JP2010186723A - Organic el device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device capable of improving light extraction efficiency and preventing an organic layer in an organic EL element from being deteriorated, and to provide a method of manufacturing the organic EL device. <P>SOLUTION: The method of manufacturing the organic EL device includes a step of forming the organic EL element having a pair of electrodes and the organic layer 10 arranged between the pair of the electrodes 12, 13, a step of forming a protective layer 14 to cut off 40% or more of exposed light having a prescribed wavelength, a step of forming a light extraction layer 15 to extract light emission from the organic layer on the protective layer, and a step of forming a plurality of recesses 16 in the light extraction layer by irradiating the exposed light having the prescribed wavelength. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic EL device with improved light extraction efficiency and a method for manufacturing the same.

In an organic EL (electro-luminescence) display device, exterior members such as a transparent lens, a protective film, or a glass tube are formed, and light is emitted to the outside from the surface of these exterior members.
The refractive index of the exterior member is generally larger than the refractive index of air, and reflection occurs at the interface when light is about to exit from the exterior member. Depending on the angle, the light reflected at this interface cannot be emitted from the exterior member to the outside, and may eventually become heat.

  Due to such reflection at the interface, there is a problem that the light extraction efficiency of the organic EL device is lowered, the temperature of the organic EL device is increased, and the life is shortened.

  As a means for solving a decrease in light extraction efficiency, a technique of providing a fine concavo-convex structure on the surface (light emitting surface) of an exterior member is disclosed (for example, see Patent Documents 1 to 3).

  In Patent Document 1, in order to form a fine concavo-convex shape on the surface (light emitting surface) of the exterior member, a mold having a fine concavo-convex shape is manufactured in advance, and the concavo-convex shape of the mold is injection molded. Alternatively, a method of forming the light emitting surface by transfer and a method of roughing the light emitting surface in a random direction with a grinder are disclosed, but the former method requires a complicated process of producing a mold, There is a problem that the production is costly, and the latter method always has a problem in performance because it is difficult to obtain a uniform rough surface.

  Patent Document 2 discloses a method of forming a line-and-space pattern having a triangular cross-section in a current diffusion layer by blade processing, and further performing high-temperature hydrochloric acid treatment to form irregularities in submicron units on the surface, and a photoresist. A method of forming a line-and-space pattern by using this method and forming minute irregularities by reactive ion etching (RIE) has been disclosed. However, these methods also have a problem that a complicated process is required. It was.

  Further, Patent Document 3 discloses a method of forming a recess by irradiating light to a recording material layer capable of changing the shape of a heat mode. By this light irradiation, an organic layer in an organic EL element is disclosed. There was a problem that would deteriorate.

JP 2003-174191 A JP 2003-209283 A JP 2008-252056 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide an organic EL device capable of improving the light extraction efficiency and preventing the organic layer in the organic EL element from deteriorating and a method for manufacturing the same.

Means for solving the problems are as follows. That is,
<1> A step of forming an organic EL element having a pair of electrodes and an organic layer disposed between the pair of electrodes, and a protective layer that shields exposure light of a predetermined wavelength by 40% or more on the organic EL element. A step of forming, a step of forming a light extraction layer for extracting light emitted from the organic layer on the protective layer, and irradiating the light extraction layer with exposure light of the predetermined wavelength, thereby And a step of forming a concave portion.
<2> The method for producing an organic EL device according to <1>, wherein the protective layer transmits 80% or more of light emitted from the organic layer.
<3> an organic EL element having a pair of electrodes and an organic layer disposed between the pair of electrodes;
A protective layer that is disposed on the organic EL element and shields exposure light having a predetermined wavelength by 40% or more; and an organic layer that is disposed on the protective layer and can change its shape by irradiation with the exposure light having the predetermined wavelength. An organic EL device comprising a light extraction layer for extracting the emitted light.
<4> The organic EL device according to <3>, wherein the protective layer transmits 80% or more of light emitted from the organic layer.
<5> The organic EL device according to any one of <3> to <4>, wherein the protective layer includes an inorganic material layer.
<6> The organic EL device according to <5>, wherein the inorganic material layer is at least one of a SiON layer and a SiN layer.
<7> The organic EL device according to any one of <5> to <6>, wherein the protective layer further includes an organic material layer.
<8> The organic EL device according to any one of <3> to <4>, wherein the protective layer is a dielectric multilayer film.

  According to the present invention, an organic EL that can solve the conventional problems and achieve the object, improve the light extraction efficiency, and prevent the organic layer in the organic EL element from deteriorating. An apparatus and a manufacturing method thereof can be provided.

FIG. 1A is a plan view of an example of a light extraction layer in the organic EL device of the present invention. FIG. 1B is a plan view of another example of the light extraction layer in the organic EL device of the present invention. FIG. 2A is a diagram illustrating the relationship between the diameter and pitch of the recesses in the light extraction layer. FIG. 2B is a diagram for explaining the relationship between the laser light emission time and the period. FIG. 3: A is a figure which shows an example of the formation process of the light extraction layer and the recessed part in the manufacturing method of the organic electroluminescent apparatus of this invention (the 1). FIG. 3B is a diagram illustrating an example of a process of forming a light extraction layer and a recess in the method for manufacturing an organic EL device of the present invention (part 2). FIG. 3: C is a figure which shows an example of the formation process of the light extraction layer and the recessed part in the manufacturing method of the organic electroluminescent apparatus of this invention (the 3). FIG. 4 is a diagram illustrating the organic EL device manufactured in Example 1. FIG. 5 is a diagram illustrating the organic EL device manufactured in Example 2. FIG. 6 is a diagram illustrating the organic EL device manufactured in Example 3. FIG. 7 is a diagram showing an organic EL device manufactured in Example 4. FIG. 8 is a graph showing the light transmittance (%) of the protective layer (SiON layer) in the organic EL device produced in Example 1. FIG. 9 is a graph showing the light transmittance (%) of the protective layer (SiN layer / SiON layer / SiN layer) in the organic EL device manufactured in Example 2. FIG. 10 is a graph showing the light transmittance (%) of the protective layer (Alq layer / SiN layer) in the organic EL device produced in Example 3. FIG. 11 is a graph showing the light transmittance (%) of the dielectric multilayer film in the organic EL device produced in Example 4. FIG. 12 is a diagram illustrating an organic EL device manufactured in Comparative Example 1.

(Organic EL device)
The organic EL device of the present invention includes at least an organic EL element, a protective layer, and a light extraction layer, and further includes other members as necessary.

<Organic EL device>
The organic EL element has a pair of electrodes (anode and cathode) and an organic layer disposed between the pair of electrodes. In view of the properties of the light emitting element, at least one of the anode and the cathode is preferably transparent.

As a form of lamination of the organic layer, an aspect in which a hole transport layer, an organic light emitting layer, and an electron transport layer are laminated in this order from the anode side is preferable. Furthermore, a hole injection layer is provided between the hole transport layer and the anode, and / or an electron transporting intermediate layer is provided between the organic light emitting layer and the electron transport layer. Further, a hole transporting intermediate layer may be provided between the organic light emitting layer and the hole transport layer, and similarly, an electron injection layer may be provided between the cathode and the electron transport layer.
Each layer may be divided into a plurality of secondary layers.

<< Anode >>
The anode usually only needs to have a function as an electrode for supplying holes to the organic layer, and there is no particular limitation on the shape, structure, size, etc., depending on the use and purpose of the light-emitting element, It can select suitably from well-known electrode materials. As described above, the anode is usually provided as a transparent anode.

  Suitable examples of the material for the anode include metals, alloys, metal oxides, conductive compounds, and mixtures thereof. Specific examples of the anode material include conductive metals such as tin oxide doped with antimony and fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). Metals such as oxides, gold, silver, chromium, nickel, and mixtures or laminates of these metals and conductive metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, polyaniline, polythiophene, polypyrrole, etc. Organic conductive materials, and a laminate of these and ITO. Among these, conductive metal oxides are preferable, and ITO is particularly preferable from the viewpoints of productivity, high conductivity, transparency, and the like.

  The anode is composed of, for example, a wet method such as a printing method and a coating method, a physical method such as a vacuum deposition method, a sputtering method, and an ion plating method, and a chemical method such as a CVD and a plasma CVD method. It can be formed on the substrate in accordance with a method appropriately selected in consideration of suitability for the material to be used. For example, when ITO is selected as the anode material, the anode can be formed according to a direct current or high frequency sputtering method, a vacuum deposition method, an ion plating method, or the like.

  In the organic EL element, the formation position of the anode is not particularly limited and can be appropriately selected according to the use and purpose of the light-emitting element, but is preferably formed on the substrate. In this case, the anode may be formed on the entire one surface of the substrate, or may be formed on a part thereof.

  The patterning for forming the anode may be performed by chemical etching such as photolithography, or may be performed by physical etching such as laser, or vacuum deposition or sputtering with a mask overlapped. It may be performed by a lift-off method or a printing method.

  The thickness of the anode can be appropriately selected depending on the material constituting the anode and cannot be generally defined, but is usually about 10 nm to 50 μm, and preferably 50 nm to 20 μm.

The resistance value of the anode is preferably 10 ³ Ω / □ or less, and more preferably 10 ² Ω / □ or less. When the anode is transparent, it may be colorless and transparent or colored and transparent. In order to take out light emission from the transparent anode side, the transmittance is preferably 60% or more, and more preferably 70% or more.

  The transparent anode is detailed in Yutaka Sawada's “New Development of Transparent Conductive Film” published by CMC (1999), and the matters described here can be applied to the present invention. In the case of using a plastic substrate having low heat resistance, a transparent anode formed using ITO or IZO at a low temperature of 150 ° C. or lower is preferable.

<< Cathode >>
The cathode usually has a function as an electrode for injecting electrons into the organic layer, and there is no particular limitation on the shape, structure, size, etc., and it is known depending on the use and purpose of the light emitting device. The electrode material can be selected as appropriate.

  Examples of the material constituting the cathode include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof. Specific examples include alkali metals (eg, Li, Na, K, Cs, etc.), alkaline earth metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, lithium-aluminum alloys, magnesium. -Rare earth metals such as silver alloys, indium and ytterbium. These may be used alone, but two or more can be suitably used in combination from the viewpoint of achieving both stability and electron injection.

Among these, as a material constituting the cathode, an alkali metal or an alkaline earth metal is preferable from the viewpoint of electron injecting property, and a material mainly composed of aluminum is preferable from the viewpoint of excellent storage stability.
The material mainly composed of aluminum is aluminum alone, an alloy of aluminum and 0.01% by mass to 10% by mass of alkali metal or alkaline earth metal, or a mixture thereof (for example, lithium-aluminum alloy, magnesium-aluminum alloy). Etc.).

  The materials for the cathode are described in detail in JP-A-2-15595 and JP-A-5-121172, and the materials described in these public relations can also be applied in the present invention.

  There is no restriction | limiting in particular about the formation method of a cathode, According to a well-known method, it can carry out. For example, the cathode described above is configured from a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, or a chemical method such as CVD or plasma CVD method. It can be formed according to a method appropriately selected in consideration of suitability with the material. For example, when a metal or the like is selected as the cathode material, one or more of them can be simultaneously or sequentially performed according to a sputtering method or the like.

  Patterning when forming the cathode may be performed by chemical etching such as photolithography, physical etching by laser, or the like, or by vacuum deposition or sputtering with the mask overlaid. It may be performed by a lift-off method or a printing method.

In the organic EL element, the cathode formation position is not particularly limited, and may be formed on the entire organic layer or a part thereof.
A dielectric layer made of an alkali metal or alkaline earth metal fluoride, oxide or the like may be inserted between the cathode and the organic layer in a thickness of 0.1 nm to 5 nm. This dielectric layer can also be regarded as a kind of electron injection layer. The dielectric layer can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

The thickness of the cathode can be appropriately selected depending on the material constituting the cathode and cannot be generally defined, but is usually about 10 nm to 5 μm, and preferably 50 nm to 1 μm.
Further, the cathode may be transparent or opaque. The transparent cathode can be formed by depositing a thin cathode material to a thickness of 1 nm to 10 nm and further laminating a transparent conductive material such as ITO or IZO.

<< Organic layer >>
The organic EL element has at least one organic layer including an organic light emitting layer, and other organic layers other than the organic light emitting layer include a hole transport layer, an electron transport layer, a hole block layer, and an electronic block. Each layer includes a layer, a hole injection layer, an electron injection layer, and the like.

  In the organic EL element, each layer constituting the organic layer can be suitably formed by any of a dry film forming method such as a vapor deposition method and a sputtering method, a wet coating method, a transfer method, a printing method, and an ink jet method.

<<< Organic Luminescent Layer >>>
The organic light emitting layer receives holes from an anode, a hole injection layer, or a hole transport layer when an electric field is applied, receives electrons from a cathode, an electron injection layer, or an electron transport layer, and recombines holes and electrons. It is a layer having a function of providing light and emitting light.
The organic light emitting layer may be composed only of a light emitting material, or may be a mixed layer of a host material and a light emitting dopant. The luminescent dopant may be a fluorescent material or a phosphorescent material, and may be two or more kinds. The host material is preferably a charge transport material. The host material may be one type or two or more types, and examples thereof include a configuration in which an electron transporting host material and a hole transporting host material are mixed. Furthermore, the organic light emitting layer may contain a material that does not have charge transporting properties and does not emit light.
Further, the organic light emitting layer may be one layer or two or more layers, and each layer may emit light in different emission colors.

As the luminescent dopant, any of a phosphorescent luminescent material, a fluorescent luminescent material, and the like can be used as a dopant (phosphorescent dopant, fluorescent luminescent dopant).
The organic light emitting layer may contain two or more kinds of luminescent dopants in order to improve color purity or to expand a light emission wavelength region. The luminescent dopant further has an ionization potential difference (ΔIp) and an electron affinity difference (ΔEa) of 1.2 eV>ΔIp> 0.2 eV and / or 1.2 eV> with the host compound. A dopant satisfying the relationship of ΔEa> 0.2 eV is preferable from the viewpoint of driving durability.

The phosphorescent dopant is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a complex containing a transition metal atom or a lanthanoid atom.
The transition metal atom is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, gold, silver, copper, and platinum, and rhenium. , Iridium, and platinum are more preferable, and iridium and platinum are particularly preferable.
The lanthanoid atom is not particularly limited and may be appropriately selected depending on the purpose.For example, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium Lutesium. Among these, neodymium, europium, and gadolinium are preferable.

Examples of the ligand of the complex include G.I. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H.C. Examples include ligands described in Yersin's "Photochemistry and Photophysics of Coordination Compounds" published by Springer-Verlag 1987, Akio Yamamoto "Organic Metal Chemistry-Fundamentals and Applications-" .
Examples of the ligand include a halogen ligand (preferably a chlorine ligand), an aromatic carbocyclic ligand (for example, a cyclopentadienyl anion, a benzene anion, a naphthyl anion, etc.). Preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12 carbon atoms, and nitrogen-containing heterocyclic ligands (for example, phenylpyridine, benzoquinoline, quinolinol) , Bipyridyl, phenanthroline and the like, preferably having 5 to 30 carbon atoms, more preferably having 6 to 30 carbon atoms, further preferably having 6 to 20 carbon atoms, and particularly preferably having 6 to 12 carbon atoms), a diketone ligand ( For example, acetylacetone etc. are mentioned), carboxylic acid ligands (for example, acetic acid ligand etc. are mentioned, and C2-C30 is preferable. , More preferably 2 to 20 carbon atoms, particularly preferably 2 to 16 carbon atoms), an alcoholate ligand (for example, a phenolate ligand), preferably 1 to 30 carbon atoms, and 1 to 20 carbon atoms. More preferably, C6-C20 is more preferable), silyloxy ligands (for example, trimethylsilyloxy ligand, dimethyl-tert-butylsilyloxy ligand, triphenylsilyloxy ligand, etc., carbon A number 3 to 40 is preferable, a number 3 to 30 is more preferable, a number 3 to 20 is particularly preferable, a carbon monoxide ligand, an isonitrile ligand, a cyano ligand, a phosphorus ligand (for example, A triphenylphosphine ligand, and the like, preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, still more preferably 3 to 20 carbon atoms, and 6 carbon atoms. 20 is particularly preferred), thiolato ligands (for example, phenylthiolato ligands, etc. are mentioned, preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and further preferably 6 to 20 carbon atoms). Phosphine oxide ligands (for example, triphenylphosphine oxide ligands, etc., preferably having 3 to 30 carbon atoms, more preferably 8 to 30 carbon atoms, and particularly preferably 18 to 30 carbon atoms) Are preferred, and nitrogen-containing heterocyclic ligands are more preferred.
The complex may have one transition metal atom in the compound, or may be a so-called binuclear complex having two or more. Different metal atoms may be contained at the same time.

  Among these, as the luminescent dopant, for example, US6303238B1, US6097147, WO00 / 57676, WO00 / 70655, WO01 / 08230, WO01 / 39234A2, WO01 / 41512A1, WO02 / 02714A2, WO02 / 15645A1, WO02 / 44189A1, WO05 / 19373A2, JP-A No. 2001-247859, JP-A No. 2002-302671, JP-A No. 2002-117978, JP-A No. 2003-133074, JP-A No. 2002-233502, JP-A No. 2003-123982, JP-A No. 2002-170684, EP No. 121157, JP-A No. 2002-2002 226495, JP 2002-234894, JP 2001-247859, JP 2001-298470, JP 2002-1736 4, JP 2002-203678, JP 2002-203679, JP 2004-357799, JP 2006-256999, JP 2007-19462, JP 2007-84635, JP 2007-96259, etc. Examples include phosphorescent light emitting compounds. Among them, Ir complex, Pt complex, Cu complex, Re complex, W complex, Rh complex, Ru complex, Pd complex, Os complex, Eu complex, Tb complex, Gd complex, Dy complex, and Ce complex are preferable, and Ir complex, Pt More preferred are complexes and Re complexes. Among these, Ir complexes, Pt complexes, and Re complexes containing at least one coordination mode of metal-carbon bond, metal-nitrogen bond, metal-oxygen bond, and metal-sulfur bond are even more preferable. Furthermore, from the viewpoints of luminous efficiency, driving durability, chromaticity, etc., an Ir complex, a Pt complex, and a Re complex containing a tridentate or higher multidentate ligand are particularly preferable.

  The fluorescent light-emitting dopant is not particularly limited and may be appropriately selected depending on the intended purpose. , Pyran, perinone, oxadiazole, aldazine, pyralidine, cyclopentadiene, bisstyrylanthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, cyclopentadiene, styrylamine, aromatic dimethylidin compound, condensed polycyclic aromatic compound (anthracene, Phenanthroline, pyrene, perylene, rubrene, or pentacene), metal complexes of 8-quinolinol, various metal complexes represented by pyromethene complexes and rare earth complexes, polythio E down, polyphenylene, polyphenylene vinylene polymer compounds such as organosilanes, and derivatives thereof.

  Examples of the luminescent dopant include the following, but are not limited thereto.

  The light-emitting dopant in the organic light-emitting layer is contained in an amount of 0.1% by mass to 50% by mass with respect to the total compound mass generally forming the organic light-emitting layer in the organic light-emitting layer. From the viewpoint of efficiency, the content is preferably 1% by mass to 50% by mass, and more preferably 2% by mass to 40% by mass.

  Although the thickness of the organic light emitting layer is not particularly limited, it is usually preferably 2 nm to 500 nm, and more preferably 3 nm to 200 nm from the viewpoint of external quantum efficiency, among which 5 nm to 100 nm. Is particularly preferred.

  As the host material, a hole-transporting host material having excellent hole-transporting property (may be described as a hole-transporting host) and an electron-transporting host compound having excellent electron-transporting property (described as an electron-transporting host) May be used).

Examples of the hole transporting host in the organic light emitting layer include the following materials.
Pyrrole, indole, carbazole, azaindole, azacarbazole, triazole, oxazole, oxadiazole, pyrazole, imidazole, thiophene, polyarylalkane, pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, hydrazone , Stilbene, silazane, aromatic tertiary amine compound, styrylamine compound, aromatic dimethylidin compound, porphyrin compound, polysilane compound, poly (N-vinylcarbazole), aniline copolymer, thiophene oligomer, polythiophene, etc. Conductive polymer oligomers, organic silanes, carbon films, and derivatives thereof.
Indole derivatives, carbazole derivatives, aromatic tertiary amine compounds, and thiophene derivatives are preferable, those having a carbazole group in the molecule are more preferable, and compounds having a t-butyl-substituted carbazole group are particularly preferable.

  The electron transporting host in the organic light emitting layer preferably has an electron affinity Ea of 2.5 eV or more and 3.5 eV or less from the viewpoint of improving durability and lowering driving voltage, and is 2.6 eV or more and 3.4 eV or less. More preferably, it is 2.8 eV or more and 3.3 eV or less. Further, from the viewpoint of improving durability and reducing driving voltage, the ionization potential Ip is preferably 5.7 eV or more and 7.5 eV or less, more preferably 5.8 eV or more and 7.0 eV or less, and 5.9 eV or more. It is particularly preferable that it is 6.5 eV or less.

Specific examples of such an electron transporting host include the following materials.
Pyridine, pyrimidine, triazine, imidazole, pyrazole, triazole, oxazole, oxadiazol, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, Fluorine-substituted aromatic compounds, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanines, and derivatives thereof (may form condensed rings with other rings), metal complexes and metals of 8-quinolinol derivatives Examples include various metal complexes represented by metal complexes having phthalocyanine, benzoxazole or benzothiazol as a ligand.

As the electron transporting host, metal complexes, azole derivatives (benzimidazole derivatives, imidazopyridine derivatives, etc.) and azine derivatives (pyridine derivatives, pyrimidine derivatives, triazine derivatives, etc.) are preferable. Is more preferable. The metal complex compound (A) is more preferably a metal complex having a ligand having at least one of a nitrogen atom, an oxygen atom and a sulfur atom coordinated to the metal.
The metal ion in the metal complex is not particularly limited and can be appropriately selected depending on the purpose, but beryllium ion, magnesium ion, aluminum ion, gallium ion, zinc ion, indium ion, tin ion, platinum ion, or Palladium ions are preferable, beryllium ions, aluminum ions, gallium ions, zinc ions, platinum ions, or palladium ions are more preferable, and aluminum ions, zinc ions, or palladium ions are particularly preferable.

  There are various known ligands contained in the metal complex. For example, “Photochemistry and Photophysics of Coordination Compounds”, Springer-Verlag, H.C. Examples include the ligands described in Yersin, published in 1987, “Organometallic Chemistry: Fundamentals and Applications”, Sakai Hanafusa, Yamamoto Akio, published in 1982, and the like.

As said ligand, a nitrogen-containing heterocyclic ligand (C1-C30 is preferable, C2-C20 is more preferable, C3-C15 is especially preferable). Further, the ligand may be a monodentate ligand or a bidentate or more ligand, but is preferably a bidentate or more and a hexadentate or less ligand. Also preferred are bidentate to hexadentate ligands and monodentate mixed ligands.
Examples of the ligand include an azine ligand (for example, a pyridine ligand, a bipyridyl ligand, a terpyridine ligand, etc.), a hydroxyphenylazole ligand (for example, hydroxyphenylbenzimidazole). Ligands, hydroxyphenylbenzoxazole ligands, hydroxyphenylimidazole ligands, hydroxyphenylimidazopyridine ligands, etc.), alkoxy ligands (eg, methoxy, ethoxy, butoxy, 2-ethylhexyl). Siloxy etc. are mentioned, C1-C30 is preferable, C1-C20 is more preferable, C1-C10 is especially preferable.), An aryloxy ligand (for example, phenyloxy, 1-naphthyloxy, 2-naphthyloxy, 2,4,6-trimethylphenyloxy, 4- Such as phenyloxy and the like, 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms) and the like.

  Heteroaryloxy ligands (for example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc. are mentioned, preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms). Alkylthio ligands (for example, methylthio, ethylthio and the like are mentioned, preferably having 1 to 30 carbon atoms, more preferably having 1 to 20 carbon atoms, and particularly preferably having 1 to 12 carbon atoms), arylthio ligands (for example, Phenylthio etc. are mentioned, C6-C30 is preferable, C6-C20 is more preferable, C6-C12 is especially preferable,) heteroarylthio ligand (for example, pyridylthio, 2-benzimidazole). Ruthio, 2-benzoxazolylthio, 2-benzthiazolylthio and the like, and those having 1 to 30 carbon atoms More preferably, carbon number 1-20 is more preferable, and carbon number 1-12 is particularly preferable.), Siloxy ligand (for example, triphenylsiloxy group, triethoxysiloxy group, triisopropylsiloxy group, etc.) Numbers 1-30 are preferable, C3-25 are more preferable, C6-20 are particularly preferable, and aromatic hydrocarbon anion ligands (for example, phenyl anion, naphthyl anion, anthranyl anion, etc.) 6 to 30 carbon atoms, more preferably 6 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms), an aromatic heterocyclic anion ligand (for example, a pyrrole anion, a pyrazole anion, a pyrazole anion, Triazole anion, oxazole anion, benzoxazole anion, thiazole anion , Benzothiazole anion, thiophene anion, benzothiophene anion, etc., preferably having 1 to 30 carbon atoms, more preferably 2 to 25 carbon atoms, and particularly preferably 2 to 20 carbon atoms. And a nitrogen-containing heterocyclic ligand, an aryloxy ligand, a heteroaryloxy group, a siloxy ligand, and the like. A nitrogen-containing heterocyclic ligand, an aryloxy ligand, and a siloxy ligand are preferred. More preferred are ligands, aromatic hydrocarbon anion ligands, aromatic heterocyclic anion ligands and the like.

  Examples of the metal complex electron transporting host include, for example, JP-A-2002-2335076, JP-A-2004-214179, JP-A-2004-221106, JP-A-2004-221105, JP-A-2004-221068, JP-A-2004-327313, etc. And the compounds described.

  In the organic light emitting layer, the triplet lowest excitation level (T1) of the host material is preferably higher than T1 of the phosphorescent light emitting material in terms of color purity, light emission efficiency, and driving durability.

  In addition, the content of the host compound is not particularly limited, but from the viewpoint of light emission efficiency and driving voltage, it may be 2% by mass or more and 95% by mass or less based on the total compound mass forming the light emitting layer. preferable.

<<< Hole Injection Layer, Hole Transport Layer >>>
The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side. The hole injection material and the hole transport material used for these layers may be a low molecular compound or a high molecular compound.
Specifically, pyrrole derivatives, carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styryl Anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, phthalocyanine compounds, porphyrin compounds, thiophene derivatives, organosilane derivatives, carbon, And the like.

  An electron-accepting dopant can be contained in the hole injection layer or the hole transport layer of the organic EL element. As the electron-accepting dopant introduced into the hole-injecting layer or the hole-transporting layer, an inorganic compound or an organic compound can be used as long as it has an electron-accepting property and oxidizes an organic compound.

  Specifically, examples of the inorganic compound include metal halides such as ferric chloride, aluminum chloride, gallium chloride, indium chloride, and antimony pentachloride, metal oxides such as vanadium pentoxide, and molybdenum trioxide.

In the case of an organic compound, a compound having a nitro group, halogen, cyano group, trifluoromethyl group or the like as a substituent, a quinone compound, an acid anhydride compound, fullerene, or the like can be preferably used.
In addition, JP-A-6-212153, JP-A-11-111463, JP-A-11-251067, JP-A-2000-196140, JP-A-2000-286054, JP-A-2000-315580, JP-A-2001-102175, JP-A-2001-2001. -160493, JP2002-252085, JP2002-56985, JP2003-157981, JP2003-217862, JP2003-229278, JP2004-342614, JP2005-72012, JP20051666667 The compounds described in JP-A-2005-209643 and the like can be preferably used.

  Among these, hexacyanobutadiene, hexacyanobenzene, tetracyanoethylene, tetracyanoquinodimethane, tetrafluorotetracyanoquinodimethane, p-fluoranyl, p-chloranil, p-bromanyl, p-benzoquinone, 2,6-dichlorobenzoquinone, 2 , 5-dichlorobenzoquinone, 1,2,4,5-tetracyanobenzene, 1,4-dicyanotetrafluorobenzene, 2,3-dichloro-5,6-dicyanobenzoquinone, p-dinitrobenzene, m-dinitrobenzene, o-dinitrobenzene, 1,4-naphthoquinone, 2,3-dichloronaphthoquinone, 1,3-dinitronaphthalene, 1,5-dinitronaphthalene, 9,10-anthraquinone, 1,3,6,8-tetranitrocarbazole, 2,4,7-trinitro-9- Luenone, 2,3,5,6-tetracyanopyridine, or fullerene C60 is preferred, and hexacyanobutadiene, hexacyanobenzene, tetracyanoethylene, tetracyanoquinodimethane, tetrafluorotetracyanoquinodimethane, p-fluoranyl, p- Chloranil, p-bromanyl, 2,6-dichlorobenzoquinone, 2,5-dichlorobenzoquinone, 2,3-dichloronaphthoquinone, 1,2,4,5-tetracyanobenzene, 2,3-dichloro-5,6-dicyano Benzoquinone or 2,3,5,6-tetracyanopyridine is more preferred, and tetrafluorotetracyanoquinodimethane is particularly preferred.

  These electron-accepting dopants may be used alone or in combination of two or more. Although the usage-amount of an electron-accepting dopant changes with kinds of material, it is preferable that it is 0.01 mass%-50 mass% with respect to hole transport layer material, and it is 0.05 mass%-40 mass%. It is more preferable that the content is 0.1% by mass to 30% by mass.

The thicknesses of the hole injection layer and the hole transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the hole transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm. In addition, the thickness of the hole injection layer is preferably 0.1 nm to 200 nm, more preferably 0.5 nm to 100 nm, and further preferably 1 nm to 100 nm.
The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. .

<<< Electron injection layer, electron transport layer >>
The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. The electron injection material and the electron transport material used for these layers may be a low molecular compound or a high molecular compound.
Specifically, pyridine derivatives, quinoline derivatives, pyrimidine derivatives, pyrazine derivatives, phthalazine derivatives, phenanthroline derivatives, triazine derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone Derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene, perylene and other aromatic ring tetracarboxylic acid anhydrides, phthalocyanine derivatives, 8-quinolinol derivative metal complexes, Metal phthalocyanines, various metal complexes represented by metal complexes with benzoxazole and benzothiazole as ligands, organosilane derivatives represented by siloles Body, or the like is preferably a layer containing.

The electron injection layer or the electron transport layer of the organic EL device of the present invention can contain an electron donating dopant. The electron donating dopant introduced into the electron injecting layer or the electron transporting layer only needs to have an electron donating property and a property of reducing an organic compound, such as an alkali metal such as Li or an alkaline earth metal such as Mg. Transition metals including rare earth metals and reducing organic compounds are preferably used. As the metal, a metal having a work function of 4.2 eV or less can be preferably used. Specifically, Li, Na, K, Be, Mg, Ca, Sr, Ba, Y, Cs, La, Sm, Gd , And Yb. Examples of the reducing organic compound include nitrogen-containing compounds, sulfur-containing compounds, and phosphorus-containing compounds.
In addition, materials described in JP-A-6-212153, JP-A-2000-196140, JP-A-2003-68468, JP-A-2003-229278, JP-A-2004-342614, and the like can be used.

  These electron donating dopants may be used alone or in combination of two or more. The amount of the electron donating dopant varies depending on the type of material, but is preferably 0.1% by mass to 99% by mass, and 1.0% by mass to 80% by mass with respect to the electron transport layer material. Is more preferable, and 2.0 mass% to 70 mass% is particularly preferable.

The thicknesses of the electron injection layer and the electron transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the electron transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and particularly preferably 10 nm to 100 nm. Further, the thickness of the electron injection layer is preferably 0.1 nm to 200 nm, more preferably 0.2 nm to 100 nm, and particularly preferably 0.5 nm to 50 nm.
The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

<<< hole blocking layer >>>
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side. A hole blocking layer can be provided as an organic layer adjacent to the light emitting layer on the cathode side.
Examples of the compound constituting the hole blocking layer include aluminum complexes such as BAlq, triazole derivatives, phenanthroline derivatives such as BCP, and the like.
The thickness of the hole blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and particularly preferably 10 nm to 100 nm.
The hole blocking layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

<<< Electronic Block Layer >>>
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side. In the present invention, an electron blocking layer can be provided as an organic layer adjacent to the light emitting layer on the anode side.
As examples of the compound constituting the electron blocking layer, for example, those mentioned as the hole transport material described above can be applied.
The thickness of the electron blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and particularly preferably 10 nm to 100 nm.
The hole blocking layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

<< Drive >>
The organic EL element can obtain light emission by applying a direct current (which may include an alternating current component if necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. .
As for the driving method of the organic EL element, JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234658, and JP-A-8-214447, patents The driving methods described in Japanese Patent No. 2784615, US Pat. Nos. 5,828,429 and 6023308, and the like can be applied.

In order to further improve the light emission efficiency, the organic EL element can take a configuration in which a charge generation layer is provided between a plurality of light emitting layers.
The charge generation layer is a layer having a function of generating charges (holes and electrons) when an electric field is applied and a function of injecting the generated charges into a layer adjacent to the charge generation layer.

The material for forming the charge generation layer may be any material having the above functions, and may be formed of a single compound or a plurality of compounds.
Specifically, it may be a conductive material, a semiconductive material such as a doped organic layer, or an electrically insulating material. 11-329748, Unexamined-Japanese-Patent No. 2003-272860, and the material of Unexamined-Japanese-Patent No. 2004-39617 are mentioned.
More specifically, transparent conductive materials such as ITO and IZO (indium zinc oxide), fullerenes such as C60, conductive organic materials such as oligothiophene, metal phthalocyanines, metal-free phthalocyanines, metal porphyrins, Conductive organic materials such as metal porphyrins, metal materials such as Ca, Ag, Al, Mg: Ag alloy, Al: Li alloy, Mg: Li alloy, hole conductive materials, electron conductive materials, and mixtures thereof Can be mentioned.
The hole conductive material is, for example, a material obtained by doping a hole transporting organic material such as 2-TNATA or NPD with an oxidant having an electron withdrawing property such as F4-TCNQ, TCNQ, or FeCl _3. Examples thereof include conductive polymers, P-type semiconductors, etc. The electron conductive material is an electron transporting organic material doped with a metal or metal compound having a work function of less than 4.0 eV, an N-type conductive polymer, An N-type semiconductor is mentioned. Examples of the N-type semiconductor include N-type Si, N-type CdS, and N-type ZnS. Examples of the P-type semiconductor include P-type Si, P-type CdTe, and P-type CuO.
Further, an electrically insulating material such as V ₂ O ₅ can be used for the charge generation layer.

  The charge generation layer may be a single layer or a stack of a plurality of layers. A structure in which a plurality of layers are stacked includes a conductive material such as a transparent conductive material and a metal material and a hole conductive material, or a structure in which an electron conductive material is stacked, and the above hole conductive material and electron conductive And a layer having a structure in which a functional material is laminated.

In general, it is preferable to select a film thickness and a material for the charge generation layer so that the visible light transmittance is 50% or more. The film thickness is not particularly limited and can be appropriately selected according to the purpose, but is preferably 0.5 to 200 nm, more preferably 1 to 100 nm, further preferably 3 to 50 nm, and particularly preferably 5 to 30 nm. .
The method for forming the charge generation layer is not particularly limited, and the organic layer formation method described above can be used.

The charge generation layer is formed between the two or more light emitting layers. The charge generation layer may include a material having a function of injecting charges into adjacent layers on the anode side and the cathode side. In order to improve the electron injection property to the layer adjacent to the anode side, for example, an electron injection compound such as BaO, SrO, Li ₂ O, LiCl, LiF, MgF ₂ , MgO, and CaF _{2 is} added to the anode side of the charge generation layer. May be laminated.
In addition to the contents mentioned above, the material for the charge generation layer should be selected based on the descriptions in JP-A-2003-45676, US Pat. Nos. 6,337,492, 6,107,734, 6,872,472, and the like. Can do.

The organic EL element may have a resonator structure. For example, a multilayer mirror made of a plurality of laminated films having different refractive indexes, a transparent or translucent electrode, a light emitting layer, and a metal electrode are superimposed on a transparent substrate. The light generated in the light emitting layer resonates repeatedly with the multilayer mirror and the metal electrode as a reflection plate.
In another preferred embodiment, a transparent or translucent electrode and a metal electrode each function as a reflector on a transparent substrate, and light generated in the light emitting layer repeats reflection and resonates between them.
In order to form a resonant structure, the optical path length determined from the effective refractive index of the two reflectors and the refractive index and thickness of each layer between the reflectors is adjusted to an optimum value to obtain the desired resonant wavelength. Is done. The calculation formula in the case of the first aspect is described in JP-A-9-180883. The calculation formula in the case of the second aspect is described in Japanese Patent Application Laid-Open No. 2004-127795.

<Protective layer>
The protective layer is not particularly limited and may be appropriately selected depending on the purpose, as long as the protective layer can shield exposure light having a predetermined wavelength irradiated for forming a recess in a light extraction layer, which will be described later, by 40% or more. However, it is preferable to transmit 80% or more of light emitted from the organic layer.
The protective layer shields exposure light of a predetermined wavelength by 40% or more, preferably 50% or more, so that the light irradiated to form the recess in the light extraction layer passes through the protective layer, It is possible to prevent deterioration of the organic layer in the organic EL element.
There is no restriction | limiting in particular as said light shielding, According to the objective, it can select suitably, For example, absorption, reflection, etc. are mentioned.
Moreover, the light extraction efficiency can be further improved by allowing the protective layer to transmit 80% or more of light emitted from the organic layer.
Examples of the structure of the protective layer include a single layer structure of an inorganic material layer, a laminated structure of an inorganic material layer, a laminated structure of an inorganic material layer and an organic material layer, and a dielectric multilayer film structure.
There is no restriction | limiting in particular as said inorganic material layer, According to the objective, it can select suitably, For example, a SiON layer, a SiN layer, etc. are mentioned. Among these, the SiON layer is preferable in that it has a high resistance to a solvent (for example, TFP (tetrafluoropropanol) solvent) used when forming the light extraction layer described later. High resistance to the solvent used when forming the light extraction layer can prevent the organic layer in the organic EL element from dissolving when the light extraction layer is formed, thus preventing the organic layer from emitting light. can do.
There is no restriction | limiting in particular as said organic material layer, According to the objective, it can select suitably, For example, an Alq (aluminum quinolole) layer etc. are mentioned.
As the dielectric multilayer film is not particularly limited and may be appropriately selected depending on the purpose, for example, TiO ₃ film, a dielectric multi-layer film composed of SiO ₂ film or the like, and the like.
The thickness of the protective layer is not particularly limited and can be appropriately selected depending on the purpose.
0.7 μm to 20 μm is preferable, 1 μm to 10 μm is more preferable, and 1.5 μm to 7 μm is particularly preferable.
If the thickness of the protective layer is less than 0.7 μm, gas, moisture, etc. may enter the organic EL layer and damage the organic layer and the electrode. If the thickness exceeds 20 μm, external stress and heat shrinkage may occur. As a result, the protective layer may peel off.

  There is no restriction | limiting in particular as a formation method of the said protective layer, According to the objective, it can select suitably, For example, a vacuum evaporation method, sputtering method, reactive sputtering method, MBE (molecular beam epitaxy) method, cluster ion beam Examples thereof include an ion plating method, a plasma polymerization method (high frequency excitation ion plating method), a plasma CVD method, a laser CVD method, a thermal CVD method, a gas source CVD method, a coating method, a printing method, and a transfer method.

<Light extraction layer>
The light extraction layer is not particularly limited as long as it is a layer whose shape can be changed by irradiation with exposure light having a predetermined wavelength, and can be appropriately selected according to the purpose. For example, the light extraction layer can be formed by heat generated by light irradiation. Examples thereof include a light extraction layer (heat mode type light extraction layer) that can be changed to form a recess, and a light extraction layer that can be changed in shape by ultraviolet irradiation to form a recess.

  Moreover, there is no restriction | limiting in particular as a material of the said light extraction layer, According to the objective, it can select suitably, For example, the organic material, an inorganic material, the composite material of an inorganic material, and an organic material etc. are mentioned. Among these, organic materials are preferable in that film formation can be easily performed by spin coating and a material having a low transition temperature can be easily obtained. The organic material is preferably a dye whose light absorption can be controlled by molecular design. Specific examples of the material include cyanine-based, phthalocyanine-based, quinone-based, squarylium-based, azulenium-based, thiol complex-based, and merocyanine-based recording materials.

The light extraction layer preferably contains a dye.
The dye is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include methine dyes (cyanine dyes, hemicyanine dyes, styryl dyes, oxonol dyes, merocyanine dyes), macrocyclic dyes (phthalocyanine dyes, Naphthalocyanine dyes, porphyrin dyes, etc.), azo dyes (including azo metal chelate dyes), arylidene dyes, complex dyes, coumarin dyes, azole derivatives, triazine derivatives, 1-aminobutadiene derivatives, cinnamic acid derivatives, quinophthalone dyes, etc. Is mentioned.

  The light extraction layer can form a film by dissolving an organic recording material in a solvent by spin coating or spray coating, and can record information only once by laser light in terms of excellent productivity. A dye-type light extraction layer is preferred. Such a dye-type light extraction layer preferably contains a dye having absorption in the recording wavelength region. The extinction coefficient k indicating the light absorption amount of the dye is preferably 10 or less, more preferably 5 or less, particularly preferably 3 or less, and most preferably 1 or less. When the extinction coefficient k is too high, light does not reach from the light incident side to the opposite side of the light extraction layer, and uneven holes may be formed. Further, the extinction coefficient k is preferably 0.0001 or more, more preferably 0.001 or more, and particularly preferably 0.1 or more. If the extinction coefficient k is too low, the amount of light absorption decreases, so that a larger laser power is required, and the processing speed may be reduced.

The light extraction layer needs to absorb light at the wavelength of the irradiated light. From this viewpoint, the dye can be appropriately selected or the structure can be modified according to the wavelength of the laser light source. .
When the oscillation wavelength of the laser light source is around 780 nm, it is preferable to select from pentamethine cyanine dye, heptamethine oxonol dye, pentamethine oxonol dye, phthalocyanine dye, naphthalocyanine dye, and the like.
When the oscillation wavelength of the laser light source is around 660 nm, it is preferably selected from trimethine cyanine dye, pentamethine oxonol dye, azo dye, azo metal complex dye, pyromethene complex dye, and the like.
Further, when the oscillation wavelength of the laser light source is around 405 nm, monomethine cyanine dye, monomethine oxonol dye, zero methine merocyanine dye, phthalocyanine dye, azo dye, azo metal complex dye, porphyrin dye, arylidene dye, complex dye , A coumarin dye, an azole derivative, a triazine derivative, a benzotriazole derivative, a 1-aminobutadiene derivative, a quinophthalone dye, and the like.

  Hereinafter, examples of preferable compounds as the light extraction layer compound will be given for the case where the oscillation wavelength of the laser light source is around 780 nm, around 660 nm, and around 405 nm. Here, the following compounds (I-1 to I-10) are compounds when the oscillation wavelength of the laser light source is around 780 nm. Moreover, the following compounds (II-1 to II-8) are compounds in the case of around 660 nm. Furthermore, the following compounds (III-1 to III-14) are compounds in the case of around 405 nm.

<Example of light extraction layer compound when the oscillation wavelength of the laser light source is around 780 nm (1)>

<Example of light extraction layer compound when the oscillation wavelength of the laser light source is around 780 nm (part 2)>

<Example of light extraction layer compound when the oscillation wavelength of the laser light source is around 660 nm (part 1)>

<Example of light extraction layer compound when the oscillation wavelength of the laser light source is around 660 nm (part 2)>

<Example of light extraction layer compound when the oscillation wavelength of the laser light source is around 405 nm (part 1)>

<Example of light extraction layer compound when the oscillation wavelength of the laser light source is around 405 nm (part 2)>

  JP-A-4-74690, JP-A-8-127174, 11-53758, 11-334204, 11-334205, 11-334206, 11-334207 The dyes described in JP-A-2000-43423, JP-A-2000-108513, JP-A-2000-158818, and the like are also preferably used.

In such a dye-type light extraction layer, a dye is dissolved in a suitable solvent together with a binder or the like to prepare a coating solution, and then this coating solution is applied on the protective layer to form a coating film. Thereafter, it can be formed by drying. In that case, the temperature (surface temperature to be coated) on which the coating liquid is applied is preferably 10 to 40 ° C. The coated surface temperature is preferably 15 ° C. or higher, more preferably 20 ° C. or higher, and particularly preferably 23 ° C. or higher. Further, the coated surface temperature is preferably 35 ° C. or lower, more preferably 30 ° C. or lower, and particularly preferably 27 ° C. or lower.
When the surface temperature to be coated is 10 to 40 ° C., it is possible to prevent the occurrence of coating unevenness and coating failure and make the thickness of the coating film uniform.

The light extraction layer may be a single layer or a multilayer, and in the case of a multilayer structure, it is formed by performing the coating process a plurality of times.
The density | concentration of the pigment | dye in the said coating liquid is 0.01 mass%-15 mass%, 0.1 mass%-10 mass% are preferable, 0.5 mass%-5 mass% are more preferable, 0.5 A mass% to 3 mass% is particularly preferred.

The solvent for the coating solution is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include esters such as butyl acetate, ethyl lactate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; dichloromethane Chlorinated hydrocarbons such as 1,2-dichloroethane and chloroform; Amides such as dimethylformamide; Hydrocarbons such as methylcyclohexane; Ethers such as tetrahydrofuran, ethyl ether and dioxane; Ethanol, n-propanol, isopropanol, n-butanol di Alcohols such as acetone alcohol; fluorine-based solvents such as 2,2,3,3-tetrafluoropropanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol Glycol ethers such as monomethyl ether; and the like.
The said solvent can be used individually or in combination of 2 or more types, considering the solubility of the pigment | dye to be used. Various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be further added to the coating solution depending on the purpose.

The coating method for the coating solution is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, a doctor Examples thereof include a blade method and a screen printing method. Among them, the spin coating method is preferable in terms of excellent productivity and easy control of the film thickness.
The light extraction layer (light extraction layer compound) is preferably dissolved at 0.3 wt% or more and 30 wt% or less with respect to the organic solvent because the spin coating method is advantageous for formation. It is more preferable to dissolve by. In particular, it is preferable to dissolve in tetrafluoropropanol (TFP) at 1 wt% or more and 20 wt% or less. The light extraction layer compound preferably has a thermal decomposition temperature of 150 ° C. or higher and 500 ° C. or lower, more preferably 200 ° C. or higher and 400 ° C. or lower.
The coating temperature of the coating solution is preferably 23 ° C to 50 ° C, more preferably 24 ° C to 40 ° C, and particularly preferably 25 ° C to 30 ° C.

  The binder contained in the coating liquid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include natural organic polymer substances such as gelatin, cellulose derivatives, dextran, rosin and rubber; polyethylene, polypropylene , Hydrocarbon resins such as polystyrene and polyisobutylene, vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride / polyvinyl acetate copolymer, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, And synthetic organic polymers such as polyvinyl alcohol, chlorinated polyethylene, epoxy resins, butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins. The amount of the binder used is 0.01 to 50 times (mass ratio) with respect to the dye, and preferably 0.1 to 5 times (mass ratio).

The light extraction layer may contain an anti-fading agent in order to improve light resistance.
There is no restriction | limiting in particular as said fading prevention agent, According to the objective, it can select suitably, For example, a singlet oxygen quencher is mentioned. There is no restriction | limiting in particular as said singlet oxygen quencher, According to the objective, it can select suitably, The thing as described in publications, such as a well-known patent specification, is mentioned.
Specific examples of the publications include JP-A-58-175893, 59-81194, 60-18387, 60-19586, 60-19587, and 60-35054. Publication No. 60-36190 Publication No. 60-36191 Publication No. 60-44554 Publication No. 60-44555 Publication No. 60-44389 Publication No. 60-44390 Publication No. 60-54892 Publication No. 60-54892 Publication No. Japanese Laid-Open Patent Publication Nos. 60-47069, 63-209995, JP-A-4-25492, JP-B-1-38680, and JP-A-6-26028, and German Patent 350399 , Journal of Chemical Society of Japan, October 1992, page 1141, and the like. The amount of the anti-fading agent used is 0.1% by mass to 50% by mass, preferably 0.5% by mass to 45% by mass, and more preferably 3% by mass to 40% by mass with respect to the amount of the pigment. Preferably, 5% by mass to 25% by mass is particularly preferable.

  Although the solvent application method in the case where the light extraction layer is a dye-type recording layer has been described above, the light extraction layer can also be formed by a film formation method such as vapor deposition, sputtering, or CVD.

In addition, the pigment | dye has a higher light absorptivity in the wavelength of the laser beam used for the process of the recessed part mentioned later than other wavelengths. In particular, it is desirable that the light absorptance is higher at the wavelength of the laser beam during processing than the emission wavelength of the organic EL element.
The wavelength of the absorption peak of the dye is not necessarily limited to that in the visible light wavelength range, and may be in the ultraviolet range or the infrared range.

In particular, when the refractive index of the material constituting the light emitting surface of the organic EL element is high, the refractive index of the light extraction layer constituting the recess is preferably high.
The dye has a wavelength range with a high refractive index on the long wave side of the peak wavelength of the absorption wavelength, and it is preferable to match this wavelength range with the emission wavelength of the organic EL element. For this purpose, the dye absorption wavelength λa is preferably shorter than the center wavelength λc of the organic EL element (λa <λc). The difference between λa and λc is preferably 10 nm or more, more preferably 25 nm or more, and particularly preferably 50 nm or more. This is because if the difference between λa and λc is too small, the absorption wavelength range of the dye is applied to the center wavelength λc of the organic EL element, and light is absorbed. The difference between λa and λc is preferably 500 nm or less, more preferably 300 nm or less, and particularly preferably 200 nm or less. This is because if the difference between λa and λc is too large, the refractive index for the light of the organic EL element becomes small.

The wavelength λw for recording the concave portion with the laser is preferably in a relationship of λa <λw. With such a relationship, the light absorption amount of the dye is appropriate, the recording efficiency is increased, and a clean uneven shape can be formed. Further, it is preferable that λw <λc. Since λw should be the wavelength that the dye absorbs, the light emitted from the light-emitting element is not absorbed by the dye and the transmittance is improved by having the center wavelength λc of the light-emitting element on the longer wavelength side than the wavelength of λw. As a result, the light extraction efficiency can be improved.
From the above viewpoint, it can be said that the relationship of λa <λw <λc is most preferable.

  The wavelength λw of the laser light for forming the concave portion is not particularly limited as long as it is a wavelength that can provide a large laser power, and can be appropriately selected according to the purpose. For example, a dye in the light extraction layer In the case of using, a wavelength of 1,000 nm or less such as 193 nm, 210 nm, 266 nm, 365 nm, 405 nm, 488 nm, 532 nm, 633 nm, 650 nm, 680 nm, 780 nm, and 830 nm can be mentioned.

  Moreover, there is no restriction | limiting in particular as a kind of laser beam, According to the objective, it can select suitably, For example, a gas laser, a solid state laser, a semiconductor laser etc. are mentioned. Among these, a solid laser and a semiconductor laser are preferable from the viewpoint of simplifying the optical system. The laser light may be continuous light or pulsed light, but laser light whose emission interval can be freely changed, for example, a semiconductor laser is preferable. If the laser cannot be directly on-off modulated, it may be modulated by an external modulation element.

  The laser power is preferably higher from the viewpoint of processing speed. However, as the laser power is increased, the scanning speed (the speed at which the light extraction layer is scanned with laser light; for example, the rotational speed of the optical disk drive described later) must be increased. Therefore, from the viewpoint of scanning speed, the laser power is preferably 100 W or less, more preferably 10 W or less, particularly preferably 5 W or less, and most preferably 1 W. The laser power is preferably 0.1 mW or more, more preferably 0.5 mW or more, and particularly preferably 1 mW or more.

  Further, the laser light is preferably light that has excellent transmission wavelength width and coherency, and can be narrowed down to a spot size comparable to the wavelength. Further, it is preferable to adopt a strategy as used in an optical disc as a recording strategy (light pulse irradiation conditions for properly forming the recesses). That is, it is preferable to adopt conditions such as recording speed, the peak value of the laser beam to be irradiated, and the pulse width as used in an optical disc.

It is preferable that the thickness of the light extraction layer corresponds to the depth of the recess described later.
There is no restriction | limiting in particular as thickness of the said light extraction layer, According to the objective, it can select suitably, For example, they are 1 nm-10,000 nm. The thickness of the light extraction layer is preferably 10 nm or more, and more preferably 30 nm or more. This is because, if the light extraction layer is too thin, the concave portion is formed shallow, and the optical effect cannot be obtained. In addition, the thickness of the light extraction layer is preferably 1,000 nm or less, and more preferably 500 nm or less. This is because if the thickness of the light extraction layer is too large, a large laser power is required, and it becomes difficult to form a deep hole, and further, the processing speed decreases.

  The thickness t of the light extraction layer and the diameter d of the recess are preferably in the following relationship. That is, the thickness t of the light extraction layer is preferably a value satisfying t <10d, more preferably a value satisfying t <5d, and particularly preferably a value satisfying t <3d. The thickness t of the light extraction layer is preferably a value satisfying t> d / 100, more preferably a value satisfying t> d / 10, and particularly preferably a value satisfying t> d / 5.

  When forming the light extraction layer, prepare a coating solution by dissolving or dispersing the substance to be the recording material in an appropriate solvent, and then apply this coating solution by a coating method such as spin coating, dip coating, or extrusion coating. It can be formed by coating.

The barrier layer is formed and optionally provided to prevent the light extraction layer from impact or the like. The material of the barrier layer is not particularly limited as long as it is a transparent material, and can be appropriately selected according to the purpose. However, polycarbonate, cellulose triacetate, etc. are preferable, and moisture absorption at 23 ° C. and 50% RH is preferable. A material having a rate of 5% or less is more preferable. In addition, as the material of the barrier layer, oxides such as SiO ₂ , ZnS, and GaO, and sulfides can be used.
“Transparent” means that the light emitted from the organic EL element is so transparent that the light is transmitted (transmittance: 80% or more).

For example, the barrier layer is prepared by dissolving a photocurable resin constituting the adhesive layer in an appropriate solvent to prepare a coating solution, and then coating the coating solution on the light extraction layer at a predetermined temperature to form a coating film. For example, a cellulose triacetate film (TAC film) obtained by, for example, plastic extrusion is laminated on the coating film, and light is irradiated from above the laminated TAC film to cure the coating film. The The TAC film preferably contains an ultraviolet absorber.
There is no restriction | limiting in particular as thickness of the said barrier layer, According to the objective, it can select suitably, It is 0.01 mm-0.2 mm, 0.03 mm-0.1 mm are preferable, 0.05 mm-0 0.095 mm is more preferable.

  A plurality of concave portions are periodically formed in the light extraction layer and the barrier layer. The concave portion is formed by irradiating light condensed on the light extraction layer and the barrier layer to deform the irradiated portion (including deformation due to disappearance).

The principle of forming the recess is as follows.
When the light extraction layer (light extraction layer compound) is irradiated with laser light having a wavelength at which the material absorbs light (wavelength absorbed by the material), the laser light is absorbed by the light extraction layer, and the absorbed light is heated. And the temperature of the light irradiated part rises. As a result, the light extraction layer undergoes chemical and / or physical changes such as softening, liquefaction, vaporization, sublimation, and decomposition. And the recessed part is formed because the material which caused such a change moves and / or lose | disappears. Since the barrier layer is a very thin layer, it moves and / or disappears together with the movement and / or disappearance of the light extraction layer.

  In addition, as a formation method of a recessed part, the formation method of a pit known for a write-once optical disk, a write-once optical disk etc. is applicable, for example. Specifically, for example, by detecting the intensity of the reflected light of the laser that changes depending on the pit size, and correcting the output of the laser so that the intensity of the reflected light is constant, a uniform pit is formed. A known running OPC technique (for example, Japanese Patent No. 3096239) can be applied.

  Further, the vaporization, sublimation or decomposition of the light extraction layer (light extraction layer compound) is preferably a steep and rapid change rate. The weight reduction rate by differential thermal balance (TG-DTA) during vaporization, sublimation or decomposition of the light extraction layer compound is preferably 5% or more, more preferably 10% or more, and particularly preferably 20% or more. The slope of weight reduction (weight reduction rate per 1 ° C. temperature increase) by differential thermal balance (TG-DTA) during vaporization, sublimation or decomposition of the light extraction layer compound is preferably 0.1% / ° C. or more, 0.2% / ° C or more is more preferable, and 0.4% / ° C or more is particularly preferable.

  In addition, the transition temperature of chemical and / or physical changes such as softening, liquefaction, vaporization, sublimation, and decomposition is preferably 2,000 ° C. or less, more preferably 1,000 ° C. or less, and particularly preferably 500 ° C. or less. If the transition temperature is too high, a large laser power may be required. The transition temperature is preferably 50 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 150 ° C. or higher. If the transition temperature is too low, the temperature gradient with respect to the surroundings is small, so that it may not be possible to form a clear hole edge shape.

  FIG. 1A is a plan view of an example of the light extraction layer in the organic EL device of the present invention, FIG. 1B is a plan view of another example of the light extraction layer in the organic EL device of the present invention, and FIG. It is a figure explaining the relationship between the diameter of a recessed part and the pitch in the organic electroluminescent apparatus of this invention, FIG. 2B is a figure explaining the relationship between the light emission time of a laser beam, and a period. As shown to FIG. 1A, the recessed part 16 is formed in a dot shape, What can arrange | position this dot in the grid | lattice form is employable. Moreover, as shown to FIG. 1B, the recessed part 16 may be formed in the shape of an elongate groove | channel, and this may connect intermittently. Further, although not shown, it can be formed as a continuous groove shape.

  The pitch P between the adjacent recesses 16 is 0.01 to 100 times the center wavelength λc of the light emitted by the organic EL element that is a light emitter.

  The pitch P of the recesses 16 is preferably 0.05 to 20 times the center wavelength λc, more preferably 0.1 to 5 times, and particularly preferably 0.5 to 2 times. More specifically, the pitch P is preferably 0.01 times or more of the center wavelength λc, more preferably 0.05 times or more, particularly preferably 0.1 times or more, and most preferably 0.2 times or more. Further, the pitch P is preferably 100 times or less, more preferably 50 times or less, particularly preferably 10 times or less, and most preferably 5 times or less the center wavelength λc.

  The diameter of the recess 16 or the width of the groove is 0.005 to 25 times the center wavelength λc, preferably 0.025 to 10 times, more preferably 0.05 to 2.5 times, and 0.25. Double to 2 times is particularly preferable. Here, the diameter or the width of the groove is a size at a half depth of the concave portion 16, that is, a so-called half-value width.

  The diameter of the recess 16 or the width of the groove can be appropriately set within the above range, but depending on the size of the pitch P so that the refractive index gradually decreases macroscopically as the distance from the organic EL element increases. It is desirable to adjust. That is, when the pitch P is large, the diameter of the concave portion 16 or the width of the groove is preferably increased, and when the pitch P is small, the diameter of the concave portion 16 or the width of the groove is preferably small. From this viewpoint, the diameter or the width of the groove is, for example, preferably 20% to 80% of the pitch P, more preferably 30% to 70%, and particularly preferably 40% to 60%. The size should be about 1 / minute.

  The depth of the recess 16 is preferably 0.01 to 20 times the center wavelength λc, more preferably 0.05 to 10 times, particularly preferably 0.1 to 5 times, and 0.2 to 2 times. Is most preferred.

The process of forming the light extraction layer and the recess in the method for manufacturing the organic EL device having the above configuration will be described.
3A to 3C are diagrams illustrating an example of a light extraction layer and a recess forming step in the method for manufacturing an organic EL device of the present invention.
As shown in FIG. 3A, first, a light emitting unit 21 that is a main body of an organic EL element 20 manufactured by a conventionally known method is prepared.
Then, as shown in FIG. 3B, the protective layer 14, the light extraction layer 15, and the barrier layer 15 a are formed in this order on the light emitting unit 21.

Next, the recess 16 is formed. The apparatus for forming the recess 16 can use the same configuration as that of a conventionally known optical disc drive. A configuration of such an optical disk drive is described in, for example, Japanese Patent Application Laid-Open No. 2003-203348. Using such an optical disk drive, a silicon wafer on which organic EL elements are formed in a matrix is formed in the same shape as the optical disk, or is attached to a dummy optical disk or the like and loaded into the disk drive. Then, according to the material of the light extraction layer 15, the light extraction layer 15 is irradiated with laser light with an output suitable for deforming the light extraction layer 15. Furthermore, a pulse signal or a continuous signal may be input to the laser light source so that this irradiation pattern matches the dot or groove pattern illustrated in FIGS. 1A and 1B. As shown in FIG. 2B, the duty ratio (light emission time τ / period T) of the laser light emitted at a predetermined period T is equal to the duty ratio of the recess 16 actually formed (the recess 16 in the laser beam scanning direction). Length d / pitch P; see FIG. 2A). Here, the laser beam shown in a circle in FIG. 2A contributes to the formation of the elliptical recess 16 by moving at a predetermined speed during the emission time τ. For example, when the length d of the concave portion 16 is 50 when the pitch P of the concave portion 16 is 100, the laser light is irradiated at a duty ratio lower than 50%. That's fine. In this case, the duty ratio of the laser beam is preferably less than 50%, more preferably less than 40%, and particularly preferably less than 35%. Further, the duty ratio of the laser beam is preferably 1% or more, more preferably 5% or more, and particularly preferably 10% or more. As described above, by setting the duty ratio, it is possible to accurately form the recesses 16 having a specified pitch.
Further, by using the same focusing technique as that of the optical disk drive, for example, the astigmatism method, even if the light emitting unit 21 is waved or warped, it can be easily condensed on the surface of the light emitting unit 21. is there.

  In this way, as shown in FIG. 3C, the laser light is condensed and irradiated by the optical system 30 of the disk drive from the light extraction layer 15 side. As in the case of recording information on the optical recording disk, the concave portion 16 can be formed in the entire light extraction layer 15 by moving the optical system 30 in the radial direction while rotating the light emitting portion 21.

The processing conditions for manufacturing the recess 16 are as follows.
The numerical aperture NA of the optical system 30 is preferably 0.4 or more, more preferably 0.5 or more, and particularly preferably 0.6 or more. The numerical aperture NA is preferably 2 or less, more preferably 1 or less, and particularly preferably 0.9 or less. If the numerical aperture NA is too small, fine processing cannot be performed, and if the numerical aperture NA is too large, the margin for the angle during recording is reduced.

  The wavelength of the optical system 30 is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include 405 ± 30 nm, 532 ± 30 nm, 650 ± 30 nm, and 780 ± 30 nm. These wavelengths make it easy to obtain a large output. A shorter wavelength is preferable because fine processing can be performed.

  The output of the optical system 30 is 0.1 mW or more, preferably 1 mW or more, more preferably 5 mW or more, and particularly preferably 20 mW or more. The output of the optical system 30 is 1000 mW or less, preferably 500 mW or less, and more preferably 200 mW or less. This is because if the output of the optical system 30 is too low, processing takes time, and if the output of the optical system 30 is too high, the durability of the members constituting the optical system 30 is reduced.

  The linear velocity for moving the optical system 30 relative to the light extraction layer 15 is 0.1 m / s or more, preferably 1 m / s or more, more preferably 5 m / s or more, and particularly preferably 20 m / s or more. . The linear velocity is 500 m / s or less, preferably 200 m / s or less, more preferably 100 m / s or less, and particularly preferably 50 m / s or less. If the line speed is too high, it is difficult to increase the machining accuracy. If the line speed is too slow, it takes a long time to process, and it cannot be processed into a good shape.

  As a specific optical processing machine including the optical system 30, for example, NE0500 manufactured by Pulstec Industrial Co., Ltd. may be mentioned.

<Other members>
There is no restriction | limiting in particular as said other member, According to the objective, it can select suitably, For example, a board | substrate etc. are mentioned.

<< Board >>
There is no restriction | limiting in particular as said board | substrate, Although it can select suitably according to the objective, It is preferable that it is a board | substrate which does not scatter or attenuate the light emission from an organic layer. Specific examples include yttria-stabilized zirconia (YSZ), inorganic materials such as glass, polyesters such as polyethylene terephthalate, polybutylene phthalate, and polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, and polycycloolefin. , Norbornene resins, and organic materials such as poly (chlorotrifluoroethylene).
For example, when glass is used as the substrate, alkali-free glass is preferably used as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. In the case of an organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, and workability.

  There is no restriction | limiting in particular about the shape of a board | substrate, a structure, a magnitude | size, It can select suitably according to the use, purpose, etc. of a light emitting element. In general, the shape of the substrate is preferably a plate shape. The structure of the substrate may be a single layer structure, a laminated structure, may be formed of a single member, or may be formed of two or more members.

  The substrate may be colorless and transparent or colored and transparent, but is preferably colorless and transparent in that it does not scatter or attenuate light emitted from the organic light emitting layer.

The substrate can be provided with a moisture permeation preventing layer (gas barrier layer) on the front surface or the back surface.
As a material for the moisture permeation preventive layer (gas barrier layer), inorganic materials such as silicon nitride and silicon oxide are preferably used. The moisture permeation preventing layer (gas barrier layer) can be formed by, for example, a high frequency sputtering method.
When a thermoplastic substrate is used, a hard coat layer, an undercoat layer, or the like may be further provided as necessary.

(Method for manufacturing organic EL device)
The method for producing an organic EL device of the present invention includes at least an organic EL element forming step, a protective layer forming step, a light extraction layer forming step, and a recess forming step, and further includes other steps as appropriate. Including.

<Organic EL element formation process>
The organic EL element forming step is a step of forming an organic EL element having a pair of electrodes and an organic layer disposed between the pair of electrodes.

<Protective layer forming step>
The protective layer forming step is a step of forming on the organic EL element a protective layer that shields 40% or more of exposure light having a predetermined wavelength irradiated in a concave portion forming step described later.

<Light extraction layer forming process>
The light extraction layer forming step is a step of forming a light extraction layer for extracting light emitted from the organic layer on the protective layer.

<Recess formation process>
The recess forming step is a step of forming a plurality of recesses by irradiating the light extraction layer with exposure light having the predetermined wavelength.

<Other processes>
There is no restriction | limiting in particular as said other process, According to the objective, it can select suitably.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
Hereinafter, the manufacturing process of the organic EL device 100 in FIG. 4 will be described in detail.
First, an Al film having a thickness of 100 nm constituting the anode 12 was formed on a glass substrate 11 subjected to ultrasonic cleaning using a W filament.
Next, on the anode 12, using a boat made of Ta and a boat made of Mo, 2-TNATA (4,4 ′, 4 ″ -tris (2-naphthylphenylamino) triphenylamine) and MoO ₃ were The first hole injection layer was formed by co-evaporation by a vacuum deposition method so that the doping concentration of MoO ₃ was 30% by mass and the thickness was 20 nm.
Next, using a boat made of Ta, 2-TNATA was deposited to a thickness of 150 nm to form a second hole injection layer.
Next, using a boat made of Ta, NPD (N, N′-dinaphthyl-N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine) has a thickness of 10 nm. In this way, a first hole transport layer was formed.
Next, using a boat made of Ta, CBP (hole transporting host), Ir (ppy) 3
(Tris (2-phenylpyridine) iridium (III)) was co-deposited by vacuum deposition so that the doping concentration of Ir (ppy) 3 was 10% by mass and the thickness was 30 nm, and the light emitting layer Formed.
Next, using a boat made of Ta, BAlq (bis (2-methyl-8-quinolinolato) (p-phenyl-phenolato) aluminum) is formed to a thickness of 40 nm to form a hole blocking layer. Formed.
Next, using a boat made of Mo, LiF is deposited by vacuum vapor deposition so that the thickness is 1 nm, and W is used so that the thickness of Al is 1.5 nm. Then, an electron injection layer was formed by vacuum deposition.
The first hole injection layer, the second hole injection layer, the first hole transport layer, the light emitting layer, the hole blocking layer, and the electron injection layer constitute the organic layer 10.
Next, using a boat made of Mo, a film of Ag was formed to a thickness of 20 nm to form the cathode 13 to produce the organic EL element 20.

Next, SiON was deposited by an ion plating method to form a protective layer 14 having a thickness of 5 μm.
Further, the light extraction layer 15 having a thickness of 100 nm was formed on the protective layer (SiON layer) 14, and then the recesses 16 having a 1 μm pitch P were processed by a laser beam having a wavelength of 405 nm, whereby the organic EL device 100 was produced. .

In addition, the formation method of the light extraction layer 15 is as follows.
2 g of a dye material having the following chemical formula was dissolved in 100 mL of a tetrafluoropropanol (TFP) solvent and spin-coated. At the time of spin coating, the coating liquid was dispensed on the inner periphery of the protective layer (SiON layer) 14 at a coating start rotation speed of 500 rpm and a coating end rotation speed of 1,000 rpm, and the rotation was gradually increased to 2,200 rpm. . The refractive index n of the dye material was 1.986, and the extinction coefficient k was 0.0418.

Moreover, the formation conditions of the recessed part 16 are as follows.
Equipment used: NE0500 manufactured by Pulstec Industrial Co., Ltd. (wavelength 405 nm, NA 0.65)
Laser power: 2mW
Line speed: 5m / s
Recording signal: 5 MHz rectangular wave

  Separately, a SiON film having a thickness of 5 μm was produced by an ion plating method, and the light transmittance of the produced SiON film was measured using a spectrophotometer (manufactured by Hitachi, Ltd.). The results are shown in FIG.

As shown in FIG. 8, the organic EL device 100 is configured so that the protective layer (SiON layer) 14 is exposed using NE0500 manufactured by Pulstec Industrial Co., Ltd. when the recess 16 is formed in the light extraction layer 15. 405 nm) is absorbed by about 40%, so that damage to the organic layer 10 in the organic EL element 20 is suppressed. Further, since the SiON layer as the protective layer 14 is resistant to the TFP (tetrafluoropropanol) solvent used when forming the light extraction layer 15, the organic EL element 20 is protected from the TFP (tetrafluoropropanol) solvent. can do.
Further, the protective layer 14 was able to transmit light having a wavelength of 520 nm by 80% or more and efficiently extract light emitted from the organic layer 10. The light extraction efficiency of the organic EL device 100 of Example 1 was 1.2 times the light extraction efficiency of the organic EL device in which the light extraction layer 15 was not provided.

(Example 2)
In Example 1, instead of forming the protective layer 14 by depositing SiON to a thickness of 5 μm by the ion plating method, SiN and SiON are deposited by the CVD method to form the SiN layer 14a (1 μm) / A protective layer 14 composed of a SiON layer 14b (4 μm) / SiN layer 14c (1 μm) is formed (FIG. 5), and only the light extraction layer 15 having a thickness of 100 nm is formed on the protective layer 14 in Example 1. Instead, an organic EL device 200 was produced in the same manner as in Example 1 except that a light extraction layer 15 having a thickness of 100 nm and a barrier layer (not shown) were formed on the protective layer 14.

Note that a thin film of ZnO—Ga ₂ O ₃ (ZnO 95 wt%, Ga ₂ O ₃ 5 wt%) was formed as a barrier layer by DC magnetron sputtering. The formation conditions are as follows.
Thickness about 5nm
Output 1kW
Film formation time 2 seconds atmosphere Ar (flow rate 50 sccm)

  Separately, a film composed of SiN layer (1 μm) / SiON layer (4 μm) / SiN layer (1 μm) was produced by the CVD method, and the produced film was subjected to light emission using a spectrophotometer (manufactured by Hitachi, Ltd.). The transmittance was measured. The results are shown in FIG.

As shown in FIG. 9, the organic EL device 200 uses NE0500 manufactured by Pulstec Industrial Co., Ltd. when the protective layer (SiN layer / SiON layer / SiN layer) 14 forms the recess 16 in the light extraction layer 15. Since about 45% of leakage of irradiated exposure light (405 nm) is absorbed, damage to the organic layer 10 in the organic EL element 20 is suppressed. Further, since the SiON layer is resistant to the TFP (tetrafluoropropanol) solvent used when the light extraction layer 15 is formed, the organic EL element 20 can be protected from the TFP (tetrafluoropropanol) solvent.
Further, the protective layer 14 transmits 80% or more of light having a wavelength of 520 nm, and can efficiently extract light emitted from the organic layer 10. The light extraction efficiency of the organic EL device 200 of Example 2 was 1.2 times the light extraction efficiency of the organic EL device 200 in which the light extraction layer 15 was not provided.

(Example 3)
In Example 1, instead of forming the protective layer 14 by depositing SiON to a thickness of 5 μm by the ion plating method, Alq (aluminum quinolole) is applied to the ion plating method to a thickness of 0.2 μm. Then, a protective layer 14 composed of an Alq layer 14d (0.2 μm) / SiON layer 14e (2 μm) was formed by ion plating to a thickness of 2 μm (FIG. 6). Except for this, the organic EL device 300 was produced in the same manner as in Example 1.

  Separately, a film composed of an Alq layer (0.2 μm) / SiON layer (2 μm) was produced by an ion plating method, and the produced film was subjected to light transmittance using a spectrophotometer (manufactured by Hitachi, Ltd.). Was measured. The results are shown in FIG.

As shown in FIG. 10, the organic EL device 300 has an exposure that the protective layer (Alq layer / SiON layer) 14 is irradiated with NE0500 manufactured by Pulstec Industrial Co., Ltd. when the recess 16 is formed in the light extraction layer 15. Since about 65% of light (405 nm) leakage is absorbed, damage to the organic layer 10 in the organic EL element 20 is suppressed. Further, since the SiON layer is resistant to the TFP (tetrafluoropropanol) solvent used when the light extraction layer 15 is formed, the organic EL element 20 can be protected from the TFP (tetrafluoropropanol) solvent.
Further, the protective layer 14 transmits 80% or more of light having a wavelength of 520 nm, and can efficiently extract light emitted from the organic layer 10. The light extraction efficiency of the organic EL device 300 of Example 3 was 1.2 times the light extraction efficiency of the organic EL device 300 in which the light extraction layer 15 was not provided.

Example 4
In Example 1, instead of forming the protective layer 14 by depositing SiON to a thickness of 5 μm by the ion plating method, TiO ₃ (titanium oxide, n = 2.3) and SiO ₂ (silicon oxide, n = 1.46) was formed by sputtering, and a dielectric multilayer film (TiO ₃ layer 14 f (45 nm) / SiO ₂ layer 14 g (90 nm) / TiO ₃ layer 14 h (90 nm) / SiO ₂ layer 14 i (90 nm) ) / TiO ₃ layer 14j (90 nm) / SiO ₂ layer 14k (90 nm) / TiO ₃ layer 14l (90 nm) / SiO ₂ layer 14m (90 nm) / TiO ₃ layer 14n (90 nm) / SiO ₂ layer 14o (90 nm) / TiO ₃ layer 14p (90nm) / SiO ₂ layer 14q (90 nm) / TiO ₃ layer 14r (90nm) / SiO ₂ layer 14s (90 nm) / TiO ₃ layer 14t 90 nm) / non-SiO ₂ layer 14u (90 nm) / TiO ₃ layer 14v (45 nm)) to form a protective layer 14 made of the high-pass filter (FIG. 7), the same procedure as in Example 1, the organic EL device 400 Produced.

  Separately, a dielectric multilayer film was produced by the sputtering method in the same manner as described above, and the light transmittance of the produced dielectric multilayer film was measured using a spectrophotometer (manufactured by Hitachi, Ltd.). The results are shown in FIG.

As shown in FIG. 11, in the organic EL device 400, the protective layer 14 leaks exposure light (405 nm) irradiated using NE0500 manufactured by Pulstec Industrial Co., Ltd. when the recess 16 is formed in the light extraction layer 15. Since it reflects about 90%, damage to the organic layer 10 in the organic EL element 20 is suppressed.
Moreover, the protective layer 14 transmits 90% or more of light having a wavelength of 520 nm, and can efficiently emit light emitted from the organic layer 10. The light extraction efficiency of the organic EL device 400 of Example 4 was 1.2 times the light extraction efficiency of the organic EL device in which the light extraction layer 15 was not provided.

(Comparative Example 1)
In Example 1, instead of forming the protective layer 14 by depositing SiON to a thickness of 5 μm by the ion plating method, the protective layer is formed by depositing SiON to a thickness of 1 μm by the ion plating method. An organic EL device 900 was produced in the same manner as in Example 1 except that (not shown) was formed (FIG. 12). In this case, since the exposure light (405 nm) irradiated using NE0500 manufactured by Pulstec Industrial Co., Ltd. when forming the recess 16 in the light extraction layer 15 is transmitted through the protective layer (not shown) by 85% or more, the organic EL The organic layer 10 in the element 20 was deteriorated, and the luminous efficiency was reduced by about 20% as compared with the organic layer in the organic EL element that was not irradiated with exposure light (405 nm).

  Since the organic EL device of the present invention can improve the light extraction efficiency and prevent the organic layer in the organic EL element from deteriorating, for example, a display element, a display, a backlight, an electrophotography, an illumination light source It is suitably used for recording light sources, exposure light sources, reading light sources, signs, signboards, interiors, optical communications, and the like.

DESCRIPTION OF SYMBOLS 10 Organic layer 11 Glass substrate 12 Anode 13 Cathode 14 Protective layer 15 Light extraction layer 15a Barrier layer 16 Recess 20 Organic EL element 21 Light emitting part 30 Optical system 100 Organic EL device 200 Organic EL device 300 Organic EL device 400 Organic EL device 400 Organic EL device

Claims (8)

Forming an organic EL element having a pair of electrodes and an organic layer disposed between the pair of electrodes;
Forming a protective layer that shields exposure light of a predetermined wavelength by 40% or more on the organic EL element;
Forming a light extraction layer for extracting light emitted from the organic layer on the protective layer;
And a step of forming a plurality of recesses by irradiating the light extraction layer with exposure light having the predetermined wavelength.   The method for producing an organic EL device according to claim 1, wherein the protective layer transmits 80% or more of light emitted from the organic layer. An organic EL element having a pair of electrodes and an organic layer disposed between the pair of electrodes;
A protective layer that is disposed on the organic EL element and shields exposure light of a predetermined wavelength by 40% or more;
An organic EL device comprising: a light extraction layer disposed on the protective layer and capable of changing shape by irradiation with exposure light having the predetermined wavelength, for extracting light emitted from the organic layer.   The organic EL device according to claim 3, wherein the protective layer transmits 80% or more of light emitted from the organic layer.   The organic EL device according to claim 3, wherein the protective layer has an inorganic material layer.   The organic EL device according to claim 5, wherein the inorganic material layer is at least one of a SiON layer and a SiN layer.   The organic EL device according to claim 5, wherein the protective layer further includes an organic material layer. The organic EL device according to claim 3, wherein the protective layer is a dielectric multilayer film.