Light-emitting device and display device

Abstract

The present disclosure provides a new technology that achieves low power consumption, high luminance, and a wide color gamut in a light-emitting device (100) provided with light-emitting elements (10). The light-emitting device (100) has a plurality of tandem-structured light-emitting elements (10) that each emit light in a specific color. In the light-emitting elements (10), electron generation layers (121, 221) are connected to cathode wiring (52, 53) capable of supplying electrons, and hole generation layers (122, 222) are connected to anode wiring (42, 43) capable of supplying holes.

Description

Light-emitting device and display device

[0001] The present disclosure relates to a light-emitting device and a display device.

[0002] Conventionally, display devices including light-emitting devices formed with organic electroluminescence (EL) elements are required to achieve both high brightness and a wide color gamut. In light of this technical background, a known technique for achieving low power consumption, high brightness, and a wide color gamut is to form a pixel with light-emitting elements of multiple colors (e.g., red, green, and blue), form dark color filters on some of the pixels, and form lighter color filters or no color filters on the remaining pixels, and arrange the dark color filter regions and the light color filter regions or regions without color filters in a checkered pattern (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 2016-133590

[0004] However, the above-mentioned conventional techniques require color filters, which absorb part of the light emitted from the light-emitting elements, and therefore there is still room for improvement, at least from the viewpoint of achieving high brightness.

[0005] An object of one embodiment of the present disclosure is to provide a new technique for achieving high luminance in a light-emitting device including a light-emitting element.

[0006] In order to solve the above-described problems, a light-emitting device according to one aspect of the present disclosure includes a plurality of light-emitting elements arranged in an arrangement direction, each of which emits light of one of two or more colors. Each of the light-emitting elements includes an anode, a cathode, two or more stacks disposed between the two electrodes, and one or more charge generation layers disposed between adjacent stacks in the stacking direction, the stacks overlapping in the stacking direction. Each of the stacks is composed of a light-emitting layer and a functional layer that supplies charge to the light-emitting layer, the functional layers overlapping in the stacking direction. Each of the charge generation layers is composed of an electron generation layer disposed on the anode side and a hole generation layer disposed on the cathode side, the functional layers overlapping in the stacking direction. The anode and the hole generation layer are each connected to two or more anode wirings that can supply a specific amount of holes to the anode and the hole generation layer. The cathode and the electron generation layer are each connected to two or more cathode wirings that can supply a specific amount of electrons to the cathode and the electron generation layer.

[0007] In order to solve the above problem, a display device according to one aspect of the present disclosure includes the above light-emitting device.

[0008] According to one aspect of the present disclosure, it is possible to provide a new technique for achieving high brightness in a light-emitting device including a light-emitting element.

[0009] 9 is a plan view schematically showing the configuration of a display device according to embodiment 1 of the present disclosure. FIG. 9 is a view schematically showing the arrangement of light-emitting elements according to embodiment 1 of the present disclosure. FIG. 9 is a view schematically showing the configuration of a light-emitting device according to embodiment 1 of the present disclosure. FIG. 9 is a view schematically showing an example of wiring in a light-emitting device according to embodiment 1 of the present disclosure when viewed in a plan view. FIG. 9 is a view schematically showing an example of wiring in a light-emitting device according to embodiment 1 of the present disclosure when viewed in a direction indicated by an arrow Y1 in FIG. 4. FIG. 9 is a view schematically showing an example of wiring in a light-emitting device according to embodiment 1 of the present disclosure when viewed in a direction indicated by an arrow X2 in FIG. 4. FIG. 9 is a view schematically showing the arrangement of light-emitting elements according to embodiment 2 of the present disclosure. FIG. 9 is a view schematically showing the configuration of a light-emitting device according to embodiment 2 of the present disclosure. FIG. 9 is a view schematically showing an example of wiring in a light-emitting device according to embodiment 2 of the present disclosure when viewed in a plan view. FIG. 9 is a view schematically showing an example of wiring in a light-emitting device according to embodiment 2 of the present disclosure when viewed in a direction indicated by an arrow Y1 in FIG. 9. FIG. 9 is a view schematically showing an example of wiring in a light-emitting device according to embodiment 2 of the present disclosure when viewed in a direction indicated by an arrow X2 in FIG. FIG. 9 is a view schematically showing the arrangement of light-emitting elements according to embodiment 3 of the present disclosure. Fig. 14 is a diagram schematically illustrating a configuration of a light-emitting device according to a third embodiment of the present disclosure. Fig. 15 is a diagram schematically illustrating an example of wiring in a light-emitting device according to a third embodiment of the present disclosure when viewed from above. Fig. 16 is a diagram schematically illustrating an example of wiring in a light-emitting device according to a third embodiment of the present disclosure when viewed from the direction of arrow Y1 in Fig. 14. Fig. 17 is a diagram schematically illustrating an example of wiring in a light-emitting device according to a third embodiment of the present disclosure when viewed from the direction of arrow X2 in Fig. 14.

[0010] An embodiment of the present disclosure will be described using an OLED as an example, with reference to the drawings as needed.

[0011] In this specification, when describing configurations relating to different luminescent colors among similar basic configurations, a symbol indicating the color is further added to the symbol of the basic configuration. For example, a symbol R is added to a configuration relating to red luminescence, a symbol G is added to a configuration relating to green luminescence, a symbol B is added to a configuration relating to blue luminescence, a symbol W is added to a configuration relating to white luminescence, a symbol C is added to a configuration relating to cyan luminescence, a symbol Y is added to a configuration relating to yellow luminescence, and a symbol M is added to a configuration relating to magenta luminescence. The above symbols may also be used to indicate the meaning of each color in the text.

[0012] In this specification, "to" means a range including both ends, and when both ends are numbers, it means a range from an upper limit to an lower limit. Furthermore, "%" means "% by mass" unless otherwise specified.

[0013] In addition, in this specification, "adjacent" is a general term for cases where two specific structures are adjacent to each other and cases where two specific structures are side by side with another structure in between, and can mean either or both of these cases.

[0014] [Embodiment 1] [Display Device] Fig. 1 is a plan view schematically illustrating the configuration of a display device according to embodiment 1 of the present disclosure. Fig. 1 illustrates a smartphone, which is an example of a display device. The display device 1 includes a display area 2 and a frame area 3 surrounding the display area 2. The display area 2 has a large number of pixels 4 arranged along the directions indicated by arrows X and Y in the figure. Note that in the figure, both arrows X and Y indicate the arrangement direction in the present disclosure, and arrow Z indicates the stacking direction.

[0015] The arrangement of light-emitting elements in this embodiment is shown schematically in FIG. 2. Each pixel 4 includes four light-emitting elements: a red light-emitting element 10R, a green light-emitting element 10G, a blue light-emitting element 10B, and a white light-emitting element 10W. The positions and sizes of these light-emitting elements are appropriately set based on the visual effect of each color, etc. These light-emitting elements are arranged in one direction in the order of red, green, blue, and white. For example, the light-emitting elements are arranged from left to right in the top row, from right to left in the bottom row, from bottom to top in the left column, and from top to bottom in the right column, relative to the plane of FIG. 1 .

[0016] [Light-Emitting Device] FIG. 3 is a diagram schematically illustrating the configuration of a light-emitting device according to the first embodiment of the present disclosure. The light-emitting device 100 is a top-emission type light-emitting device including light-emitting elements in a so-called tandem structure. As shown in FIG. 2, the light-emitting device 100 includes four light-emitting elements: a red light-emitting element 10R, a green light-emitting element 10G, a blue light-emitting element 10B, and a white light-emitting element 10W, which are appropriately arranged in the X and Y directions. As described above, the light-emitting device 100 has multiple light-emitting elements arranged in the arrangement direction, each of which emits light in one of two or more colors. The light-emitting device 100 corresponds to the aforementioned pixel 4. For convenience, FIG. 3 illustrates the arrangement of the light-emitting elements in the X direction.

[0017] [Light-emitting element] The light-emitting element 10 has an anode 101, a hole injection layer 102, a first stack 11, a first charge generation layer 12, a second stack 21, a second charge generation layer 22, a third stack 31, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107, in this order along the Z direction. That is, the red light-emitting element 10R has an anode 101R, a hole injection layer 102, a first stack 11R, a first charge generation layer 12, a second stack 21R, a second charge generation layer 22, a third stack 31R, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The green light-emitting element 10G includes an anode 101G, a hole injection layer 102, a first stack 11G, a first charge generation layer 12, a second stack 21G, a second charge generation layer 22, a third stack 31G, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The blue light-emitting element 10B includes an anode 101B, a hole injection layer 102, a first stack 11B, a first charge generation layer 12, a second stack 21B, a second charge generation layer 22, a third stack 31B, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The white light-emitting element 10W has an anode 101W, a hole injection layer 102, a first stack 11W, a first charge generation layer 12, a second stack 21W, a second charge generation layer 22, a third stack 31W, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107.

[0018] Thus, each light-emitting element 10 has an anode 101, a cathode 104, which are stacked in the Z direction, three stacks (11, 21, and 31) disposed between the two electrodes, and two charge generating layers (12 and 22) disposed between adjacent stacks in the Z direction.

[0019] The anode 101 is formed corresponding to the emitted color and is formed independently for each light-emitting element. Hereinafter, the layers formed corresponding to each color are also referred to as "independent layers." The hole injection layer 102, the electron injection layer 103, the cathode 104, the auxiliary layer 105, the buffer layer 106, and the sealing layer 107 are all formed integrally across the light-emitting elements 10 of each color. Hereinafter, the layers formed integrally across the light-emitting elements of different colors are also referred to as "common layers." Furthermore, the cathode 104, the auxiliary layer 105, the buffer layer 106, and the sealing layer 107 are configured integrally across multiple light-emitting devices 100.

[0020] The anode 101 is a light-reflective electrode, for example, an indium tin oxide / Ag laminate. In the present disclosure, the anode is one of a pair of electrodes, an anode and a cathode, and is an electrode for supplying holes to each layer constituting the light-emitting element. The anode is conductive. Furthermore, the anode may have optical properties, for example, reflecting part of visible light and transmitting the rest. Typically, the anode includes both an electrode material that reflects visible light and an electrode material that transmits visible light.

[0021] To enhance hole injection properties, a material with a relatively high work function (e.g., a material with a work function of 4.5 eV or more) is preferably used as the anode material. Examples of electrode materials with a high work function include Pt (5.65 eV), Ir (5.25 eV), Ni (5.2 eV), Au (5.15 eV), and Pd (5.15 eV), as well as indium tin oxide (In—Sn—O).

[0022] Examples of electrode materials that reflect visible light include metal materials such as Al, Mg, Li, Ag, Pd, and Cu, as well as alloys of these metal materials (e.g., APC (Ag-Pd-Cu) alloy, etc.).

[0023] Examples of electrode materials that transmit visible light include thin films of transparent metal oxides (e.g., indium tin oxide, indium zinc oxide (In—Zn—O, indium zinc oxide), indium gallium oxide (In—Ga—O, indium gallium oxide), and indium gallium zinc oxide (In—Ga—Zn—O, indium tin gallium zinc oxide)), thin films made of metal materials such as Al, Mg, and Ag, and nanowires (NW) made of these metal materials.

[0024] Among transparent metal oxides, indium tin oxide has a relatively high work function of 4.6 to 5.0 eV and is therefore suitable for use as an anode material. Furthermore, for the anode, a laminate (e.g., indium tin oxide / Ag) in which indium tin oxide is formed on the surface of a metal material can be used for the purpose of improving the conductivity as an electrode or adding the function of reflecting visible light.

[0025] The hole injection layer 102 is disposed adjacent to the anode 101, for example, and may be composed of a hole transport material and an electron accepting material (hole supply material). In the present disclosure, the material of the hole injection layer may be the same inorganic or organic material as the material of the hole transport layer described later. The specific material of the hole injection layer in the light-emitting element may be the same as or different from the material of the hole generation layer described later.

[0026] The hole injection layer may be composed of a material containing, for example, an organic hole transport material and an organic electron accepting material (hole supply material) added in the range of 1 to 10%. Examples of organic hole transport materials include known triarylamine organic compounds. Examples of organic electron accepting materials include TCNQ (tetracyanoquinodimethane), TNAP (tetracyano-2,6-naphthoquinodimethane), DCNQI (dicyanoquinomethane), TCNQ-4F (1,2,3,4-fluorinated tetracyanoquinodimethane), TNAP-4F (1,2,3,4,5,6-fluorinated tetracyano-2,6-naphthoquinodimethane), DCTCNQ (dicyanotetracyanoquinodimethane), and the like. Examples of suitable materials for the hole injection layer include tetracyanoquinodimethane (TCNTQ), tetracyanoterphenylquinomethane (TCNDQ), tetracyanodiphenylquinomethane (TNAT), tetracyanoanthracenylquinodimethane (M(dmit)2), a type of metal complex, OCNAQ (octacyanoanthracenylquinotetramethane), and HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile). The hole injection layer may be made of one or more materials. By using the hole transport material and electron accepting material described above as the material for the hole injection layer, it is possible to realize a hole injection layer having sufficient hole injection capability.

[0027] The electron injection layer 103 contributes to the transport of electrons and contains an electron transport material. The electron transport material may be an inorganic electron transport material or an organic electron transport material. The electron transport material can be appropriately selected from materials commonly used in this field.

[0028] Examples of inorganic electron transport materials include metal oxides containing one or more metal elements selected from the group consisting of Zn, Ti, Mg, Zr, Sn, and Nb. The inorganic electron transport material may be in the form of nanoparticles.

[0029] Examples of organic electron transporting materials include compounds containing one or more nitrogen-containing heterocycles such as oxadiazole rings, triazole rings, triazine rings, quinoline rings, phenanthroline rings, pyrimidine rings, pyridine rings, imidazole rings, and carbazole rings, as well as complexes containing one or more such nitrogen-containing heterocycles. Specific examples of organic electron transporting materials include 1,10-phenanthroline derivatives such as bathocuproine and bathophenanthroline, benzimidazole derivatives such as 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI), metal complexes such as bis(10-benzoquinolinolato)beryllium complex, 8-hydroxyquinoline Al complex, and bis(2-methyl-8-quinolinato)-4-phenylphenolate aluminum, and 4,4'-biscarbazole biphenyl.

[0030] Examples of electron transport materials constituting the electron injection layer include lithium fluoride (LiF), which is an inorganic material. The electron injection layer may be composed solely of an organic material such as an oxadiazole compound, may be composed by doping an organic material with a metal material (e.g., Li or Yb), or may be composed solely of a metal material (e.g., Li or Yb).

[0031] LiF used in the electron injection layer exhibits excellent electron injection properties. On the other hand, the formation of a functional layer containing an inorganic material, such as Yb, including but not limited to LiF, is generally carried out at a higher temperature than the formation of an emitting layer and other functional layers made of organic materials due to the high melting point of the inorganic material. This may cause thermal damage to the organic material and (near-)infrared emitting material that have been previously formed. Therefore, if possible, it is preferable to form a light-emitting element using only organic materials, without including inorganic materials. Even when the electron injection layer is made only of organic materials, high electron injection properties can be maintained by including metals, such as Yb, Li, and Al, in the cathode 104, which can form a vapor-deposited layer at a relatively low temperature.

[0032] The development of organic electron injection materials such as BUPH1, BPen, p-MeO-Phen, p-NMe2-Phen, and p-Pyrrd-Phen is underway as materials for electron injection layers that can have sufficient properties when combined with a cathode made of aluminum (Al) or the like, which allows for the formation of a vapor deposition layer at a relatively low temperature, and which can be used to form an electron injection layer substantially entirely from organic materials.

[0033] However, the electron injection ability of an electron injection layer using an organic material may still be inferior to that of an electron injection layer using an inorganic material such as LiF. Therefore, when an electron injection layer made of an organic material is disposed adjacent to the cathode, the amount of carriers (electrons) supplied to the light-emitting layer formed on the cathode side may be reduced. In such cases, the electron injection ability of the entire light-emitting element may be appropriately adjusted to balance with the hole injection level on the anode side.

[0034] The cathode 104 is a light-transmitting electrode, for example, an Mg / Ag layer in which Mg and Ag are mixed in a predetermined amount. In the present disclosure, the cathode is the other electrode of a pair of electrodes, an anode and a cathode, and is an electrode for supplying electrons to each layer constituting the light-emitting element. The cathode is disposed opposite the anode in the stacking direction. The cathode has, for example, electrical conductivity and transparency to visible light.

[0035] For example, a material with a relatively small work function is preferably used as the cathode material, in order to enhance electron injection. Examples of electrode materials constituting the cathode include metal materials such as alkali metals, alkaline earth metals, and Al, alloys containing these, and nanowires (e.g., Ag nanowires). Examples of alloys include an alloy of Mg and Ag, and Al doped with a small amount of Li.

[0036] The auxiliary layer 105 is a layer for improving the viewing angle. The buffer layer 106 and the sealing layer 107 are both layers for preventing moisture from penetrating into the light-emitting element 10. For example, the buffer layer 106 is a LiF layer, and the sealing layer 107 is a resin film.

[0037] [Stack] Each stack in each light-emitting element 10 is composed of a light-emitting layer and a functional layer that are stacked in the Z direction. The functional layer is a layer that has the function of supplying the light-emitting layer with charges to be recombined in the light-emitting layer.

[0038] More specifically, the first stack 11R of the red light-emitting element 10R is composed of a hole transport layer 111, an electron blocking layer 112R, a red light-emitting layer 113R, a hole blocking layer 114, and an electron transport layer 115. The second stack 21R of the red light-emitting element 10R is composed of a hole transport layer 211, an electron blocking layer 212R, a red light-emitting layer 213R, a hole blocking layer 214, and an electron transport layer 215. The third stack 31R of the red light-emitting element 10R is composed of a hole transport layer 311, an electron blocking layer 312R, a red light-emitting layer 313R, a hole blocking layer 314, and an electron transport layer 315.

[0039] Furthermore, the first stack 11G of the green light-emitting element 10G is composed of a hole transport layer 111, an electron blocking layer 112G, a green light-emitting layer 113G, a hole blocking layer 114, and an electron transport layer 115. The second stack 21G of the green light-emitting element 10G is composed of a hole transport layer 211, an electron blocking layer 212G, a green light-emitting layer 213G, a hole blocking layer 214, and an electron transport layer 215. The third stack 31G of the green light-emitting element 10G is composed of a hole transport layer 311, an electron blocking layer 312G, a green light-emitting layer 313G, a hole blocking layer 314, and an electron transport layer 315.

[0040] Furthermore, the first stack 11B of the blue light-emitting element 10B is composed of a hole transport layer 111, an electron blocking layer 112B, a blue light-emitting layer 113B, a hole blocking layer 114, and an electron transport layer 115. The second stack 21B of the blue light-emitting element 10B is composed of a hole transport layer 211, an electron blocking layer 212B, a blue light-emitting layer 213B, a hole blocking layer 214, and an electron transport layer 215. The third stack 31B of the blue light-emitting element 10B is composed of a hole transport layer 311, an electron blocking layer 312B, a blue light-emitting layer 313B, a hole blocking layer 314, and an electron transport layer 315.

[0041] Furthermore, the first stack 11W of the white light-emitting element 10W is composed of a hole transport layer 111, an electron blocking layer 112W, a first light-emitting layer 113W, a hole blocking layer 114, and an electron transport layer 115. The second stack 21W of the white light-emitting element 10W is composed of a hole transport layer 211, an electron blocking layer 212W, a second light-emitting layer 213W, a hole blocking layer 214, and an electron transport layer 215. The third stack 31W of the white light-emitting element 10W is composed of a hole transport layer 311, an electron blocking layer 312W, a third light-emitting layer 313W, a hole blocking layer 314, and an electron transport layer 315. The first light-emitting layer 113W is a red light-emitting layer, the second light-emitting layer 213W is a green light-emitting layer, and the third light-emitting layer 313W is a blue light-emitting layer.

[0042] Note that the light-emitting layers of each color in the light-emitting device 100 are all light-emitting layers of the same color. For example, the red light-emitting layers 113R, 213R, 313R, and 113W are all light-emitting layers of the same red color, the green light-emitting layers 113G, 213G, 313G, and 113G are all light-emitting layers of the same green color, and the blue light-emitting layers 113B, 213B, 313B, and 113W are all light-emitting layers of the same blue color.

[0043] In the present disclosure, the term "same color" refers to a commonality in which the emission spectra of two or more light-emitting layers have a color that is essentially the same. For example, from the viewpoint of enhancing color purity, the difference in peak wavelengths of the emission spectra of two or more light-emitting layers of the same color is preferably 10 nm or less, or more preferably ±5 nm or less, and the smaller the difference, the better.

[0044] <Light-emitting layer> The light-emitting layer of each color may be a host-guest light-emitting layer formed by doping a guest compound into a host compound, examples of which include a fluorescent light-emitting layer and a phosphorescent light-emitting layer. Each light-emitting layer may be composed of a light-emitting layer material appropriate for the emitted color. For example, the blue light-emitting layer (blue light-emitting layers 113B, 213B, 313B, and third light-emitting layer 313W) may be a fluorescent light-emitting layer. Examples of light-emitting materials for the blue light-emitting layer include pyrene-based compounds and anthracene-based compounds, which are fluorescent dopants.

[0045] Furthermore, for example, the red light-emitting layers (red light-emitting layers 113R, 213R, 313R, and first light-emitting layer 113W) and the green light-emitting layers (green light-emitting layers 113G, 213G, 313G, and second light-emitting layer 213W) may be phosphorescent light-emitting layers. Examples of phosphorescent dopants in the light-emitting materials of the red light-emitting layers and green light-emitting layers include iridium complexes, palladium-based complexes, and platinum-based complexes.

[0046] Complexes containing iridium, palladium, or platinum-based elements used as phosphorescent dopants are very expensive even in small amounts, due to the limited production of these metal elements and their uneven distribution in production areas, and stable supply can be difficult. Therefore, reducing the amount of phosphorescent dopants using these metal-based complexes is extremely important from the perspectives of cost reduction and economic security. The host-guest emitting layer can be formed by a co-evaporation method using multiple evaporation sources.

[0047] Various known examples of host-guest emitting layer materials can be used. Examples of host compounds include known emitting layer materials for each color. The emitting layer material may be a hole transport material or an electron transport material.

[0048] Examples of the guest compound include the above-mentioned fluorescent dopants and phosphorescent dopants, as well as TADF and hyperfluorescent materials. Examples of the fluorescent dopants include the above-mentioned pyrene-based and anthracene-based compounds, as well as perylene, DPT, Coumarin 6, PMDFB, quinacridone, rubrene, BTX, ABTX, DCM, and DCJT.

[0049] Among examples of phosphorescent dopants, examples of iridium complexes include Ir(ppy) ３ , Ir(thpy) ３ , Ir(t5m-thpy) ３ , Ir(t-5CF ３ -py) ３ , Ir(t-5t-py) ３ , Ir(mt-5mt-py) ３ , Ir(btpy) ３ , Ir(tflpy)３ , Ir(piq) ３ , Ir(tiq) ３ , Ir(fliq) ３ , FIrpic, FIr6, Ir(ppy), Ir(tpy), Ir(bzq), Ir(thp), Ir(op), Ir(bo), Ir(bt), Ir(bon), Ir(αbsn), Ir(btp), Ir(ppo), Ir(C6), Ir(pq), Ir(β-bsn), and Ir(ppz). Examples of platinum-based complexes include PtON-TBBI, PtON7-t-Bu, and PtOEP.

[0050] <Functional Layer> In this embodiment, the layers other than the light-emitting layer in each stack, that is, the hole transport layer, the electron blocking layer, the hole blocking layer, and the electron transport layer, correspond to the functional layers described above.

[0051] The hole transport layer may be composed of an organic or inorganic hole transport material. Examples of hole transport materials include polystyrene sulfonate-doped polyethylenedioxythiophene (PEDOT:PSS), 4,4',4''-tris(9-carbazoyl)triphenylamine (TCTA), 4,4'-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl (NPB), zinc phthalocyanine (ZnPC), di[4-(N,N-ditolylamino)phenyl]cyclohexane (TAPC), 4,4'-bis(carbazoyl)triphenylamine (TCTA), 4,4'-bis(carbazoyl)triphenylamine (NPB), 4,4'-bis(carbazoyl)triphenylamine (4,4'-bis(carbazoyl)triphenylamine ... Examples of suitable fluorenes include 2,7-(9,9-di-n-octylfluorene)-(1,4-phenylene-(4-sec-butylphenyl)imino)-1,4-phenylene (TFB), and poly(triphenylamine) derivatives (Poly-TPD).

[0052] The electron blocking layer, like the hole transport layer, can be made of an organic or inorganic hole transport material. The material of the electron blocking layer may be the same as or different from the material of the hole transport layer.

[0053] The hole blocking layer is a layer through which holes have difficulty passing, and contains an electron transport material or has insulating properties. The electron transport material may be the inorganic electron transport material described above, or may be an organic electron transport material. Examples of the organic electron transport material include oxadiazole-based compounds and phenanthroline-based compounds. The material of the hole blocking layer may contain lithium quinoline (Liq) in addition to the electron transport material described above.

[0054] The electron transport layer contributes to electron transport and contains an electron transport material, and the various electron transport materials described above can be used as the electron transport material constituting the electron transport layer.

[0055] The electron blocking layers 112, 212, and 312 in each light-emitting element 10 have different thicknesses for each emitted color in order to achieve an appropriate optical path length according to the wavelength of light generated in the light-emitting layer of each light-emitting element 10. For example, the thickness of the electron blocking layer is the thickest in the red light-emitting element 10A, and gradually decreases in the order of red, green, and blue.

[0056] The thickness of each stack 11, 21, and 31 is determined so that the amount of light emitted in the light-emitting layer of each light-emitting element is a theoretical value or a value close to it. In the present disclosure, it is preferable to set the thickness of the stack according to the thickness of the light-emitting color of the light-emitting layer from the viewpoint of improving the light-emitting efficiency of the light-emitting element. Note that the thickness of the stack is calculated as the sum of the thicknesses of the light-emitting layer and the functional layer in the stack, but among the light-emitting layer and the functional layer, layers with a very small thickness (for example, a layer with a thickness of less than 1 nm) may be ignored when calculating the thickness of the stack.

[0057] [Charge Generation Layer] The first charge generation layer 12 is composed of two layers: an electron generation layer 121 on the anode 101 side and a hole generation layer 122 on the cathode side, and the second charge generation layer 22 is composed of two layers: an electron generation layer 221 on the anode 101 side and a hole generation layer 222 on the cathode side. In this way, each charge generation layer is composed of an electron generation layer arranged on the anode 101 side and a hole generation layer arranged on the cathode 104 side, which overlap in the Z direction.

[0058] Here, the anode 101 is connected to a hole supply circuit that supplies holes to the light-emitting device 100 via an anode wiring 41. The hole generation layer 122 of the first charge generation layer 12 is connected to the hole supply circuit via an anode wiring 42, and the hole generation layer 222 of the second charge generation layer 22 is connected to the hole supply circuit via an anode wiring 43. The hole supply circuit is configured to be able to supply a specific amount of holes to each of the anode wirings 41, 42, and 43 independently.

[0059] Similarly, the cathode 104 is connected to an electron supply circuit for supplying electrons to the light-emitting device 100 via a cathode wiring 51. The electron generating layer 221 of the second charge generating layer 22 is connected to the electron supply circuit via a cathode wiring 52, and the electron generating layer 121 of the first charge generating layer 12 is connected to the electron supply circuit via a cathode wiring 53. The electron supply circuit is configured to be able to supply a specific amount of electrons to each of the cathode wirings 51, 52, and 53 independently.

[0060] In this way, the anode 101, the hole generating layer 122, and the hole generating layer 222 are each connected to three anode wires (41, 42, and 43) that can independently supply a specific amount of holes to them, and the cathode 104, the electron generating layer 121, and the electron generating layer 221 are each connected to three cathode wires (51, 52, and 53) that can independently supply a specific amount of electrons to them.

[0061] In the present disclosure, the electron generating layer is a layer that generates electrons. Electrons generated in the electron generating layers 121 and 221 are supplied to the light-emitting layer on the anode 101 side. The electron generating layers 121 and 221 are connected to an electron supply circuit, similar to the cathode 104, and may be made of the same material as the cathode 104. For example, it is preferable that the electron generating layers 121 and 221 be made of one or more metals selected from the group consisting of Mg, Ag, Al, and alloys thereof, from the viewpoint of sufficient electron generation in each light-emitting element 10. Note that the electron generating layers 121 and 221 may be made of the same material or different materials.

[0062] If the thickness of the electron generating layers 121 and 221 is too thick, it may reduce the luminous efficiency of the light-emitting element 10, while if it is too thin, there may be areas where no film is formed, causing black spots to occur in the display area 2. From the viewpoint of preventing the occurrence of black spots, the thickness of the electron generating layers 121 and 221 is preferably 2 nm or more, more preferably 5 nm or more, and even more preferably 8 nm or more. Furthermore, from the viewpoint of suppressing the influence on the luminous efficiency of the light-emitting element 10, the thickness of the electron generating layers 121 and 221 is preferably 30 nm or less, more preferably 25 nm or less, and even more preferably 20 nm or less. The thicknesses of the electron generating layers 121 and 221 may be the same as or different from each other.

[0063] In the present disclosure, a hole-generating layer is a layer that generates holes. Holes generated in the hole-generating layers 122 and 222 are supplied to the light-emitting layer on the cathode 104 side. The hole-generating layers 122 and 222 are connected to a hole supply circuit like the anode 101 and may be made of the same material as the anode 101. For example, from the viewpoint of sufficiently generating holes in each light-emitting element 10, it is preferable that the hole-generating layers 122 and 222 be made of one or more metal oxides selected from the group consisting of indium tin oxide, indium zinc oxide, indium gallium oxide, and indium gallium zinc oxide. Note that the hole-generating layers 122 and 222 may be made of the same material or different materials.

[0064] If the thickness of the hole generating layers 122 and 222 is too thick, it may reduce the luminous efficiency of the light emitting element 10, while if it is too thin, there may be areas where no film is formed, causing black spots to occur in the display area 2. From the viewpoint of preventing the occurrence of black spots, the thickness of each of the hole generating layers 122 and 222 is preferably 2 nm or more, more preferably 5 nm or more, and even more preferably 8 nm or more. Furthermore, from the viewpoint of suppressing the effect on the luminous efficiency of the light emitting element 10, the thickness of each of the hole generating layers 122 and 222 is preferably 30 nm or less, more preferably 25 nm or less, and even more preferably 20 nm or less. The thicknesses of the hole generating layers 122 and 222 may be the same as or different from each other.

[0065] [Example of Wiring of Charge Generation Layer] An example of wiring of the electrodes and charge generation layer in the present disclosure will be described with reference to Fig. 4 to Fig. 6. Fig. 4 shows an example of wiring of the light-emitting device of this embodiment when viewed in a plan view. Fig. 5 shows an example of wiring of the light-emitting device of this embodiment when viewed from the direction of arrow Y1 in Fig. 4, and Fig. 6 shows an example of wiring of the light-emitting device of this embodiment when viewed from the direction of arrow X2 in Fig. 4. For convenience, Figs. 5 and 6 show the light-emitting elements arranged in the order of R, G, B, and W.

[0066] 4, each of the light-emitting elements 10R, 10G, 10B, and 10W is disposed on a substrate 5. The substrate 5 is, for example, an active matrix substrate. A rectangular region that approximately circumscribes the light-emitting elements 10R, 10G, 10B, and 10W is set as a display region 40. The pixel 4 is set as a rectangular region that includes the display region 40. In both the X direction and the Y direction, there is a gap of several nanometers or more between the display region 40 and the pixel 4.

[0067] Cathode wires 51 extend in the X direction from one of a pair of short sides of the display area 40, and anode wires 41 of each color of R, G, B, and W extend in the X direction from the other of the pair of short sides of the display area 40. Cathode wires 52 and cathode wires 53 of each color of R, G, B, and W extend in the Y direction from one of a pair of long sides of the display area 40, and anode wires 42 and anode wires 43 of each color of R, G, B, and W extend in the Y direction from the other of the pair of long sides of the display area 40.

[0068] 5 , the cathode wiring 51 is connected to the cathode 104, and extends from the end of the cathode 104, passing along the side of the light-emitting element, to a portion outside the display area 40 on the substrate 5. The anode wiring 41 is connected to the anode 101 of each color, and extends in the X direction on the substrate 5 from the end of the anode 101 to a portion outside the display area 40.

[0069] 6 , the cathode wiring 52 is connected to the electron generating layers 221 of each color of R, G, B, and W in the second stack 21, and extends from the end of the electron generating layer 221 to a portion outside the display region 40 on the substrate 5, passing along the side of the light-emitting element from the end of the electron generating layer 221. The cathode wiring 53 is connected to the electron generating layers 121 of each color of R, G, B, and W in the first charge generating layer 12, and extends from the end of the electron generating layer 121 to a portion outside the display region 40 on the substrate 5, passing along the side of the light-emitting element from the end of the electron generating layer 121.

[0070] 6 , the anode wiring 42 is connected to the hole generating layers 122 of each color of R, G, B, and W in the first charge generating layer 12, and extends from the end of the hole generating layer 122 to the side of the light-emitting element to a portion outside the display region 40 on the substrate 5. The anode wiring 43 is connected to the hole generating layers 222 of each color of R, G, B, and W in the second stack 21, and extends from the end of the hole generating layer 222 to the side of the light-emitting element to a portion outside the display region 40 on the substrate 5.

[0071] [Manufacturing Example of Light-Emitting Element] The light-emitting element 10 can be manufactured by known techniques for manufacturing known tandem-structure EL light-emitting elements, except for the wiring of the charge generation layer. Furthermore, the wiring of the charge generation layer can be manufactured by known techniques for forming wiring from a specific layer in a laminated element on a substrate to the substrate along the lamination direction. An example of a manufacturing method for the light-emitting element of this embodiment will be described below.

[0072] First, an active substrate is prepared on which a reflective anode electrode is formed as the anode 101. Next, the active substrate is cleaned.

[0073] Next, a hole injection layer 102 and a hole transport layer 111 are formed in this order as a common layer on the active substrate by vapor deposition. Because these layers are common layers, the above vapor deposition is performed without using a fine metal mask (FMM) for separating them by color.

[0074] Next, using FMM, an electron blocking layer 112 and an emitting layer 113 are formed in this order as independent layers by vapor deposition for each color. The vapor deposition for forming the emitting layer 113 is, for example, co-evaporation of a host compound and a dopant compound.

[0075] Next, the hole blocking layer 114 and the electron transport layer 115 are formed in this order as a common layer by vapor deposition. The electron transport layer 115 may be formed by co-evaporation of an electron transport compound and Liq (lithium quinoline), for example. In this way, the first stack 11 is formed on the hole injection layer 102.

[0076] Next, the electron generating layer 121 is formed as an independent layer by vapor deposition to a desired thickness, for example, 10 nm or less. At this time, the cathode wiring 53 is also formed. For example, the electron generating layer 121 and the cathode wiring 53 can be formed by vapor deposition using a specific mask, such as an FMM, that has openings corresponding to light-emitting elements of each color and that extend to the outside of the display area 40 described above.

[0077] Alternatively, the electron generating layer 121 and the cathode wiring 53 can be formed by photolithography. When photolithography is used, the electron generating layer 121 and the cathode wiring 53 can be formed by first forming a film of the electron generating layer 121 as a common layer, then applying a metal stripping solution and a developer appropriately according to the light-emitting elements and cathode wiring 53 of each color, and then performing mask exposure and development processes. Forming the electron generating layer 121 and the cathode wiring 53 by photolithography is preferable from the viewpoint of achieving finer patterning.

[0078] Next, the hole generating layer 122 is formed as an independent layer by vapor deposition to a desired thickness, for example, 10 nm or less. The hole generating layer 122 can be formed in the same manner as the electron generating layer 121, and can be formed together with the anode wiring 42 by vapor deposition using a specific mask such as FMM, or by a photolithography method. In this way, the first charge generating layer 12 is formed on the first stack 11.

[0079] Next, the same steps as those for manufacturing the hole transport layer 111 to the electron transport layer 115 described above are repeated to form the hole transport layer 211 to the electron transport layer 215 on the first charge generation layer 12, thereby forming the second stack 21 on the first charge generation layer 12.

[0080] Next, similar to the formation of the first charge generation layer 12, an electron generation layer 221 is formed on the electron transport layer 215 together with cathode wiring 52 by vapor deposition or photolithography using a specific mask such as FMM, and a hole generation layer 222 is formed on the electron generation layer 221 together with anode wiring 43. In this manner, a second charge generation layer 22 is formed on the second stack 21.

[0081] Next, the same steps as those for manufacturing the hole transport layer 111 to the electron transport layer 115 described above are repeated to form the hole transport layer 311 to the electron transport layer 315 on the second charge generation layer 22, thereby forming the third stack 31 on the second charge generation layer 22.

[0082] Next, an electron injection layer 103 is formed on the third stack 31 as a common layer by vapor deposition.

[0083] Next, the cathode 104 is formed as a common layer by vapor deposition. This vapor deposition can be performed, for example, by using a specific mask for forming the common layer, which further has openings corresponding to the cathode wiring 51. Alternatively, the cathode 104 may be formed by the photolithography method described above.

[0084] The display device 1 can be fabricated by forming the auxiliary layer 105, the buffer layer 106, and the sealing layer 107 in this order on the cathode 104 using a known technique. These layers can be fabricated as uniform layers over the entire display area 2 of the display device 1 using a method appropriate for the materials of these layers.

[0085] In the above-described method for manufacturing a light-emitting element, light-emitting layers of the same color can be manufactured using the same light-emitting layer material under similar manufacturing conditions. The use of light-emitting layers of the same color in light-emitting elements of a tandem structure is also advantageous from the viewpoint of easily manufacturing the light-emitting device of the present disclosure.

[0086] [Light Emission Mechanism] In the light emitting device 100, an optimum amount of current for the light emitting element 10 of each color is supplied between the anode 101 and the cathode 104 of the light emitting element 10 of each color via the anode wiring 41 and the cathode wiring 51. In addition, an amount of current to compensate for the carrier deficiency is supplied via the anode wiring 42 or 43 or the cathode wiring 52 or 53 to the electron generating layer 121 or the hole generating layer 122 in the first charge generating layer 12 or the electron generating layer 221 or the hole generating layer 222 in the second charge generating layer 22 adjacent to the first stack 11, the second stack 21, or the third stack 31 including the light emitting layer 113, 213, or 313 in the light emitting element 10 of each color where the amount of carrier injection is insufficient.

[0087] In a tandem light-emitting device in which multiple light-emitting layers are arranged in series between a pair of cathodes and anodes, the amount of current flowing through each light-emitting layer is the same according to Kirchhoff's first law. On the other hand, in a tandem light-emitting device having two or more light-emitting layers and a charge-generating layer (electron-generating layer and hole-generating layer) interposed between two adjacent light-emitting layers, optimizing the amount of charge (electrons or holes) supplied to one light-emitting layer relative to the charge-generating layer may result in the amount of charge supplied to the other light-emitting layer deviating from the optimal value. As a result, an imbalance in the charge supply balance may occur among the multiple light-emitting layers included in the same light-emitting device. According to the above-described current application method of this embodiment, the amount of current applied to each individual light-emitting layer in which the amount of charge injection is insufficient is optimized, thereby optimizing the charge supply balance among all light-emitting layers.

[0088] This current application method is advantageous for optimizing the carrier balance in each light-emitting layer, and is suitable for cases where the light-emitting device includes multiple types of light-emitting layers, such as when two or more light-emitting layers of the same color are made of different materials.

[0089] Alternatively, in the light-emitting device 100, an optimal amount (theoretical amount) of current is supplied to each of the first stack 11, second stack 21, and third stack 31 of each color between the anode 101 and the electron generating layer 121, between the hole generating layer 122 and the electron generating layer 221, and between the hole generating layer 222 and the cathode 104 in the light-emitting elements 10 of each color via the anode wiring 41 and the cathode wiring 53, the anode wiring 42 and the cathode wiring 52, and the anode wiring 43 and the cathode wiring 51. An optimal amount of carriers is supplied to each of the first stack 11, second stack 21, and third stack 31 in the light-emitting elements 10 of each color, and the first stack 11, second stack 21, and third stack 31 each achieve a light-emitting current efficiency that is substantially the theoretical value, thereby achieving a light-emitting current efficiency that is substantially the theoretical value throughout the light-emitting device 100.

[0090] This current application method is particularly suitable when light-emitting layers of the same color are designed with a common material and each stack of each color is designed to have a common theoretical value for the amount of current supplied, and is advantageous from the perspective of simplifying the design of light-emitting elements and light-emitting devices.

[0091] [Major Effects] The light emitting device 100 of this embodiment has a plurality of light emitting elements arranged in an arrangement direction, each of which emits light in one of two or more colors, and is a so-called side-by-side light emitting device.

[0092] Each of the light-emitting elements 10R, 10G, 10B, and 10W of each color in the light-emitting device 100 includes an anode 101, a cathode 104, two or more stacks (11, 21, and 31) disposed between the anode and cathode, and one or more charge-generating layers (12 and 22) disposed between adjacent stacks in the stacking direction. Each stack includes an emissive layer (113) and functional layers (111, 112, 114, and 115) for supplying charge to the emissive layer, which are disposed in the stacking direction. Each charge-generating layer includes an electron-generating layer (121 and 221) disposed on the anode side and a hole-generating layer (122 and 222) disposed on the cathode side, which are disposed in the Z direction. Thus, each of the light-emitting elements 10R, 10G, 10B, and 10W has a so-called tandem structure.

[0093] Here, in a conventional side-by-side light-emitting device having a light-emitting element with a tandem structure, the charge generation layer (electron generation layer and hole generation layer) is known to be a layer formed by doping a small amount of a carrier generating material into an organic material. For example, the hole generation layer is a layer formed by doping an organic material (hole transport material) with a metal (Mo, etc.) or an electron accepting material in an amount of less than 20%, and the electron generation layer is a layer formed by doping an organic material (electron transport material) with a metal (Li, Yb, etc.) in an amount of less than 20%.

[0094] In such a conventional side-by-side type tandem structure light-emitting device, the applied voltage can be twice or more as high as that of a side-by-side type light-emitting device having a normal single structure light-emitting element, making it difficult to reduce power consumption, while the current light-emitting efficiency can be high, sometimes about 1.7 times as high. However, because the applied voltage of a conventional side-by-side type tandem structure light-emitting device is twice as high as that of a side-by-side type single structure light-emitting device, the power consumption of the light-emitting element portion (excluding the backplane) in the display can actually be high.

[0095] In contrast, in the light-emitting device 100 of this embodiment, both the hole-generating layer and the electron-generating layer in the tandem-structured charge-generating layer are thin layers made of electrode materials, and these layers are directly connected to wiring so that charge can be supplied from the wiring. Therefore, it is possible to apply voltage independently to each of the charge-generating layers, and it is possible to independently control and drive each of the light emissions in the three-stage stack. Furthermore, in the light-emitting device 100, each of the charge-generating layers is an independent layer corresponding to the light-emitting element, so it is possible to independently control and drive each of the light-emitting elements in each stack.

[0096] In light-emitting devices with a side-by-side tandem structure, the charge generation capability of the charge generation layer is generally important for improving the light-emitting efficiency of the light-emitting device. In the light-emitting device 100 of this embodiment, charges are directly injected into the charge generation layer via electrode wiring and supplied from the charge generation layer to the light-emitting layers of each stack. Therefore, the voltage applied to each light-emitting element in the light-emitting device 100 of this embodiment is substantially the same as that applied to a conventional side-by-side single-structure light-emitting device. In this way, the light-emitting device 100 is advantageous over conventional side-by-side tandem-structure light-emitting devices in terms of reducing the applied voltage. Therefore, the light-emitting device 100 can reduce the applied voltage to the same level as a conventional side-by-side single-structure light-emitting device, while further improving the current light-emitting efficiency.

[0097] Furthermore, the light-emitting device 100 of this embodiment includes a white light-emitting element 10W in addition to the red light-emitting element 10R, the green light-emitting element 10G, and the blue light-emitting element 10B. Therefore, the light-emitting device 100 has a higher screen brightness than a light-emitting device including only red, green, and blue light-emitting elements. Therefore, the light-emitting device 100 can reduce power consumption while maintaining the same level of brightness, or can increase luminance while maintaining the same level of power consumption, compared to a red, green, and blue light-emitting device. Furthermore, the light-emitting device 100 can achieve a wider color gamut without reducing resolution, compared to a red, green, and blue light-emitting device.

[0098] In the light-emitting device 100, the white light-emitting element 10W is realized by a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer that are stacked in the Z direction. Therefore, the light-emitting layer of the light-emitting element 10W can be the same as the light-emitting layer of the other light-emitting elements, which is advantageous from the viewpoint of simple manufacturing.

[0099] [Embodiment 2] The arrangement of light-emitting elements in this embodiment is shown schematically in Figure 7. Each pixel 4 of the display device of this embodiment includes six light-emitting elements: a light-emitting element 20R that emits red light, a light-emitting element 20G that emits green light, a light-emitting element 20B that emits blue light, a light-emitting element 20Y that emits yellow light, a light-emitting element 20C that emits cyan light, and a light-emitting element 20R that emits magenta light. For convenience, the light-emitting elements are shown aligned in a line along the X direction in Figure 7, but the arrangement order of these light-emitting elements in the X and Y directions may be determined as appropriate as long as the effects of this embodiment can be achieved.

[0100] 8 is a diagram showing a schematic configuration of a light-emitting device according to this embodiment. The light-emitting device 200 is a top-emission type light-emitting device including light-emitting elements of a so-called tandem structure, and is configured similarly to the light-emitting device 100 described above, except that it includes six-color light-emitting elements 20 and each light-emitting element 20 is configured as a two-stage stack with one charge-generating layer interposed therebetween.

[0101] The light-emitting element 20 has an anode 101, a hole injection layer 102, a first stack 11, a first charge generation layer 12, a second stack 21, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107 in this order along the Z direction.

[0102] That is, the red-emitting light-emitting element 20R includes an anode 101R, a hole injection layer 102, a first stack 11R, a first charge generation layer 12, a second stack 21R, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The light-emitting layer 113R of the first stack 11R and the light-emitting layer 213R of the second stack 21R are both red light-emitting layers. The green-emitting light-emitting element 10G includes an anode 101G, a hole injection layer 102, a first stack 11G, a first charge generation layer 12, a second stack 21G, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The light-emitting layer 113G of the first stack 11G and the light-emitting layer 213G of the second stack 21G are both green light-emitting layers. The blue-emitting light-emitting element 20B includes an anode 101B, a hole injection layer 102, a first stack 11B, a first charge generation layer 12, a second stack 21B, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The light-emitting layer 113B of the first stack 11B and the light-emitting layer 213B of the second stack 21B are both blue light-emitting layers.

[0103] The yellow-emitting light-emitting element 20Y includes an anode 101Y, a hole injection layer 102, a first stack 11Y, a first charge generation layer 12, a second stack 21Y, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The light-emitting layer 113Y of the first stack 11Y is a red-emitting layer, and the light-emitting layer 213Y of the second stack 21Y is a green-emitting layer. The cyan-emitting light-emitting element 20C includes an anode 101C, a hole injection layer 102, a first stack 11C, a first charge generation layer 12, a second stack 21C, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The light-emitting layer 113C of the first stack 11C is a green-emitting layer, and the light-emitting layer 213C of the second stack 21C is a blue-emitting layer. The magenta-emitting light-emitting element 20M includes an anode 101B, a hole injection layer 102, a first stack 11M, a first charge generation layer 12, a second stack 21M, an electron injection layer 103, a cathode 104, an auxiliary layer 105, a buffer layer 106, and a sealing layer 107. The light-emitting layer 113M of the first stack 11M is a blue light-emitting layer, and the light-emitting layer 213M of the second stack 21M is a red light-emitting layer.

[0104] The light-emitting layers 113R, 213R, 113Y, and 213M are all light-emitting layers of the same color, red. The light-emitting layers 113G, 213G, 213Y, and 113C are all light-emitting layers of the same color, green. The light-emitting layers 113B, 213B, 213C, and 113M are all light-emitting layers of the same color, blue.

[0105] As described above, each of the light-emitting elements 20 has an anode, a cathode, two or more stacks disposed between the electrodes, and one or more charge generating layers disposed between adjacent stacks in the Z direction, which are overlapping in the Z direction.

[0106] The first charge generating layer 12 is composed of an electron generating layer 121 arranged on the anode 101 side and a hole generating layer 122 arranged on the cathode 104 side, which overlap in the Z direction. The anode 101 and the hole generating layer 122 are each connected to two or more anode wirings 41 and 42, respectively, each capable of supplying a specific amount of charge, and the cathode 104 and the electron generating layer 121 are each connected to two or more cathode wirings 51 and 53, respectively, each capable of supplying a specific amount of electrons.

[0107] [Wiring Example] Next, an example of wiring for the electrodes and charge generating layers in this embodiment will be described. When the pixel 4 is viewed in plan, light-emitting elements 10R, 10G, 10B, 10Y, 10C, and 10M are appropriately arranged in a display area 40 within the pixel 4 shown in FIG. 9 . Cathode wires 51 extend in the X direction from one of a pair of short sides of the display area 40, and anode wires 41 for each of the R, G, B, Y, C, and M colors extend in the X direction from the other of the pair of short sides of the display area 40. Cathode wires 53 for each of the R, G, B, Y, C, and M colors extend in the Y direction from one of a pair of long sides of the display area 40, and anode wires 42 for each of the R, G, B, Y, C, and M colors extend in the Y direction from the other of the pair of long sides of the display area 40.

[0108] When the pixel 4 is viewed from the direction of arrow Y1, as shown in Fig. 10 , the cathode wiring 51 extends in the X direction from the end of the cathode 104, passing along the side of the light-emitting element, to a portion on the substrate 5 outside the display region 40, and the anode wiring 41 extends in the X direction from the end of the anode 101 of each color to a portion on the substrate 5 outside the display region 40. When the pixel 4 is viewed from the direction of arrow X2, as shown in Fig. 11 , the cathode wiring 53 extends from the end of the electron generating layer 121 of each color of R, G, B, Y, C, and M in the first charge generating layer 12, passing along the side of the light-emitting element, to a portion on the substrate 5 outside the display region 40. Furthermore, the anode wiring 42 extends from the end of the hole generating layer 122 of each color of R, G, B, Y, C, and M in the first charge generating layer 12, passing along the side of the light-emitting element, to a portion on the substrate 5 outside the display region 40.

[0109] [Major Effects] As with the light-emitting device 100, the light-emitting device 200 also emits light with desired light-emitting characteristics by supplying an optimal amount of current between the anode 101 and the cathode 104 according to the light-emitting element 20 of each color, and supplying the insufficient current to the electron-generating layer 121 or the hole-generating layer 122 in the charge-generating layer adjacent to the stack including the light-emitting layer lacking charge, or by supplying an optimal amount of current according to each stack to each stack via the anode 101, the electron-generating layer 121, and the hole-generating layer 122, and the cathode 104. As a result, as with the light-emitting device 100, the light-emitting device 200 can reduce the applied voltage to the same extent as a conventional side-by-side type light-emitting device with a single structure, and can further increase the current luminous efficiency.

[0110] Furthermore, the light-emitting device 200 has light-emitting elements of six colors: red (R), green (G), blue (B), yellow (Y), cyan (C), and magenta (M). Therefore, compared to a light-emitting device including only light-emitting elements of the three colors red, green, and blue, it has a wider color gamut, and can achieve an equivalent color gamut with lower brightness. Therefore, compared to a light-emitting device including only light-emitting elements of the three colors red, green, and blue, the light-emitting device 200 can reduce power consumption while maintaining an equivalent color gamut, or can widen the color gamut with the same power consumption.

[0111] In the light-emitting device 200, the yellow-emitting light-emitting element 20Y has a red light-emitting layer and a green light-emitting layer, the cyan-emitting light-emitting element 20C has a green light-emitting layer and a blue light-emitting layer in the Z direction, and the magenta-emitting light-emitting element 20M has a blue light-emitting layer and a red light-emitting layer. Therefore, the light-emitting layers of the yellow, cyan, and magenta light-emitting elements 20 can be the same as the light-emitting layers of the red, green, and blue light-emitting elements, which is advantageous from the viewpoint of easy manufacturing.

[0112] [Embodiment 3] In this embodiment, the light-emitting device of the present disclosure is configured with two tandem light-emitting devices. Hereinafter, when referring to one of the two light-emitting devices that make up the light-emitting device 300 of this embodiment, the reference character "A" will be added, and when referring to the other light-emitting device, the reference character "B" will be added.

[0113] 12 , in the display device of this embodiment, pixel 4 includes subpixels 4A and 4B. Subpixel 4A is provided with a light-emitting device 300A including red, green, and blue light-emitting elements 20R, 20G, and 20B, and subpixel 4B is provided with a light-emitting device 300B including yellow, cyan, and magenta light-emitting elements 20Y, 20C, and 20M, with these light-emitting devices 300A and 300B working together to form light-emitting device 300. In this manner, in light-emitting device 300, the three light-emitting elements 20R, 20G, and 20B that emit light in red, green, and blue, respectively, form one first subpixel, and the three light-emitting elements 20Y, 20C, and 20M that emit light in yellow, cyan, and magenta, respectively, form one second subpixel.

[0114] The shape and size of the light-emitting elements 20 of each color in a planar view can be set as appropriate, as described above. Therefore, the shapes and sizes of the sub-pixels 4A and 4B in this embodiment may also be set as appropriate depending on the types of light-emitting elements 20 arranged therein, the visibility of the display device, and the like. The area ratio of the sub-pixels 4A to the sub-pixels 4B is usually 5 / 5, but from the above-mentioned viewpoint, it may be 4 / 6 or more and 6 / 4 or less, or 3 / 7 or more and 7 / 3 or less.

[0115] The light emitting device 300 of this embodiment is configured in the same manner as the second embodiment described above, except that it is divided into two three-color light emitting devices 300A and 300B as shown in FIG.

[0116] [Layer Structure] The light-emitting device 300A has red, green, and blue light-emitting elements 20R, 20G, and 20B. The light-emitting element 20R has a red light-emitting layer of the same color in the stacking direction, the light-emitting element 20G has a green light-emitting layer of the same color in the stacking direction, and the light-emitting element 20B has a blue light-emitting layer of the same color in the stacking direction. As such, the layer structures of the light-emitting elements 20R, 20G, and 20B are the same as those in embodiment 2 (light-emitting device 200). Similarly to the light-emitting device 200, the light-emitting device 300A also has an anode wiring 41A connected to the anode 101, an anode wiring 42A connected to the hole generating layer 122, a cathode wiring 51A connected to the cathode 104, and a cathode wiring 53A connected to the electron generating layer 121.

[0117] The light-emitting device 300B has yellow, cyan, and magenta light-emitting elements 20Y, 20C, and 20M. The layer configuration of these light-emitting elements is the same as that of embodiment 2 (light-emitting device 200). Similarly to the light-emitting device 200, the light-emitting device 300B also has an anode wire 41B connected to the anode 101, an anode wire 42B connected to the hole generating layer 122, a cathode wire 51B connected to the cathode 104, and a cathode wire 53B connected to the electron generating layer 121.

[0118] [Wiring Example] When pixel 4 is viewed in plan, light-emitting elements 10R, 10G, and 10B are appropriately arranged in display region 40A within subpixel 4A shown in Fig. 14, and light-emitting elements 10Y, 10C, and 10M are appropriately arranged in display region 40B within subpixel 4B. Display regions 40A and 40B are adjacent to each other and share one side, and this shared side forms a center line that divides display region 40 in half. In both display region 40A and display region 40B, a pair of opposing sides and a side connecting them form the outer edge of display region 40.

[0119] Cathode wires 53A of the R, G, and B colors extend in the Y direction from one of a pair of sides of the display area 40A, and anode wires 42A of the R, G, and B colors extend in the Y direction from the other of the pair of sides of the display area 40A. In addition, cathode wires 51A and anode wires 41A of the R, G, and B colors extend in the X direction from the other side of the outer edge of the display area 40A.

[0120] Cathode wires 53B of the colors Y, C, and M extend in the Y direction from one of a pair of sides of the display area 40B, and anode wires 42B of the colors Y, C, and M extend in the Y direction from the other of the pair of sides of the display area 40B. In addition, cathode wires 51B and anode wires 41B of the colors Y, C, and M extend in the X direction from the other side of the outer edge of the display area 40B.

[0121] 15 , when the pixel 4 is viewed from the direction of the arrow Y1, the cathode wiring 51A extends from one end of the portion of the cathode 104 that is included in the light-emitting elements 20R, 20G, and 20B, past the side of the light-emitting element 20, to a portion outside the display region 40A on the substrate 5. In addition, the anode wiring 41A extends in the X direction from the end of the anode 101 of each of the R, G, and B colors to a portion outside the display region 40A.

[0122] The cathode wiring 51B extends from the other end of the portion of the cathode 104 that is included in the light emitting elements 20Y, 20C, and 20M, passing along the side of the light emitting element 20, to a portion outside the display region 40B on the substrate 5. The anode wiring 41B also extends in the X direction from the end of the anode 101 for each of the Y, C, and M colors to a portion outside the display region 40B.

[0123] 16 , when the pixel 4 is viewed from the direction of arrow X2, the cathode wiring 53 in both the subpixel 4A and the subpixel 4B extends from an end of the electron generating layer 121 of each color of R, G, B, Y, C, and M in the first charge generating layer 12, past a side of the light-emitting element, to an outer portion of one side of the display region 40 on the substrate 5. The anode wiring 42 in both the subpixel 4A and the subpixel 4B extends from an end of the hole generating layer 122 of each color of R, G, B, Y, C, and M in the first charge generating layer 12, past a side of the light-emitting element, to an outer portion of the other side of the display region 40 on the substrate 5.

[0124] The light-emitting device 300 also achieves the same effects as the light-emitting device 200. In addition, in the light-emitting device 300, three light-emitting elements 20 that emit light in the colors blue, green, and red respectively constitute one first sub-pixel 4A, and three light-emitting elements 20 that emit light in the colors cyan, yellow, and magenta respectively constitute one second sub-pixel 4B. Therefore, the light-emitting device 300 is advantageous from the viewpoint of optimizing the layer configurations of the light-emitting devices 300A and 300B for each of the three colors in accordance with the emitted light colors, and driving each of the light-emitting devices 300A and 300B under optimal conditions based on the combination of the individual emitted colors.

[0125] In the light-emitting device 300, the area ratio of the sub-pixel 4A to the sub-pixel 4B is 3 / 7 or more and 7 / 3 or less. This configuration is advantageous from the viewpoint of adjusting visibility in the display device of this embodiment or achieving desired performance of the display device.

[0126] In the light emitting device 300A, the light emitting element 20R has red light emitting layers of the same color in the stacking direction, the light emitting element 20G has green light emitting layers of the same color in the stacking direction, and the light emitting element 20B has blue light emitting layers of the same color in the stacking direction. This configuration is advantageous from the viewpoint of further improving the color purity of the red, green, and blue emissions in the light emitting device 300A and from the viewpoint of easier manufacturing of the light emitting device 300A.

[0127] Other Embodiments In the above-described embodiments, the number of types of light emitted by the light-emitting elements of the light-emitting device of the present disclosure may be two or more, as long as the effects of the present disclosure can be obtained.

[0128] Furthermore, in the above-described embodiments, the shape and size of the light-emitting elements of each color when viewed in a plane may all be the same. Furthermore, the light-emitting elements of each color may be arranged in other arrangements, such as a Pentile arrangement. Arranging the light-emitting elements in a dot arrangement, as in the above-described embodiments, is preferable from the viewpoint of ensuring a uniform color gamut across the entire display area 2 of the display device 1. Alternatively, in the present disclosure, the light-emitting elements may be arranged in a line arrangement of R, G, and B lines and C, Y, and M lines. Arranging the light-emitting elements in a line arrangement is preferable from the viewpoint of facilitating manufacturing and increasing the productivity of the display device or light-emitting device of the present disclosure.

[0129] In the above-described embodiment, the light-emitting layer may be a light-emitting layer containing quantum dots as the light-emitting material.

[0130] In the above-described embodiment, the cathode 104 may be fabricated independently for each light-emitting element of each color, and each light-emitting element may be wired separately. This configuration is even more effective in terms of precisely controlling the supply of current to the light-emitting elements of each color and realizing high-definition display of images on the display device 1.

[0131] Furthermore, in the above-described embodiment, a portion of the tandem structure of the light-emitting element (for example, only one of the charge generation layers 12 and 22) may be made of the same material as the electrode as shown in the above-described embodiment, as long as the effects of the present disclosure are obtained. This configuration is advantageous from the viewpoint of supplying sufficient charge without excess or deficiency.

[0132] In the above-described embodiment, only one of the electron generating layer and the hole generating layer in the charge generating layer may have electrode wiring, as long as the effects of the present disclosure are obtained. This configuration is advantageous from the viewpoint of reducing the number of wirings and thereby reducing the number of processes.

[0133] Furthermore, in the above-described first embodiment, the combination of light-emitting layers in the white light-emitting element may be a combination of light-emitting layers of other colors than the combination of white light-emitting layers in the first embodiment, as long as white light emission can be achieved. Furthermore, when a white light-emitting element is configured with two types (two colors) of light-emitting layers, each of the light-emitting elements in the first embodiment may be configured with a two-stage stack and one charge generating layer between them.

[0134] In the second and third embodiments, the light-emitting layers of the six-color light-emitting elements may be light-emitting layers of colors other than red, green, blue, yellow, cyan, and magenta, or a combination including light-emitting layers of such colors, as long as a wide color gamut can be achieved.

[0135] In the third embodiment, while one of the light-emitting devices 300A and 300B has electrode wiring connected to the charge generation layer as described above, the other of the light-emitting devices 300A and 300B may have a structure in which electrode wiring is not connected to the charge generation layer, as long as the balance of charge supply in the light-emitting layer of each stack is optimized. For example, the other of the light-emitting devices 300A and 300B may have a structure in which the thickness of the light-emitting layer of each stack is different, or a structure in which the doping amount of the guest compound in the light-emitting layer of each stack is different.

[0136] The display device of the present disclosure is not limited to the smartphone exemplified in the above embodiment, and may be any display device that requires high-definition and high-quality image display. The display device of the present disclosure is particularly suitable for head-mounted displays, tablets, notebook PC monitors, amusement applications, in-vehicle applications, etc.

[0137] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0138] The embodiments of the present disclosure will be described more specifically.

[0139] Example 1 An example light-emitting device 1 having a six-color tandem light-emitting element (two-layer light-emitting layer structure) as shown in FIG. 5 was fabricated.

[0140] The anode 101 is a reflective electrode with a laminated structure in which an ITO (indium tin oxide) film is formed on a thin silver film. The hole injection layer 102 is a layer made of a triphenylamine-based compound with 3% TCNQ-4F added as an electron-accepting material, and has a thickness of 10 nm. The electron injection layer 103 is a LiF layer with a thickness of 2 nm. The cathode 104 is a layer made of a mixture of 10% Mg and 90% Ag, and has a thickness of 20 nm. The auxiliary layer 105 is a triphenylamine-based compound layer with a thickness of 40 nm. The buffer layer 106 is a LiF layer with a thickness of 2 nm. The sealing layer 107 is, for example, a layer of fluororesin (PTFE) and has a thickness of 5000 nm.

[0141] In the first stack 11, the hole transport layer 111 is a layer of a triphenylamine-based compound and has a thickness of 110 nm.

[0142] The electron blocking layer 112 is a layer made of a carbazole-based compound. The electron blocking layer 112R and the electron blocking layer 112Y each have a thickness of 70 nm. The electron blocking layer 112G and the electron blocking layer 112C each have a thickness of 35 nm. The electron blocking layer 112B and the electron blocking layer 112M each have a thickness of 5 nm.

[0143] The light-emitting layers 113R and 113Y are both layers containing a mixture of a hole-transporting material and an electron-transporting material as a host compound and an iridium complex-based red-light-emitting compound as a guest compound, and are 30 nm thick. The light-emitting layers 113G and 113C are both layers containing a mixture of a hole-transporting material and an electron-transporting material as a host compound and an iridium complex-based green-light-emitting compound as a guest compound, and are 30 nm thick. The light-emitting layers 113B and 113M are both layers containing a perylene-based compound as a host compound and a pyrene-based compound as a guest compound, and are 15 nm thick.

[0144] The hole blocking layer 114 is a layer of a phenanthroline-based compound and has a thickness of 10 nm.

[0145] The electron transport layer 115 is a layer of a mixture of an oxadiazole-based compound and Liq, and has a thickness of 25 nm.

[0146] In the first charge generating layer 12, the electron generating layer 121 is a layer made of a mixture of 10% Mg and 90% Ag and has a thickness of 5 nm, and the hole generating layer 122 is a layer made of ITO and has a thickness of 5 nm.

[0147] In the second stack 21, the hole transport layer 211 is a layer of a triphenylamine-based compound and has a thickness of 30 nm.

[0148] The electron blocking layer 212 is a layer made of a carbazole-based compound. The electron blocking layer 212R and the electron blocking layer 212M each have a thickness of 40 nm. The electron blocking layer 212G and the electron blocking layer 212Y each have a thickness of 25 nm. The electron blocking layer 212B and the electron blocking layer 212C each have a thickness of 5 nm.

[0149] The composition of the light-emitting layer 213 of each color is the same as that of the light-emitting layer 113 of the first stack 11. The light-emitting layer 213R and the light-emitting layer 213M each have a thickness of 30 nm. The light-emitting layer 213G and the light-emitting layer 213Y each have a thickness of 30 nm. The light-emitting layer 213B and the light-emitting layer 213C each have a thickness of 15 nm.

[0150] The composition and thickness of the hole blocking layer 214 and the electron transporting layer 215 are the same as those of the hole blocking layer 114 and the electron transporting layer 115 .

[0151] Comparative Example 1 A comparative light-emitting device 1 was fabricated, which had the same configuration as the light-emitting device of Example 1, except that it did not have anode wiring 41 and cathode wiring 53, the electron-generating layer 121 was a layer obtained by doping an organic electron-transporting material with a metal (Li and Yb) in an amount of less than 20%, and the hole-generating layer 122 was a layer obtained by doping an organic hole-transporting material with a metal (Mo, etc.) or an electron-accepting material in an amount of less than 20%.

[0152] [Evaluation 1] Each of the example light-emitting device 1 and the comparative light-emitting device 1 was driven, and the current luminous efficiency (cd / A), DCI-P3 coverage (%), and voltage (V) at 1000 nit were determined. The results are shown in Table 1.

[0153]

[0154] As is clear from Table 1, the current luminous efficiency of Example light-emitting device 1 is 103 (cd / A), which is slightly higher than that of Comparative example light-emitting device 1. In addition, the DCI-P3 coverage rate of Example light-emitting device 1 is 115%, which is higher than that of Comparative example light-emitting device 1. Furthermore, the 1000 nit voltage of Example light-emitting device 1 is 5 V, which is less than half that of Comparative example light-emitting device 1. This is thought to be due to the fact that in Example light-emitting device 1, charges are supplied directly to the charge generation layer.

[0155] Example 2 An example light-emitting device 1 having a four-color tandem light-emitting element (three-layer light-emitting layer structure) as shown in FIG. 3 was fabricated.

[0156] The compositions and thicknesses of the anode 101, hole injection layer 102, electron injection layer 103, cathode 104, auxiliary layer 105, buffer layer 106, and sealing layer 107 are the same as those of the example light-emitting device 1. The composition and thickness of the first charge generation layer 12 are the same as those of the example light-emitting device 1. The composition and thickness of the second charge generation layer 22 are the same as those of the first charge generation layer 12. The composition and thickness of each layer in the first stack 11 and the second stack 21 are the same as those of the example light-emitting device 1, except for the thicknesses of the electron blocking layer 112 and the light-emitting layer 113. The composition and thickness of each layer in the third stack 31 are the same as those of the second stack 21, except for the electron blocking layer 112 and the light-emitting layer 113.

[0157] In the red light-emitting element 10R, the thickness of the electron blocking layer 112 is 70 nm, and the thickness of the light-emitting layer 113 is 30 nm. The thickness of the electron blocking layer 212 is 40 nm, and the thickness of the light-emitting layer 213 is 30 nm. The thickness of the electron blocking layer 312 is 40 nm, and the thickness of the light-emitting layer 313 is 30 nm.

[0158] In addition, in green light-emitting element 10G, electron blocking layer 112 is 35 nm thick, and light-emitting layer 113 is 30 nm thick. Electron blocking layer 212 is 25 nm thick, and light-emitting layer 213 is 25 nm thick. Electron blocking layer 312 is 25 nm thick, and light-emitting layer 313 is 25 nm thick.

[0159] In addition, in blue light-emitting element 10G, electron blocking layer 112 is 5 nm thick, and light-emitting layer 113 is 15 nm thick. Electron blocking layer 212 is 5 nm thick, and light-emitting layer 213 is 15 nm thick. Electron blocking layer 312 is 5 nm thick, and light-emitting layer 313 is 15 nm thick.

[0160] In the white light-emitting element 10G, the electron blocking layer 112 is 70 nm thick, and the red light-emitting layer 113 is 30 nm thick. The electron blocking layer 212 is 25 nm thick, and the green light-emitting layer 213 is 25 nm thick. The electron blocking layer 312 is 5 nm thick, and the blue light-emitting layer 313 is 15 nm thick.

[0161] Comparative Example 2 A comparative light-emitting device 2 was produced, which had the same configuration as the light-emitting device of Example 2, except that it did not have anode wiring 41, 42 and cathode wiring 52, 53, the electron-generating layers 121 and 221 were layers formed by doping an organic electron-transporting material with a metal (Li and Yb) in an amount of less than 20%, and the hole-generating layers 122 and 222 were layers formed by doping an organic hole-transporting material with a metal (Mo, etc.) or an electron-accepting material in an amount of less than 20%.

[0162] [Evaluation 2] Each of Example Light-Emitting Device 2 and Comparative Light-Emitting Device 2 was driven to determine the current luminous efficiency (cd / A), DCI-P3 coverage (%), and voltage (V) at 1000 nits. The results are shown in Table 2.

[0163]

[0164] As is clear from Table 2, the current luminous efficiency of Example light-emitting device 2 is 135 (cd / A), which is slightly higher than that of Comparative example light-emitting device 2. In addition, the DCI-P3 coverage rate of Example light-emitting device 2 is 115%, which is higher than that of Comparative example light-emitting device 2. Furthermore, the 1000 nit voltage of Example light-emitting device 2 is 4 V, which is less than one-third of that of Comparative example light-emitting device 2. This is thought to be due to the fact that charges are supplied directly to the charge generation layer in Example light-emitting device 2.

[0165] REFERENCE SIGNS LIST 1 display device 2, 40 display area 3 frame area 4 pixel 4A, 4B sub-pixel 5 substrate 10, 20 light-emitting element 11 first stack 12 first charge generation layer 21 second stack 22 second charge generation layer 31 third stack 41, 42, 43 anode wiring 51, 52, 53 cathode wiring 100, 200, 300 light-emitting device 101 anode 102 hole injection layer 103 electron injection layer 104 cathode 105 auxiliary layer 106 buffer layer 107 sealing layer 111, 211, 311 hole transport layer 112, 212, 312 electron blocking layer 113, 213, 313 light-emitting layer 114, 214, 314 hole blocking layer 115, 215, 315 Electron transport layer 121, 221 Electron generating layer 122, 222 Hole generating layer R Symbol representing the configuration of red light emission G Symbol representing the configuration of green light emission B Symbol representing the configuration of blue light emission W Symbol representing the configuration of white light emission Y Symbol representing the configuration of yellow light emission C Symbol representing the configuration of cyan light emission M Symbol representing the configuration of magenta light emission A Symbol representing the configuration of red, green, and blue light emitting devices B Symbol representing the configuration of yellow, cyan, and magenta light emitting devices

Claims

1. A light-emitting device comprising a plurality of light-emitting elements arranged in an arrangement direction, each of which emits light in a respective one of two or more colors, wherein each of the light-emitting elements comprises an anode, a cathode, two or more stacks disposed between the electrodes, and one or more charge generation layers disposed between adjacent stacks in the stacking direction, the stacks being overlapped in a stacking direction intersecting the arrangement direction, each of the stacks being composed of a light-emitting layer and a functional layer that supplies charge to the light-emitting layer, the functional layers being overlapped in the stacking direction, each of the charge generation layers being composed of an electron generation layer disposed on the anode side and a hole generation layer disposed on the cathode side, the electron generation layer and the anode are each connected to two or more anode wirings that can supply a specific amount of holes to the anode and the hole generation layer, and the cathode and the electron generation layer are each connected to two or more cathode wirings that can supply a specific amount of electrons to the cathode and the electron generation layer, 2. The light emitting device according to claim 1, wherein the light emitting elements that emit light in the colors blue, green, red, and white are arranged in the arrangement direction.

3. The light emitting device according to claim 1, wherein the light emitting elements emit light in six colors in the arrangement direction.

4. The light emitting device of claim 3, wherein the six colors are blue, green, red, cyan, yellow, and magenta.

5. The light-emitting device according to claim 3 or 4, wherein three of the light-emitting elements emitting light in the colors blue, green, and red respectively constitute one first sub-pixel, and three of the light-emitting elements emitting light in the colors cyan, yellow, and magenta respectively constitute one second sub-pixel.

6. The light-emitting device according to claim 5, wherein the area ratio of the first sub-pixel to the second sub-pixel is 3 / 7 or more and 7 / 3 or less.

7. The light-emitting device according to claim 4 or 5, wherein the light-emitting element that emits red light has the light-emitting layer of the same red color in the stacking direction, the light-emitting element that emits green light has the light-emitting layer of the same green color in the stacking direction, and the light-emitting element that emits blue light has the light-emitting layer of the same blue color in the stacking direction.

8. The light-emitting device according to claim 4 or 5, wherein the light-emitting element that emits cyan light has a green light-emitting layer and a blue light-emitting layer in the stacking direction, the light-emitting element that emits yellow light has a red light-emitting layer and a green light-emitting layer in the stacking direction, and the light-emitting layer that emits magenta light has a blue light-emitting layer and a red light-emitting layer in the stacking direction.

9. The light-emitting device according to any one of claims 1 to 8, wherein the electron generating layer is made of one or more metals selected from the group consisting of Mg, Ag, Al, and alloys thereof.

10. The light-emitting device according to claim 9, wherein the electron generating layer has a thickness of 2 nm or more and 30 nm or less.

11. The light-emitting device according to any one of claims 1 to 10, wherein the hole-generating layer is made of one or more metal oxides selected from the group consisting of indium tin oxide, indium zinc oxide, indium gallium oxide, and indium gallium zinc oxide.

12. The light-emitting device according to claim 11, wherein the thickness of the hole-generating layer is 2 nm or more and 30 nm or less.

13. A display device comprising a light-emitting device according to any one of claims 1 to 12.

Images