Light-emitting element and its manufacturing method

Abstract

This mechanism provides a light-emitting element that can produce sufficient light compared to conventional light-emitting elements that combine elements that generate electricity through vibration or pressure with light-emitting elements. [Solution] A light-emitting element comprising a power generation unit that generates electricity through vibration or deformation and an organic electroluminescent unit stacked adjacent to each other, The organic electroluminescent unit has a structure in which a plurality of layers, each containing a charge generation layer and an emissive layer, are stacked between an anode and a cathode, and has a plurality of charge generation layers and emissive layers, and is characterized by having at least one of the following structures: a structure in which charge generation layers are present between the plurality of emissive layers, or a structure in which emissive layers are present between the plurality of charge generation layers.

Description

[Technical Field]

[0001] This invention relates to a light-emitting element and a method for manufacturing the same. More specifically, it relates to a light-emitting element that can be used as a self-illuminating marker or the like and a method for manufacturing the same. [Background technology]

[0002] Currently, light-emitting elements, which are mainly used in displays and lighting fixtures, are small and lightweight, making them suitable for a variety of other applications, but securing a power source remains a challenge. To address this challenge, devices combining elements that generate electricity through vibration or pressure with light-emitting elements have been disclosed for use as diving luminaires and amusement toys that light up when pressure is applied (see Patent Documents 1 and 2). Various structures of organic electroluminescent elements have been proposed as light-emitting elements in these devices, including tandem-type organic electroluminescent elements having multiple light-emitting layers between the cathode and anode (see Non-Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2002-63801 [Patent Document 2] Japanese Patent Publication No. 2008-142561 [Non-patent literature]

[0004] [Non-Patent Document 1] Applied Physics Letters 97,063303(2010). [Overview of the project] [Problems that the invention aims to solve]

[0005] Organic electroluminescent elements, which are small and lightweight and are expected to be used as light-emitting elements, are driven by electric current. In contrast, elements that generate electricity through vibration or pressure can generate high voltages but have low current values ​​due to their principle of operation. Therefore, when combining elements that generate electricity through vibration or pressure with organic electroluminescent elements, there is a problem in that sufficient light emission cannot be obtained. This means that the organic electroluminescent element cannot be used as a surface light-emitting element, which is a characteristic of organic electroluminescent elements, and the usefulness of organic electroluminescent elements is diminished.

[0006] This invention has been made in view of the above-mentioned situation, and aims to provide a mechanism that can extract sufficient light compared to conventional light-emitting elements that combine elements that generate electricity by vibration or pressure with light-emitting elements, and as a result, to provide surface light emission using an organic electroluminescent element. [Means for solving the problem]

[0007] The inventors of the present invention investigated light-emitting elements that emit more light than conventional light-emitting elements that combine elements that generate electricity by vibration or pressure with light-emitting elements. They discovered that when an organic electroluminescent unit, which comprises an organic electroluminescent element having a stacked structure between a cathode and an anode that includes a charge generation layer and a light-emitting layer, and having at least one of the charge generation layer and the light-emitting layer multiple times, with the charge generation layer existing between the multiple light-emitting layers, or the light-emitting layer existing between the multiple charge generation layers, is combined with a power generation unit that generates electricity by vibration or deformation, a light-emitting element that emits more light than conventional light-emitting elements that combine elements that generate electricity by vibration or pressure with light-emitting elements is obtained, leading to the present invention.

[0008] In other words, the present invention is as follows. [1] A light-emitting element comprising a power generation unit that generates electricity through vibration or deformation and an organic electroluminescent unit stacked adjacent to each other, The organic electroluminescent unit has a structure in which a plurality of layers including a charge generation layer and a light-emitting layer are laminated between an anode and a cathode, has at least one of the charge generation layer and the light-emitting layer in plurality, and has at least one of a structure in which a charge generation layer exists between a plurality of light-emitting layers or a structure in which a light-emitting layer exists between a plurality of charge generation layers. A light-emitting device characterized by this.

[0009] [2] The light-emitting device according to [1], characterized in that the organic electroluminescent unit has two or more light-emitting layers, and a charge generation layer exists between any two light-emitting layers.

[0010] [3] The light-emitting device according to [1] or [2], characterized in that the organic electroluminescent unit has one light-emitting layer and two charge generation layers, and a light-emitting layer exists between the two charge generation layers.

[0011] [4] The charge generation layer has a layer composed of a hole-transporting material and an electron-accepting material, and a layer composed of an electron-transporting material and an electron-donating material, the light-emitting device according to any one of [1] to [3].

[0012] [5] The charge generation layer has a structure in which a layer composed of a hole-transporting material and an electron-accepting material and a layer composed of an electron-transporting material and an electron-donating material are laminated adjacent to each other, the light-emitting device according to [4].

[0013] [6] The light-emitting device according to any one of [1] to [5], characterized in that the organic electroluminescent unit has a metal oxide layer between the anode and the cathode.

[0014] [7] The light-emitting device according to any one of [1] to [6], characterized in that the cathode of the organic electroluminescent unit is adjacent to the power generation unit.

[0015] [8] The power generation unit includes a charged body having a first electrode, a layer containing self-orienting polar organic molecules provided on the first electrode, and a second electrode provided on the side of the layer containing the self-orienting polar organic molecules opposite to the side having the first electrode, and a laminate having an uncharged body laminated on an electrode provided on at least one side of the charged body, The first electrode and the layer containing the self-orienting polar organic molecules, and the second electrode and the layer containing the self-orienting polar organic molecules are in contact with each other. The laminate is a power generation unit that generates electricity by vibrating or deforming in the stacking direction between the layer containing the self-oriented polar organic molecules and the uncharged body. A light-emitting element according to any one of [1] to [7], characterized in that the self-orienting polar organic molecules contained in the layer containing the self-orienting polar organic molecules include at least one selected from self-orienting polar organic molecules having a dipole moment magnitude in the range of 0D to 10D.

[0016] [9] The light-emitting element according to [8], characterized in that it comprises at least one selected from the following group of compounds.

[0017] [ka]

[0018]

[10] The light-emitting element according to [8] or [9], characterized in that it has two or more layers of the charged body.

[0019]

[11] The light-emitting element according to any one of [8] to

[10] , characterized in that the non-charged body includes an elastic organic material. [Effects of the Invention]

[0020] The present invention provides an independent surface light-emitting body with sufficient luminescence intensity, without requiring a power source, which is always necessary for conventional light-emitting devices, by combining an element that generates electricity through vibration or pressure with a light-emitting device. Furthermore, as a result of this mechanism, it is flexible and lightweight. Due to these characteristics, it can be suitably used as a wearable light-emitting device and the like. [Brief explanation of the drawing]

[0021] [Figure 1] This is an explanatory diagram of the energy levels in a charge generation layer without dopant addition. [Figure 2] This is an explanatory diagram of the energy levels in a dopant-doped charge generation layer. [Figure 3] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 4] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 5] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 6] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 7] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 8] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 9] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 10] This figure shows an example of the laminated structure of an organic electroluminescent unit in the light-emitting element of the present invention. [Figure 11] This figure shows an example of the stacked structure of a power generation unit having a light-emitting element of the present invention. [Figure 12] This figure shows an example of the stacked structure of a power generation unit having a light-emitting element of the present invention. [Figure 13]This is a schematic diagram showing one aspect of the cross-section of the charged body of the power generation unit of the light-emitting element of the present invention. [Modes for carrying out the invention]

[0022] The present invention will be described in detail below. Furthermore, combinations of two or more of the individual preferred embodiments of the present invention described below are also preferred embodiments of the present invention.

[0023] <hibi> The light-emitting element of the present invention consists of a power generation unit that generates electricity through vibration or deformation and an organic electroluminescent unit, which are stacked adjacent to each other. The organic electroluminescent unit has a structure in which multiple layers, each containing a charge generation layer and an emissive layer, are stacked between the anode and the cathode, and is characterized by having multiple layers, at least one of the charge generation layer and the emissive layer, with charge generation layers existing between the multiple emissive layers, or at least one of the two structures. The charge generation layer is a layer that emits electrons and holes. If the organic electroluminescent unit has a structure in which multiple light-emitting layers are located between the anode and cathode, and a charge generation layer is located between the multiple light-emitting layers, then the charge generation layer functions similarly to an electrode, resulting in a structure similar to that of multiple organic electroluminescent devices connected in series. When n organic electroluminescent devices are connected in series, the amount of current required per organic electroluminescent device to obtain the same total amount of light emission can be reduced to 1 / n, meaning that a large amount of light emission can be obtained even with a small amount of current. Furthermore, in a structure where a light-emitting layer exists between multiple charge-generating layers, the charge-generating layers act as sources of electrons and holes. Therefore, even when using a power source with a high voltage but low current, such as a device that generates electricity through vibration or deformation, sufficient electrons and holes can be supplied to the light-emitting layer, resulting in significant light emission. The organic electroluminescent unit of the light-emitting element of the present invention may have at least one of the following structures: a structure in which a charge generation layer exists between a plurality of light-emitting layers, or a structure in which a light-emitting layer exists between a plurality of charge generation layers, or it may have both of these structures.

[0024] The organic electroluminescent unit of the light-emitting element of the present invention may have at least one of the following structures: a structure in which a charge generation layer is present between a plurality of charge generation layers and a light-emitting layer, or a structure in which a light-emitting layer is present between a plurality of charge generation layers. However, having two or more light-emitting layers, with a charge generation layer present between any two of these light-emitting layers, is one preferred embodiment of the light-emitting element of the present invention. As described above, having such a structure results in the same structure as when two or more organic electroluminescent elements are connected in series, and the current required for each organic electroluminescent element to emit light is reduced, so a large amount of light can be obtained even when using a power generation unit with a low current value. The number of light-emitting layers in an organic electroluminescent unit is more preferably two or more, even more preferably three or more, and particularly preferably four or more. There is no particular upper limit to the number of light-emitting layers, but three or fewer is preferable considering the manufacturing cost.

[0025] Another preferred form of the light-emitting element of the present invention is a structure in which the organic electroluminescent unit of the light-emitting element of the present invention has one light-emitting layer and two charge-generating layers, with the light-emitting layer located between the two charge-generating layers. In this case, since electrons and holes are supplied from two charge generation layers, even if the number of electrons and holes generated from the electrodes is small, a sufficient amount of electrons and holes are supplied to the light-emitting layer, and a large amount of light emission can be obtained even when a power generation unit with a high voltage but low current is used as the power source. In this case, it is preferable that the two charge generation layers be positioned adjacent to the electrodes. This allows a sufficient amount of electrons and holes to be supplied from the charge generation layers to the light-emitting layer.

[0026] The light-emitting element of the present invention may be a laminated structure comprising an organic electroluminescent unit formed on a substrate, with a laminated structure comprising a power generation unit formed on top of that, or a laminated structure comprising a power generation unit formed on a substrate, with a laminated structure comprising an organic electroluminescent unit formed on top of that. Preferably, (1) a laminated structure constituting an organic electroluminescent unit is formed on a substrate, and a laminated structure constituting a power generation unit is formed on top of that, with the cathode of the organic electroluminescent unit formed adjacent to the substrate (a structure in which the cathode of the organic electroluminescent unit is adjacent to the power generation unit), or (2) a laminated structure constituting a power generation unit is formed on a substrate, and a laminated structure constituting an organic electroluminescent unit is formed on top of that, with the cathode of the organic electroluminescent unit formed adjacent to the power generation unit. In such a structure, it is possible to use a material with high atmospheric stability for the cathode, thereby making the organic electroluminescent unit more atmospherically stable. More preferably, (1) is used, which eliminates the need to use a top emission structure with a complex layer structure, enabling stable manufacturing and atmospheric stability. In addition, although it is possible to form the organic electroluminescent unit and the power generation unit as a single unit, forming the organic electroluminescent unit on the substrate side allows for fabrication on a flatter plane, enabling stable device manufacturing. In the light-emitting element of the present invention, at locations where the organic electroluminescent unit and the power generation unit are adjacent, the organic electroluminescent unit and the power generation unit share electrodes. Therefore, in the case of the structure described in (2) above, the organic electroluminescent unit and the power generation unit share a cathode. Although the electrodes are shared, the structure may be a stacked structure of two or more layers, and the constituent elements may be the same or different.

[0027] <Method for manufacturing luminescent elements> The organic electroluminescent unit and the power generation unit of the present invention may be manufactured separately, and their respective manufacturing methods will be described later. However, since both stacked structures can be formed using similar methods such as vacuum deposition, it is also possible to form the organic electroluminescent unit and the power generation unit as a single unit. The fact that the entire light-emitting element can be manufactured as a single unit is one of the advantageous features of the present invention. A method for manufacturing a light-emitting element that integrally forms such an organic electroluminescent unit and a power generation unit, that is, a method for manufacturing a light-emitting element that includes a power generation unit manufacturing step of forming a laminated structure of a power generation unit on a substrate and an organic electroluminescent unit manufacturing step of forming a laminated structure of an organic electroluminescent unit on the power generation unit, and a method for manufacturing a light-emitting element that includes an organic electroluminescent unit manufacturing step of forming a laminated structure of an organic electroluminescent unit on a substrate and a power generation unit manufacturing step of forming a laminated structure of a power generation unit on the organic electroluminescent unit, is also one of the present inventions.

[0028] In the above-described method for manufacturing a light-emitting element, the method for producing the power generation unit and the organic electroluminescent unit is not particularly limited as long as it is possible to form them integrally, but vacuum deposition, sputtering, chemical vapor deposition, atomic layer deposition, and inkjet coating are preferred. Vacuum deposition is more preferred.

[0029] The above-described method for manufacturing a light-emitting element may include other steps besides the power generation unit manufacturing step and the organic electroluminescent unit manufacturing step. Examples of other steps include the step of sealing the light-emitting element.

[0030] <Charge generation layer> The charge generation layer of the above-described organic electroluminescent unit is not particularly limited as long as it can generate electrons and holes, but it is preferable to have a layer made of a hole-transporting material and an electron-accepting material, and a layer made of an electron-transporting material and an electron-donating material. With such a structure, the charge generation layer can more fully perform its function as a supply of electrons and holes. Such a charge generation layer consists only of a layer made of a hole-transporting material and an electron-accepting material (hereinafter also referred to as a p-doped layer) and a layer made of an electron-transporting material and an electron-donating material (hereinafter also referred to as an n-doped layer). These layers may be stacked adjacent to each other, or there may be a layer made only of an electron-accepting material or an electron-donating material (hereinafter also referred to as a dopant layer) between these layers. Among these, the charge generation layer of the above-mentioned organic electroluminescent unit preferably has a structure in which a layer made of a hole-transporting material and an electron-accepting material and a layer made of an electron-transporting material and an electron-donating material are laminated adjacent to each other. With such a structure, the number of steps required for manufacturing the charge generation layer can be reduced.

[0031] Referring to Figures 1 and 2, the mechanism of charge generation in the charge generation layer and the roles of dopants (electron-accepting materials and electron-donating materials) will be explained. Figure 1 shows the energy levels of the charge generation layer without dopant addition, and Figure 2 shows the energy levels of the charge generation layer with dopant addition. As shown in Figure 1, the behavior of electrons (●) in the hole-transporting material with a low ionization energy of the HOMO contained in the p-doped layer is key to electron injection into the device. If electrons can be efficiently transferred from the p-doped layer to the n-doped layer, electrons can be efficiently injected into the organic electroluminescent unit. To facilitate this charge flow, dopants (electron-accepting materials and electron-donating materials) are necessary. As disclosed in Non-Patent Document 1, elemental metals such as alkali metals and metal oxides can be used as electron-accepting and electron-donating materials. However, since the organic electroluminescent unit in the present invention is flexible and atmospheric stability is important, it is preferable that the charge generation layer does not contain alkali metals or metal oxides, which can cause degradation. Note that "not containing alkali metals" includes not only not containing elemental alkali metals, but also not containing alkali metal alloys or alkali metal compounds (for example, complexes containing alkali metals). If the charge generation layer is composed solely of organic materials and does not contain alkali metals or metal oxides, then, for example, when fabricating the charge generation layer in a vacuum chamber, it can be easily fabricated in an organic deposition chamber alone, resulting in fewer process constraints and making it easier to use as a material for the layer constituting the organic electroluminescent unit. This is another advantage of the light-emitting element of the present invention.

[0032] Figure 2 shows the energy changes when dopants (electron-accepting materials and electron-donating materials) are added to the p-doped and n-doped layers. By adding a dopant (electron-accepting material) to the p-doped layer, the energy level in the p-doped layer shifts upward (towards a lower ionization energy), making it easier to transfer electrons to the LUMO of the n-doped layer. On the other hand, by adding a dopant (electron-donating material) to the n-doped layer, in the n-doped layer, as one method that does not use alkali metals, the electron-donating material and the electron-transporting material form hydrogen bonds. This shifts the energy level of the electron-transporting material downward (towards a higher electron affinity), making it easier to accept electrons to the LUMO of the n-doped layer. Furthermore, the increased ionization energy improves the blocking performance of holes carried from the light-emitting layer, resulting in improved luminescence efficiency. In this way, by utilizing the energy level shift caused by the addition of dopants (electron-accepting materials, electron-donating materials), the charge generation capability in the charge generation layer can be improved.

[0033] "p-doped layer" The above p-doped layer includes a hole-transporting material and an electron-accepting material. The p-doped layer is composed of a hole-transporting material with a low ionization energy and an electron-accepting material. The electron-accepting material attracts electrons from the hole-transporting material, making it easier to inject these electrons into the device. In the p-doped layer, the mixing ratio (mass ratio) of hole-transporting material to electron-accepting material is preferably 0.1:9.9 to 9.9:0.1, and more preferably 1:9 to 9:1.

[0034] The average thickness of the above p-doped layer is preferably 1 to 100 nm, and more preferably 3 to 20 nm. The average thickness of the p-doped layer can be measured using a stylus step meter or spectroscopic ellipsometry.

[0035] The hole-transporting material contained in the above-mentioned p-doped layer preferably has an ionization potential less than 5.7 eV. In this case, the ionization energy of the HOMO of the p-doped layer is small, making it easier to transfer electrons to the LUMO of the n-doped layer. The ionization potential of hole-transporting materials is measured by photoelectron spectroscopy or photoelectron yield spectroscopy.

[0036] As the hole-transporting material mentioned above, one or more types of various p-type polymer materials (organic polymers) and various p-type low-molecular-weight materials can be used. Examples of hole-transporting materials include 4,4',4”-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), 3,3'-bi[1,4]benzoxazino[2,3,4-kl]phenoxazine, N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD), and N4,N4'-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4'-diphenylbiphenyl Examples include ru-4,4'-diamine (DBTPB), polyarylamines, fluorene-arylamine copolymers, fluorene-bithiophene copolymers, poly(N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylenevinylene), polythienylenevinylene, pyreneformaldehyde resin, ethylcarbazoleformaldehyde resin, or derivatives thereof. These hole-transporting materials can also be used as mixtures with other compounds. Among these, materials with low ionization energy are particularly preferred, such as triarylamines like 4,4',4”-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA) and phenoxazine derivatives like 3,3'-bi[1,4]benzoxazino[2,3,4-kl]phenoxazine.

[0037] As the electron-accepting material included in the above-mentioned p-doped layer, elemental metals such as alkali metals or metal oxides can be used, as described above, but it is preferable that the material contains substituents with high electronegativity selected from fluorine, chlorine, cyano group, nitro group, and carbonyl group. Furthermore, as mentioned above, elemental metals such as alkali metals and metal oxides can be used as electron-donating materials, but it is preferable that the electron-donating material is one of the following: tertiary amines, phosphazene compounds, guanidine compounds, heterocyclic compounds containing an amidine structure, hydrocarbon compounds having a cyclic structure, phenanthroline compounds, terpyridine compounds, or cyclic pyridine compounds, all of which have an acid dissociation constant pKa of 1 or higher.

[0038] The electron-accepting material described above is preferably an organic substance capable of forming a charge-transfer complex with a hole-transporting material through a redox reaction. In this case, the ionization energy of the HOMO in the p-doped layer becomes smaller, making it easier to transfer electrons to the LUMO in the n-doped layer. The electron-donating material is preferably an organic substance capable of forming hydrogen bonds with the electron-transporting material. In this case, the energy level of the electron-transporting material in the n-doped layer becomes lower, making it easier for the LUMO of the n-doped layer to accept electrons.

[0039] The electron-accepting material described above is preferably a material containing a highly electronegative substituent selected from fluorine, chlorine, cyano group, nitro group, and carbonyl group. Examples of electron-accepting materials that can be used include 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), shown in structural formula (1-1) below; 1,3,4,5,7,8-hexafluoro-tetracyanonaphthoquinodimethane (F6TCNNQ), shown in structural formula (1-2) below; hexacyano-trimethylene-cyclopropane (CN6-CP), shown in structural formula (1-3) below; and 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), shown in structural formula (1-4) below. The electron-accepting material may be a single material or a combination of two or more materials.

[0040] [ka]

[0041] "n-doped layer" The above n-doped layer includes an electron-transporting material and an electron-donating material. The n-doped layer is composed of an electron-transporting material with high electron affinity and an electron-donating material, and plays the role of receiving electrons from the p-doped layer and transporting them into the device. The presence of the electron-donating material increases the electron affinity of the electron-transporting material, making it easier to inject electrons into the device, and also increases the ionization energy of the electron-transporting material, which is effective in blocking holes transported from the light-emitting layer, for example, leading to higher efficiency. In the n-doped layer, the mixing ratio (mass ratio) of electron-transporting material to electron-donating material is preferably 0.1:9.9 to 9.9:0.1, and more preferably 1:9 to 9:1.

[0042] The average thickness of the above n-doped layer is preferably 1 to 100 nm, and more preferably 3 to 20 nm. The average thickness of the n-doped layer can be measured using a stylus step meter or spectroscopic ellipsometry.

[0043] As the electron-transporting material mentioned above, any material that can be commonly used as a material for the electron transport layer of an organic electroluminescent device may be used. As electron transport materials, phosphine oxide derivatives such as phenyl-dipyrenylphosphine oxide (POPy2), pyridine derivatives such as tris-1,3,5-(3'-(pyridin-3”-yl)phenyl)benzene (TmPhPyB), quinoline derivatives such as 2-(3-(9-carbazolyl)phenyl)quinoline (mCQ), pyrimidine derivatives such as 2-phenyl-4,6-bis(3,5-dipyridylphenyl)pyrimidine (BPyPPM), pyrazine derivatives, and vasophenanes are used. Phenanthroline derivatives such as throline (BPhen), triazine derivatives such as 2,4-bis(4-biphenyl)-6-(4'-(2-pyridinyl)-4-biphenyl)-[1,3,5]triazine (MPT), 2,4,6-tris(m-pyridine-3-yl-phenyl)triazine (TmPPyTz), triazole derivatives such as 3-phenyl-4-(1'-naphthyl)-5-phenyl-1,2,4-triazole (TAZ), oxazole derivatives, 2-(4-biphenylyl)- Oxadiazole derivatives such as 5-(4-tert-butylphenyl-1,3,4-oxadiazole) (PBD), imidazole derivatives such as 2,2',2”-(1,3,5-bentriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBI), aromatic ring tetracarboxylic anhydrides such as naphthalene and perylene, and various other compounds such as bis[2-(2-hydroxyphenyl)benzothiazolato]zinc (Zn(BTZ)2) and tris(8-quinolinolato)aluminum (Alq3). Examples include metal complexes, organosilane derivatives such as silole derivatives like 2,5-bis(6'-(2',2”-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), and boron-containing compounds described in Japanese Patent Publication No. 2013-239691, International Publication No. 2014 / 133141, Japanese Patent Publication No. 2016-172728, Japanese Patent Publication No. 2016-199507, and Japanese Patent Publication No. 2016-199508. One or more of these can be used. Among these electron-transporting materials, it is particularly preferable to use triazine derivatives such as TmPPyTz, phosphine oxide derivatives such as POPy2, metal complexes such as Alq3, and pyridine derivatives such as TmPhPyB.

[0044] The electron-donating material described above is preferably selected from tertiary amines, phosphazene compounds, guanidine compounds, heterocyclic compounds containing an amidine structure, hydrocarbon compounds having a cyclic structure, phenanthroline compounds, terpyridine compounds, and cyclic pyridine compounds, all of which have an acid dissociation constant pKa of 1 or higher. The electron-donating material may be used individually or in combination of two or more types. These electron-donating materials have an acid dissociation constant pKa of 1 or greater and are basic compounds. In this invention, "pKa" usually means "acid dissociation constant in water," but if it cannot be measured in water, it means "acid dissociation constant in dimethyl sulfoxide (DMSO)," and if it cannot be measured even in DMSO, it means "acid dissociation constant in acetonitrile." Preferably, it means "acid dissociation constant in water."

[0045] The above-mentioned tertiary amine (tertiary amine derivative) may be a linear or cyclic amine compound, and if cyclic, it may be a heterocyclic amine compound, or a heterocyclic amine compound such as an aliphatic amine or an aromatic amine. The tertiary amine preferably has 1 to 4 amino groups, and more preferably 1 or 2 amino groups. The amine compound may also be a compound having an alkyl group, an alkylamino group, or an alkoxy group. Specifically, examples include (mono, di, tri)alkylamines; aromatic amines having 1 to 3 alkylamino groups; and aromatic amines having 1 to 3 alkoxy groups.

[0046] The tertiary amines mentioned above are preferably those that do not contain primary or secondary amines. Specifically, the tertiary amines are dialkylaminopyridines such as dimethylaminopyridine (DMAP) shown in the following structural formula (2-1) or (2-2), and NRs such as triethylamine shown in the following structural formula (2-3). 21 R 22 R 23 Amine having a structure represented by (however, R 21 , R 22 , R 23 ) represents a hydrocarbon group that may have substituents, either identical or different. Examples include acridine orange (AOB) shown in the following structural formula (2-4).

[0047] [ka]

[0048] The above R 21 ~R 23 The hydrocarbon group in this compound preferably has 1 to 30 carbon atoms, more preferably 1 to 8 carbon atoms, even more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. If the hydrocarbon group has substituents, it is preferable that the total number of carbon atoms, including the substituents, is within these limits. Examples of hydrocarbon groups include alkyl groups, alkenyl groups, and alkynyl groups, but alkyl groups are preferred. Examples of substituents in hydrocarbon groups include halogen atoms, heterocyclic groups, cyano groups, hydroxyl groups, alkoxy groups, aryloxy groups, and amino groups.

[0049] In the above-mentioned dimethylaminopyridine, it is preferable that the position of the electron-donating dimethylamino group attached to the pyridine ring is at position 2 (2-DMAP) or position 4 (4-DMAP), as in (2-1) or (2-2) above. In particular, 4-dimethylaminopyridine, in which the dimethylamino group is attached to position 4 of the pyridine ring, has a high pKa.

[0050] As the above-mentioned tertiary amine, an alkoxypyridine derivative such as a methoxypyridine derivative can also be used. As the alkoxy group, an alkoxy group having 1 to 30 carbon atoms is preferable, an alkoxy group having 1 to 8 carbon atoms is more preferable, an alkoxy group having 1 to 4 carbon atoms is still more preferable, and 1 or 2 alkoxy groups are even more preferable. The alkoxypyridine derivative also includes a compound having a structure in which one or more hydrogen atoms of alkoxypyridine are substituted with substituents. Examples of the substituent are the same as those of the substituent of the hydrocarbon group of the above-mentioned tertiary amine. As the methoxypyridine derivative, 4-methoxypyridine (4-MeOP) represented by the following structural formula (2-5) in which the position where the methoxy group is bonded to the pyridine ring is the 4-position or 3-methoxypyridine (3-MeOP) represented by the following structural formula (2-6) in which the position is the 3-position is preferable. In particular, 4-methoxypyridine in which a methoxy group is bonded to the 4-position of the pyridine ring is preferable because of its high pKa.

[0051] [Chemical formula]

[0052] As the above-mentioned tertiary amine, it is preferable to use one or more selected from heterocyclic aromatic amines having a dialkylamino group and / or an alkoxy group and trialkylamines, and it is particularly preferable to use one or more selected from dialkylaminopyridine, trialkylamine, and alkoxypyridine derivatives.

[0053] The above-mentioned phosphazene compound (phosphazene base derivative) is, for example, a compound containing a structure represented by the following general formula (3-1).

[0054] [Chemical formula]

[0055] In the above formula (3-1), R 31 represents a hydrogen atom or a hydrocarbon group, and R32 ~R 34 R' represents a hydrogen atom, a hydrocarbon group, -NR'R'' (where R' and R'' independently represent a hydrogen atom and a hydrocarbon group, respectively), or a group represented by the following formula (3-2), where n represents a number from 1 to 5.

[0056] [ka]

[0057] In the above equation (3-2), R 35 ~R 37 'R'' represents a hydrogen atom, a hydrocarbon group, or -NR'R'' (where R' and R'' independently represent a hydrogen atom or a hydrocarbon group), and m represents a number from 1 to 5. In the above formulas (3-1) and (3-2), the hydrocarbon group is preferably a group having 1 to 8 carbon atoms, and more preferably a group having 1 to 4 carbon atoms. Furthermore, an alkyl group is preferred as the hydrocarbon group. 34 A tert-butyl group is particularly preferred.

[0058] Examples of the phosphazene base derivatives mentioned above include the compound shown in the following structural formula (3-3).

[0059] [ka]

[0060] The guanidine compounds mentioned above are compounds containing the structure represented by the following general formula (4-1).

[0061] [ka]

[0062] In the above equation (4-1), R 41 ~R 45 R represents a hydrogen atom or a hydrocarbon group, either identical or different. 41 ~R 45Two or more of these may be bonded together to form a cyclic structure. Furthermore, the guanidine compound may have multiple structures represented by the general formula (4-1).

[0063] As the above guanidine compound, guanidine cyclic derivatives can be used. Examples of guanidine cyclic derivatives include 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene (MTBD), shown in the following structural formula (4-2); 1,5,7-triazabicyclo[4.4.0]deca-5-ene (TBD), shown in the following structural formula (4-3); and the compound (Py-hpp2), shown in the following structural formula (4-4).

[0064] [ka]

[0065] In the heterocyclic compound containing the above amidine structure, the amidine structure is defined as R 51 -C(=NR 52 )-NR 53 R 54 The structure represented by (however, R 51 ~R 54 ) represents a hydrogen atom or a hydrocarbon group, either identical or different. Examples of heterocyclic compounds containing an amidine structure include diazabicyclononene derivatives and diazabicycloundecene derivatives. R 51 ~R 54 The hydrocarbon group is the R mentioned above. 21 ~R 23 Examples include those similar to the hydrocarbon group shown.

[0066] Examples of the above-mentioned diazabicyclononene derivatives include 1,5-diazabicyclo[4.3.0]nonene-5(DBN), shown in the following structural formula (5-1). Examples of diazabicycloundecene derivatives include 1,8-diazabicyclo[5.4.0]undecene-7(DBU), shown in the following structural formula (5-2).

[0067] [ka]

[0068] The above-mentioned diazabicyclononene derivatives include compounds in which one or more hydrogen atoms of diazabicyclononene are substituted with substituents, and the diazabicycloundecene derivatives also include compounds in which one or more hydrogen atoms of diazabicycloundecene are substituted with substituents. Examples of substituents are the same as those for the hydrocarbon group of the tertiary amine described above.

[0069] As hydrocarbon compounds having the above-mentioned ring structure, compounds having a 5-membered ring or a 6-membered ring as the ring structure are preferred, and compounds having a ring structure in which a 5-membered ring and a 6-membered ring are fused, or a ring structure in which multiple 6-membered rings are fused, are also preferred. Examples of 5-membered rings include cyclopentane rings and cyclopentadiene rings, and examples of 6-membered rings include benzene rings. Preferred hydrocarbon compounds having a ring structure include compounds with only a ring structure, compounds in which an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10, more preferably 1 to 5 carbon atoms, is bonded to the ring structure, and compounds in which multiple ring structures are bonded directly or via linking groups of hydrocarbons having 1 to 20 carbon atoms, preferably 1 to 10, more preferably 1 to 5 carbon atoms. Specific examples of hydrocarbon compounds having a ring structure include the compounds shown in formulas (6-1) to (6-14) below. Note that Ph in the formulas represents a phenyl group.

[0070] [ka]

[0071] The above phenanthroline compounds have the following structural formula (7-1):

[0072] [ka]

[0073] The present invention comprises phenanthroline represented by [formula] and a compound in which one or more hydrogen atoms in the phenanthroline are substituted with a monovalent organic group (hereinafter sometimes referred to as a "phenanthroline derivative"). Here, the monovalent organic group may be a substituted aryl group, heterocyclic group, alkyl group, alkenyl group, alkynyl group, alkoxy group, aryloxy group, arylalkoxy group, silyl group, hydroxy group, amino group, alkylamino group, arylamino group, halogen atom, carboxyl group, thiol group, epoxy group, acyl group, a substituted oligoaryl group, monovalent oligoheterocyclic group, alkylthio group, arylthio group, arylalkyl group, arylalkoxy group, arylalkylthio group, azo group, staniyl group, phosphino group, a substituted arylphosphino group, a substituted alkylphosphino group, arylphosphinyl group, a substituted alkylphosphinyl group, silyloxy group, a substituted aryloxycarbonyl group, a substituted alkoxycarbonyl group, a substituent Examples include carbamoyl groups which may have a substituent, arylcarbonyl groups which may have a substituent, alkylcarbonyl groups which may have a substituent, arylsulfonyl groups which may have a substituent, alkylsulfonyl groups which may have a substituent, arylsulfinyl groups which may have a substituent, alkylsulfinyl groups which may have a substituent, formyl groups, cyano groups, nitro groups, arylsulfonyloxy groups, alkylsulfonyloxy groups; alkylsulfonate groups such as methanesulfonate groups, ethanesulfonate groups, and trifluoromethanesulfonate groups; arylsulfonate groups such as benzenesulfonate groups and p-toluenesulfonate groups; arylalkylsulfonate groups such as benzylsulfonate groups; boryl groups, sulfonium methyl groups, phosphonium methyl groups, phosphonate methyl groups, arylsulfonate groups, aldehyde groups, acetonitrile groups, and the like.

[0074] The substituents on the above monovalent organic group include halogen atoms such as fluorine, chlorine, bromine, and iodine; haloalkyl groups such as methyl chloride, methyl bromide, methyl iodide, fluoromethyl, difluoromethyl, and trifluoromethyl; linear or branched alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and tert-butyl; cyclic alkyl groups having 5 to 7 carbon atoms such as cyclopentyl, cyclohexyl, and cycloheptyl; methoxy, ethoxy, and propoxy groups. Linear or branched alkoxy groups having 1 to 20 carbon atoms, such as isopropoxy groups, butoxy groups, isobutoxy groups, tert-butoxy groups, pentyloxy groups, hexyloxy groups, heptyloxy groups, and octyloxy groups; hydroxyl groups; thiol groups; nitro groups; cyano groups; amino groups; azo groups; mono or dialkylamino groups having 1 to 40 carbon atoms, such as methylamino groups, ethylamino groups, dimethylamino groups, and diethylamino groups; amino groups such as diphenylamino groups and carbazolyl groups; acyl groups such as acetyl groups, propionyl groups, and butyryl groups; vinyl groups , C2-C20 alkenyl groups such as 1-propenyl group, allyl group, butenyl group, and styryl group; C2-C20 alkynyl groups such as ethynyl group, 1-propynyl group, propargyl group, and phenylacetylyl; alkenyloxy groups such as vinyloxy group and allyloxy group; alkynyloxy groups such as ethynyloxy group and phenylacetyloxy group; aryloxy groups such as phenoxy group, naphthoxy group, biphenyloxy group, and pyrenyloxy group; perfluoro methyl group, trifluoromethoxy group, pentafluoroethoxy group, and perfluorophenyl group. Perfluoro groups and even longer-chain perfluoro groups; boryl groups such as diphenylboryl group, dimethylboryl group, bis(perfluorophenyl)boryl group, and 4,4,5,5-tetramethyl-1,3,2-dioxavoranyl group; carbonyl groups such as acetyl group and benzoyl group; carbonyloxy groups such as acetoxy group and benzoyloxy group; alkoxycarbonyl groups such as methoxycarbonyl group, ethoxycarbonyl group, and phenoxycarbonyl group; sulfinyl groups such as methylsulfinyl group and phenylsulfinyl group; sulfonyl groups such as methylsulfonyl group and phenylsulfonyl group;Alkyl sulfonyloxy groups; aryl sulfonyloxy groups; phosphino groups; phosphinyl groups such as diethylphosphinyl and diphenylphosphinyl; silyl groups such as trimethylsilyl, triisopropylsilyl, dimethyl-tert-butylsilyl, trimethoxysilyl, and triphenylsilyl; silyloxy groups; staniyl groups; phenyl groups, 2,6-xylyl, mesityl, duryl, biphenyl, terphenyl, naphthyl, anthryl, pyrenyl, toluyl, anisyl, fluorophenyl, diphenylaminophenyl, dimethylaminophenyl, diethylaminophenyl, and phenanthrenyl groups (aromatherapy hydrocarbon ring groups that may be substituted); halogen atoms, alkyl groups, alkoxy groups, etc.; aryl groups (aromatherapy hydrocarbon ring groups that may be substituted); halogen atoms, alkyl groups, alkoxy groups, etc. Examples include heterocyclic groups (aromatic heterocyclic groups that may be substituted) such as thienyl groups, furyl groups, silacyclopentadienyl groups, oxazolyl groups, oxadiazolyl groups, thiazolyl groups, thiadiazolyl groups, acridinyl groups, quinolyl groups, quinoxaloyl groups, phenanthloryl groups, benzothienyl groups, benzothiazolyl groups, indolyl groups, carbazolyl groups, pyridyl groups, pyrrolyl groups, benzoxazolyl groups, pyrimidyl groups, and imidazolyl groups; carboxyl groups; carboxylic acid esters; epoxy groups; isocyano groups; cyanate groups; isocyanate groups; thiocyanate groups; isothiocyanate groups; carbamoyl groups; N,N-dialkylcarbamoyl groups such as N,N-dimethylcarbamoyl and N,N-diethylcarbamoyl groups; formyl groups; nitroso groups; formyloxy groups; and the like. These groups may be substituted with halogen atoms, alkyl groups, aryl groups, etc. Furthermore, these groups may bond to each other at arbitrary locations to form a ring.

[0075] The above-mentioned phenanthroline derivative may be a compound having multiple phenanthroline structures in its molecular structure. Examples of phenanthroline derivatives include the compounds shown in the following structural formulas (7-2) to (7-9).

[0076] [ka]

[0077] The aforementioned terpyridine compound is a compound having a terpyridine structure (a structure in which three pyridines are bonded together), and its structural formula is as follows (8-1):

[0078] [ka]

[0079] This includes terpyridine represented by [formula] and compounds in which one or more hydrogen atoms in the terpyridine are substituted with a monovalent organic group (hereinafter sometimes referred to as "terpyridine derivatives"). Here, specific examples of a monovalent organic group and substituents when the monovalent organic group has substituents are the same as the specific examples of a monovalent organic group and substituents when the monovalent organic group has substituents in the compound in which one or more hydrogen atoms in phenanthroline shown in structural formula (7-1) above are substituted with a monovalent organic group.

[0080] Examples of the above terpyridine compounds include 2,2':6',2"-terpyridine, 1,3-bis(4'-(2,2':6',2"-terpyridinyl))benzene, 6"-(3-(5H-dibenzo[b,d]borol-5-yl)-5-(4',6'-diethyl-[2,2'-bipyridine]-6-yl)thiophen-2-yl)-4,6-diethyl-2,2':6',3"-terpyridine.

[0081] The above-mentioned cyclic pyridine compounds are compounds having a structure in which multiple pyridines are bonded in a ring, and it is preferable that the multiple pyridine rings are bonded directly or via nitrogen atoms to form a ring structure. Examples of such cyclic pyridine compounds include compounds having a structure represented by the following general formula (9-1).

[0082] [ka]

[0083] In the above general formula (9-1), R 9 n represents a hydrogen atom or a monovalent organic group, either identical or different. n is an integer of 0 or 1, either identical or different. m is an integer between 3 and 10. In the above general formula (9-1), R 9 When the group is a monovalent organic group, the specific examples of the monovalent organic group are the same as those for the monovalent organic group in the compound in which one or more hydrogen atoms in phenanthroline, shown in structural formula (7-1) above, are substituted with a monovalent organic group. The specific examples of substituents when the monovalent organic group has substituents are also the same. Among them, R 9 Preferred monovalent organic groups are methyl, ethyl, phenyl, n-propyl, isopropyl, and isobutyl groups.

[0084] In the above general formula (9-1), m is an integer between 3 and 10, but in terms of the strength of the interaction with hydrogen, it is preferably between 3 and 8, and more preferably between 3 and 6.

[0085] In the general formula (9-1) above, n can be the same or different integers, 0 or 1. That is, for example, if a cyclic pyridine compound is a compound having six pyridine rings, the possible integers for the six n in the structure are combinations from [i](0,0,0,0,0,0) to [xii](1,1,1,1,1,1), and since it is a cyclic structure, the other possibilities are [ii](1,0,0,0,0,0), [iii](1,1,0,0,0,0), [i [v](1,0,1,0,0,0), [v](1,0,0,1,0,0), [vi](1,1,1,0,0,0), [vii](1,1,0,1,0,0), [viii](0,0,1,1,1,1), [ix](0,1,0,1,1,1), [x](0,1,1,0,1,1), and [xi](0,1,1,1,1,1) are possible, for a total of 12 possible combinations. All of these are candidates. However, the above [vi], [vii], and [xii] in which 6 or 3 of the values ​​are 1 are preferred. More preferably, [xii] in which the number of values ​​of n that are 1 is the same as the number of values ​​of m. That is, among the cyclic pyridine compounds represented by general formula (9-1), it is preferable that they are azacalyxpyridine derivatives in which all n in general formula (9-1) are 1.

[0086] As a cyclic pyridine compound having the structure represented by the above general formula (9-1), compounds represented by the following general formulas (9-2) to (9-5) are preferred. Note that R in general formulas (9-2) to (9-5) 9 This is R in general formula (9-1). 9 It is synonymous with [the above].

[0087] [ka]

[0088] As the above cyclic pyridine compounds, compounds in which the hydrogen atom at the para position of the pyridine ring in the above general formula (9-1) is substituted with a monovalent organic group, where the monovalent organic group is R 9 Monovalent organic groups are similarly cited. Among these monovalent organic groups, heterocyclic groups are preferred, and pyrrolidinyl groups are particularly preferred. Specific examples of the above-mentioned cyclic pyridine compounds include, for example, the compounds represented by the following structural formulas (9-6) to (9-7).

[0089] [ka]

[0090] "Dopant layer" The dopant layer described above consists solely of the electron-accepting material or the electron-donating material. Here, the electron-accepting material can be any of the materials described in the "p-doped layer" section. The electron-donating material can be any of the materials described in the "n-doped layer" section. In the present invention, the charge generation layer preferably does not contain alkali metals or metal oxides. In this case, since the charge generation layer does not contain alkali metals, it does not contain alkali metal-containing complexes as described above, and therefore it can be manufactured by co-deposition and is less prone to degradation in the presence of oxygen and moisture.

[0091] <Method for manufacturing a charge generation layer> The method for manufacturing the charge generation layer in the present invention is not particularly limited, but it can be manufactured by a manufacturing method that includes a p-doped layer formation step of co-depositing a hole-transporting material and an electron-accepting material to form a layer (p-doped layer) made of a hole-transporting material and an electron-accepting material, and an n-doped layer formation step of co-depositing an electron-transporting material and an electron-donating material to form a layer (n-doped layer) made of an electron-transporting material and an electron-donating material. Furthermore, the method for manufacturing the charge generation layer in the present invention may optionally include a dopant layer formation step in which an electron-accepting material or an electron-donating material is deposited to form a layer consisting only of an electron-accepting material or a layer consisting only of an electron-donating material (dopant layer). The order of the p-doping layer formation step and the n-doping layer formation step is not particularly limited and can be appropriately selected depending on the desired device structure. Furthermore, it is preferable to perform the dopant layer formation step between the p-doping layer formation step and the n-doping layer formation step. A standard vacuum deposition apparatus can be used for the co-deposition and deposition processes described above.

[0092] The organic electroluminescent unit and power generation unit of the light-emitting element of the present invention will be described in order below. Both the organic electroluminescent unit and the power generation unit have electrodes at both ends of a laminated structure. However, the light-emitting element of the present invention has a structure in which the organic electroluminescent unit and the power generation unit are stacked adjacent to each other, and they share one electrode at the adjacent locations. In addition, the electrodes on the sides that are not shared are connected (wired) together.

[0093] <Organic electroluminescent unit> The organic electroluminescent unit in the present invention has an anode, a cathode, a charge generation layer, and a light-emitting layer, but it is preferable to have an electron transport layer and a hole transport layer between these layers, and it may further have a hole injection layer and a coated intermediate layer. An embodiment of the laminated structure of the organic electroluminescent unit according to the present invention will be described with reference to the drawings. Figures 3 to 10 show the laminated structure of the organic electroluminescent unit in the present invention. The organic electroluminescent unit in Figure 3 has two light-emitting layers 5 and one charge generation layer 1 (consisting of a p-doped layer 1a and an n-doped layer 1b) between the cathode 2 and the anode 3, and the charge generation layer 1 is located between the two light-emitting layers 5. An electron transport layer 4 is located between the cathode 2 and the light-emitting layer 5 closer to the cathode 2, and a hole transport layer 6 is located between the light-emitting layer 5 and the charge generation layer 1. An electron transport layer 4 is located between the charge generation layer 1 and the other light-emitting layer 5, and a hole transport layer 6 is located between the other light-emitting layer 5 and the anode 3. Of the two layers constituting the charge generation layer 1, the n-doped layer 1b is adjacent to the electron transport layer 4, and the p-doped layer 1a is adjacent to the hole transport layer 6. The organic electroluminescent unit shown in Figure 3 is a two-layer tandem type organic electroluminescent unit, which corresponds to two organic electroluminescent elements coupled in series.

[0094] The organic electroluminescent unit in Figure 4 has a stacked structure in which the stacking order of the organic electroluminescent unit in Figure 3 is reversed. The organic electroluminescent unit in Figure 4 is also a two-layer tandem type organic electroluminescent unit, which corresponds to two organic electroluminescent elements coupled in series.

[0095] The organic electroluminescent unit in Figure 5 has a laminated structure in which an electron injection layer 7 is located between the cathode 2 and electron transport layer 4 of the organic electroluminescent unit in Figure 4, and a hole injection layer 8 is located between the anode 3 and hole transport layer 6. The organic electroluminescent unit in Figure 5, like those in Figures 3 and 4, is a two-layer tandem type organic electroluminescent unit, which consists of two organic electroluminescent elements coupled in series. As will be described later, metal oxides can be used as materials for the electron injection layer and hole injection layer. Thus, having a metal oxide layer in the organic electroluminescent unit is one of the preferred embodiments of the light-emitting device of the present invention.

[0096] The organic electroluminescent unit shown in Figure 6 is a multilayer tandem type organic electroluminescent unit having a structure equivalent to having even more organic electroluminescent elements coupled in series. The organic electroluminescent unit in Figure 6 has multiple charge generation layers 1 (consisting of p-doped layers 1a and n-doped layers 1b) between the cathode 2 and the anode 3. Between the cathode 2 and the charge generation layers 1, between the charge generation layers 1 and the charge generation layers 1, and between the charge generation layers 1 and the anode 3, there are electron transport layers 4, light-emitting layers 5 and hole transport layers 6 adjacent to each other in the order shown from the side closest to the cathode 2. Of the two layers constituting the charge generation layer 1, the n-doped layer 1b is adjacent to the electron transport layer 4, and the p-doped layer 1a is adjacent to the hole transport layer 6. When there are m charge generation layers 1, it is equivalent to connecting m+1 organic field-emitting elements in series. In this structure, the organic electroluminescent unit will have both a structure in which a charge generation layer exists between multiple light-emitting layers, and a structure in which a light-emitting layer exists between multiple charge generation layers.

[0097] The organic electroluminescent unit in Figure 7 has a stacked structure in which the stacking order of the organic electroluminescent unit in Figure 6 is reversed. The organic electroluminescent unit shown in Figure 7 is also a multilayer tandem type organic electroluminescent unit having a structure equivalent to that of many organic electroluminescent elements coupled in series.

[0098] The organic electroluminescent unit in Figure 8 has a laminated structure in which an electron injection layer 7 is located between the cathode 2 and electron transport layer 4 of the organic electroluminescent unit in Figure 7, and a hole injection layer 8 is located between the anode 3 and hole transport layer 6. The organic electroluminescent unit in Figure 8, like those in Figures 6 and 7, is a multilayer tandem type organic electroluminescent unit with a structure corresponding to many organic electroluminescent elements coupled in series.

[0099] The organic electroluminescent unit in Figure 9 has two charge generation layers and one light-emitting layer. Adjacent to the anode 3 is a charge generation layer 1 (consisting of an n-doped layer 1b and a p-doped layer 1a), and adjacent to it are a hole transport layer 6 and a light-emitting layer 5. On the cathode 2 side, there is also a charge generation layer 1 (consisting of a p-doped layer 1a and an n-doped layer 1b) adjacent to the cathode 2, and adjacent to that is an electron transport layer 4. The electron transport layer 4 is adjacent to the light-emitting layer 5. In this structure, holes and electrons are supplied to the light-emitting layer 5 from the two charge-generating layers on the anode and cathode sides. Therefore, even if the power generation unit used as the power source, which generates electricity through vibration and deformation, cannot generate a large amount of current, a sufficient amount of holes and electrons can be supplied from the charge-generating layers to the light-emitting layer if the voltage is high enough.

[0100] The organic electroluminescent unit in Figure 10 has a stacked structure in which the stacking order is reversed compared to the organic electroluminescent unit in Figure 9. In this structure as well, since holes and electrons are supplied to the light-emitting layer from the two charge generation layers on the anode and cathode sides, a sufficient amount of holes and electrons can be supplied to the light-emitting layer even when a power generation unit that generates electricity through vibration or deformation is used as the power source.

[0101] Figures 3 to 10 above show examples of the stacked structure of the organic electroluminescent unit of the light-emitting element of the present invention. The light-emitting element of the present invention may be formed in which a laminated structure of the organic electroluminescent unit is formed on a substrate and a laminated structure of a power generation unit is formed adjacent thereon, or it may be formed in which a laminated structure of a power generation unit is formed on a substrate and a laminated structure of the organic electroluminescent unit is formed adjacent thereon.

[0102] The materials of the substrate and each layer constituting the organic electroluminescent unit in the present invention will be described below. "cathode" For the cathode material, in the case of a bottom emission element, conductive oxide materials such as ITO (indium tin oxide), IZO (indium zinc oxide), FTO (fluorinated tin oxide), In3O3, SnO2, Sb-containing SnO2, and Al-containing ZnO are preferred as transparent electrodes. However, since electrons are generated in the charge generation layer 10, any material can be used, not only metal oxides, but also metals, organic conductive films, carbon nanotubes, graphene, etc. If the organic electroluminescent unit has an inverted structure with the lower electrode as the cathode, then ITO, which has high atmospheric stability, can be used as the cathode. This results in a highly atmospherically stable organic electroluminescent unit, which in turn extends the lifespan of the light-emitting element.

[0103] The average thickness of the cathode is not particularly limited, but is preferably 10 to 500 nm, and more preferably 100 to 200 nm. The average thickness of the cathode can be measured using a stylus step meter or spectroscopic ellipsometry.

[0104] "Middle class" In the organic electroluminescent unit of the present invention, a coated intermediate layer may be provided adjacent to the cathode or anode for the purpose of suppressing leakage. By providing a coated intermediate layer, leakage (short circuit) of current due to particles or the like can be suppressed. For the coating intermediate layer, highly conductive polymer materials such as poly(3,4-ethylenedioxythiophene / styrene sulfonic acid) (PEDOT / PSS) can be used. For example, Heraeus' "Clevios HIL1.3" can be used.

[0105] The average thickness of the coated intermediate layer is preferably around several tens of nanometers, and more preferably between 10 nm and 90 nm. The average thickness of the coated intermediate layer can be measured using a stylus-type step meter or spectroscopic ellipsometry. The coated intermediate layer can be formed, for example, by a spin coating method.

[0106] "Electron injection layer" The organic electroluminescent unit of the present invention may have an electron injection layer in its laminated structure. The electron injection layer is provided adjacent to the cathode. The electron injection layer is a layer of semiconductor or insulating multilayer thin film consisting of a single metal oxide film, or a layer formed by stacking and / or mixing single or two or more metal oxides. The metal elements constituting the metal oxide are selected from the group consisting of magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, indium, gallium, iron, cobalt, nickel, copper, zinc, cadmium, aluminum, and silicon. Of these, it is preferable that at least one of the metal elements constituting the laminated or mixed metal oxide layer is made of magnesium, aluminum, calcium, zirconium, hafnium, silicon, titanium, or zinc, and among these, if it is a single metal oxide, it is preferable that it contains a metal oxide selected from the group consisting of magnesium oxide, aluminum oxide, zirconium oxide, hafnium oxide, silicon oxide, titanium oxide, and zinc oxide. In this invention, materials with a sheet resistance lower than 100 Ω / □ are classified as conductors, while materials with a sheet resistance higher than 100 Ω / □ are classified as semiconductors or insulators. Therefore, thin films known as transparent electrodes, such as ITO (tin-doped indium oxide), ATO (antimond-doped indium oxide), IZO (indium-doped zinc oxide), AZO (aluminum-doped zinc oxide), and FTO (fluorine-doped indium oxide), do not fall under the category of semiconductors or insulators due to their high conductivity and are not considered to be one of the electron injection layers in this invention.

[0107] The average thickness of the electron injection layer described above can range from 1 nm to several μm, but is preferably 1 to 1000 nm, given the requirement for an organic electroluminescent unit that can be driven at a low voltage. More preferably, it is 2 to 100 nm. The average thickness of the electron injection layer can be measured using a stylus step meter or spectroscopic ellipsometry.

[0108] "Electron transport layer" Materials for the electron transport layer include pyridine derivatives such as tris-1,3,5-(3'-(pyridin-3''-yl)phenyl)benzene (TmPyPhB), quinoline derivatives such as (2-(3-(9-carbazolyl)phenyl)quinoline (mCQ)), pyrimidine derivatives such as 2-phenyl-4,6-bis(3,5-dipyridylphenyl)pyrimidine (BPyPPM), pyrazine derivatives, phenanthroline derivatives such as bathophenanthroline (BPhen), triazine derivatives such as 2,4-bis(4-biphenyl)-6-(4'-(2-pyridinyl)-4-biphenyl)-[1,3,5]triazine (MPT), triazole derivatives such as 3-phenyl-4-(1'-naphthyl)-5-phenyl-1,2,4-triazole (TAZ), oxazole derivatives, and 2-(4-bi Examples include oxadiazole derivatives such as phenylyl)-5-(4-tert-butylphenyl-1,3,4-oxadiazole) (PBD), imidazole derivatives such as 2,2',2''-(1,3,5-bentriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBI), aromatic ring tetracarboxylic anhydrides such as naphthalene and perylene, various metal complexes represented by bis[2-(2-hydroxyphenyl)benzothiazolat]zinc (Zn(BTZ)2) and tris(8-hydroxyquinolinato)aluminum (Alq3), and organosilane derivatives represented by silole derivatives such as 2,5-bis(6'-(2',2''-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), and one or more of these can be used.

[0109] The average thickness of the electron transport layer is not particularly limited, but is preferably 10 to 150 nm. More preferably, it is 40 to 100 nm. The average thickness of the electron transport layer can be measured using a quartz crystal thickness gauge for low molecular weight compounds, and using a contact-type step gauge for high molecular weight compounds.

[0110] "Charge generation layer" As described above, the charge generation layer has a layer (p-doped layer) 1 made of a hole-transporting material and an electron-accepting material, and a layer (n-doped layer) 2 made of an electron-transporting material and an electron-donating material, and may further have a dopant layer 3 between the p-doped layer 1 and the n-doped layer 2. The material and average thickness of the dopant layer between the p-doped layer and the n-doped layer are as described above.

[0111] "Luminous layer" As the material for forming the light-emitting layer, any material that can be commonly used as a material for a light-emitting layer may be used, or a mixture of multiple materials may be used. For example, bis[2-(2-benzothiazolyl)phenolate]zinc(II) (Zn(BTZ)2) and tris[1-phenylisoquinoline]iridium(III) (Ir(piq)3) can be used as materials for the light-emitting layer. Furthermore, the material forming the light-emitting layer may be a low-molecular-weight material or a high-molecular-weight material. In this invention, a low-molecular-weight material means a material that is not a high-molecular-weight material (polymer), and does not necessarily mean an organic compound with a low molecular weight. Examples of polymer materials that form the light-emitting layer include polyacetylene compounds such as trans-type polyacetylene, cis-type polyacetylene, poly(di-phenylacetylene) (PDPA), and poly(alkylphenylacetylene) (PAPA); poly(para-phenylene vinylene) (PPV), poly(2,5-dialkoxy-para-phenylene vinylene) (RO-PPV), cyano-substituted-poly(para-phenylene vinylene) (CN-PPV), and poly(2- Poly(P)-(P)(2-methoxy,5-(2'-ethylhexoxy)-P)-(P)(2-methoxy,5-(2'-ethylhexoxy)-P)-(P)(2-methoxy,5-(2'-ethylhexoxy)-P)-(P)(2-methoxy,5-(2'-ethylhexoxy)-P)-(P)(2-methoxy,5-(2'-ethylhexoxy)-P)-(P)(2-methoxy,5-(2'-ethylhexoxy)-P)-(P)(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-methoxy,5-(2'-ethylhexoxy)-P)-(2-phenylenevinylene)-(2-phenylenevinylene)-(2-methoxy,5-(2'-ethylhexoxy)-P Polyfluorene compounds such as alto-benzothiadiazole (F8BT), α,ω-bis[N,N'-di(methylphenyl)aminophenyl]-poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2 / 6am4), and poly(9,9-dioctyl-2,7-divinylenefluorenyl-ortho-co(anthracene-9,10-diyl)); poly(para-phenylene) (PPP), poly(1,5-dialkoxy-para-phenylene) Examples include poly(p-phenylene) compounds such as (nilen)(RO-PPP); polycarbazole compounds such as poly(N-vinylcarbazole)(PVK); polysilane compounds such as poly(methylphenylsilane)(PMPS), poly(naphthylphenylsilane)(PNPS), and poly(biphenylylphenylsilane)(PBPS); and boron compound polymer materials described in Japanese Patent Publication No. 2011-184430 and Japanese Patent Publication No. 2012-151148.

[0112] Examples of low molecular weight materials that form the luminescent layer include three-coordinate iridium complexes with 2,2'-bipyridine-4,4'-dicarboxylic acid as a ligand, such as Factlis(2-phenylpyridine)iridium(Ir(ppy)3), tris(8-quinolinolate)aluminum(Alq3), tris(4-methyl-8-quinolinolate)aluminum(III)(Almq3), 8-hydroxyquinoline zinc(Znq2), and (1,10-phenanthroline)-tris-(4,4,4-trifluoro-1-(2-thienyl)-butane-1,3-dionete)europ Various metal complexes such as um(III)(Eu(TTA)3(phen)), 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II); benzene compounds such as distyrylbenzene (DSB) and diaminodistyrylbenzene (DADSB); naphthalene compounds such as naphthalene and Nile Red; phenanthrene compounds such as phenanthrene; chrysene compounds such as chrysene and 6-nitrochrysene; perylene, N,N'-bis(2,5-di-t-butylphenyl)-3,4,9,10-perylene-di-cal Perylene compounds such as boximide (BPPC); coronene compounds such as coronene; anthracene compounds such as anthracene and bis-styrylanthracene; pyrene compounds such as pyrene; pyrane compounds such as 4-(di-cyanomethylene)-2-methyl-6-(para-dimethylaminostyryl)-4H-pyran (DCM); acridine compounds such as acridine; stilbene compounds such as stilbene; thiophene compounds such as 2,5-dibenzoxazolethiophene; benzoxazole compounds such as benzoxazole; benzimidazole compounds Zoimidazole compounds; benzothiazole compounds such as 2,2'-(para-phenylenedivinylene)-bisbenzothiazole; butadiene compounds such as bistyryl(1,4-diphenyl-1,3-butadiene) and tetraphenylbutadiene; naphthalimide compounds such as naphthalimide; coumarin compounds such as coumarin; perinone compounds such as perinone; oxadiazole compounds such as oxadiazole; aldazine compounds; cyclopentadiene compounds such as 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP);Examples include quinacridone compounds such as quinacridone and quinacridone red; pyridine compounds such as pyrrolopyridine and thiadiazolopyridine; spiro compounds such as 2,2',7,7'-tetraphenyl-9,9'-spirobifluorene; metallic or non-metallic phthalocyanine compounds such as phthalocyanine (H2Pc) and copper phthalocyanine; and boron compound materials described in Japanese Patent Publication No. 2009-155325, Japanese Patent Publication No. 2011-184430, and Japanese Patent Publication No. 2012-151149.

[0113] The average thickness of the light-emitting layer is not particularly limited, but is preferably 10 to 150 nm, and more preferably 20 to 100 nm. The average thickness of the light-emitting layer may be measured using a stylus-type step meter, or it may be measured during the deposition of the light-emitting layer using a quartz crystal thickness gauge.

[0114] "Hole transport layer" As hole-transporting organic materials used in the hole transport layer, various p-type polymer materials (organic polymers) and various p-type low-molecular-weight materials can be used individually or in combination. Examples of materials for the hole transport layer include N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD), N4,N4'-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4'-diphenylbiphenyl-4,4'-diamine (DBTPB), polyarylamines, fluorene-arylamine copolymers, fluorene-bithiophene copolymers, poly(N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylenevinylene), polythienylenevinylene, pyreneformaldehyde resin, ethylcarbazoleformaldehyde resin, or derivatives thereof. These hole transport layer materials can also be used as mixtures with other compounds. As an example, polythiophene-containing mixtures used as materials for hole transport layers include poly(3,4-ethylenedioxythiophene / styrenesulfonic acid) (PEDOT / PSS).

[0115] The average thickness of the hole transport layer is not particularly limited, but is preferably 10 to 150 nm, and more preferably 20 to 100 nm. The average thickness of the hole transport layer 70 can be measured, for example, by a stylus step meter or spectroscopic ellipsometry.

[0116] "Hole injection layer" The hole implantation layer may be made of an inorganic material or an organic material. Inorganic materials are more stable than organic materials, and therefore tend to have higher resistance to oxygen and water compared to when organic materials are used. There are no particular limitations on the inorganic material, but for example, one or more metal oxides such as vanadium oxide (V2O5), molybdenum oxide (MoO3), and ruthenium oxide (RuO2) can be used. On the other hand, as organic materials, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitride (HAT-CN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), etc. can be used.

[0117] The average thickness of the hole injection layer is not particularly limited, but is preferably 1 to 1000 nm, and more preferably 5 to 50 nm. The average thickness of the hole injection layer can be measured during film formation using a quartz crystal film thickness gauge.

[0118] "anode" Materials used for the anode include ITO, IZO, Au, Pt, Ag, Cu, Al, or alloys containing these materials. Among these, it is preferable to use ITO, IZO, Au, Ag, or Al as the anode material.

[0119] The average thickness of the anode is not particularly limited, but is preferably 10 to 1000 nm, and more preferably 30 to 150 nm. Furthermore, even when an opaque material is used as the anode material, by setting the average thickness to, for example, 10 to 30 nm, it can be used as a transparent anode in a top-emission type organic EL device. The average thickness of the anode can be measured during anode deposition using a quartz crystal film thickness gauge.

[0120] Methods for forming each layer constituting the organic electroluminescent unit in the present invention include sputtering, vacuum deposition, sol-gel deposition, spray pyrolysis (SPD), atomic layer deposition (ALD), vapor deposition, and liquid deposition. A method of joining metal foils may be used to form the cathode. Alternatively, a coating method may be used in which an organic compound solution containing the materials for each layer is applied.

[0121] <Power generation unit> Next, the power generation unit of the light-emitting element of the present invention will be described. The power generation unit of the light-emitting element of the present invention is not particularly limited as long as it generates electricity by vibration or deformation, but it includes a charged body having a first electrode, a layer containing self-orienting polar organic molecules provided on the first electrode, and a second electrode provided on the side of the layer containing the self-orienting polar organic molecules opposite to the side having the first electrode, and a laminate having an uncharged body laminated on an electrode provided on at least one side of the charged body, wherein the first electrode and the layer containing the self-orienting polar organic molecules and the second electrode and the layer containing the self-orienting polar organic molecules are in contact with each other, and the power generation unit generates electricity by the laminate vibrating or deforming in the lamination direction between the layer containing the self-orienting polar organic molecules and the uncharged body, and it is preferable that the self-orienting polar organic molecules contained in the layer containing the self-orienting polar organic molecules include at least one selected from self-orienting polar organic molecules having a dipole moment magnitude in the range of 0D to 10D. Such power generation units have a polar organic molecular layer with controlled orientation that does not require poling during manufacturing. The polar organic molecular layer is distorted by vibrations and deformations applied to the power generation unit, generating an electric potential and thus generating electricity. In this invention, "charged body" refers to a charged structural portion having a laminated structure in which a layer containing self-oriented polar organic molecules is sandwiched between two electrodes. As long as it has such a laminated structure and is charged, the magnitude of the potential generated is not particularly limited. In this invention, "uncharged body" refers to a structural portion that is not charged, and as long as it is not charged, its structure is not particularly limited and may consist of a single layer or have a laminated structure. The terms "first electrode" and "second electrode" are used for convenience to indicate that there are two distinct electrodes in contact with the layer containing the polar organic polymer on both sides of the layer containing the polar organic polymer. They do not refer to the positional location of each electrode.

[0122] The above-mentioned power generation unit has controlled orientation, does not require polling during manufacturing, and is equipped with a flat plate-shaped charged body that is thinner in thickness relative to its surface area. Because it has a thin, flat plate-shaped charged body with good flexibility, it can generate electricity from slight vibrations applied to the power generation element, resulting in good power generation efficiency.

[0123] Figures 11 and 12 show an example of the structure of the power generation unit in the present invention. The power generation unit in the present invention has a laminate in which a charged body 14, which has a first electrode 11, a layer 12 containing self-orienting polar organic molecules, and a second electrode 13, and an uncharged body 15 are laminated together, as shown in Figure 11. As shown in Figure 11, the first electrode 11 and the layer 12 containing self-orienting polar organic molecules, and the layer 12 containing self-orienting polar organic molecules and the second electrode 13 are in contact with each other. Figure 12 is a schematic diagram showing one embodiment of a power generation element with a bimorph structure having two layers of charged bodies 14. The laminate has two layers of charged bodies 14. In the bimorph structure, it is preferable to have an uncharged body 15 between the two layers of charged bodies 14 because vibrations are more easily transmitted evenly to each self-oriented polar organic molecule in the two layers of charged bodies 14.

[0124] The following describes the various components of the preferred power generation unit according to the present invention.

[0125] "Self-orienting organic molecules" The layer containing self-orienting polar organic molecules in the power generation unit of the present invention contains at least one type of self-orienting organic molecule. The self-orienting organic molecule is selected from self-orienting polar organic molecules having a dipole moment magnitude in the range of 0D (Debye: the same applies hereinafter) to 10D. The magnitude of the dipole moment of the self-orienting organic molecule is preferably in the range of 1D to 7D, and more preferably in the range of 2D to 5D, from the viewpoint that the slope of the surface potential with respect to the film thickness of the layer containing the self-orienting polar organic molecule is in a more preferable range, and the orientation of the organic molecule is more easily maintained in a state suitable for power generation. The magnitude of the dipole moment of an organic molecule can be calculated using the molecular orbital calculation program GAUSSIAN03, applying the basis set B3LYP / 6-31 G(d). The basis set to be applied to the GAUSSIAN03 program should be selected based on the molecular structure being calculated.

[0126] As a self-orienting polar organic molecule with a dipole moment magnitude in the range of 0D to 10D, the present inventors previously found that in a thin film of a polar molecule used in organic light-emitting diodes, the surface potential increases in proportion to the film thickness, reaching several volts at 100 nm, and that the retention time of the above surface potential is long (Japanese Patent Publication No. 2020-036423). The phenomenon described in Japanese Patent Publication No. 2020-036423 means that polarization charges appear on the surface and back surface of the above polar molecular film. In the power generation unit of the present invention, by applying the above polar molecules to the power generation element, the process of adjusting the gap between electrodes, which was necessary in Japanese Patent Application Publication No. 2020-036423, is eliminated, and the simpler configuration is optimized, making it easier to manufacture. Furthermore, because the polar organic molecular layer and the electrodes are in contact, we believe that the power generation performance is improved.

[0127] Figure 13 is a schematic diagram showing one aspect of the cross-section of the charged body 14 in the present invention. The charged body 14 has a first electrode 11 and a second electrode 13, and a layer 12 containing self-orienting polar organic molecules located between the first electrode 11 and the second electrode 13. Figure 13 schematically shows the self-orienting organic molecules 22 in the layer 12 containing the self-orienting polar organic molecules. In Figure 13, the orientation direction of the dipoles in the self-orienting organic molecules 22, which are schematically represented as circles, is schematically shown. Since each self-orienting organic molecule 22 is self-orienting, the dipoles are oriented in one direction, and a region of positive potential 24 is created near the second electrode 13 shown in Figure 13, while a region of negative potential is created near the opposing first electrode 11. In other words, a charged body 14 containing self-orienting polar organic molecules with a dipole moment magnitude in the range of 0D to 10D does not require polarization treatment (poling treatment) by applying a strong electric field to orient the material, and the charged body 14 becomes polarly oriented.

[0128] The power generation unit in the present invention uses the above material in a layer containing self-orienting polar organic molecules, and employs a charged body equipped with electrodes in close contact with both sides of the self-orienting polar organic molecule layer, thereby achieving a good amount of power generation with a simple configuration.

[0129] Examples of self-orienting polar organic molecules with dipole moments in the range of 0D to 10D include compounds 1 to 16, which have the structures shown below. Note that self-orienting organic molecules are not limited to these compounds. The abbreviations for each compound are shown in parentheses after the compound numbers.

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] The magnitudes of the dipole moments of the above example compounds are shown below.

[0135] [Table 1]

[0136] From the viewpoint of the magnitude of the dipole moment, the self-orienting polar organic molecule used in the power generation unit of the present invention preferably includes at least one selected from the following group of compounds, and more preferably includes at least one selected from compound 3 and compound 4. These compounds can be obtained by synthesis, or they can be purchased commercially from companies such as Tokyo Chemical Industry Co., Ltd. and Lumtec.

[0137] [ka]

[0138] The polar organic molecular layer can be formed by imparting self-orienting organic molecules to one side of the first electrode, as described later. Methods for imparting the self-orienting organic polymer include vapor-phase methods such as vacuum deposition, and it is preferable to form it by vacuum deposition from the viewpoint of uniformity of the layer containing the self-orienting polar organic molecules and adhesion to the first electrode.

[0139] There are no particular restrictions on the thickness of the layer containing the self-orienting polar organic molecules, and it can be appropriately selected depending on the intended use of the light-emitting device. In particular, from the viewpoint of miniaturizing the light-emitting device, the thickness of the layer containing the self-orienting polar organic molecules is preferably in the range of 100 nm to 10 μm.

[0140] "First electrode and second electrode" The first and second electrodes, which are provided on both sides of the layer containing the self-orienting polar organic molecules, can be made of known electrode materials without any particular limitations. Examples of electrode materials include individual metallic materials such as Au, Al, Ag, Cu, Cr, Pt, Ti, and Ni, as well as mixtures of two or more of these metallic materials, inorganic materials such as Si, and inorganic mixtures such as ITO (Indium Tin Oxide) and FTO (Fluorine-Doped Tin), which are selected as appropriate depending on the purpose. Among these, Al, Cu, and Ni are preferred due to their light weight, good conductivity, and processability. The electrode material constituting the first electrode and the electrode material constituting the second electrode may be the same or different from each other.

[0141] There are no particular restrictions on the thickness of the first and second electrodes. From the viewpoint of achieving conductivity and minimizing the suppression of vibrations of the charged body caused by stress on the charged body, a thickness of 100 nm to 1 μm is preferred.

[0142] There are no particular restrictions on the method of manufacturing the electrodes. For example, one method involves forming a first electrode on a substrate by a vapor phase method such as vacuum deposition, forming a layer containing self-orienting polar organic molecules and a second electrode on the first electrode by the same vacuum deposition method, and then removing the substrate. Another method involves using a first electrode made from a thin metal sheet prepared in advance, and forming a layer containing self-orienting polar organic molecules and a second electrode on the metal sheet first electrode. In the power generation unit of the present invention, the charged body generates electricity through vibration or deformation. The charged body includes a first electrode, a polar organic molecular layer, and a second electrode. In the power generation unit of the present invention, the first electrode and the layer containing self-orienting polar organic molecules, and the second electrode and the layer containing self-orienting polar organic molecules are in contact with each other, so that the current generated in the layer containing self-orienting polar organic molecules can be efficiently transmitted to the electrodes.

[0143] "Non-charged body" The power generation unit in this invention has a non-charged body. The power generation unit in the present invention has a laminate of a charged material and an uncharged material. As the non-static material, a sheet made of a synthetic resin material having the required strength and durability can be appropriately selected and used. The non-charged material preferably contains an elastic organic material. Examples of materials that constitute a non-charged material include organic materials such as polyimide, polyester, polyurethane, polycarbonate, and fluororesin.

[0144] There are no particular restrictions on the thickness of the non-charged material; it is selected considering the required strength and rigidity. From the viewpoint of miniaturizing the power generation unit and improving power generation efficiency, the thickness can be 80 μm to 500 μm, with 80 μm to 300 μm being preferred.

[0145] "Laminated structure" The size of the laminate in the power generation unit of the present invention is appropriately selected according to the intended use of the light-emitting element.

[0146] Because the power generation unit in the present invention has the above configuration, even if slight vibrations or deformations are applied, the potential fluctuations generated by the strain of the laminate having a layer containing self-oriented polar organic molecules can be efficiently transmitted to the electrodes, and power can be efficiently supplied to the organic electroluminescent unit.

[0147] There are no particular limitations on the method for manufacturing the power generation unit in the present invention, and known methods for forming laminates can be applied without restriction. In particular, it is preferable to manufacture it by the manufacturing method described below. The preferred manufacturing method for the power generation unit in the present invention will be described below. Note that the power generation unit obtained by the manufacturing method described below is the power generation unit in the present invention as described above, and the materials used in manufacturing, the thickness of each layer, etc. are the same as those of the power generation element in the present invention as described above, so a detailed description will be omitted.

[0148] <Manufacturing method for power generation units> The present invention provides a method for manufacturing a power generation unit, comprising a charged body having a first electrode, a layer provided on the first electrode and containing self-orienting polar organic molecules, and a second electrode provided on the side of the layer containing the self-orienting polar organic molecules opposite to the side having the first electrode, and a non-charged body laminated on an electrode provided on at least one side of the charged body, wherein the first electrode, the layer containing the self-orienting polar organic molecules, and the second electrode and the layer containing the self-orienting polar organic molecules are in contact with each other, and the method for manufacturing a vibration power generation element comprises the steps of obtaining the first electrode (also referred to as "step A"), forming a layer containing self-orienting polar organic molecules by depositing at least one selected from the self-orienting polar organic molecules (also referred to as "step B"), forming the second electrode (also referred to as "step C"), and forming the non-charged body (also referred to as "step D") to obtain the laminate. The manufacturing method of the present disclosure may further include other steps in addition to steps A, B, C, and D.

[0149] In the manufacturing method of this disclosure, there are no restrictions on the order in which steps A, B, C, and D are performed when obtaining the laminate. For example, in one embodiment, a non-charged material (e.g., a resin sheet) is first prepared (step D), a second electrode is formed on one side of the non-charged material (step C), a layer containing self-orienting polar organic molecules is formed on the side of the second electrode opposite to the side in contact with the non-charged material (step B), and then a first electrode is formed on the side of the layer containing the self-orienting polar organic molecules opposite to the side in contact with the second electrode (step A) to form a laminate. Furthermore, in another embodiment, for example, a first electrode may be formed (step A), a layer containing self-orienting polar organic molecules may be formed on one surface of the first electrode (step B), a second electrode may be formed on the surface of the layer containing the self-orienting polar polymer opposite to the side in contact with the first electrode (step C), and then a non-charged material, such as a resin sheet, may be bonded to the surface of the second electrode opposite to the side in contact with the layer containing the self-orienting polar organic molecules (step D) to form a laminate. For example, in process A, the phrase "process of obtaining" the first electrode is used to include both the "process of forming" the first electrode using electrode material and the "process of preparing" a sheet-like electrode material that functions as an electrode as the first electrode. The same applies to other processes.

[0150] (Process A) Step A is a step of preparing a first electrode. The first electrode may be obtained using a commercially available thin electrode sheet, or by applying an electrode material to a predetermined substrate and forming a film. Alternatively, the electrode may be formed by applying an electrode material to a layer containing self-oriented polar organic molecules obtained in step B. The method for applying electrode material to a substrate or the like may be a liquid-phase method such as coating, or a gas-phase method such as vacuum deposition. The electrode material constituting the electrode is the same as that described in the power generation element according to the present invention, and the preferred example is also the same. In particular, from the viewpoint of easy control of the thickness of the resulting electrodes and the uniformity of the resulting electrodes, it is preferable that step A includes applying electrode material to a substrate or a layer containing self-oriented polar organic molecules by vacuum deposition. When forming the first electrode by vacuum deposition, a substrate or a layer containing self-orienting polar organic molecules is placed in a vacuum chamber, and a metal material is deposited using a known method.

[0151] (Process B) Step B is a step in which at least one self-oriented polar organic molecule, selected from those having a dipole moment magnitude in the range of 0D to 10D, is applied to the first electrode (Step A) or the second electrode obtained in Step C described later, and a film is formed to create a layer containing the self-oriented polar organic molecule that is in contact with the first electrode or the second electrode. The self-orienting organic molecules used to form the layer containing the self-orienting polar organic molecules are as previously described, and the preferred examples are also as described above.

[0152] A method for applying polar organic molecules to the surface of the first electrode obtained in step A or the second electrode obtained in step C is a gas-phase method such as vacuum deposition. In particular, the step of applying self-orienting polar organic molecules and forming a film preferably includes applying the self-orienting polar organic molecules onto the surface of the first electrode or the second electrode by vacuum deposition. A preferred embodiment of step B is one in which a first electrode (including one placed on a substrate) or a second electrode is placed in a vacuum chamber, and polar organic molecules are sprayed and deposited onto the first electrode to form a layer containing self-orienting polar organic molecules. According to the manufacturing method of the present invention, when providing a layer containing self-orienting polar organic molecules only in a part of the first electrode or the second electrode, for example, in a region excluding the peripheral edge, it is also possible to define the deposition site of the polar organic molecules using a shadow mask tailored to the target region, thereby forming a layer containing self-orienting polar organic molecules in any region. By directly depositing polar organic molecules onto an electrode using a vacuum deposition method, a layer containing self-oriented polar organic molecules that has a semi-permanent electrostatic field in contact with the first or second electrode can be formed. The layer containing self-orienting polar organic molecules obtained in step B becomes a layer with a semi-permanent magnetic field where the magnetic direction is unidirectional. Therefore, a layer containing self-orienting polar organic molecules with good power generation properties can be formed without performing any special charging treatment, heating treatment, or other polling treatments.

[0153] (Process C) Step C is a step of forming a second electrode in contact with the layer containing the self-orienting polar organic molecules, on the side of the layer containing the self-orienting polar organic molecules formed in Step B that is opposite to the side having the first electrode. There are no particular restrictions on the method for forming the second electrode in step C, but from the viewpoint of adhesion between the second electrode and the layer containing self-oriented polar organic molecules, and the uniformity of the second electrode, it is preferable that the second electrode be formed by vacuum deposition. For example, a preferred method for manufacturing a charged body is to sequentially form a first electrode, a layer containing self-orienting polar organic molecules, and a second electrode in the same vacuum chamber using a vacuum deposition method, while changing the target.

[0154] (Process D) Step D is a step to obtain a laminate by forming an uncharged material on the side of at least one of the first electrode and the second electrode of the charged material obtained through steps A to C, on the side opposite to the side in contact with the layer containing self-oriented polar organic molecules. As the non-charged material, a sheet made of a resin such as polyimide with a thickness of approximately 80 μm to 300 μm can be used. When joining an electrode to a non-charged body, methods such as vacuum deposition of an electrode material, such as Al, onto one side of a resin sheet, thermocompression bonding of a resin sheet used for forming the non-charged body to an already formed electrode, or bonding via an adhesive or bonding agent suitable for the resin sheet material can be employed. The material and thickness of the non-charged element should be appropriately selected according to the strength, flexibility, and other requirements of the laminate in the power generation unit. The laminate obtained through the above processes A, B, C, and D becomes the main part of the power generation unit.

[0155] As described above, the manufacturing method of the present invention may further include other steps after obtaining the laminate. Other steps include providing lead wires to the first electrode and the second electrode, and connecting them to the organic electroluminescent unit, which is the recipient of the power supply, via these lead wires, i.e., wiring.

[0156] <Circuit board> The power generation element of the present invention has a power generation unit and an organic electroluminescent unit formed on a substrate. The light-emitting element may have a power generation unit formed on a substrate and an organic electroluminescent unit formed on top of it, or it may have an organic electroluminescent unit formed on a substrate and a power generation unit formed on top of it. Examples of substrate materials include resin materials, ultrathin glass materials, and cellulose. Examples of resin materials used for substrates include polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate, and polyarylate. When a resin material is used as the substrate material, an organic EL element with excellent flexibility can be obtained, which is preferable. On the other hand, examples of glass materials used for substrates include quartz glass and soda glass. When the light-emitting element is of the bottom-emission type, a transparent substrate is used as the substrate material. On the other hand, when the light-emitting element is of the top-emission type, not only a transparent substrate but also an opaque substrate may be used as the substrate material. Examples of opaque substrates include substrates made of ceramic materials such as alumina, substrates with an oxide film (insulating film) formed on the surface of a metal plate such as stainless steel, and substrates made of resin materials.

[0157] The average thickness of the substrate can be determined according to the substrate material, and is preferably 0.1 to 30 mm, and more preferably 0.1 to 10 mm. The average thickness of the circuit board can be measured using a digital multimeter or calipers.

[0158] <Sealing of light-emitting elements> The light-emitting element of the present invention may be sealed as needed. The sealing method is not particularly limited and includes methods such as bonding a sealing container in an inert gas or directly forming a sealing film on the light-emitting element. In addition to these, a method of sealing with a moisture absorbent material may also be used in combination. Materials used to encapsulate the light-emitting element include resin materials and ultra-thin glass materials, and the resin and glass materials are the same as those used for the substrate. [Explanation of Symbols]

[0159] 1: Charge generation layer 1a: p-doped layer 1b: n-doped layer 2: Cathode 3: Anode 4:Electron transport layer 5: Emitting layer 6: Hole transport layer 7:Electron injection layer 8: Hole injection layer 11: First electrode 12: Layer containing self-orienting polar organic molecules 13: Second electrode 14: Charged body 15: Non-charged body 22: Self-orienting organic molecules 24: Positive potential region

Claims

1. A light-emitting element comprising a power generation unit that generates electricity through vibration or deformation and an organic electroluminescent unit stacked adjacent to each other, The organic electroluminescent unit has a structure in which multiple layers, including a charge generation layer and an emissive layer, are stacked between the anode and the cathode, and has at least multiple charge generation layers and emissive layers, with charge generation layers existing between the multiple emissive layers, or at least one of the above structures. A light-emitting element characterized by the above.

2. The light-emitting element according to claim 1, characterized in that the organic electroluminescent unit has two or more light-emitting layers, and a charge-generating layer exists between any two of the light-emitting layers.

3. The light-emitting element according to claim 1, characterized in that the organic electroluminescent unit has one light-emitting layer and two charge-generating layers, with the light-emitting layer located between the two charge-generating layers.

4. The light-emitting element according to claim 1, characterized in that the charge generation layer comprises a layer made of a hole-transporting material and an electron-accepting material, and a layer made of an electron-transporting material and an electron-donating material.

5. The light-emitting element according to claim 4, characterized in that the charge generation layer has a structure in which a layer made of a hole-transporting material and an electron-accepting material and a layer made of an electron-transporting material and an electron-donating material are stacked adjacent to each other.

6. The light-emitting element according to claim 1, characterized in that the organic electroluminescent unit has a metal oxide layer between the anode and the cathode.

7. The light-emitting element according to claim 1, characterized in that the cathode of the organic electroluminescent unit is adjacent to the power generation unit.

8. The power generation unit includes a charged body having a first electrode, a layer containing self-orienting polar organic molecules provided on the first electrode, and a second electrode provided on the side of the layer containing the self-orienting polar organic molecules opposite to the side having the first electrode, and a laminate having an uncharged body laminated on an electrode provided on at least one side of the charged body. The first electrode and the layer containing the self-orienting polar organic molecules, and the second electrode and the layer containing the self-orienting polar organic molecules are in contact with each other. The laminate is a power generation unit that generates electricity by vibrating or deforming in the stacking direction between the layer containing the self-oriented polar organic molecules and the uncharged body. The layer containing the self-orienting polar organic molecules includes at least one self-orienting polar organic molecule selected from self-orienting polar organic molecules having a dipole moment magnitude in the range of 0D to 10D. The light-emitting element according to feature 1.

9. The light-emitting element according to claim 8, characterized in that the self-orienting polar organic molecule includes at least one selected from the following group of compounds. 【Chemistry 1】

10. The light-emitting element according to claim 8, characterized in that it has two or more layers of the charged body.

11. The light-emitting element according to claim 8, characterized in that the non-charged body includes an elastic organic material.

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