JP2021044499A - Light-emitting element - Google Patents

Abstract

To provide a light-emitting device that can be manufactured more easily than conventional three-dimensional light sources using organic electroluminescent devices, and that can easily meet the demand for small quantities of a wide variety of products.SOLUTION: The light-emitting device has an organic electroluminescent element with a structure consisting of a plurality of layers stacked between an anode and a cathode, and a three-dimensionally shaped member that is placed in contact with the organic electroluminescent element and has at least part of its surface in the form of a curved surface.SELECTED DRAWING: None

Description

The present invention relates to a light emitting device. More specifically, the present invention relates to a light emitting element that can be used as a display device such as a display unit of an electronic device or a lighting device.

When used as a display device, the organic electroluminescent element enables high-brightness and high-definition display, and has excellent features such as a wider viewing angle than a liquid crystal display device. Therefore, televisions and mobile phones Is expected to expand its use as a display and lighting device. In addition, a method for more effectively using the organic electroluminescent element is also being studied, and a film or an optical member is placed on the element in order to increase the brightness or eliminate the uneven brightness when used as a lighting device. The arrangement is disclosed (see Patent Documents 1 and 2). Further, in recent years, it has been considered to use an organic electroluminescent element as a three-dimensional light source. For example, a light source device in which a plurality of organic electroluminescent elements arranged in parallel are covered with a curved cover has been proposed. (See Patent Document 3).

JP-A-2018-185940 Japanese Patent No. 6119460 JP-A-2017-208226

As described above, as a three-dimensional light source using an organic electroluminescent element, a light source device in which a plurality of organic electroluminescent elements arranged in parallel are covered with a curved cover has been proposed, but the structure is complicated. In addition, when changing the shape of the light source, it is necessary to change the design of a plurality of parts constituting the light source depending on the shape, so that there are many problems in meeting the demand for small quantity and high variety.

The present invention has been made in view of the above situation, and provides a light emitting element that can be easily manufactured as compared with a conventional three-dimensional light source using an organic electroluminescent element and can easily meet the demands of a wide variety of small quantities. The purpose is.

The present inventor has studied a light emitting element that can be used as a three-dimensional light source that is easy to manufacture and can easily meet the demands of a wide variety of small quantities, and has a three-dimensional shape in which at least a part of the surface is curved in contact with the organic electroluminescent element. We have arrived at the present invention by finding that a three-dimensional light source that is easy to manufacture and can easily meet the demands of a wide variety of small quantities can be obtained by arranging the members of

That is, the present invention is an organic electroluminescent device having a structure in which a plurality of layers are laminated between an anode and a cathode, and a solid that is arranged in contact with the organic electroluminescent device and has at least a curved surface. It is a light emitting element characterized by having a member having a shape.

In the above-mentioned light emitting element, it is preferable that a three-dimensional light diffusing member is arranged on at least a part of the light extraction surface of the organic electroluminescent element.

It is also preferable that the light emitting element is arranged so that the surface opposite to the light extraction surface of the organic electroluminescent element is in contact with the curved surface of the three-dimensional member.

The three-dimensional member is preferably a printed object.

The organic electroluminescent device is preferably an organic electroluminescent device having a structure in which a plurality of layers are laminated between an anode and a cathode formed on a substrate.

The organic electroluminescent device preferably has a total film thickness of 200 μm or less.

The present invention is also a display device or a lighting device, which comprises the light emitting element of the present invention.

The light emitting device of the present invention can be easily manufactured, and since the shape can be easily changed, it is easy to meet the demands of a wide variety of small quantities, and it can be used in various applications in which a three-dimensional light source is desired. ..

It is a photograph of the light emitting element 1 in which a three-dimensional member was formed on the organic electroluminescent element produced in Example 1. It is a photograph of the light emitting element 2 in which a three-dimensional member was formed on the organic electroluminescent element produced in Example 2.

The present invention will be described in detail below.
A combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

The light emitting device of the present invention is arranged in contact with an organic electroluminescent device having a structure in which a plurality of layers are laminated between an anode and a cathode, and the organic electroluminescent device, and at least a part of the surface is curved. It is characterized by having a member having a certain three-dimensional shape.
When the organic electroluminescent element is in contact with a three-dimensional member on the light extraction surface side, if the three-dimensional member transmits and diffuses light, the light from the light extraction surface of the organic electroluminescent element is three-dimensional. It passes through the inside of the shaped member and is emitted from the surface of the three-dimensional member (the surface of the light emitting element of the present invention). Here, if at least a part of the surface of the three-dimensional member from which light is emitted (that is, the portion of the surface of the three-dimensional member that is not in contact with the organic electroluminescent element) is curved, the present invention is used. The light emitting element is a three-dimensional light source.
Further, when the curved surface portion of the three-dimensional member is in contact with the organic electroluminescent element, the surface of the organic electroluminescent element is curved, so that the outer surface of the organic electroluminescent element (in contact with the three-dimensional member) is in contact with the organic electroluminescent element. If the surface opposite to the side on which the light is emitted is the light extraction surface, the light emitting element becomes a three-dimensional light source.
In this way, by combining the organic electroluminescent element and the three-dimensional member having at least a curved surface, a three-dimensional light source can be easily manufactured, and the shape of the three-dimensional member can be changed. As a result, the shape of the three-dimensional light source can be easily changed, so it is easy to meet the demand for a wide variety of products in small quantities.
In the light emitting element of the present invention, the three-dimensional member having at least a curved surface has a curved surface having a size such that at least a part of the outer surface of the entire member can be visually confirmed. It means a three-dimensional member. Therefore, at least a part of the surface of the light diffusing plate, the light diffusing sheet, etc., which has a fine curved surface (unevenness) that cannot be confirmed without a microscope and has a flat shape as a whole, is a curved surface in the present invention. It is not included in the three-dimensional member.
Further, in the light emitting element of the present invention, in the form in which the organic electroluminescent element and the three-dimensional member having a partially curved surface are in contact with each other, the three-dimensional member is directly formed on the surface of the organic electroluminescent element. In addition to the case where the surface of the organic electroluminescent element is in contact with the three-dimensional member, the case where the light extraction surface and the light-shielding member are in contact with each other via an adhesive layer or the like described later is also included.

The thickness of the thickest portion of the three-dimensional member is preferably 1 mm or more. By having a member having such a thickness, the light emitting element of the present invention can more fully exhibit the function as a three-dimensional light source. The thickness of the thickest portion is more preferably 5 mm or more, still more preferably 10 mm or more. Further, from the viewpoint of ease of manufacturing a three-dimensional member, the thickness of the thickest portion is preferably 100 mm or less.
The three-dimensional member may have a hollow shape, and when the member has a hollow shape, the thickness of the outer shape of the member is preferably the above value.
The thickness of the three-dimensional member can be measured with a caliper or the like.

It is preferable that the curved surface of the three-dimensional member has a convex shape. With such a shape, the light emitting element of the present invention can more fully exhibit the function as a three-dimensional light source. More preferably, the thickest portion of the three-dimensional member at the center of the convex portion with respect to the thickness of the thinnest portion of the convex portion of the three-dimensional member. The shape has a thickness ratio of 1 to 1000. With such a shape, the light emitting element can more fully exert its function as a three-dimensional light source, and the organic electroluminescent element can be arranged along the curved surface portion of the three-dimensional member. It's easy. The ratio is more preferably 1 to 100, and particularly preferably 1 to 10.
Here, the thickness of the end portion of the convex shape portion is only one tenth of the thickness of the outermost end of the convex shape portion and the length from the end to the center of the convex shape portion. It means the average value with the thickness of the position closer to the center.

Further, in the three-dimensional member, the surface area of the curved surface portion is preferably 50% or more of the light emitting area of the organic electroluminescent element. When the curved surface portion has such a size, the light emitting element can more fully exhibit the function as a three-dimensional light source. The surface area of the curved surface portion is more preferably 70% or more, and further preferably 90% or more of the light emitting area of the organic electroluminescent element.

A three-dimensional light diffusing member is arranged on at least a part of the light emitting element on the light extraction surface of the organic electroluminescent element, and at least a part of the surface of the light diffusing member that is not in contact with the organic electroluminescent element is curved. Is one of the preferred embodiments of the present invention.
As described above, if the organic electroluminescent element and the three-dimensional light diffusing member are arranged in this way, the light from the light extraction surface of the organic electroluminescent element passes through the inside of the three-dimensional member and has a three-dimensional shape. It is emitted from the curved surface of the member and becomes a three-dimensional light source. With such a configuration, the organic electroluminescent element remains in a planar shape and the light emitting element serves as a three-dimensional light source. Therefore, a three-dimensional light source can be obtained even when an organic electroluminescent element that is thick and difficult to bend is used. ..
Hereinafter, this embodiment is also referred to as a first embodiment of the light emitting device of the present invention.

It is also one of the preferred embodiments of the present invention that the light emitting element is arranged so that the surface opposite to the light extraction surface of the organic electroluminescent element is in contact with the curved surface of the three-dimensional member. is there.
As described above, when the curved surface portion of the three-dimensional member and the surface opposite to the light extraction surface of the organic electroluminescent element are in contact with each other, the organic electroluminescent element has a curved surface shape with the light extraction surface side facing outward. Therefore, it becomes a three-dimensional light source.
Hereinafter, this embodiment is also referred to as a second embodiment of the light emitting device of the present invention.

In the case of the first embodiment, since it is required that the three-dimensional member transmits light, it is preferable to use a material having a visible light transmittance of 5% or more. More preferably, it is 20% or more of the material.
As the material in the case of the first embodiment, it is preferable to use a resin, glass, silicone or the like satisfying the visible light transmittance as the material.
In the case of the second embodiment, it is not required that the three-dimensional member is transparent. Therefore, the material of the three-dimensional member is not particularly limited, and various materials such as metal, wood, resin, and glass can be used.
Among them, ABS resin, PLA resin, acrylic resin, and epoxy resin, which are widely used as materials for the three-dimensional printing method, can be easily formed by using the three-dimensional printing method described later. , Nylon, Polycarbonate, Polycarbonate, etc .; It is a preferable practice of the present invention to select and use a suitable material from metals such as SUS, titanium, copper, aluminum, etc. according to the embodiment of the light emitting element. It is one of the forms.

The material of the three-dimensional member used in the first embodiment is preferably a material having a refractive index difference of 0.01 or less from the sealing material of the organic electroluminescent element. By using a three-dimensional member formed by using such a material, light reflection is less likely to occur at the interface between the organic electroluminescent element and the three-dimensional member, and the light emitting element of the present invention can be used as a three-dimensional light source. It becomes an element that emits more beautiful light. The difference in refractive index is more preferably 0.05 or less, still more preferably 0.1 or less.
The refractive index of the material of the three-dimensional member and the sealing material of the organic electroluminescent element can be confirmed by a refractometer.

The method for forming the three-dimensional member is not particularly limited, but the three-dimensional printing method is preferable. By using the three-dimensional printing method, it is possible to efficiently form a member having a desired three-dimensional shape with high dimensional accuracy. Therefore, it is one of the preferred embodiments of the present invention that the three-dimensional member is a printed object.
A 3D printer can be selected and used according to the material for forming the printed matter.

When the light emitting device of the present invention is of the above-mentioned first embodiment, it may be manufactured by directly forming a three-dimensional member on the organic electroluminescent device, and after separately forming the three-dimensional member, the light emitting element may be manufactured. It may be manufactured by arranging it on an organic electroluminescent device.
When the light emitting element of the present invention is of the second embodiment, after forming a three-dimensional member separately, the organic electroluminescent element is in contact with the curved surface portion of the three-dimensional member and the organic electroluminescent element. The element can be arranged and manufactured.
When the three-dimensional member is separately formed and then arranged so that the organic electroluminescent element and the three-dimensional member are in contact with each other, an adhesive layer is provided between the organic electroluminescent element and the three-dimensional member. May be good.
As a material for forming the adhesive layer, an ordinary adhesive or the like capable of forming a transparent adhesive layer such as an epoxy resin can be used. When the light emitting element of the present invention is of the first embodiment, the difference in refractive index between the material of the three-dimensional member and the adhesive is preferably 0.01 or less, so such an adhesive. It is preferable to select and use.

The organic electroluminescent device preferably has a total film thickness of 200 μm or less. When the total thickness of the organic electroluminescent element is 200 μm or less, the organic electroluminescent element tends to have a curved surface shape, which is particularly suitable as the organic electroluminescent element used in the second embodiment. The total film thickness of the organic electroluminescent device is more preferably 150 μm or less, still more preferably 100 μm or less. The total film thickness of the organic electroluminescent device is usually 1000 μm or more.
The total film thickness of the organic electroluminescent device can be measured with a digital caliper.

Hereinafter, the structure and material of the organic electroluminescent device constituting the light emitting device of the present invention will be described.
The organic electroluminescent device constituting the light emitting device of the present invention has a structure in which a plurality of organic compound layers are laminated between an anode and a cathode. The configuration of the organic electroluminescent device in the present invention is not particularly limited, but each layer of the cathode, the electron injection layer and / or the electron transport layer, the light emitting layer, the hole transport layer and / or the hole injection layer, and the anode is adjacent to each other in this order. It is preferable that the element is provided. Each of these layers may be composed of one layer or two or more layers.
In the organic electric field element having the above configuration, when the element has only one of the electron injection layer and the electron transport layer, the one layer is laminated adjacent to the cathode and the light emitting layer, and the element When has both an electron injecting layer and an electron transporting layer, these layers are laminated adjacent to each other in the order of the cathode, the electron injecting layer, the electron transporting layer, and the light emitting layer. When the device has only one of the hole transport layer and the hole injection layer, the one layer is laminated adjacent to the light emitting layer and the anode, and the device transports holes. When both the layer and the hole injection layer are provided, these layers are laminated adjacent to each other in the order of the light emitting layer, the hole transport layer, the hole injection layer, and the anode.

The organic electroluminescent device may be an element having a forward structure in which an anode is formed on a substrate, or an element having a reverse structure in which a cathode is formed on a substrate, but is formed on a substrate. It is preferable that the device has an inverted structure having a structure in which a plurality of layers are laminated between the cathode and the anode.
In an organic electroluminescent device having an inverse structure, by using a material having high atmospheric stability for the cathode, it is possible to obtain an element having higher atmospheric stability than an organic electroluminescent device having a forward structure in which an anode is formed on a substrate. Since strict sealing is not required, the thickness of the element can be reduced. This makes it possible to use more various printers without any trouble when forming a three-dimensional member on the organic electroluminescent element by using the 3D printer in the first embodiment. Further, also in the second embodiment, since the thickness of the element is reduced, it becomes easy to align the organic electroluminescent element along the curved surface portion of the three-dimensional member.

The organic electroluminescent device constituting the light emitting device of the present invention is preferably an organic-inorganic hybrid type organic electroluminescent device further having a metal oxide layer between the cathode and the anode. By using the metal oxide as the material of the device, the device becomes more excellent in continuous drive life and storage stability.
The organic electroluminescent element in the present invention is an organic-inorganic hybrid type organic electroluminescent element in which a cathode is formed adjacent to a substrate and a metal oxide layer is provided between the anode and the cathode, and the light emitting layer and the anode are used. It has an electron injection layer and, if necessary, an electron transport layer between the cathode and the light emitting layer, and a hole transport layer and / or a hole injection layer between the anode and the light emitting layer. It is preferable that the element has a structure of. The organic electroluminescent device in the present invention may have another layer between each of these layers, but is preferably an element composed of only each of these layers. That is, it is preferable that the element is such that the cathode, the electron injection layer, and if necessary, the electron transport layer, the light emitting layer, the hole transport layer and / or the hole injection layer, and the anode layers are laminated adjacent to each other in this order. Each of these layers may be composed of one layer or two or more layers.

In the organic electroluminescent element constituting the light emitting element of the present invention, any compound that can be usually used as a material of the light emitting layer can be used as the material for forming the light emitting layer, and even a low molecular weight compound is a polymer. It may be a compound, or a mixture of these may be used.
In the present invention, the low molecular weight material means a material that is not a high molecular weight material (polymer), and does not necessarily mean an organic compound having a low molecular weight.

Examples of the polymer material forming the light emitting layer include polyacetylene compounds such as trans-type polyacetylene, cis-type polyacetylene, poly (di-phenylacetylene) (PDPA), and poly (alkyl, phenylacetylene) (PAPA); Poly (para-phenylene) (PPV), poly (2,5-dialkoxy-para-phenylene vinylene) (RO-PPV), cyano-substituted-poly (para-phenylene) (CN-PPV), poly ( Polyparaphenylene vinylenes such as 2-dimethyloctylsilyl-para-phenylene vinylene) (DMOS-PPV), poly (2-methoxy, 5- (2'-ethylhexoxy) -para-phenylene vinylene) (MEH-PPV) Compounds; Polythiophene compounds such as poly (3-alkylthiophene) (PAT), poly (oxypropylene) triol (POPT); poly (9,9-dialkylfluorene) (PDAF), poly (dioctylfluorene-alto-benzo) Thianazol) (F8BT), α, ω-bis [N, N'-di (methylphenyl) aminophenyl] -poly [9,9-bis (2-ethylhexyl) fluorene-2,7-zil] (PF2 / 6am4) ), Poly (9,9-dioctyl-2,7-divinylenefluorenyl-ortho-co (anthracene-9,10-diyl)) polyfluorene compounds; poly (para-phenylene) (PPP), Polyparaphenylene compounds such as poly (1,5-dialkoxy-para-phenylene) (RO-PPP); polycarbazole compounds such as poly (N-vinylcarbazole) (PVK); poly (methylphenylsilane) ) (PMPS), poly (naphthylphenylsilane) (PNPS), poly (biphenylylphenylsilane) (PBPS) and other polysilane compounds; further described in Japanese Patent Application No. 2010-230995 and Japanese Patent Application No. 2011-6457. Examples include boron compound-based polymer materials.

Examples of the low molecular weight material forming the light emitting layer include a tricoordinated iridium complex having 2,2'-bipyridine-4,4'-dicarboxylic acid as a ligand, and factories (2-phenylpyridine). Iridium (Ir (ppy) ₃ ), 8-hydroxyquinolin aluminum (Alq ₃ ), tris (4-methyl-8 quinolinolate) aluminum (III) (Almq ₃ ), 8-hydroxyquinolin zinc (Znq ₂ ), (1, 10-Phenantroline) -Tris- (4,4,4-trifluoro-1- (2-thienyl) -butane-1,3-geonate) Europium (III) (Eu (TTA) ₃ (phen)), 2, Various metal compounds such as 3,7,8,12,13,17,18-octaethyl-21H, 23H-porphin platinum (II); benzenes such as distyrylbenzene (DSB), diaminodistyrylbenzene (DADSB) Phosphoric compounds; Naphthalene compounds such as naphthalene and Nile Red; Phenantren compounds such as phenanthrene; Crescent compounds such as chrysene and 6-nitrochrycene; Perylene, N, N'-bis (2,5-di-) Perylene compounds such as t-butylphenyl) -3,4,9,10-perylene-di-carboxyimide (BPPC); coronene compounds such as coronen; anthracene compounds such as anthracene and bisstyrylanthracene; Pyrene compounds such as pyrene; pyrane compounds such as 4- (di-cyanomethylene) -2-methyl-6- (para-dimethylaminostyryl) -4H-pyran (DCM); aclysine compounds such as aclysine Compounds; Stilben compounds such as Stilben; thiophene compounds such as 2,5-dibenzoxazolethiophene; benzoxazole compounds such as benzoxazole; benzoimidazole compounds such as benzoimidazole; 2,2'-( Para-phenylenedivinylene) -benzothiazole compounds such as bisbenzothiazole; butadiene compounds such as bistilyl (1,4-diphenyl-1,3-butadiene), tetraphenylbutadiene; naphthalimide such as naphthalimide Compounds; Cumarin compounds such as coumarin; Perinone compounds such as perinone; Oxaziazole compounds such as oxadiazole; Ardazine compounds; 1,2,3,4,5-pentaf Cyclopentadiene compounds such as enyl-1,3-cyclopentadiene (PPCP); quinacridone compounds such as quinacridone and quinacridone red; pyridine compounds such as spirolopyridine and thiadiazolopyridine; 2,2', 7 , 7'-Tetraphenyl-9,9'-Spiro compound such as spirobifluorene; metal or non-metallic phthalocyanine compounds such as _{phthalocyanine (H 2 Pc), copper phthalocyanine;} Examples thereof include the boron compound materials described in Japanese Patent Application No. 2010-230995 and Japanese Patent Application No. 2011-6458. Further, KHLHS-04, KHLDR-03 and the like, which are products of Chemipro Kasei Co., Ltd., can also be used.

The average thickness of the light emitting layer is not particularly limited, but is preferably 10 to 150 nm. It is more preferably 20 to 100 nm, and even more preferably 40 to 100 nm.
The average thickness of the light emitting layer can be measured by a crystal oscillator film thickness meter in the case of a low molecular weight compound and by a contact type step meter in the case of a high molecular weight compound.

When the organic electroluminescent device constituting the light emitting device of the present invention has an electron transport layer, any compound that can be usually used as a material for the electron transport layer can be used as the material, and these can be mixed. You may use it.
Examples of compounds that can be used as materials for the electron transport layer include pyridine derivatives such as Tris-1,3,5- (3'-(pyridine-3''-yl) phenyl) benzene (TmPyPhB). Kinolin 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 basophenanthroline (BPhen), 2,4-bis (4-biphenyl) -6- (4'-(2-pyridinyl) -4-biphenyl)-[1,3,5] triazine Triazine derivatives such as (MPT), triazole derivatives such as 3-phenyl-4- (1'-naphthyl) -5-phenyl-1,2,4-triazole (TAZ), oxazole derivatives, 2- (4- (4- Oxaziazole derivatives such as biphenylyl) -5- (4-tert-butylphenyl-1,3,4-oxadiazole) (PBD), 2,2', 2''-(1,3,5-) Imidazole derivatives such as benzyl) -tris (1-phenyl-1-H-benzimidazole) (TPBI), aromatic ring tetracarboxylic acid anhydrides such as naphthalene and perylene, bis [2- (2-hydroxyphenyl) benzothiazolate] Various metal complexes typified by zinc (Zn (BTZ) ₂ ), tris (8-hydroxyquinolinato) aluminum (Alq3), etc., 2,5-bis (6'-(2', 2''-bipyridyl)) Examples thereof include organic silane derivatives typified by syrol derivatives such as -1,1-dimethyl-3,4-diphenylsilol (PyPySPyPy), and one or more of these can be used.
Among these, _{a metal complex such as Alq 3} and a pyridine derivative such as TmPyPhB are preferable.

As the electron injection layer, a layer made of a nitrogen-containing film formed of a nitrogen-containing compound can be used.
Examples of the nitrogen-containing compound forming the layer composed of the nitrogen-containing film include pyrrolidones such as polyvinylpyrrolidone, pyrroles such as polypyrrole or anilins such as polyaniline, and pyridines such as polyvinylpyridine. , Pyrrolidines, imidazoles, piperidines, pyrimidines, triazines and other compounds having a nitrogen-containing heterocycle, and amine compounds.

As the nitrogen-containing compound, a compound having a high nitrogen content is preferable, and polyamines are preferable. Since polyamines have a high ratio of the number of nitrogen atoms to the total number of atoms constituting the compound, they are suitable from the viewpoint of making the organic electroluminescent element have high electron injection property and drive stability.
As the polyamines, those capable of forming a layer by coating are preferable, and they may be low molecular weight compounds or high molecular weight compounds. As the low molecular weight compound, polyalkylene polyamines such as diethylenetriamine and pentamethyldiethylenetriamine are preferably used, and as the high molecular weight compound, a polymer having a polyalkyleneimine structure is preferably used. Polyethyleneimine is particularly preferable. Above all, it is one of the preferred embodiments of the present invention that the nitrogen-containing compound is polyethyleneimine or diethylenetriamine.
Here, the low molecular weight compound means a compound that is not a high molecular weight compound (polymer), and does not necessarily mean a compound having a low molecular weight.

The average thickness of the nitrogen-containing film is not particularly limited, but is preferably 0.5 to 10 nm. It is more preferably 1 to 5 nm, and even more preferably 1 to 3 nm.
The average thickness of the light emitting layer can be measured by a crystal oscillator film thickness meter in the case of a low molecular weight compound.

When the organic electroluminescent device constituting the light emitting device of the present invention has a hole transport layer, the hole transporting organic material used as the hole transport layer includes various p-type polymer materials and various p-type. The electroluminescent materials can be used alone or in combination.
Examples of the p-type polymer material (organic polymer) include polyarylamine, fluorene-arylamine copolymer, fluorene-bithiophene copolymer, poly (N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, and polythiophene. Examples thereof include polyalkylthiophene, polyhexylthiophene, poly (p-phenylene vinylene), polytinylene vinylene, pyrene formaldehyde resin, ethylcarbazole formaldehyde resin or a derivative thereof.
These compounds can also be used as a mixture with other compounds. As an example, a mixture containing polythiophene includes poly (3,4-ethylenedioxythiophene / styrenesulfonic acid) (PEDOT / PSS) and the like.

Examples of the p-type low molecular weight material include 1,1-bis (4-di-para-triaminophenyl) cyclohexane and 1,1'-bis (4-di-para-trilaminophenyl)-. Arylcycloalkane compounds such as 4-phenyl-cyclohexane, 4,4', 4''-trimethyltriphenylamine, N, N, N', N'-tetraphenyl-1,1'-biphenyl-4, 4'-diamine, N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine (TPD1), N, N'-diphenyl-N , N'-bis (4-methoxyphenyl) -1,1'-biphenyl-4,4'-diamine (TPD2), N, N, N', N'-tetrakis (4-methoxyphenyl) -1,1 '-Biphenyl-4,4'-diamine (TPD3), N, N'-di (1-naphthyl) -N, N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD) ), Arylamine compounds such as TPTE, N, N, N', N'-tetraphenyl-para-phenylenediamine, N, N, N', N'-tetra (para-tolyl) -para-phenylenediamine , N, N, N', N'-tetra (meth-trill) -meth-phenylenediamine (PDA) and other phenylenediamine compounds, carbazole, N-isopropylcarbazole, N-phenylcarbazole and other carbazole compounds. , stilbene, 4-di - para - stilbene compounds such as tolyl aminostilbene, oxazole compounds, such as _{O x} Z, triphenylmethane, triphenylmethane compounds such as m-MTDATA, 1-phenyl-3 -Pyrazoline compounds such as (para-dimethylaminophenyl) pyrazoline, benzine (cyclohexadiene) compounds, triazole compounds such as triazole, imidazole compounds such as imidazole, 1,3,4-oxadiazol, Oxaziazole compounds such as 2,5-di (4-dimethylaminophenyl) -1,3,4-oxadiazole, anthracene, anthracene compounds such as 9- (4-diethylaminostyryl) anthracene, fluorenone , 2,4,7-Trinitro-9-fluorenone, 2,7-bis (2-hydroxy-3- (2-chlorophenylcarbamoyl) -1-naphthylazo) fluorenone compounds such as fluorenone, polyani Aniline compounds such as phosphorus, silane compounds, pyrrol compounds such as 1,4-dithioketo-3,6-diphenyl-pyrrolo- (3,4-c) pyrrolopyrrole, floren compounds such as floren, Porphyrin, metal tetraphenyl Porphyrin compounds such as porphyrin, quinacridone compounds such as quinacridone, phthalocyanines, copper phthalocyanines, tetra (t-butyl) copper phthalocyanines, metal or metal-free phthalocyanines such as iron phthalocyanines, copper Metallic or metal-free naphthalocyanine compounds such as naphthalocyanine, vanadyl naphthalocyanine, monochlorogally naphthalocyanine, N, N'-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine, N, N , N', N'-Benzidine-based compounds such as tetraphenylbenzidine and the like can be mentioned.

When the organic electroluminescent device constituting the light emitting device of the present invention has an electron transport layer and a hole transport layer, the average thickness of these layers is not particularly limited, but is preferably 10 to 150 nm. It is more preferably 20 to 100 nm, and even more preferably 40 to 100 nm.
The average thickness of the electron transport layer and the hole transport layer can be measured by a crystal oscillator film thickness meter in the case of a low molecular weight compound and by a contact type step meter in the case of a high molecular weight compound.

When the organic electroluminescent element constituting the light emitting element of the present invention has a metal oxide layer, the metal oxide layer is provided in either or both of the cathode to the light emitting layer and the anode to the light emitting layer. However, it is preferable to have a metal oxide layer both between the cathode and the light emitting layer and between the light emitting layer and the anode. Assuming that the metal oxide layer between the cathode and the light emitting layer is the first metal oxide layer and the metal oxide layer between the anode and the light emitting layer is the second metal oxide layer, the first metal oxide The layer is preferably used as an electron injection layer, and the second metal oxide layer is preferably used as a hole injection layer. An example of the configuration of a preferable element of the organic electroluminescent device in the present invention is as follows: a cathode, a first metal oxide layer, a layer made of a nitrogen-containing film, a light emitting layer, a hole transport layer, and a second metal oxide layer. , The anodes are laminated adjacent to each other in this order. An electron transport layer may be provided between the layer made of the nitrogen-containing film and the light emitting layer, if necessary. The importance of the metal oxide layer is higher in the first metal oxide layer, and the second metal oxide layer can be replaced with an organic material having an extremely deep minimum unoccupied molecular orbital, for example, HATCN. ..

The first metal oxide layer is a semiconductor or insulator laminated thin film which is a layer composed of one layer of a single metal oxide film, or a layer in which a simple substance or two or more kinds of metal oxides are laminated and / or mixed. It is a layer. Metal elements that make up metal oxides include magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, indium, gallium, iron, cobalt, nickel, and copper. , Zinc, cadmium, aluminum, silicon. Of these, at least one of the metal elements constituting the laminated or mixed metal oxide layer is preferably a layer composed of magnesium, aluminum, calcium, zirconium, hafnium, silicon, titanium, and zinc, and among them, a single metal. The oxide preferably 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.

Examples of the single layer or a layer in which two or more kinds of metal oxides are laminated and / or mixed are titanium oxide / zinc oxide, titanium oxide / magnesium oxide, titanium oxide / zirconium oxide, titanium oxide / aluminum oxide, titanium oxide / Laminate and / or stack combinations of metal oxides such as hafnium oxide, titanium oxide / silicon oxide, zinc oxide / magnesium oxide, zinc oxide / zirconium oxide, zinc oxide / hafnium oxide, zinc oxide / silicon oxide, calcium oxide / aluminum oxide. Mixed or titanium oxide / zinc oxide / magnesium oxide, titanium oxide / zinc oxide / zirconium oxide, titanium oxide / zinc oxide / aluminum oxide, titanium oxide / zinc oxide / hafnium oxide, titanium oxide / zinc oxide / silicon oxide, Examples thereof include laminated and / or mixed combinations of three types of metal oxides such as indium oxide / gallium oxide / zinc oxide. Among these, a IGZO and electride an oxide semiconductor having good characteristics as a special composition 12CaO · _7Al 2 _{O 3} are also included.
These first metal oxide layers can be said to be electron injection layers and also electrodes (cathodes).
In the present invention, a material having a sheet resistance lower than 100Ω / □ is classified as a conductor, and a material having a sheet resistance higher than 100Ω / □ is classified as a semiconductor or an insulator. Therefore, ITO (tin-doped indium oxide), ATO (antimon-doped indium oxide), IZO (indium-doped zinc oxide), AZO (aluminum-doped zinc oxide), FTO (fluorine-doped indium oxide), etc., which are known as transparent electrodes, are used. Since the thin film has high conductivity and is not included in the category of semiconductor or insulator, it does not correspond to the layer constituting the first metal oxide layer.

Further, the first metal oxide layer may be a laminate of a metal oxide layer and a single metal layer as long as the metal oxide layer is included.
The elements constituting the metal oxide are as described above.
Examples of the metal used as the material for the layer of the metal alone include silver, palladium, and the like, and one or more of these can be used.

When the first metal oxide layer is a layer of a metal oxide layer and a layer of a single metal, the layer of the metal oxide and the layer of a single metal may be alternately laminated. preferable. In this case, the number of the metal oxide layer and the metal single layer is preferably two layers of the metal oxide layer and one layer of the single metal layer. That is, a structure in which one metal simple substance layer is sandwiched between two metal oxide layers is preferable.

The metal oxide forming the second metal oxide layer is not particularly limited, but is limited to vanadium oxide (V ₂ O ₅ ), molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), and ruthenium oxide (RuO _2). ) Etc., or two or more types can be used. Among these, those containing vanadium oxide or molybdenum oxide as a main component are preferable. When the second metal oxide layer is composed mainly of vanadium oxide or molybdenum oxide, the second metal oxide layer injects holes from the anode and transports them to the light emitting layer or the hole transport layer. It becomes more excellent due to its function as a hole injection layer. Further, since vanadium oxide or molybdenum oxide has high hole transporting property itself, it has an advantage that it is possible to preferably prevent a decrease in the injection efficiency of holes from the anode into the light emitting layer or the hole transporting layer. There is. More preferably, it is composed of vanadium oxide and / or molybdenum oxide.

The average thickness of the first metal oxide layer is acceptable from 1 nm to several μm, but is preferably 1 to 1000 nm from the viewpoint of an organic electroluminescent device that can be driven at a low voltage. More preferably, it is 2 to 100 nm.
The average thickness of the second metal oxide layer is not particularly limited, but is preferably 1 to 1000 nm. More preferably, it is 5 to 50 nm.
The average thickness of the first metal oxide layer can be measured by a stylus type step meter and spectroscopic ellipsometry.
The average thickness of the second metal oxide layer can be measured at the time of film formation with a crystal oscillator film thickness meter.

In the organic electroluminescent device constituting the light emitting device of the present invention, known conductive materials can be appropriately used as the anode and the cathode, but it is preferable that at least one of them is transparent for light extraction. Examples of known transparent conductive materials include ITO (tin-doped indium oxide), ATO (antimon-doped indium oxide), IZO (indium-doped zinc oxide), AZO (aluminum-doped zinc oxide), and FTO (fluorine-doped indium oxide). Is raised. Examples of opaque conductive materials include calcium, magnesium, aluminum, tin, indium, copper, silver, gold, platinum and alloys thereof.
Among these, ITO, IZO, and FTO are preferable as the cathode.
Among these, Au, Ag, and Al are preferable as the anode.
As described above, since the metal generally used for the anode can be used for the cathode and the anode, it is possible to easily realize the case where light is taken out from the upper electrode (in the case of the top emission structure), and the above electrode can be used. It can be selected in various ways and used for each electrode. For example, Al is used as the lower electrode, ITO is used as the upper electrode, and the like. In an organic EL having a reverse structure, ITO having high atmospheric stability can be used as a cathode, so that the device can have high atmospheric stability and a long device life.

The average thickness of the cathode is not particularly limited, but is preferably 10 to 500 nm. More preferably, it is 100 to 200 nm. The average thickness of the cathode can be measured by a stylus profilometer or spectroscopic ellipsometry.
The average thickness of the anode is not particularly limited, but is preferably 10 to 1000 nm. More preferably, it is 30 to 150 nm. Even when an opaque material is used, it can be used as a top emission type or transparent type anode by setting the average thickness to about 10 to 30 nm, for example.
The average thickness of the anode can be measured at the time of film formation with a crystal oscillator film thickness meter.

In the organic electroluminescent element of the present invention, the method for forming a layer formed of an organic compound is not particularly limited, and various methods can be appropriately used according to the characteristics of the material, but when it can be applied as a solution, it can be applied. Spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, slit coating method, dip coating method, spray coating method, screen printing method, flexographic printing method, offset printing. The film can be formed by using various coating methods such as a printing method and an inkjet printing method. Of these, the spin coating method and the slit coating method are preferable because the film thickness can be more easily controlled. When not coated or when the solvent solubility is low, a vacuum vapor deposition method, an ESDUS (Evaporative Spray Deposition Solution from Ultra-dilute Solution) method and the like can be mentioned as preferable examples.

When the layer formed from the above organic compound is formed by applying an organic compound solution, the solvent used for dissolving the organic compound is, for example, nitrate, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide. , Inorganic solvents such as carbon tetrachloride, ethylene carbonate, ketone solvents such as methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MICK), cyclohexanone, methanol, ethanol, isopropanol, Alcohol-based solvents such as ethylene glycol, diethylene glycol (DEG) and glycerin, diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, Ether-based solvents such as diethylene glycol dimethyl ether (digrim) and diethylene glycol ethyl ether (carbitol), cellosolve-based solvents such as methyl cellosolve, ethyl cellosolve, and phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, and cyclohexane, and toluene. , Aromatic hydrocarbon solvents such as xylene, benzene, aromatic heterocyclic solvents such as pyridine, pyrazine, furan, pyrrol, thiophene, methylpyrrolidone, N, N-dimethylformamide (DMF), N, N-dimethyl Amid solvents such as acetoamide (DMA), halogen compound solvents such as chlorobenzene, dichloromethane, chloroform, 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate and ethyl formate, dimethyl sulfoxide (DMSO), sulfolane and the like. Sulfur compound solvent, nitrile solvent such as acetonitrile, propionitrile, acrylonitrile, various organic solvents such as organic acid solvent such as formic acid, acetic acid, trichloroacetic acid, trifluoroacetic acid, or mixed solvent containing these. Can be mentioned.
Among these, non-polar solvents are preferable as the solvent, and for example, aromatic hydrocarbon solvents such as xylene, toluene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, and tetramethylbenzene, pyridine, pyrazine, furan, Examples thereof include aromatic heterocyclic solvent such as pyrrole, thiophene and methylpyrrolidone, and aliphatic hydrocarbon solvent such as hexane, pentane, heptane and cyclohexane, and these can be used alone or in combination.

The cathode, anode, and oxide layer are formed by a sputtering method, a vacuum deposition method, a sol-gel method, a spray pyrolysis (SPD) method, an atomic layer deposition (ALD) method, a vapor phase deposition method, a liquid phase deposition method, or the like. Can be formed by A metal foil bond can also be used to form the anode and cathode. These methods are preferably selected according to the characteristics of the material of each layer, and the production method may be different for each layer. Among these, the second metal oxide layer is more preferably formed by using a vapor phase film forming method. According to the vapor phase film forming method, the organic compound layer can be formed cleanly and in good contact with the anode without damaging the surface, and as a result, the effect of having the second metal oxide layer as described above is obtained. Becomes more prominent.

For the reason of further improving the characteristics of the organic electroluminescent device, for example, a hole blocking layer, an electron blocking layer, or the like may be provided, if necessary. As the material for forming these layers, a material usually used for forming these layers can be used, and the layers can be formed by a method usually used for forming these layers.

Further, after forming the final electrode of the laminated structure, a passivation layer for protecting the surface may be formed on the passivation layer. As the material of the passivation layer, a material usually used for forming these layers can be used. For example, the material of the hole transport layer and / or the material of the metal oxide layer described above can be used, but the combination is not limited as long as it can maintain insulation.

The average thickness of the passivation layer is not particularly limited, but is preferably 20 to 300 nm. More preferably, it is 50 to 200 nm.
The average thickness of the passivation layer can be measured at the time of film formation with a crystal oscillator film thickness meter.

In the organic electroluminescent device constituting the light emitting device of the present invention, examples of the substrate material include a resin material and a glass material.
Examples of the resin material used for the substrate include polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethylmethacrylate, polycarbonate, polyarylate and the like. When a resin material is used as the substrate material, an organic electroluminescent device having excellent flexibility can be obtained.
Examples of the glass material used for the substrate include quartz glass and soda glass.

The average thickness of the substrate is preferably 10 to 150 μm. More preferably, it is 10 to 50 μm.
The average thickness of the substrate can be measured with a digital caliper.

The organic electroluminescent device may further have a sealing layer on the passivation layer. As the material for forming the sealing layer, the same material as that of the substrate can be used, and it is preferable that the thickness of the sealing layer is also the same as the thickness of the substrate.

When sealing the organic electroluminescent device constituting the light emitting device of the present invention, a usual method can be appropriately used as the sealing step. For example, a method of adhering a sealing container in an inert gas, a method of forming a sealing film directly on an organic electroluminescent device, and the like can be mentioned. In addition to these, a method of encapsulating a moisture absorbing material may be used in combination.
The above-mentioned reverse-structured organic electroluminescent device does not require strict sealing as compared with the forward-structured organic electroluminescent device, but may be sealed if necessary.

The organic electroluminescent device may be a top emission type device that extracts light to the side opposite to the side where the substrate is located (that is, the side opposite to the side where the substrate is located is the light extraction surface), and has the substrate. It may be a bottom emission type that extracts light to the side (that is, the side where the substrate is located is the light extraction surface).

The light emitting element of the present invention is an element that can be suitably used as a three-dimensional light source, and can be suitably used for a display device, a lighting device, or the like. A display device or a lighting device including such a light emitting element of the present invention is also one of the present inventions.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

1. 1. Fabrication of Organic Electroluminescent Device (Manufacturing Example 1)
The organic electroluminescent device 1 was manufactured by the method shown below.
[Step 1]
As the substrate 1, SU-8 manufactured by Nippon Kayaku Co., Ltd. was applied by spin coating on a PET film with a barrier layer having a thickness of 25 μm purchased from Oike Kogyo, and baked on a hot plate heated to 100 ° C.
[Step 2]
The substrate 1 was set in a sputtering apparatus, and a zinc oxide (ZnO) layer having an average thickness of 20 nm was formed on the substrate 1 by a sputtering method using zinc metal as a target and argon as a carrier gas as a reaction gas. .. Then, it was set in a vacuum vapor deposition apparatus to form a silver layer having an average thickness of 8 nm. Then, it was set in the sputtering apparatus again to form a zinc oxide layer having an average thickness of 2 nm. The substrate 1 was moved to the atmosphere and annealed on a hot plate at 100 ° C. for 30 minutes to form the transparent electrode 2 and the oxide layer 3.
[Step 3]
Next, polyethyleneimine manufactured by Nippon Shokubai was applied onto the oxide layer 3 by spin coating to form an electron injection layer 4. The average thickness of the electron injection layer 4 was 2 nm.
[Step 4]
Next, the substrate 1 on which each layer up to the electron injection layer 4 was formed was fixed to the substrate holder of the vacuum vapor deposition apparatus. In addition, KHLHS-04 and KHLDR-03 purchased from Chemipro Kasei, N, N'-di (1-naphthyl) -N, N'-diphenyl-1,1'-biphenyl-4 represented by the following formula (1). , 4'-Diamine (α-NPD) were placed in the alumina crucible and set in the vapor deposition source. Then, the pressure inside the vacuum vapor deposition apparatus ^{was reduced to about 1 × 10 −5} Pa, and KHLHS-04 was vapor-deposited at 10 nm to form an electron transport layer 5. Next, KHLHS-04 and α-NPD were used as host materials, and KHLDR-03 was used as a light emitting dopant to co-deposit at 15 nm to form a light emitting layer 6. Next, the hole transport layer 7 was formed by depositing α-NPD at 40 nm. Further, molybdenum trioxide MoO ₃ was formed by vapor deposition in a vacuum-consistent manner to form a hole injection layer 8 having a film thickness of 10 nm.
[Step 5]
Next, aluminum (anode 9) was deposited on the substrate 1 on which the hole injection layer 8 was formed so that the film thickness was 70 nm.
[Step 6]
Next, α-NPD was deposited at 100 nm on the substrate 1 formed up to the anode 9, and then zinc oxide was deposited at 20 nm with a sputtering apparatus to obtain a passivation layer 10.
[Step 7]
Next, the substrate 1 formed up to the passivation layer 10 was transported to the glove box, and TB1655 manufactured by ThreeBond and a PET film with a barrier layer having a thickness of 25 μm purchased from Oike Kogyo were laminated on the substrate 1 and heated to 90 ° C. The sealing layer 11 was formed by annealing on a hot plate for 1 hour to obtain an "organic electroluminescent element 1".
When the thickness of the organic electroluminescent device 1 obtained by Mitutoyo's digital indicator ID-C112AB was measured, the total film thickness was 72 μm.

2. Fabrication of a light emitting element having an organic electroluminescent element and a three-dimensional member (Example 1)
Using a 3D printer manufactured by XYZ Printing Co., Ltd., Nobel 1.0, 3D printing was performed on the organic electroluminescent device 1 manufactured in Production Example 1 using a clear color standard resin as a material, as shown in the photograph shown in FIG. By forming a three-dimensional member having a 3D curved surface in which a large number of columns having a thickness of about 65 mm and a width of about 45 mm are combined, a light emitting element 1 guided to the curved surface surface was obtained. The surface area of the three-dimensional shape member formed by 3D printing was 200% or more of the area of the light emitting surface of the organic electroluminescent element 1. Using a refractometer DR-M2 manufactured by ATAGO, the difference in refractive index between the encapsulant of the organic electroluminescent element 1 and the 3D-printed cured resin was 0.05.

(Example 2)
Using a 3D printer manufactured by XYZ Printing Co., Ltd., Nobel 1.0, 3D printing is performed on the organic electroluminescent device 1 manufactured in Production Example 1 using a clear color standard resin as a material, as shown in the photograph shown in FIG. By forming a member having a shape in which six leaves having a thickness of about 65 mm and a width of about 45 mm hang down from a central pillar having a diameter of about 3 mm, a light emitting element 2 guided to a curved surface surface was obtained. .. The surface area of the three-dimensional shape member formed by 3D printing was 200% or more of the area of the light emitting surface of the organic electroluminescent element 1. Using a refractometer DR-M2 manufactured by ATAGO, the difference in refractive index between the encapsulant of the organic electroluminescent element 1 and the 3D-printed cured resin was 0.05.

Claims (8)

An organic electroluminescent device having a structure in which a plurality of layers are laminated between an anode and a cathode,
A light emitting element that is arranged in contact with the organic electroluminescent element and has a three-dimensional member having a curved surface at least a part of the surface. The light emitting element according to claim 1, wherein a three-dimensional light diffusing member is arranged on at least a part of the light extraction surface of the organic electroluminescent element. The light emitting element according to claim 1, wherein a surface opposite to the light extraction surface of the organic electroluminescent element is arranged in contact with a curved surface of a three-dimensional member. The light emitting element according to any one of claims 1 to 3, wherein the three-dimensional member is a printed object. Any of claims 1 to 4, wherein the organic electroluminescent device is an organic electroluminescent device having a structure in which a plurality of layers are laminated between an anode and a cathode formed on a substrate. The light emitting element according to. The light emitting element according to any one of claims 1 to 5, wherein the organic electroluminescent element has a total film thickness of 200 μm or less. A display device comprising the light emitting element according to any one of claims 1 to 6. A lighting device comprising the light emitting element according to any one of claims 1 to 6.

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