thereof, according to one aspect of the present invention, to a part of the furniture installed in the room, it is possible to create a lighting device that also functions as furniture.

[0351] As described above, various lighting devices can be obtained by applying a light-emitting device. These lighting devices are included in one aspect of the present invention.

[0352] Furthermore, the configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. [Examples]

[0353] In this embodiment, the element structure, manufacturing method, and characteristics of light-emitting devices 1 and 2, which are blue fluorescent light-emitting devices fabricated as a light-emitting device according to one aspect of the present invention, will be described. For the element characteristics, comparative light-emitting device 3 and reference light-emitting device 4 were fabricated and their device characteristics were compared. The device structure of the light-emitting device used in this embodiment is shown in Figure 23, and the specific configuration is shown in Table 1. The chemical formulas of the materials used in this embodiment are shown below.

[0354] [Table 1]

[0355] [ka]

[0356] Manufacturing of light-emitting devices The light-emitting devices shown in this embodiment all have a structure in which a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 are sequentially stacked on a first electrode 901 formed on a substrate 900, as shown in Figure 23, and a second electrode 903 is stacked on the electron injection layer 915. Furthermore, each light-emitting device has a device structure in which the same material is used for each functional layer, as shown in Table 1. However, these light-emitting devices differ in part of their manufacturing process. Compared to Reference Light-Emitting Device 4, which is formed continuously from the first electrode 901 to the second electrode 903 and the cap layer (CAP) 904, Light-Emitting Device 1 is formed by first forming the electron transport layer 914-2, then temporarily exposing it to a nitrogen atmosphere (dew point -78.0°C, moisture concentration: 0.8 ppm, oxygen concentration: 1 ppm) for 1 hour (also called N2 exposure treatment), and then continuously depositing the electron injection layer 915, the second electrode 903, and the cap layer 904. Furthermore, Light-Emitting Device 2 is formed by first forming the electron transport layer 914-1, then temporarily exposing it to a nitrogen atmosphere (dew point -78.0°C, moisture concentration: 0.8 ppm, oxygen concentration: 1 ppm) for 1 hour, and then continuously depositing the electron transport layer 914-2, the electron injection layer 915, the second electrode 903, and the cap layer 904. Furthermore, after forming the light-emitting layer 913, the device is temporarily exposed to a nitrogen atmosphere (dew point of -78.0°C, moisture concentration: 0.8 ppm, oxygen concentration: 1 ppm) for 1 hour, and then the electron transport layer 914 (914-1, 914-2), electron injection layer 915, second electrode 903, and cap layer 904 are continuously deposited to form a light-emitting device which is referred to as the comparative light-emitting device, or comparative light-emitting device 3.

[0357] First, a first electrode 901 was formed on the substrate 900. The electrode area was 4 mm². 2 The dimensions were set to (2mm x 2mm). A glass substrate was used for the substrate 900. The first electrode 901 was formed by depositing indium tin oxide (ITSO) containing silicon oxide to a thickness of 10 nm using the sputtering method, then depositing silver (Ag) to a thickness of 100 nm using the sputtering method, and finally depositing ITSO to a thickness of 10 nm.

[0358] Here, as a pretreatment, the surface of substrate 900 was washed with water, baked at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds. After that, 1 × 10 -4 The substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa. After vacuum firing at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus, the substrate was allowed to cool for about 30 minutes.

[0359] Next, a hole injection layer 911 was formed on the first electrode 901. The hole injection layer 911 was deposited within the vacuum deposition apparatus at a rate of 1 × 10⁻⁶ -4 After reducing the pressure to Pa, N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF) and an electron acceptor material containing fluorine with a molecular weight of 672 (OCHD-003) were co-deposited in a ratio of PCBBiF:OCHD-003 = 1:0.03 (mass ratio) to form a film thickness of 10 nm.

[0360] Next, hole transport layers 912 (hole transport layer 912-1 and hole transport layer 912-2) were formed on the hole injection layer 911. First, hole transport layer 912-1 was formed by depositing PCBBiF to a film thickness of 97.5 nm. Then, hole transport layer 912-2 was formed by depositing N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP) to a film thickness of 10 nm.

[0361] Next, a light-emitting layer 913 was formed on the hole transport layer 912.

[0362] The luminescent layer 913 was co-deposited using 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth) and 3,10-bis[N-(9-phenyl-9H-carbazole-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02) as a guest material (fluorescent material), with a weight ratio of αN-βNPAnth:3,10PCA2Nbf(IV)-02 = 1:0.015. The film thickness was set to 25 nm. For the comparative luminescent device 3, the surface of the luminescent layer 913 was temporarily exposed to a nitrogen atmosphere (dew point of -78.0°C, moisture concentration: 0.8 ppm, oxygen concentration: 1 ppm) for 1 hour to perform N2 exposure treatment.

[0363] Next, an electron transport layer 914 (electron transport layer 914-1 and electron transport layer 914-2) was formed on the light-emitting layer 913.

[0364] An electron transport layer 914-1 was formed by depositing 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)-1,1'-biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as mFBPTzn) to a thickness of 20 nm.

[0365] In the light-emitting device 2, the surface of the electron transport layer 914-1 was temporarily exposed to a nitrogen atmosphere (dew point of -78.0°C, moisture concentration: 0.8 ppm, oxygen concentration: 1 ppm) for 1 hour to perform N2 exposure treatment. Next, 2-{4-[9,10-di(naphthalene-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviated as ZADN) and 8-hydroxyquinolina tritium (abbreviated as Liq) were co-deposited in a weight ratio of ZADN:Liq = 1:1 to form the electron transport layer 914-2 with a film thickness of 15 nm. In the light-emitting device 1, the surface of the electron transport layer 914-2 was temporarily exposed to a nitrogen atmosphere (moisture concentration: 1 ppm, oxygen concentration: 1 ppm) for 1 hour to perform N2 exposure treatment.

[0366] Next, an electron injection layer 915 was formed on the electron transport layer 914. The electron injection layer 915 was formed by depositing lithium fluoride (LiF) to a thickness of 1 nm.

[0367] Next, a second electrode 903 was formed on the electron injection layer 915. The second electrode 903 was co-deposited using silver (Ag) and magnesium (Mg) in a weight ratio of Ag:Mg = 1:0.1. The film thickness was 15 nm. In this embodiment, the second electrode 903 is translucent and functions as a cathode.

[0368] Through the above process, a light-emitting device was formed on a substrate 900, comprising an EL layer 902 sandwiched between a pair of electrodes, and a top-emission type light-emitting device that extracts light from a second electrode 903. Reference light-emitting device 4 shown in Table 1 represents a light-emitting device that has not undergone any nitrogen atmosphere exposure (N2 exposure) treatment in the processes up to this point. The hole injection layer 911, hole transport layer 912, light-emitting layer 913, electron transport layer 914, and electron injection layer 915 described in the above process are functional layers that constitute the EL layer in one embodiment of the present invention. Furthermore, in the deposition process in the manufacturing method shown in this embodiment, a resistance heating deposition method was used for all steps.

[0369] Furthermore, as described above, the fabricated light-emitting device has a cap layer (CAP) 904 on the second electrode 903. The cap layer 904 was formed by depositing 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P-II) to a film thickness of 80 nm.

[0370] The element with the cap layer deposited is sealed on another substrate (not shown). When sealing with another substrate (not shown), another substrate (not shown), coated with a sealant that solidifies upon exposure to ultraviolet light, was fixed onto substrate 900 in a glove box under a nitrogen atmosphere. The substrates were then bonded together so that the sealant adhered around the light-emitting device formed on substrate 900. During sealing, 365 nm ultraviolet light at 6 J / cm² was applied. 2The sealant was solidified by irradiation and then stabilized by heat treatment at 80°C for 1 hour.

[0371] <<Operating characteristics of light-emitting devices>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were performed at room temperature. The results of the operating characteristics of each light-emitting device are shown in Figure 24 (luminance-current density characteristics), Figure 25 (luminance-voltage characteristics), Figure 26 (current efficiency-luminance characteristics), Figure 27 (current density-voltage characteristics), and Figure 28 (blue index (BI)-luminance characteristics). A spectroradiometer (Topcon SR-UL1R) was used to measure luminance, CIE chromaticity, and emission spectrum at room temperature.

[0372] Furthermore, the Blue Index (BI) shown in Figure 28 is a value obtained by dividing the current efficiency (cd / A) by the y-chromaticity, and is one of the indicators that represent the emission characteristics of blue light emission. Blue light emission tends to have higher color purity as the y-chromaticity decreases. High-color-purity blue light emission can express a wide range of blue colors even with a small luminance component, and by using high-color-purity blue light emission, the required luminance to express blue decreases, resulting in a reduction in power consumption. For this reason, BI, which takes into account y-chromaticity as one of the indicators of blue purity, is suitably used as a means of representing the efficiency of blue light emission, and it can be said that light-emitting devices with a high BI are more efficient as blue light-emitting devices used in displays.

[0373] From the results above, it was found that, in the initial characteristics shown in Figures 24 to 28, the light-emitting devices 1 and 2 in this embodiment show some differences in current efficiency and power efficiency on the low-brightness side, but on the high-brightness side, which affects the characteristics of the light-emitting device, they show good luminous efficiency comparable to that of the reference light-emitting device 4.

[0374] Furthermore, each light-emitting device has a emission level of 1000 cd / m². 2 Current density required to emit light at a certain brightness level (10-15 mA / cm²) 2Figure 29 shows the emission spectra when current is passed through the device. As shown in Figure 29, the emission spectra of these light-emitting devices have a peak around 460 nm, suggesting that all of them originate from the emission of 3,10PCA2Nbf(IV)-02 contained in the light-emitting layer 913.

[0375] Next, reliability tests were performed on light-emitting device 1, light-emitting device 2, comparison light-emitting device 3, and reference light-emitting device 4. The results of the reliability tests are shown in Figure 30. In Figure 30, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device operating time (h). The reliability tests were conducted with a current density of 50 mA / cm². 2 A constant current density drive test was performed at room temperature to measure the change in brightness under constant conditions. As shown in Figure 30, the light-emitting device 1, which was exposed to N2 after the deposition of the electron transport layer 914-2, and the light-emitting device 2, which was exposed to N2 after the deposition of the electron transport layer 914-1, showed a similarly high level of reliability compared to the reference light-emitting device 4, which was never exposed to a nitrogen atmosphere (N2 exposure) during the manufacturing process of the light-emitting device. On the other hand, the comparative light-emitting device 3, which was exposed to N2 after the deposition of the light-emitting layer 913, showed lower reliability compared to light-emitting devices 1 and 2. Therefore, in the formation of the EL layer of a blue fluorescent light-emitting device, it was found that N2 exposure does not significantly affect the reliability of the light-emitting device, at least not immediately after the formation of the light-emitting layer 913, but after the formation of functional layers such as the electron transport layer 914 formed on the light-emitting layer 913. From these results, it can be said that after the formation of functional layers such as the electron transport layer 914 formed on the light-emitting layer 913, it is possible to perform atmospheric exposure and pattern formation using photolithography. In other words, in the manufacturing of multiple light-emitting devices, after forming functional layers such as the electron transport layer 914, pattern formation using photolithography can be performed, and the functional layers formed thereafter can be formed using layers common to multiple light-emitting devices, thereby simplifying the manufacturing process. [Examples]

[0376] This embodiment describes the element structure, manufacturing method, and characteristics of a light-emitting device 5, which is a blue fluorescent light-emitting device fabricated as one embodiment of the present invention. Light-emitting device 5 is a light-emitting device in which the surface of the electron transport layer 914-2 is temporarily exposed to a nitrogen atmosphere (moisture concentration: 0.5 ppm, oxygen concentration: 4 ppm) for 1 hour to perform N2 exposure treatment, and then the electron injection layer 915, the second electrode 903, and the cap layer 904 are sequentially formed. For the element characteristics, a reference light-emitting device 6 that was never exposed to a nitrogen atmosphere (N2 exposure treatment) was fabricated and the device characteristics were compared. The device structure of the light-emitting device used in this embodiment is shown in Figure 23, and the specific configuration is shown in Table 2. The chemical formulas of the materials used in this embodiment are shown below. The element was fabricated in the same manner as in Example 1.

[0377] [Table 2]

[0378] [ka]

[0379] In the above chemical formula, the terms are 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) and 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen).

[0380] <<Operating characteristics of light-emitting devices>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were performed at room temperature. The results of the operating characteristics of each light-emitting device are shown in Figure 31 (luminance-current density characteristics), Figure 32 (luminance-voltage characteristics), Figure 33 (current efficiency-luminance characteristics), Figure 34 (current density-voltage characteristics), and Figure 35 (blue index (BI)-luminance characteristics). A spectroradiometer (Topcon SR-UL1R) was used to measure luminance, CIE chromaticity, and emission spectrum at room temperature.

[0381] From the results above, it was found that the light-emitting device 5 shown in this embodiment shows some differences in current efficiency and power efficiency on the low-brightness side in the initial characteristics shown in Figures 31 to 35, but exhibits good luminous efficiency on the high-brightness side, which affects the characteristics of the light-emitting device, comparable to that of the reference light-emitting device 6.

[0382] Furthermore, each light-emitting device has a emission level of 1000 cd / m². 2 Current density required to emit light at a certain brightness level (10-20 mA / cm²) 2 Figure 36 shows the emission spectra when current is passed through the device. As shown in Figure 36, the emission spectra of these light-emitting devices have a peak around 457 nm, suggesting that all of them originate from the emission of 3,10PCA2Nbf(IV)-02 contained in the light-emitting layer 913.

[0383] Next, reliability tests were performed on light-emitting device 5 and reference light-emitting device 6. The results of the reliability tests are shown in Figure 37. In Figure 37, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device operating time (h). The reliability tests were conducted with a current density of 50 mA / cm². 2 A constant current density drive test was performed at room temperature to measure the change in brightness under constant conditions. As shown in Figure 37, the light-emitting device 5, which was exposed to N2 after the deposition of the electron transport layer 914-2, showed a similarly high level of reliability compared to the reference light-emitting device 6, which was never exposed to a nitrogen atmosphere (N2 exposure) during the manufacturing process of the light-emitting device. Therefore, it was found that in the formation of the EL layer of a blue fluorescent light-emitting device, if functional layers such as the electron transport layer 914 are formed first, the impact of N2 exposure on the reliability of the light-emitting device is minimal. It can be said that if functional layers such as the electron transport layer 914 are formed first, it is possible to perform atmospheric exposure and pattern formation using photolithography. In other words, in the manufacturing of multiple light-emitting devices, it is possible to simplify the manufacturing process by performing pattern formation using photolithography after the formation of functional layers such as the electron transport layer, and then forming the functional layers that are formed thereafter using layers common to multiple light-emitting devices. [Examples]

[0384] This embodiment describes the element structure, manufacturing method, and characteristics of a light-emitting device 7, which is a red phosphorescent light-emitting device fabricated as one embodiment of the present invention. The light-emitting device 7 is a light-emitting device in which the surface of the electron transport layer 914-2 is temporarily exposed to a nitrogen atmosphere (dew point around -80°C, moisture concentration: 0.5 ppm, oxygen concentration: 3 ppm) for 1 hour to perform N2 exposure treatment, and then the electron injection layer 915, the second electrode 903, and the cap layer 904 are sequentially formed. For the element characteristics, a reference light-emitting device 8 that was never exposed to a nitrogen atmosphere (N2 exposure treatment) was fabricated and the device characteristics were compared. The device structure of the light-emitting device used in this embodiment is shown in Figure 23, and the specific configuration is shown in Table 3. The chemical formulas of the materials used in this embodiment are shown below. The element was fabricated in the same manner as in Example 1.

[0385] [Table 3]

[0386] [ka]

[0387] In the above chemical formula, the abbreviation is 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr).

[0388] <<Operating characteristics of light-emitting devices>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were performed at room temperature. The results of the operating characteristics of each light-emitting device are shown in Figure 38 (luminance-current density characteristics), Figure 39 (luminance-voltage characteristics), Figure 40 (current efficiency-luminance characteristics), and Figure 41 (current density-voltage characteristics). A spectroradiometer (Topcon SR-UL1R) was used to measure luminance, CIE chromaticity, and emission spectrum at room temperature.

[0389] From the results above, it was found that the light-emitting device 7 shown in this embodiment exhibits a good luminous efficiency comparable to that of the reference light-emitting device 8 in the initial characteristics shown in Figures 38 to 41.

[0390] Furthermore, each light-emitting device has a emission level of 1000 cd / m². 2 Current density required to emit light at a certain brightness level (10-20 mA / cm²) 2 Figure 42 shows the emission spectra when current is passed through the device. As shown in Figure 42, the emission spectra of these light-emitting devices have a peak around 624 nm, suggesting that this is all due to the emission of the red phosphorescent dopant OCPG-006 contained in the light-emitting layer 913.

[0391] Next, reliability tests were performed on light-emitting device 7 and reference light-emitting device 8. The results of the reliability tests are shown in Figure 43. In Figure 43, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device operating time (h). The reliability tests were conducted with a current density of 50 mA / cm². 2 A constant current density drive test was performed at room temperature to measure the change in brightness under constant conditions. As shown in Figure 43, the light-emitting device 7, which was exposed to N2 after the deposition of the electron transport layer 914-2, showed a similarly high level of reliability compared to the reference light-emitting device 8, which was never exposed to a nitrogen atmosphere (N2 exposure) during the manufacturing process of the light-emitting device. Therefore, it was found that in the formation of the EL layer of a red phosphorescent light-emitting device, if functional layers such as the electron transport layer 914 are formed first, the impact of N2 exposure on the reliability of the light-emitting device is minimal. From these results, it can be said that if functional layers such as the electron transport layer 914 are formed first, it is possible to perform atmospheric exposure and pattern formation using photolithography. In other words, in the manufacturing of multiple light-emitting devices, it is possible to simplify the manufacturing process by performing pattern formation using photolithography after the formation of functional layers such as the electron transport layer, and then forming the functional layers that are formed thereafter using layers common to multiple light-emitting devices. [Examples]

[0392] This embodiment describes the element structure, manufacturing method, and characteristics of a light-emitting device 9, which is a green phosphorescent light-emitting device fabricated as one aspect of the present invention. The light-emitting device 9 is a light-emitting device in which the surface of the electron transport layer 914-2 is temporarily exposed to a nitrogen atmosphere (dew point around -80°C, moisture concentration: 0.5 ppm, oxygen concentration: 3 ppm) for 1 hour to perform N2 exposure treatment, and then the electron injection layer 915, the second electrode 903, and the cap layer 904 are sequentially formed. For the element characteristics, a reference light-emitting device 10 that was never exposed to a nitrogen atmosphere (N2 exposure treatment) was fabricated and the device characteristics were compared. The device structure of the light-emitting device used in this embodiment is shown in Figure 23, and the specific configuration is shown in Table 4. The chemical formulas of the materials used in this embodiment are shown below. The element was fabricated in the same manner as in Example 1.

[0393] [Table 4]

[0394] [ka]

[0395] In the above chemical formula, we use the following terms: 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), [2-d3-methyl-(2-pyridinyl-κN)benzoflo[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy-d3)]), and 9-phenyl-9H-3-(9-phenyl-9H-carbazole-3-yl)carbazole (abbreviation: PCCP).

[0396] <<Operating characteristics of light-emitting devices>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were performed at room temperature (in an atmosphere maintained at 25°C). The results of the operating characteristics of each light-emitting device are shown in Figure 44 (luminance-current density characteristics), Figure 45 (luminance-voltage characteristics), Figure 46 (current efficiency-luminance characteristics), and Figure 47 (current density-voltage characteristics). A spectroradiometer (Topcon SR-UL1R) was used to measure luminance, CIE chromaticity, and emission spectrum at room temperature.

[0397] From the results above, it was found that the light-emitting device 9 shown in this embodiment exhibits a good luminous efficiency comparable to that of the reference light-emitting device 10 in the initial characteristics shown in Figures 44 to 47.

[0398] Furthermore, each light-emitting device has a emission level of 1000 cd / m². 2 Current density required to emit light at a certain brightness level (10-20 mA / cm²) 2 Figure 48 shows the emission spectra when current is passed through the device. As shown in Figure 48, the emission spectra of these light-emitting devices have a peak around 528 nm, suggesting that this is all due to the emission of the green phosphorescent dopant, [Ir(ppy)2(mbfpypy-d3)], contained in the light-emitting layer 913.

[0399] Next, reliability tests were performed on light-emitting device 9 and reference light-emitting device 10. The results of the reliability tests are shown in Figure 49. In Figure 49, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device operating time (h). The reliability tests were conducted with a current density of 50 mA / cm². 2A constant current density drive test was performed at room temperature to measure the change in brightness under constant conditions. As shown in Figure 49, the light-emitting device 9, which was exposed to N2 after the deposition of the electron transport layer 914-2, showed a similarly high level of reliability compared to the reference light-emitting device 10, which was never exposed to a nitrogen atmosphere (N2 exposure) during the manufacturing process of the light-emitting device. Therefore, it was found that in the formation of the EL layer of a green phosphorescent light-emitting device, if functional layers such as the electron transport layer 914 are formed first, the impact of N2 exposure on the reliability of the light-emitting device is minimal. From these results, it can be said that if functional layers such as the electron transport layer 914 are formed first, it is possible to perform atmospheric exposure and pattern formation using photolithography. In other words, in the manufacturing of multiple light-emitting devices, it is possible to simplify the manufacturing process by performing pattern formation using photolithography after the formation of functional layers such as the electron transport layer, and then forming the functional layers that are formed thereafter using layers common to multiple light-emitting devices. [Examples]

[0400] In this embodiment, the element structure, manufacturing method, and characteristics of light-emitting devices 11 and 12, which are red phosphorescent light-emitting devices fabricated as light-emitting devices according to one aspect of the present invention, will be described. Light-emitting device 11 is a light-emitting device in which, after the formation of the electron transport layer 914-2, a pattern was formed using the photolithography method, and then the electron injection layer 915, the second electrode 903, and the cap layer 904 were sequentially formed. Light-emitting device 12 is a light-emitting device similar to the light-emitting device 100 described using Figure 1(B) in Embodiment 1, in which, after the formation of the electron transport layer 914-2, a pattern was formed using the photolithography method, and then an insulating film was formed to protect the sides (or edges) of the hole injection layer 911, hole transport layer 912, light-emitting layer 913, electron transport layer 914-1, and electron transport layer 914-2. For the element characteristics, a reference light-emitting device 13 without pattern formation using the photolithography method was fabricated, and the device characteristics were compared. The device structure of the light-emitting device used in this embodiment is shown in Figure 23, and the specific configuration is shown in Table 5. The chemical formulas of the materials used in this embodiment are shown below.

[0401] [Table 5]

[0402] [ka]

[0403] In the above chemical formula, 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κ 2 Let's call it iridium(III) (abbreviated as Ir(dmdppr-P)2(dibm)) O,O').

[0404] <<Operating characteristics of light-emitting devices>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were performed at room temperature. The results of the operating characteristics of each light-emitting device are shown in Figure 50 (luminance-current density characteristics), Figure 51 (luminance-voltage characteristics), Figure 52 (current efficiency-luminance characteristics), Figure 53 (current density-voltage characteristics), Figure 54 (power efficiency-luminance characteristics), and Figure 55 (external quantum efficiency-luminance characteristics). A spectroradiometer (Topcon SR-UL1R) was used to measure luminance, CIE chromaticity, and emission spectrum at room temperature.

[0405] From the results above, it was found that the light-emitting devices 11 and 12, which were patterned using photolithography, exhibited good initial characteristics.

[0406] Furthermore, in the brightness-voltage characteristics shown in Figure 51, the light-emitting device 11 showed a higher voltage compared to the reference light-emitting device 13, while the light-emitting device 12 showed results equivalent to the reference light-emitting device 13. From this, it was found that the increase in voltage of the light-emitting device can be suppressed by forming an insulating film to protect the sides (or edges) of the hole injection layer 911, hole transport layer 912, light-emitting layer 913, electron transport layer 914-1, and electron transport layer 914-2 after pattern formation using the photolithography method.

[0407] Furthermore, each light-emitting device has a emission level of 1000 cd / m². 2 Current density required to emit light at a certain brightness level (10-20 mA / cm²) 2 Figure 56 shows the emission spectra when current is passed through the device. As shown in Figure 56, the emission spectra of these light-emitting devices have a peak around 635 nm, suggesting that this is all due to the emission of the red phosphorescent dopant Ir(dmdppr-P)2(dibm) contained in the light-emitting layer 913.

[0408] Next, reliability tests were performed on light-emitting device 11, light-emitting device 12, and reference light-emitting device 13. The results of the reliability tests are shown in Figure 57. In Figure 57, the vertical axis represents the normalized brightness (%) with the initial brightness set to 100%, and the horizontal axis represents the device operating time (h). The reliability tests were conducted with a current density of 50 mA / cm². 2 A constant current density drive test was conducted at room temperature to measure the change in brightness while keeping the current density constant.

[0409] As shown in Figure 57, the results indicate that the reliability of light-emitting devices 11 and 12 is not significantly different from that of the reference light-emitting device 13. Therefore, it was found that when forming the EL layer of a light-emitting device, if pattern formation is performed using photolithography after the formation of functional layers such as the electron transport layer 914, it does not significantly affect the reliability of the light-emitting device. In other words, in the manufacturing of multiple light-emitting devices, it is possible to simplify the manufacturing process by performing pattern formation using photolithography after the formation of functional layers such as the electron transport layer, and then forming the functional layers that are formed thereafter using layers common to multiple light-emitting devices. [Explanation of symbols]

[0410] 100 Light-emitting devices 101 First electrode 102 Second electrode 103 EL layer 103a EL layer 103b EL layer 103c EL layer 103B EL layer 103G EL layer 103R EL layer 103P EL layer 103Q EL layer 104 Hole injection / transport layer 104B Hole injection / transport layer 104G Hole Injection / Transport Layer 104R Hole injection / transport layer 104P Hole injection / transport layer 104Q Hole injection / transport layer 106 Charge generation layer 106a Charge generation layer 106b Charge generation layer 106B Charge generation layer 10⁶G charge generation layer 106R charge generation layer 107 Insulating layer 107B Insulating layer 107G insulating layer 107R Insulating layer 108 Electron transport layer 108B Electron transport layer 108G electron transport layer 108R Electron transport layer 108Q electron transport layer 109 Electron injection layer 111 Hole injection layer 111a Hole injection layer 111b Hole injection layer 112 Hole transport layer 112a Hole transport layer 112b Hole transport layer 113 Emitting layer 113a Light-emitting layer 113b Emitting layer 113c emissive layer 113B Emitting layer 113G emissive layer 113R emissive layer 113Q Emitting Layer 114 Electron transport layer 114b Electron transport layer 115 Electron injection layer 115b Electron injection layer 231 Display area 400 circuit boards 401 First electrode 403 EL layer 404 Second electrode 405 sealant 406 Sealant 407 Sealing substrate 412 pads 420 IC chips 501C insulating film 501D insulating film 504 Conductive film 506 Insulating film 508 Semiconductor film 508A area 508B area 508C area 510 First substrate 512A Conductive film 512B Conductive film 519 terminals 520 Functional Layers 524 Conductive film 528 Bulkhead 528B opening 528G opening 528R opening 530B Pixel Circuit 530G Pixel Circuit 540 Insulating layer 550B Light-Emitting Device 550G Light-emitting Device 550R Light-Emitting Device 551B Electrode 551G electrode 551R electrode 552 Electrode 573 Insulating layer 580 Gap 700 Light-emitting devices 702B pixels 702G pixels 702R pixels 703 pixels 705 Insulating layer 770 circuit boards 900 circuit boards 901 First electrode 902 EL layer 903 Second electrode 904 Cap layer 911 Hole injection layer 912 Hole transport layer 913 Emitting layer 914 Electron transport layer 914-1 Electron transport layer 914-2 Electron transport layer 915 Electron injection layer 951 circuit board 952 Electrode 953 Insulating layer 954 Partition layer 955 EL layer 956 Electrode 5200B Electronic equipment 5210 Arithmetic unit 5220 Input / Output Device 5230 Display section 5240 Input Section 5250 Detection Unit 5290 Communications Department 8001 Ceiling Light 8002 Footlight 8003 Sheet-type lighting 8004 Lighting device 8005 Desk Lamp 8006 light source

Claims

1. A light-emitting layer above a first electrode; an electron transport layer above the light emitting layer; an electron injection layer in contact with a side surface of the light emitting layer and a side surface of the electron transport layer; a second electrode in contact with the electron injection layer.

2. A light-emitting layer above a first electrode; an electron transport layer above the light emitting layer; an insulating layer in contact with a side surface of the light-emitting layer and a side surface of the electron transport layer; an electron injection layer in contact with the insulating layer; a second electrode in contact with the electron injection layer.

3. In claim 2, A light emitting device, wherein the insulating layer is one of aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide.

4. In any one of claims 1 to 3, The light-emitting device, wherein the electron injection layer comprises any of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth metal compound, and a rare earth metal compound.

5. In any one of claims 1 to 3, The electron injection layer comprises an organic compound and a substance that exhibits electron donating properties to the organic compound.

6. In any one of claims 1 to 3, A light-emitting device, wherein the electron injection layer comprises an organic compound and any of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth metal compound, and a rare earth metal compound.

7. In any one of claims 1 to 3, A light-emitting device, wherein the electron injection layer comprises an organic compound and a metal from Group 5, 7, 9, 11, or 13 of the periodic table.

8. In any one of claims 5 to 7, The organic compound has a LUMO level of -3.6 eV or more and -2.3 eV or less.

9. In any one of claims 5 to 8, The organic compound is a heterocyclic compound having a pyridine skeleton, a diazine skeleton, or a triazine skeleton.

10. A light emitting device according to any one of claims 1 to 9, A light emitting device comprising at least one of a transistor and a substrate.

11. A light emitting device according to claim 10, An electronic device having at least one of a sensor, an operation button, a speaker, and a microphone.

12. A lighting device having a light-emitting device according to any one of claims 10 and a housing.

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