JP5790651B2 - Transparent conductor, organic EL element, and organic photoelectric conversion element - Google Patents

Description

  The present invention relates to a transparent conductor used for organic electronic elements such as organic electroluminescence elements (hereinafter referred to as organic EL elements) and organic solar cells, and in particular, a transparent conductor having a transparent conductive layer provided on a transparent support. The present invention relates to a transparent conductor that can improve device performance such as driving voltage, efficiency, and lifetime of an organic electronic device.

  In recent years, organic electronic elements such as organic EL elements and organic solar cells have attracted attention. In such elements, a transparent conductor in which a transparent conductive layer is provided on a transparent support is an essential constituent technology.

  Conventionally, a transparent conductor is an ITO transparent conductive support obtained by forming a composite oxide (ITO) film of indium-tin on a transparent substrate such as glass or a transparent plastic film by a vacuum deposition method or a sputtering method. It has been mainly used from the viewpoint of performance such as conductivity and transparency. However, transparent conductors using a vacuum deposition method or a sputtering method have problems in that the productivity is low and the manufacturing cost is high, and the flexibility is inferior, so that the transparent conductor cannot be applied to element applications requiring flexibility. .

  On the other hand, a method of forming a transparent conductive layer by coating or printing using a coating solution in which a conductive polymer is dissolved or dispersed in a suitable solvent has been proposed (for example, see Patent Document 1). However, when compared with a metal oxide transparent conductive support such as ITO formed by a vacuum film forming method, there is a problem that both transparency and conductivity are remarkably lowered. Furthermore, when an organic electronic device such as an organic EL device is formed using this, in addition to the low conductivity of the transparent conductor itself, a behavior that is considered to have high interface resistance with the functional layer provided on the transparent conductor ( For example, in an organic EL element, a drive voltage is increased), and there is a problem that performance as an element is deteriorated.

  On the other hand, in recent years, development of transparent conductive films using carbon materials such as carbon nanotubes and graphene has become active.

  Carbon has four known general structures, including diamond, graphite, fullerene and carbon nanotubes. Crystal structure refers to a lattice arrangement of atoms. Carbon nanotubes are tubular structures grown with single or multiple layers, and can be thought of as a rolled sheet, formed of multiple hexagons, with each sheet having three adjacent carbon atoms. It is formed by bonding with a carbon atom. Carbon nanotubes have a diameter of about a few angstroms to a few hundred nanometers. Carbon nanotubes can function as conductors similar to metals or as semiconductors, depending on the orientation of the hexagonal lattice of carbon atoms relative to the tube axis and the tube diameter.

  Carbon nanotubes were generated for the first time (for example, see Non-Patent Document 1) by arc discharge between two graphite rods. This technique mainly produced multi-walled carbon nanotubes. Later, a method for producing mainly single-walled carbon nanotubes (for example, see Non-Patent Document 2) was discovered and reported.

  Further, these carbon materials have been experimentally verified for the existence of metallic / semiconductor properties of carbon nanotubes and high mobility in metallic carbon nanotube molecules (see, for example, Non-Patent Document 3). A transparent conductive film (see Patent Document 2) characterized by having a conductive polymer layer and a carbon nanotube layer in a fixed order has been disclosed.

  A transparent conductive film containing single-walled carbon nanotubes (see Patent Document 3) and a transparent conductive film using a molecular semiconductor in combination with a thin film containing carbon nanotubes (see Patent Document 4) are disclosed. However, not only does not reach the sheet resistance of ITO due to the purity problem of the carbon nanotube itself and the interfacial resistance problem between the molecules, but the surface smoothness of the transparent conductive film is not sufficient, and the level of conductivity and surface smoothness is high. There is no technology that can achieve both. For this reason, when it was used as an electrode for an organic electronic device, sufficient performance was not obtained and practical use was not achieved. This application is made in view of these.

JP-A-6-273964 JP 2009-211978 A Special table 2010-506824 gazette Special table 2008-544946

Sumio Iijima, Nature, Vol. 354, November 7, 1991, 56-58 D. S. Bethune et al., Nature, Vol. 363, 605 pages (1993) T. T. et al. W. Ebesen et al .: Nature, Vol. 382, July 4, 1996, 54-56

  The object of the present invention has been made in view of the above circumstances, and has good characteristics when an organic electronic element such as a flexible organic EL element or an organic solar cell is formed that has both high conductivity and transparency. It is related to a novel transparent conductor that can be obtained, and by using the configuration of the present invention suitably, it is possible to provide a large area surface electrode that is substantially entirely transparent without using a metal grid or the like by a coating type process, In addition, good characteristics can be obtained as an organic electronic element such as an organic EL element and an organic solar battery.

  The above object of the present invention can be achieved by the following configuration.

1. A transparent conductor having a transparent conductive layer containing carbon nanotubes on a transparent substrate,
The transparent conductive layer contains at least one π-conjugated compound selected from a porphyrin compound, a phthalocyanine compound, and a graphene compound,
The average transmittance at a spectral wavelength of 400 to 700 nm is 70% or more ,
2 The sheet resistance value at 50 ° C. and 50% RH is less than 10Ω / □ ,
Below the arithmetic average roughness Ra of 10nm of the transparent conductive layer surface, and the ten-point average roughness Rz Ri der less 40 nm,
Transparent conductor in which the concentration of carbon nanotubes in the transparent conductive layer is characterized in der Rukoto least 75 wt%.

2. 2. The transparent conductor according to 1 above, wherein the transparent conductive layer further has a conductive polymer-containing layer.

3. 3. The transparent conductor according to 2 above, wherein the conductive polymer-containing layer further contains a hydroxyl group-containing nonconductive polymer.

4). A transparent conductor having a transparent conductive layer having a carbon nanotube-containing layer and a conductive polymer-containing layer on a transparent substrate,
The carbon nanotube-containing layer contains at least one π-conjugated compound selected from a porphyrin compound, a phthalocyanine compound, and a graphene compound,
The conductive polymer-containing layer further contains a hydroxyl group-containing nonconductive polymer,
The average transmittance at a spectral wavelength of 400 to 700 nm is 70% or more,
The sheet resistance value at 25 ° C. and 50% RH is less than 10Ω / □,
An arithmetic average roughness Ra of the surface of the transparent conductive layer is 10 nm or less, and a ten-point average roughness Rz is 40 nm or less.

  5. 5. An organic EL device, wherein at least an organic phosphorescent light emitting layer is provided on the transparent conductive layer of the transparent conductor according to any one of 1 to 4 above.

  6). 5. An organic photoelectric conversion element, wherein at least an organic power generation layer is provided on the transparent conductive layer of the transparent conductor according to any one of 1 to 4 above.

  According to the present invention, it is possible to obtain a novel transparent conductor that has high conductivity and transparency and that can obtain good characteristics when an organic electronic element such as a flexible organic EL element or an organic solar battery is formed. I was able to. Also, by using the structure of the present invention suitably, it is possible to provide a large area surface electrode that is substantially entirely transparent without using a metal grid or the like by a coating type process, and is said to be an organic EL element or an organic solar cell. Good characteristics were obtained as an organic electronic device.

It is sectional drawing of the organic electronic element which concerns on this invention.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

<Board>
In the present invention, a plastic film, a plastic plate, glass or the like can be used as the substrate, and it is preferable to use a transparent plastic film from the viewpoint of lightness and flexibility.

  Examples of raw materials for plastic films and plastic plates include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene and EVA, and polyvinyl chloride. , Vinyl resins such as polyvinylidene chloride, polyether ether ketone (PEEK), polysulfone (PSF), polyether sulfone (PES), polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), etc. Can be used. Of these, PET and PEN are preferred.

  In the transparent conductor and the organic electronic element, the substrate is preferably excellent in surface smoothness. The smoothness of the surface is preferably an arithmetic average roughness Ra of 5 nm or less and a maximum height Rz of 50 nm or less, more preferably Ra of 2 nm or less and Rz of 30 nm or less, and still more preferably Ra of 1 nm or less. Rz is 20 nm or less. The surface of the substrate may be smoothed by applying an undercoat layer such as a thermosetting resin, an ultraviolet curable resin, an electron beam curable resin, or a radiation curable resin, or may be smoothed by mechanical processing such as polishing. You can also. Here, the smoothness of the surface can be determined according to the surface roughness standard (JIS B 0601-2001) from measurement by an atomic force microscope (AFM) or the like.

  The substrate is preferably provided with a gas barrier layer for the purpose of blocking oxygen and moisture in the atmosphere. As a material for forming the gas barrier layer, metal oxides such as silicon oxide, silicon nitride, silicon oxynitride, aluminum nitride, and aluminum oxide, and metal nitrides can be used. These materials have an oxygen barrier function in addition to a water vapor barrier function. In particular, silicon nitride and silicon oxynitride having favorable barrier properties, solvent resistance, and transparency are preferable. In addition, the barrier layer may have a multilayer structure as necessary. As a method for forming the gas barrier layer, a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used depending on the material. The thickness of each inorganic layer constituting the gas barrier layer is not particularly limited, but typically it is preferably in the range of 5 nm to 500 nm per layer, more preferably 10 nm to 400 nm per layer. The gas barrier layer is provided on at least one surface of the substrate, and more preferably on both surfaces.

  Further, the surface of the substrate may be subjected to a protective layer treatment with a hard coat layer or the like. The hard coat layer is formed by uniformly applying a photo-radical generating material and a mixture of radical polymerizable monofunctional and / or polyfunctional monomers to a desired film thickness, and then irradiating the necessary amount of ultraviolet light with radical polymerization. It is a transparent and high-hardness polymer layer obtained by making it.

<Underlayer>
The transparent conductor of the present invention preferably has an undercoat layer formed by applying a silane coupling agent to the substrate surface.

  Examples of the silane coupling agent that can be used for the undercoat layer include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, and β- (3,4). -Epoxycyclohexyl) ethyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylmethoxysilane hydrochloride, γ -Glycidoxypropyltrimethoxysilane, aminosilane, methyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, vinyltris (β-methoxyethoxy) silane , Ok Tadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, methyltrichlorosilane, dimethyldichlorosilane and the like can be mentioned. Among them, preferred are those having either a mercapto group or a dialkylamino group in the molecule, specifically, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyl. Dimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylmethoxysilane / hydrochloride, γ-mercaptopropyltrimethoxysilane and the like are particularly preferable.

  In order to form an undercoat layer using a silane coupling agent, the silane coupling agent is dissolved in water, an organic solvent, or the like, applied, and then dried. The solvent not only dissolves the silane coupling agent but also affects the developability and wettability on the inorganic substrate. In the case of using water, in the case of aminosilane, it is easy to dissolve and pH adjustment is not necessary, but other silane coupling agents are preferably used in the vicinity of pH 4.

  Drying is preferably performed at a temperature of room temperature to 100 ° C. for about 2 to 30 minutes. Drying causes a chemical reaction between the silane coupling agent and the equipment, the organic functional groups of the silane coupling agent are oriented outside the equipment surface, and interact with the transparent conductive layer containing the carbon nanotubes formed in a pattern on it. It is thought to act and improve adhesion.

<Conductive layer>
The transparent conductive layer containing carbon nanotubes of the present invention contains at least carbon nanotubes, and can be suitably used as a single layer or a plurality of layers.

  The layer containing carbon nanotubes may be formed of only carbon nanotubes or may be mixed with other compounds. In order to reduce the resistance between carbon nanotube molecules, a π-conjugated compound is used. It is preferable to contain.

  Moreover, the carbon nanotube has a function as a transparent surface electrode like ITO, and the preferable form of the transparent conductive film of the present invention preferably contains any one of the following forms.

Single layer mainly composed of carbon nanotubes Multiple layers mainly composed of carbon nanotubes Grid electrode and conductive polymer layer mainly composed of carbon nanotubes Name of surface electrode and conductive polymer layer mainly composed of carbon nanotubes Can do. Hereinafter, carbon nanotubes that can be suitably used in the present invention will be described.

(Carbon nanotube (hereinafter also referred to as CNT))
Carbon nanotubes suitable for use in the transparent conductive layer of the present invention can be formed by any method known to those skilled in the art (laser ablation, CVD, arc discharge). The carbon nanotubes preferably have minimal or no carbonaceous impurities (graphite, amorphous, diamond, non-tubular fullerene, multi-walled carbon nanotubes) or metal impurities that are not carbon nanotubes. It has been found that transparency increases significantly as the level of metallic and carbonaceous impurities decreases. As the amount of metal impurities and carbonaceous impurities decreases, the film quality as evidenced by layer uniformity, surface roughness, and particle reduction also improves, and the CNT component is preferably 50% by weight or more, More preferably, it is 90 mass% or more, and most preferably 95 mass% or more.

  In order to achieve high electron conductivity, single-walled carbon nanotubes (SWCNTs) are the most preferred type of carbon nanotubes.

  In addition, CNT is a mixture of metallic and semiconducting materials, both of which can be suitably used. However, synthesis and isolation of a single characteristic product is a preferred embodiment. In particular, in organic solar cells (OPV), since infrared absorption due to metal characteristics is not preferable in terms of efficiency characteristics, a transparent conductive film composed mainly of CNT having semiconductor characteristics with extremely small infrared absorption is good. . In addition, SWCNTs immediately after synthesis are not functionalized covalently through acid pickling of impurities, annealing, or directional functionalization, but in the present invention, high purity is preferable as described above. Of course, functionalized SWCNTs are preferably used for this purpose. Preferred functional groups are hydrophilic species selected from carboxylic acids, carboxylic acid anions (carboxylates), hydroxyls, sulfur-containing groups, carbonyls, phosphates, nitrates, or combinations of these hydrophilic species. Such functionalization is preferred because it can improve the compatibility of SWCNTs in certain polymer matrices.

  The most preferred covalent surface functional groups are carboxylic acids or carboxylic acid salts, or mixtures thereof (hereinafter simply referred to as carboxylic acids). For functionalization based on carboxylic acids, the preferred functionalized carbon level on SWCNT is 0.5 to 100 atomic percent. In this case, 1 atomic percent of functionalized carbon means that for every 100 carbons in the SWCNT, there are covalently bonded functional groups. The functionalized carbon may be present anywhere on the nanotube (open or closed end, outer or inner sidewall). As already mentioned, preferably the functionalization takes place on the outer surface of the SWCNT. More preferably, the functionalized percent range is from 0.5 to 50 atomic percent, and most preferably from 0.5 to 5 atomic percent.

  The functionalization of SWCNTs within these atomic percent ranges makes it possible to prepare stable dispersions at the solids concentration required to form highly conductive transparent films by common coating means. Become. This method allows very effective dispersion in a substantially aqueous dispersion and can form a solution that does not require a dispersant. The most preferred material in the present invention is to provide a desired dispersion without functionally changing the electronic properties of the carbon nanotubes by functionalization. The transmittance is 70% in the transparent conductive film of the present invention. Is necessary. This transmittance can be achieved by producing a thin coating with a thickness of less than 1 micrometer, more preferably with a thickness of less than 500 nm, particularly preferably less than 200 nm and most preferably less than 100 nm. is there. Functionalization can be performed by a number of routes. Typically, the raw material (unfunctionalized) SWCNT is a strong oxidant (hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, oleum, nitric acid, citric acid, which may be a mixture. Oxalic acid, chlorosulfonic acid, phosphoric acid, trifluoromethanesulfonic acid, glacial acetic acid, monobasic organic acid, dibasic organic acid, potassium permanganate, persulfate, serate, bromate, hydrogen peroxide, heavy Chromate) bath. Sulfuric acid, nitric acid, permanganic acid, and chlorosulfonic acid are preferred based on the effectiveness of oxidation and functionalization. A temperature of 20-120 ° C. is typically used in refluxing this mixture of SWCNT and strong oxidant with appropriate stirring over a process time of 1 hour to several days. At the end of this process, the raw SWCNT is now functionalized SWCNT. Residual oxidizing agent is removed via separation techniques (filter washing, centrifugation, cross-flow filtration) so that the powder of functionalized SWCNT (mainly carboxylic acid functionalized) remains after appropriate heating until dry. Is done.

  The pH of the dispersion and coating composition is also important. As the pH becomes more basic (beyond the pKa of the carboxylic acid group), the carboxylic acid is ionized, thereby making the carboxylic acid anion a bulky repulsive group that can aid stability. A preferred pH is 3 to 10 pH. A more preferred pH is 3-6.

  The length of SWCNT is 20 nm to 1 m, more preferably 20 nm to 50 μm, and particularly preferably 100 nm to 50 μm. SWCNTs can exist as individual SWCNTs or as SWCNT bundles. The diameter of SWCNT in the transparent conductive layer is preferably 0.05 nm to 5 nm, more preferably 0.5 nm to 4 nm, and particularly preferably 1 to 3 nm. The bundle diameter may be between 1 nm and 1 μm. Preferably, the bundle has a diameter of less than 50 nm, particularly preferably less than 20 nm, and a length of 20 nm to 50 mm. To facilitate electron transport, a larger surface area is achieved and has a smaller bundle size, thereby exposing the surface of the SWCNT that is located inside the bundle and cannot be accessed. It is important that a larger effective surface area be achieved. The end of SWCNT is preferably closed by a hemispherical buckyball of an appropriate size, but both or only one end of SWCNT may be open.

  In the present invention, it is preferable to form an aqueous dispersion having a SWCNT solids concentration in the range of 0.05 to 10% by weight (500 to 100,000) ppm. For such embodiments, functionalized SWCNTs (described above) It is a preferred embodiment to be manufactured as such or purchased from a supplier. By setting it as such solid content concentration, roll application | coating and inkjet printing can be performed easily. Functionalized SWCNTs are advantageous in that they minimize liquid viscosity. Functionalized SWCNTs are in powder / flake form and require energy for dispersion. A typical dispersion process uses high shear mixing equipment (homogenizer, microfluidizer, cowl blade high shear mixer, automatic media mill, ball mill) for several minutes to 1 hour. In this respect as well, functionalized SWCNTs were found to be easily dispersed and superior, and standard sonication and bath sonication were found to be sufficient. Typically, 1000 ppm SWCNT dispersion in deionized water is formed by a bath sonicator over 2-24 hours (depending on the level of hydrophilic functionalization). After the dispersion process, the pH can be adjusted to the desired range. Centrifugation or filtration processes are used to remove large particles. The resulting dispersion is stable for several months at rest (depending on the level of hydrophilic functionalization).

The transparent conductive layer of the present invention preferably contains a functionalized SWCNT having a dry coating mass of about 0.1 to about 1000 mg / m ² , more preferably 0.5 to about 500 mg / m ² , particularly preferably. 1 to 300 mg / m ² , most preferably 5 to 100 mg / m ² functionalized SWCNT. Such SWCNT ranges in dry coatings can be easily reached by standard application methods, providing the best transmission properties and minimizing the cost to achieve the most desirable sheet resistance . The actual dry coating mass is determined by the properties of the particular conductive functionalized SWCNT employed and by the requirements for the particular application, which can include, for example, layer conductivity, transparency, optical density, cost Etc. may be included.

  As a preferable conductive SWCNT of the present invention, a substituent such as carboxylic acid, carboxylate anion (carboxylate), hydroxyl, sulfur-containing group, carbonyl, phosphate, nitrate, etc. is added at any position of the carbon nanotube. Carbon nanotubes. These carbon nanotubes are preferable for forming the transparent conductive layer of the present invention.

  In a more preferred embodiment, the functional group is represented by the following general formula.

R-SO _x Z _y
Where R is carbon inside the lattice of SWCNT, x may be 1 to 3 and Z is a hydrogen atom or Na, Mg, K, Ca, Zn, Mn, Ag, Au, It may be a metal cation of a metal such as Pd, Pt, Fe, Co, and y may be 1 or 1 / n (n: metal valence). The above general formula may contain sulfonic acids, sulfonic acids, and / or sulfonic acids, and / or the corresponding anions or mixtures thereof. The most preferred sulfur-containing groups for covalent surface functionalization are sulfonic acids or sulfonates or mixtures thereof (hereinafter simply referred to as sulfonic acids). Covalent sulfonic acid provides the best carbon nanotube dispersion among the sulfur-containing groups.

  In the present invention, a dispersant can also be used for dispersion of SWCNTs. The amount of the dispersant in the present invention is preferably as small as possible, and is less than 5% by mass of the mass of SWCNT. Most preferred is less than 1% by weight. As the amount of dispersant decreases, the electronic conductivity increases. Any known dispersant can be suitably used, but preferred dispersants are octylphenol ethoxylate (TX-100), sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, poly (styrene sulfonate), sodium salt. Poly (vinyl pyrrolidone), block copolymers of ethylene oxide and propylene oxide (Pluronics or Poloxamers), polyoxyethylene alkyl ethers (Brij 78, Brij 700), and cetyltrimethylammonium bromide or dodecyltrimethylammonium bromide. These dispersants are preferable because they have little influence on the electron conductivity. By using these dispersants in the necessary minimum amount, the carbon nanotubes can be effectively dispersed. Suitable mixtures of these dispersants can be utilized.

  Although it is also a preferable aspect to use the above carbon nanotubes alone or in combination, a particularly preferable aspect in the present invention is to use in combination with a π-conjugated compound.

<Π-conjugated compound>
The π-conjugated compounds preferably used in the present invention are porphyrin compounds, phthalocyanine compounds, and graphene compounds.

  The π-conjugated compound means a compound having 7 or more aromatic π electrons. Specific general formulas of porphyrin compounds are shown in compounds 1 and 3, and general formulas of phthalocyanine compounds are shown in compounds 2 and 4.

  The graphene used in the present invention or the layered graphene in which a plurality of graphene synthesized by the process of exfoliating the monoatomic layer graphite from the graphite is a sheet-like carbon material in which several to 20 monoatomic layer graphenes are stacked. There is typically a flat sheet-like carbon film having a thickness of about 2 to 10 nm and a width of about 1 to 5 mm. A major difference from graphite is that there is no regularity in the direction perpendicular to the film, that is, in the stacking direction, since the monoatomic layers are peeled once and then stacked again. In the graphite crystal, the monoatomic graphite has a hexagonal crystal structure in which ABCABC comes to the same position every three times, and the degree of overlap between graphenes has complete regularity. Further, the distance between the graphenes has a strictly constant (0.335 nm) inter-plane distance. On the other hand, in layered graphene, since the graphene monoatomic layer sheets are randomly overlapped, the inter-plane distance is not constant and is increased compared to graphite. Layered graphene is a carbon material that can take any structural form unlike crystalline graphite because it has a flexible sheet structure.

  Furthermore, there is a novel electrode material in which sub-nanometer platinum clusters are supported in a graphene sheet shape. Several monoatomic graphene layers are stacked, and the interplane distance of graphene is increased compared to graphite.

  The size of the platinum / graphene is a very small size cluster of 1 nm or less, and is very small, about 1/10 of the number (2-4) nm size platinum particles used so far. It is a cluster material. In addition, since platinum atoms are strongly bonded to the graphene to form a covalent bond and not to surface diffusion, such small but stable platinum ultrafine particles are fixed.

Furthermore, the transparent conductive layer of the present invention particularly preferably contains a conductive polymer and a hydroxyl group-containing nonconductive polymer .

Such a conductive polymer and a hydroxyl group-containing non-conductive polymer are preferably used in the same layer as CNT as described above, but are particularly preferably provided as an upper layer provided with a layer mainly composed of CNT.

As such an embodiment, when a layer containing CNT as a main component is formed as a surface electrode in which a grid electrode is provided with a uniform layer containing a conductive polymer and a hydroxyl group-containing non-conductive polymer , a uniform layer containing CNT as a main component is used. Any of the surface electrodes may be suitably used in the case where the surface electrode is further provided with a uniform layer containing a conductive polymer and a hydroxyl group-containing non-conductive polymer on the surface electrode, and the latter is the preferred embodiment.

<Conductive polymer>
As the conductive polymer compound, those having a basic skeleton of polyphenylene vinylene, polythiophene, poly (thiophene vinylene), polyacetylene, polypyrrole, poly (p-phenylene), or polyaniline are preferable (x is an integer of 1 or more. preferable.).

  Preferred specific examples of polyphenylene vinylene and derivatives thereof are shown (n, m, k, j are integers of 0 or more, and x is an integer of 2 or more).

  Preferred specific examples of polythiophene and derivatives thereof are shown (n and m are integers of 0 or more, k is an integer of 1 or more, and x is an integer of 2 or more).

  Preferred specific examples of poly (thiophene vinylene) and derivatives thereof are shown (n, m, k, j are integers of 0 or more, and x is an integer of 2 or more).

  Preferred specific examples of polyacetylene and derivatives thereof are shown (n and m are integers of 0 or more, and x is an integer of 2 or more).

  Preferable specific examples of polypyrrole and derivatives thereof are shown (n is an integer of 0 or more, k is an integer of 1 or more, and x is an integer of 1 or more).

  Preferred specific examples of polyfluorene and derivatives thereof are shown (n and m are integers of 0 or more, and x is an integer of 1 or more).

  Preferred specific examples of poly (p-phenylene) and derivatives thereof are shown (n and m are integers of 0 or more, and x and y are integers of 1 or more).

  Preferred specific examples of polyaniline and derivatives thereof are shown (n is an integer of 0 or more, and x is an integer of 2 or more).

  The conductive polymer of the present invention is preferably a conductive polymer comprising a π-conjugated compound and a polyanion. Such a conductive polymer can be easily produced by chemical oxidative polymerization of a precursor monomer that forms a π-conjugated compound described later in the presence of an appropriate oxidizing agent, an oxidation catalyst, and a polyanion described later.

(Polyanion)
The polyanion is a substituted or unsubstituted polyalkylene, a substituted or unsubstituted polyalkenylene, a substituted or unsubstituted polyimide, a substituted or unsubstituted polyamide, a substituted or unsubstituted polyester, and a copolymer thereof. It consists of a structural unit having an anionic group and a structural unit having no anionic group.

  The polyanion is a solubilized polymer that solubilizes the π-conjugated compound in a solvent. In addition, the anion group of the polyanion functions as a dopant for the π-conjugated compound and improves the conductivity and heat resistance of the π-conjugated compound.

  The anion group of the polyanion may be a functional group capable of undergoing chemical oxidation doping to the π-conjugated compound. Among them, from the viewpoint of ease of production and stability, a monosubstituted sulfate group, a monosubstituted group A phosphate group, a phosphate group, a carboxy group, a sulfo group and the like are preferable. Furthermore, from the viewpoint of the doping effect of the functional group on the π-conjugated compound, a sulfo group, a monosubstituted sulfate group and a carboxy group are more preferable.

  Specific examples of the polyanion include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid, poly-2-acrylamido-2-methylpropane sulfonic acid, polyisoprene. Examples include sulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryl carboxylic acid, polymethacryl carboxylic acid, poly-2-acrylamido-2-methylpropane carboxylic acid, polyisoprene carboxylic acid, polyacrylic acid and the like. It is done.

  These homopolymers may be sufficient and 2 or more types of copolymers may be sufficient. Moreover, the polyanion which has a fluorine in a compound may be sufficient. Specific examples include Nafion containing a perfluorosulfonic acid group (manufactured by Dupont), Flemion made of perfluoro vinyl ether containing a carboxylic acid group (manufactured by Asahi Glass Co., Ltd.), and the like.

  Among these, when the compound having a sulfo group is formed by coating and drying the conductive polymer-containing layer, the coating film is washed when heat treatment is performed at a temperature of 100 ° C. or more and 200 ° C. or less. Since resistance and solvent tolerance improve remarkably, it is more preferable. Furthermore, among these, polystyrene sulfonic acid, polyisoprene sulfonic acid, polyacrylic acid ethylsulfonic acid, and polyacrylic acid butylsulfonic acid are preferable. These polyanions have high compatibility with the binder resin, and can further increase the conductivity of the obtained conductive polymer.

  The degree of polymerization of the polyanion is preferably in the range of 10 to 100,000 monomer units, and more preferably in the range of 50 to 10,000 from the viewpoint of solvent solubility and conductivity.

  Examples of methods for producing polyanions include a method of directly introducing an anionic group into a polymer having no anionic group using an acid, a method of sulfonating a polymer having no anionic group with a sulfonating agent, and anionic group-containing polymerization. And a method of production by polymerization of a functional monomer.

  Examples of the method for producing an anion group-containing polymerizable monomer by polymerization include a method for producing an anion group-containing polymerizable monomer in a solvent by oxidative polymerization or radical polymerization in the presence of an oxidizing agent and / or a polymerization catalyst. Specifically, a predetermined amount of the anionic group-containing polymerizable monomer is dissolved in a solvent, kept at a constant temperature, and a solution in which a predetermined amount of an oxidizing agent and / or a polymerization catalyst is dissolved in the solvent is added to the predetermined amount. React with time. The polymer obtained by the reaction is adjusted to a certain concentration by the solvent. In this production method, an anionic group-containing polymerizable monomer may be copolymerized with a polymerizable monomer having no anionic group. The oxidizing agent, oxidation catalyst, and solvent used in the polymerization of the anionic group-containing polymerizable monomer are the same as those used in the polymerization of the precursor monomer that forms the π-conjugated compound. When the obtained polymer is a polyanionic salt, it is preferably transformed into a polyanionic acid. Examples of the method for converting to an anionic acid include an ion exchange method using an ion exchange resin, a dialysis method, an ultrafiltration method, and the like. Among these, the ultrafiltration method is preferable from the viewpoint of easy work.

  A commercially available material can be preferably used for such a conductive polymer. For example, a conductive polymer (abbreviated as PEDOT / PSS) made of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid is H.264. C. It is commercially available from Starck as the Clevios series, from Aldrich as PEDOT / PSS 483095, 560596 and from Nagase Chemtex as the Denatron series. Polyaniline is also commercially available from Nissan Chemical as the ORMECON series. In the present invention, such an agent can also be preferably used.

  2nd. A water-soluble organic compound may be contained as a dopant. There is no restriction | limiting in particular in this water-soluble organic compound, It can select suitably from well-known things, For example, an oxygen containing compound is mentioned suitably. The oxygen-containing compound is not particularly limited as long as it contains oxygen, and examples thereof include a hydroxyl group-containing compound, a carbonyl group-containing compound, an ether group-containing compound, and a sulfoxide group-containing compound. Examples of the hydroxyl group-containing compound include ethylene glycol, diethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, glycerin, and the like. Among these, ethylene glycol and diethylene glycol are preferable. Examples of the carbonyl group-containing compound include isophorone, propylene carbonate, cyclohexanone, and γ-butyrolactone. Examples of the ether group-containing compound include diethylene glycol monoethyl ether. Examples of the sulfoxide group-containing compound include dimethyl sulfoxide. These may be used alone or in combination of two or more, but at least one selected from dimethyl sulfoxide, ethylene glycol, and diethylene glycol is preferably used.

<Hydroxyl-containing non-conductive polymer>
As the hydroxyl group-containing nonconductive polymer in the present invention, polymer (A) is preferred. The main copolymerization component of the polymer (A) is composed of the following monomers M1, M2, and M3, and the copolymer component is a copolymer polymer in which 50 mol% or more of the copolymer components are any of the monomers or the total is 50 mol% or more. The total of the monomer components is more preferably 80 mol% or more, and it may be a homopolymer formed from any single monomer, which is a preferred embodiment.

Monomer ^{_{M1 CH 2 = C (X 1}} ) O-R 1 -OH
Monomer ^{_{M2 CH 2 = C (X 2}} ) COO-R 2 -OH
Monomer ^{_{M3 CH 2 = C (X 3}} ) CONH-R 3 -OH
In the formula, X ^{1 to} X ³ each independently represent a hydrogen atom or a methyl group, and R ^{1 to} R ³ each independently represents an alkylene group having 5 or less carbon atoms.

Among these, a polymer of the monomer M1 is particularly preferable. More specifically, in the monomer M1, X ¹ is preferably a hydrogen atom. R ¹ is particularly preferably an ethylene group.

  In the polymer (A), other monomer components may be copolymerized as long as they are soluble in an aqueous solvent, but a monomer component having high hydrophilicity is more preferable. The polymer (A) preferably has a number average molecular weight of 1000 or less in a content of 0 to 5%. When there are few low molecular components, the preservation | save property of an element and the behavior which has a barrier in the electroconductivity of a perpendicular | vertical direction with respect to a conductive layer can be reduced more.

  As a method for adjusting the content of the polymer (A) having a number average molecular weight of 1000 or less to 0 to 5%, a low molecular weight component is obtained by synthesizing a monodisperse polymer by living polymerization in a reprecipitation method or preparative GPC. A method of removing or suppressing the generation of low molecular weight components can be used.

  In the reprecipitation method, the polymer is dissolved in a solvent in which the polymer can be dissolved and dropped into a solvent having a lower solubility than the solvent in which the polymer is dissolved, thereby precipitating the polymer and removing low molecular weight components such as monomers, catalysts, and oligomers. It is a method to do.

  In addition, preparative GPC is, for example, recycled preparative GPCLC-9100 (manufactured by Nihon Analytical Industrial Co., Ltd.), polystyrene gel column, and the polymer dissolved solution can be separated by molecular weight to cut the desired low molecular weight. This is how you can do it.

  In the living polymerization, the generation of the starting species does not change with time, and there are few side reactions such as termination reaction, and a polymer having a uniform molecular weight can be obtained. Since the molecular weight can be adjusted by the addition amount of the monomer, for example, if a polymer having a molecular weight of 20,000 is synthesized, the formation of a low molecular weight body can be suppressed. The reprecipitation method and living polymerization are preferable from the viewpoint of production suitability.

  The molecular weight of the polymer (A) of the present invention is preferably in the range of 3,000 to 2,000,000, more preferably 4,000 to 500,000, still more preferably 5,000 to 100,000. The molecular weight distribution of the polymer (A) of the present invention is preferably from 1.01 to 1.30, more preferably from 1.01 to 1.25. In the distribution obtained by GPC, the content having a number average molecular weight of 1000 or less was converted by multiplying the area having a number average molecular weight of 1000 or less and dividing by the area of the entire distribution. The living polymerization solvent is inactive under reaction conditions and is not particularly limited as long as it can dissolve the monomer and the polymer to be formed, but a mixed solvent of an alcohol solvent and water is preferable. The living radical polymerization temperature varies depending on the initiator used, but is generally -10 to 250 ° C, preferably 0 to 200 ° C, more preferably 10 to 100 ° C.

<Aqueous solvent>
In the present invention, the aqueous solvent represents a solvent in which 50% by mass or more is water. Of course, pure water containing no other solvent may be used. The component other than water in the aqueous solvent is not particularly limited as long as it is a solvent compatible with water, but an alcoholic solvent can be preferably used, and isopropyl alcohol having a boiling point relatively close to water can be used. This is advantageous for the smoothness of the film to be formed.

  The dispersion containing the conductive polymer of the present invention and the hydroxyl group-containing non-conductive polymer further contains other transparent non-conductive polymers and additives as long as the conductivity, transparency and smoothness of the conductive layer are simultaneously satisfied. May be.

  As the transparent non-conductive polymer, a natural polymer resin or a synthetic polymer resin can be widely selected and used, and a water-soluble polymer or an aqueous polymer emulsion is particularly preferable. Examples of water-soluble polymers include natural polymers such as starch, gelatin, and agar, semi-synthetic polymers such as hydroxypropylmethylcellulose, carboxymethylcellulose, and hydroxyethylcellulose, cellulose derivatives, synthetic polymers such as polyvinyl alcohol, and polyacrylic acid polymers. , Polyacrylamide, polyethylene oxide, polyvinyl pyrrolidone, etc., and aqueous polymer emulsions include acrylic resins (acrylic silicon modified resins, fluorine modified acrylic resins, urethane modified acrylic resins, epoxy modified acrylic resins, etc.), polyester resins, urethane Resin, vinyl acetate resin and the like can be used.

  In addition, the synthetic polymer resin of the aqueous polymer emulsion may be a transparent thermoplastic resin (for example, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polymethyl methacrylate, nitrocellulose, chlorinated polyethylene, chlorinated polypropylene). , Vinylidene fluoride) and transparent curable resins that are cured by heat, light, electron beam, or radiation (for example, melamine acrylate, urethane acrylate, epoxy resin, polyimide resin, silicone resin such as acrylic-modified silicate). it can.

  Examples of the additive include plasticizers, stabilizers such as antioxidants and sulfurization inhibitors, surfactants, dissolution accelerators, polymerization inhibitors, and colorants such as dyes and pigments. Furthermore, from the viewpoint of improving workability such as coating properties, solvents (for example, water, organic solvents such as alcohols, glycols, cellosolves, ketones, esters, ethers, amides, hydrocarbons, etc.) are used. May be included.

  The case of providing a CNT grid electrode and providing a uniform conductive polymer layer will be described in detail below. However, when the CNT is also a uniform plane electrode, it is produced in accordance with the method for forming the second conductive layer. It can be suitably manufactured.

  The transparent conductive layer of the present invention is preferably composed of a first conductive layer containing carbon nanotubes and a second conductive layer containing a conductive polymer. As a method for forming the conductive layer, it is preferable to form a first conductive layer by printing and baking a fine line pattern of a carbon nanotube paste on a substrate having the undercoat layer by a printing method. By applying a coating liquid for the second conductive layer so as to cover the substrate and the first conductive layer formed on the base material, the electrode is developed even between the thin line patterns without the first conductive layer. I can do it.

(First conductive layer)
First, a fine line pattern made of carbon nanotubes is formed as a first conductive layer on a substrate. The fine line pattern can be formed by a printing method such as a gravure printing method, a flexographic printing method, and a screen printing method using a dispersion of carbon nanotubes. For each printing method, a method generally used for electrode pattern formation can be applied to the present invention. Specific examples of the gravure printing method include those described in JP2009-295980A, JP2009-259826A, JP2009-96189A, and JP2009-90662A, and the like. The methods described in Japanese Patent Application Laid-Open Nos. 2004-268319 and 2003-168560 are disclosed, and the screen printing methods are described in Japanese Patent Application Laid-Open Nos. 2010-34161, 2010-10245, and 2009-302345. An example is the method described in Japanese Patent Publication.

  Similarly, a method of patterning by oxygen plasma etching after providing a uniform layer of CNTs can also be suitably used. In addition, it is possible to make the grid height lower than that of the printing method, which is advantageous and preferable from the viewpoint of manufacturing a substantially transparent electrode.

  Although the line | wire width of the thin wire | line in a 1st conductive layer is arbitrary, 10-400 micrometers is preferable, 20-200 micrometers is more preferable, 30-120 micrometers is more preferable. The height of the thin wire is preferably 0.001 to 2.0 μm, and more preferably 0.005 to 1.5 μm.

  The surface specific resistance of the thin wire portion of the first conductive layer is preferably 5Ω / □ or less, and more preferably 1Ω / □ or less. The surface specific resistance can be measured based on, for example, JIS K6911, ASTM D257, etc., and can be easily measured using a commercially available surface resistivity meter.

(Second conductive layer)
Further, as the second conductive layer, a dispersion liquid made of a conductive polymer is applied and dried so as to cover the patterned first conductive layer, thereby forming a film. In addition to the above-mentioned printing methods such as gravure printing method, flexographic printing method, screen printing method, the application of the second conductive layer is performed by roll coating method, bar coating method, dip coating method, spin coating method, casting method, die coating method. A coating method such as a blade coating method, a bar coating method, a gravure coating method, a curtain coating method, a spray coating method, a doctor coating method, or an inkjet method can be used.

  The second conductive layer preferably further contains a hydroxyl group-containing non-conductive polymer having an effect of enhancing the conductivity of the conductive polymer. Thereby, high electroconductivity, high transparency, and water resistance can be satisfy | filled simultaneously.

  By forming the conductive layer of the present invention having such a laminated structure, high conductivity that cannot be obtained with a metal or metal oxide fine wire or a conductive polymer layer alone can be obtained uniformly in the electrode plane. it can.

  The ratio of the conductive polymer of the second conductive layer to the hydroxyl group-containing non-conductive polymer is preferably 30 to 900 parts by mass of the hydroxyl group-containing non-conductive polymer when the conductive polymer is 100 parts by mass. From the viewpoints of preventing current leakage, enhancing the conductivity of the hydroxyl group-containing non-conductive polymer, and transparency, the hydroxyl group-containing non-conductive polymer is more preferably 100 parts by mass or more.

  The dry thickness of the second conductive layer is preferably 1 nm to 200 nm. The thickness is more preferably 10 nm or more from the viewpoint of conductivity, and further preferably 100 nm or more from the viewpoint of the surface smoothness of the electrode. Moreover, it is more preferable that it is 50 nm or less from the point of transparency.

  After apply | coating a 2nd conductive layer, a drying process can be given suitably. Although there is no restriction | limiting in particular as conditions of a drying process, It is preferable to dry-process at the temperature of the range which does not damage a base material or a conductive layer. For example, a drying process can be performed at 80 to 150 ° C. for 10 seconds to 10 minutes. In the present invention, after the completion of drying, the crosslinking reaction of the hydroxyl group-containing nonconductive polymer can be promoted and completed by further heat treatment. Thereby, the cleaning resistance and solvent resistance of the electrode are remarkably improved, and the device performance is further improved. In particular, in an organic EL element, effects such as reduction in driving voltage and improvement in life can be obtained.

  The heat treatment is preferably performed at a temperature of 50 ° C. or higher and 200 ° C. or lower for 30 minutes or longer. If it is less than 50 ° C., the reaction promoting effect is small, and if it exceeds 200 ° C., thermal damage to the material increases, or the effect is small. The treatment temperature is more preferably 80 ° C. or more and 150 ° C. or less, and the treatment time is more preferably 1 hour or more. The upper limit of the treatment time is not particularly limited, but is preferably 24 hours or less from the viewpoint of productivity. The heat treatment may be performed on-line or off-line after applying and drying the conductive layer. In the case of off-line, it is preferable to further carry out under reduced pressure because it leads to accelerated drying of moisture.

  In the present invention, the crosslinking reaction of the hydroxyl group-containing nonconductive polymer can be promoted and completed using an acid catalyst. As the acid catalyst, hydrochloric acid, sulfuric acid or ammonium sulfate can be used. Moreover, in the polyanion used as a dopant for a conductive polymer, a dopant and a catalyst can be used together by using a sulfo group-containing polyanion. In addition, the heat treatment described above can be performed in combination with the use of an acid catalyst, which is preferable because it shortens the treatment time.

<Configuration of organic electronic device>
The organic electronic device according to the present invention will be described with reference to the drawings. In FIG. 1, it has the 1st electrode (11) and 2nd electrode (12) which oppose on a board | substrate (10), and at least 1 layer of organic is between a 1st electrode (11) and a 2nd electrode (12) electrode. It has a functional layer (13). In the present invention, the first electrode (11) includes a first conductive layer (14) containing carbon nanotubes, and a second conductive layer (15) composed of a conductive polymer and a hydroxyl group-containing nonconductive polymer, The second conductive layer composed of the polymer and the hydroxyl group-containing non-conductive polymer is filled in the gap between the first conductive layer containing the carbon nanotubes.

  Examples of the organic functional layer (13) according to the present invention include an organic light emitting layer, an organic photoelectric conversion layer, a liquid crystal polymer layer, and the like without any particular limitation. This is particularly effective in the case of an organic light emitting layer or an organic photoelectric conversion layer.

<Organic functional layer configuration>
(Organic EL device)
(Organic light emitting layer)
The organic electronic device having an organic light emitting layer in the present invention is used in combination with an organic light emitting layer such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a hole block layer, and an electron block layer in addition to the organic light emitting layer. Thus, a layer for controlling light emission may be provided. Since the conductive polymer-containing layer of the present invention can also function as a hole injection layer, it can also serve as a hole injection layer, but a hole injection layer may be provided independently.

Although the preferable specific example of a structure is shown below, this invention is not limited to these.
(I) (first electrode part) / light emitting layer / electron transport layer / (second electrode part)
(Ii) (first electrode part) / hole transport layer / light emitting layer / electron transport layer / (second electrode part)
(Iii) (first electrode part) / hole transport layer / light emitting layer / hole block layer / electron transport layer / (second electrode part)
(Iv) (first electrode part) / hole transporting layer / light emitting layer / hole blocking layer / electron transporting layer / cathode buffer layer / (second electrode part)
(V) (first electrode part) / anode buffer layer / hole transport layer / light emitting layer / hole block layer / electron transport layer / cathode buffer layer / (second electrode part)
Here, the light-emitting layer may be a monochromatic light-emitting layer having a light emission maximum wavelength in the range of 430 to 480 nm, 510 to 550 nm, and 600 to 640 nm, respectively, or by laminating at least three of these light emitting layers. A white light emitting layer may be used, and a non-light emitting intermediate layer may be provided between the light emitting layers. The organic EL device of the present invention is preferably a white light emitting layer.

  In addition, as the light emitting material or doping material that can be used in the organic light emitting layer in the present invention, anthracene, naphthalene, pyrene, tetracene, coronene, perylene, phthaloperylene, naphthaloperylene, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, bisbenzo Xazoline, bisstyryl, cyclopentadiene, quinoline metal complex, tris (8-hydroxyquinolinato) aluminum complex, tris (4-methyl-8-quinolinato) aluminum complex, tris (5-phenyl-8-quinolinato) aluminum complex, Aminoquinoline metal complex, benzoquinoline metal complex, tri- (p-terphenyl-4-yl) amine, 1-aryl-2,5-di (2-thienyl) pyrrole derivative, pyran, quinacridone Rubrene, distyrylbenzene derivatives, di still arylene derivatives, and various fluorescent dyes and rare earth metal complex, there are phosphorescent materials, but is not limited thereto. It is also preferable to include 90 to 99.5 parts by mass of a light emitting material selected from these compounds and 0.5 to 10 parts by mass of a doping material. The organic light emitting layer is prepared by a known method using the above materials and the like, and examples thereof include vapor deposition, coating, and transfer. The thickness of the organic light emitting layer is preferably 0.5 to 500 nm, particularly preferably 0.5 to 200 nm.

[Second electrode part]
The second electrode according to the present invention is a cathode in the organic EL element. The second electrode portion according to the present invention may be a conductive material single layer, but in addition to a conductive material, a resin for holding these may be used in combination. As the conductive material of the second electrode portion, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm.

  If a metal material is used as the conductive material of the second electrode part, the light coming to the second electrode side is reflected and returns to the first electrode part side. The carbon nanotubes of the first electrode part scatter or reflect a part of the light backward, but by using a metal material as the conductive material of the second electrode part, this light can be reused and the extraction efficiency is improved. .

<Organic photoelectric conversion element>
The organic photoelectric conversion element has a structure in which a first electrode portion, a photoelectric conversion layer (hereinafter also referred to as a bulk heterojunction layer) having a bulk heterojunction structure (p-type semiconductor layer and n-type semiconductor layer), and a second electrode portion are stacked. Have.

  An intermediate layer such as an electron transport layer may be provided between the photoelectric conversion layer and the second electrode portion.

[Photoelectric conversion layer]
The photoelectric conversion layer is a layer that converts light energy into electric energy, and constitutes a bulk heterojunction layer in which a p-type semiconductor material and an n-type semiconductor material are uniformly mixed. The p-type semiconductor material functions relatively as an electron donor (donor), and the n-type semiconductor material functions relatively as an electron acceptor (acceptor). Here, the electron donor and the electron acceptor are “an electron donor in which, when light is absorbed, electrons move from the electron donor to the electron acceptor to form a hole-electron pair (charge separation state)”. And an electron acceptor ”, which does not simply donate or accept electrons like an electrode, but donates or accepts electrons by a photoreaction.

  Examples of the p-type semiconductor material include various condensed polycyclic aromatic compounds and conjugated compounds.

  As the condensed polycyclic aromatic compound, for example, anthracene, tetracene, pentacene, hexacene, heptacene, chrysene, picene, fluorene, pyrene, peropyrene, perylene, terylene, quaterylene, coronene, ovalene, sarkham anthracene, bisanthene, zestrene, heptazelene, Examples thereof include compounds such as pyranthrene, violanthene, isoviolanthene, cacobiphenyl, anthradithiophene, and derivatives and precursors thereof.

  Examples of the conjugated compound include polythiophene and its oligomer, polypyrrole and its oligomer, polyaniline, polyphenylene and its oligomer, polyphenylene vinylene and its oligomer, polythienylene vinylene and its oligomer, polyacetylene, polydiacetylene, tetrathiafulvalene compound, quinone Compounds, cyano compounds such as tetracyanoquinodimethane, fullerenes and derivatives or mixtures thereof.

  In particular, among polythiophene and oligomers thereof, thiophene hexamer, α-seccithiophene α, ω-dihexyl-α-sexualthiophene, α, ω-dihexyl-α-kinkethiophene, α, ω-bis (3- An oligomer such as butoxypropyl) -α-sexithiophene can be preferably used.

  Other examples of the polymer p-type semiconductor include polyacetylene, polyparaphenylene, polypyrrole, polyparaphenylene sulfide, polythiophene, polyphenylene vinylene, polycarbazole, polyisothianaphthene, polyheptadiyne, polyquinoline, polyaniline, and the like. Substituted-unsubstituted alternating copolymer polythiophenes such as JP-A-2006-36755, JP-A-2007-51289, JP-A-2005-76030, J. Org. Amer. Chem. Soc. , 2007, p4112, J.A. Amer. Chem. Soc. , 2007, p7246, etc., polymers having a condensed ring thiophene structure, WO2008 / 000664, Adv. Mater. , 2007, p4160, Macromolecules, 2007, Vol. Examples thereof include thiophene copolymers such as 40 and p1981.

  Furthermore, porphyrin, copper phthalocyanine, tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bisethylenetetrathiafulvalene (BEDTTTTF) -perchloric acid complex, BEDTTTF-iodine complex, TCNQ-iodine complex, etc. Organic molecular complexes, fullerenes such as C60, C70, C76, C78 and C84, carbon nanotubes such as SWNT, dyes such as merocyanine dyes and hemicyanine dyes, σ-conjugated polymers such as polysilane and polygerman, and Organic / inorganic hybrid materials described in 2000-260999 can also be used.

  Among these π-conjugated materials, at least one selected from the group consisting of condensed polycyclic aromatic compounds such as pentacene, fullerenes, condensed ring tetracarboxylic acid diimides, metal phthalocyanines, and metal porphyrins is preferable. Further, pentacenes are more preferable.

  Examples of pentacenes include substituents described in International Publication No. 03/16599, International Publication No. 03/28125, US Pat. No. 6,690,029, Japanese Patent Application Laid-Open No. 2004-107216, and the like. A pentacene derivative described in U.S. Patent Application Publication No. 2003/136964 and the like; Amer. Chem. Soc. , Vol127. Examples thereof include substituted acenes described in No. 14.4986 and the like and derivatives thereof.

  Among these compounds, compounds that have high solubility in organic solvents to the extent that solution processing is possible, can form a crystalline thin film after drying, and can achieve high mobility are preferable. Such compounds include those described in J. Org. Amer. Chem. Soc. , Vol. 123, p9482; Amer. Chem. Soc. , Vol. 130 (2008), no. No. 9, 2706 and the like, acene-based compounds substituted with a trialkylsilylethynyl group, a pentacene precursor described in U.S. Patent Application Publication No. 2003/136964, etc., and Japanese Patent Application Laid-Open No. 2007-224019 Examples include precursor type compounds (precursors) such as porphyrin precursors.

  Among these, the latter precursor type can be preferably used.

  This is because the precursor type is insolubilized after conversion, so when forming the hole transport layer, electron transport layer, hole block layer, electron block layer, etc. on the bulk hetero junction layer by solution process, bulk hetero junction This is because the layer does not dissolve and the material constituting the layer and the material forming the bulk heterojunction layer are not mixed, and further improvement in efficiency and life can be achieved. .

  The p-type semiconductor material is a compound that has undergone a chemical structural change by a method such as exposing the precursor of the p-type semiconductor material to vapor of a compound that causes heat, light, radiation, or a chemical reaction, and converted into a p-type semiconductor material. Preferably there is. Among them, compounds that cause a scientific structural change by heat are preferred.

  Examples of n-type semiconductor materials include fullerene, octaazaporphyrin, p-type semiconductor perfluoro compounds (perfluoropentacene, perfluorophthalocyanine, etc.), naphthalenetetracarboxylic anhydride, naphthalenetetracarboxylic diimide, perylenetetracarboxylic acid Examples thereof include polymer compounds containing an anhydride, an aromatic carboxylic acid anhydride such as perylenetetracarboxylic acid diimide, or an imidized product thereof as a skeleton.

  Among these, fullerene-containing polymer compounds are preferable. Fullerene-containing polymer compounds include fullerene C60, fullerene C70, fullerene C76, fullerene C78, fullerene C84, fullerene C240, fullerene C540, mixed fullerene, fullerene nanotubes, multi-walled nanotubes, single-walled nanotubes, nanohorns (conical type), etc. Examples thereof include a polymer compound having a skeleton. As the fullerene-containing polymer compound, a polymer compound (derivative) having fullerene C60 as a skeleton is preferable.

  The fullerene-containing polymers are roughly classified into polymers in which fullerene is pendant from a polymer main chain and polymers in which fullerene is contained in the polymer main chain. Fullerene is contained in the polymer main chain. Are preferred.

  This is not because fullerene is contained in the main chain because the polymer does not have a branched structure, so that it can be packed with high density when solidified, resulting in high mobility. It is estimated that.

  Examples of a method for forming a bulk heterojunction layer in which an electron acceptor and an electron donor are mixed include a vapor deposition method and a coating method (including a casting method and a spin coating method).

  As a form which uses the photoelectric conversion element of this invention as photoelectric conversion materials, such as a solar cell, a photoelectric conversion element may be utilized by a single layer and may be laminated | stacked (tandem type) and may be utilized.

  Further, since the photoelectric conversion material is not deteriorated by oxygen, moisture, or the like in the environment, the photoelectric conversion material is preferably sealed by a known method.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1
[Production of Transparent Conductor B-1; Comparative Example]
SWCNT: A P3 SWCNT product supplied by Carbon Solutions was used on a 100 μm-thick polyethylene terephthalate film support with a gas barrier layer on both sides, using a spin coater so that the basis weight was 75 mg / m ^2. It was applied and dried. Subsequently, the coating layer was calendered to produce a transparent conductor B-1.

[Production of Transparent Conductors B-2 to 4; Comparative Example]
SWCNT: except that P3 SWCNT product supplied by Carbon Solutions and PEDOT / PSS CLEVIOS PH510 (solid content 1.89%) (manufactured by HC Starck) were mixed according to the ratio in Table 1. Transparent conductors B-2 to 4 were produced in the same manner as the transparent conductor B-1.

[Preparation of Transparent Conductors A-1 to 9; Present Invention]
SWCNT: A transparent conductor A- similar to the transparent conductor B-1, except that the P3 SWCNT product supplied by Carbon Solutions and the π-conjugated compound shown in Table 1 were mixed in accordance with the ratios shown in Table 1. 1-9 were produced.

  The graphene shown in Table 1 is a planar sheet-like carbon film having a thickness of 2 to 5 nm and a width of 1 to 5 μm. Porphyrins A to D are shown below.

<< Measurement and evaluation of transparent electrodes >>
The surface resistivity of each conductive layer produced was measured and evaluated by the following method.

(Surface resistivity)
For the surface resistivity, the surface resistivity of the transparent conductor was measured by a four-terminal method using a resistivity meter Loresta GP manufactured by Dia Instruments.

(Transmittance)
As evaluation of transparency, the total light transmittance was measured using a HAZE METER NDH5000 manufactured by Tokyo Denshoku Co., Ltd., and a numerical value was obtained.

(Roughness Ra, Rz)
The produced transparent conductive layer was measured in a PSI mode by 20 times measurement with a non-contact three-dimensional surface roughness meter (WYKO NT9300) to obtain Ra and Rz data.

<< Production of organic EL element >>
In each of the produced transparent conductive layer patterns, a square tile-shaped transparent pattern having a pattern side length of 2 inch square and 10 inch square (1 inch is 2.540 cm) square is cut out so as to be arranged in the center. ), And an organic EL element was produced by the following procedure.

  The cut out transparent conductive layer pattern was set in a commercially available vacuum deposition apparatus, and each of the deposition materials in the vacuum deposition apparatus was filled with the constituent material of each layer in an optimum amount for device fabrication. The evaporation crucible used was made of a resistance heating material made of molybdenum or tungsten.

  Subsequently, each light emitting layer was provided in the following procedures.

First, after depressurizing to a vacuum degree of 1 × 10 ⁻⁴ Pa, the energization crucible containing α-NPD was energized and heated, evaporated at a deposition rate of 0.1 nm / second, and a 30 nm hole transport layer was formed. Provided.

  Ir-1 and Ir-14 and compound 1-7 were co-deposited at a deposition rate of 0.1 nm / second so that the concentration of Ir-1 was 13% by mass and Ir-14 was 3.7% by mass. A green-red phosphorescent light emitting layer having a maximum wavelength of 622 nm and a thickness of 10 nm was formed.

  Next, E-66 and compound 1-7 were co-evaporated at a deposition rate of 0.1 nm / second so that E-66 was 10% by mass, and a blue phosphorescent light emitting layer having an emission maximum wavelength of 471 nm and a thickness of 15 nm was formed. Formed.

  Thereafter, M-1 is vapor-deposited to a thickness of 5 nm to form a hole blocking layer, and CsF is co-deposited with M-1 so that the film thickness ratio is 10%, and an electron transport layer having a thickness of 45 nm is formed. Formed.

On the formed electron transport layer, Al is used as a second electrode (cathode) forming material having a first electrode external lead terminal and a pattern side length of 2 inch angle and 10 inch (1 inch is 2.540 cm) angle. Mask vapor deposition was performed under a vacuum of × 10 ⁻⁴ Pa to form a second electrode having a thickness of 100 nm.

Furthermore, an adhesive is applied to the periphery of the second electrode except for the end portion so that external terminals for the first electrode and the second electrode can be formed, and Al ₂ O ₃ is deposited with a thickness of 300 nm using polyethylene terephthalate as a base material. After bonding the flexible sealing member, the adhesive was cured by heat treatment to form a sealing film, and organic EL elements having a light emitting area of 2 inch angle and a 10 inch angle were produced.

About each produced organic EL element, it was made to light-emit so that a luminance might be set to 300 cd / m < ² > by applying a DC voltage using the source measure unit 2400 type made from KEITHLEY, and the light emission state was visually evaluated on the following references | standards, Table 1 shows.

○: The whole surface emits light uniformly ○ △: The whole surface emits light, but the central part is slightly dark △: The edge is brightly lit but the center is clearly dark △: The edge is lighted However, the center part does not emit light. X: The edge part emits light slightly or the entire surface does not emit light. The rectification ratio is the current value when a voltage of +3 V / -3 V is applied to each organic EL element. The measurement is performed, the rectification ratio is obtained by the following calculation formula, the following criteria are evaluated, and the results are shown in Table 1. If there is leakage between electrodes, the rectification ratio becomes a low value.

  Rectification ratio = Current value when + 3V is applied / Current value when -3V is applied

  As is apparent from the results shown in Table 1, the transparent conductor not taking the configuration of the present invention has low conductivity. In addition, an organic EL element manufactured using a transparent conductor that does not have the configuration of the present invention does not emit light due to current leakage, does not emit light due to low conductivity, or emits unevenly due to electric field concentration. On the other hand, the transparent conductor of the present invention was excellent in conductivity, and light emission from a larger pixel could be confirmed. In addition, the organic EL element using the transparent conductor of the present invention can emit light uniformly in the light emitting area due to the effect of current leakage prevention by the conductive polymer layer and the in-plane current distribution of the conductive part. .

Example 2
[Preparation of transparent conductors A-11 to 19]
SWCNT: P3 swcnt product supplied by Carbon Solutions and a π-conjugated compound were mixed according to the ratios in Table 2 and used on a 100 μm thick polyethylene terephthalate film support provided with a gas barrier layer on both sides. Was applied using a spin coater so as to be 75 mg / m ² and dried. Subsequently, the coating layer was calendered to produce a transparent conductive film.

  Furthermore, the conductive polymer liquid P-1 prepared by the following method was formed with a spin coater so that the dry film thickness was 30 nm, and heated at 80 ° C. for 30 minutes to produce a two-layered transparent conductive film Produced the transparent conductors A-11 to 19 in the same manner as in Example 1.

(Preparation of conductive polymer liquid P-1)
(Synthesis of poly (2-hydroxyethyl acrylate))
2-Bromoisobutyryl bromide (7.3 g, 35 mmol), triethylamine (2.48 g, 35 mmol) and THF (20 ml) were added to a 50 ml three-necked flask, and the internal temperature was kept at 0 ° C. with an ice bath. In this solution, 30 ml of 33% THF solution of oligoethylene glycol (10 g, 23 mmol, ethylene glycol units 7-8, manufactured by Laporte Specialties) was added dropwise. After stirring for 30 minutes, the solution was brought to room temperature and further stirred for 4 hours. After THF was removed under reduced pressure by a rotary evaporator, the residue was dissolved in diethyl ether and transferred to a separatory funnel. Water was added and the ether layer was washed three times, and then the ether layer was dried with MgSO ₄ . The ether was distilled off under reduced pressure using a rotary evaporator to obtain 8.2 g (yield 73%) of initiator 1.

  Initiator 1 (500 mg, 1.02 mmol), 2-hydroxyethyl acrylate (4.64 g, 40 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), 50 ml of 50:50 v / v% methanol / water mixed solvent was put into a Schlenk tube, The Schlenk tube was immersed in liquid nitrogen under reduced pressure for 10 minutes. The Schlenk tube was taken out of liquid nitrogen and replaced with nitrogen after 5 minutes. After performing this operation three times, bipyridine (400 mg, 2.56 mmol) and CuBr (147 mg, 1.02 mmol) were added under nitrogen, and the mixture was stirred at 20 ° C. After 30 minutes, the reaction solution was dropped onto a 4 cm Kiriyama funnel with filter paper and silica, and the reaction solution was recovered under reduced pressure. The solvent was distilled off under reduced pressure using a rotary evaporator and then dried under reduced pressure at 50 ° C. for 3 hours. As a result, 2.60 g (yield 84%) of water-soluble binder resin 1 having a number average molecular weight of 13,100, a molecular weight distribution of 1.17, and a content of number average molecular weight <1000 of 0% was obtained.

The structure and molecular weight were measured by ¹ H-NMR (400 MHz, manufactured by JEOL Ltd.) and GPC (Waters 2695, manufactured by Waters), respectively.

<GPC measurement conditions>
Apparatus: Wagers 2695 (Separations Module)
Detector: Waters 2414 (Refractive Index Detector)
Column: Shodex Asahipak GF-7M HQ
Eluent: Dimethylformamide (20 mmol LiBr)
Flow rate: 1.0 ml / min
Temperature: 40 ° C
The obtained water-soluble binder resin 1 was dissolved in pure water to prepare a water-soluble binder resin 1 aqueous solution having a solid content of 50%.

  Next, a conductive polymer liquid P-1 was prepared as follows.

(Conductive polymer liquid P-1)
Water-soluble binder resin 1 aqueous solution (solid content 50% aqueous solution) 0.14 g
PEDOT / PSS CLEVIOS PH510 (solid content 1.89%)
(Manufactured by HC Starck) 1.59 g
The obtained transparent conductors A-11 to A-19 were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

  As is clear from the results shown in Table 2, it was confirmed that the structure of the present invention showed uniform light emission with a very good rectification ratio by using a conductive polymer in the lower layer of CNT as the upper layer. . In addition, it is a more preferable embodiment because both high transmittance and high conductivity are achieved at a better level.

Example 3
Photoelectric conversion element B-1 and photoelectric conversion element A-8 were produced by the following method using B-1 and A-8 of Example 1.

<Deposition of electron transport layer>
A TiOx precursor was prepared by a sol-gel method.

  First, 12.5 ml of 2-methoxyethanol and 6.25 mmol of titanium tetraisopropoxide were placed in a 100 ml three-necked flask and cooled in an ice bath for 10 minutes. Next, 12.5 mmol of acetylacetone was slowly added and stirred in an ice bath for 10 minutes. Next, the mixed solution was heated at 80 ° C. for 2 hours and refluxed for 1 hour. Finally, it was cooled to room temperature to obtain a TiOx precursor. The above steps were all performed in a nitrogen atmosphere.

  Next, this 150 mmol TiOx precursor solution was spin-coated (rotation speed 2000 rpm, rotation time 60 s) on the transparent conductive layers B-1 and A-8. Next, after removing unnecessary parts by wiping, the TiOx precursor was hydrolyzed by taking it out from the glove box into the air and leaving it at room temperature for 30 minutes. Next, the TiOx precursor was heat-treated at 150 ° C. for 1 hour to obtain a 30 nm TiOx layer (amorphous oxide semiconductor layer).

<Bulk heterojunction layer deposition>
Next, a plex core OS2100 (poly-3-alkylthiophene, manufactured by Plextronics) and Nanom Spectra E100H (phenyl-C61-methyl butyrate, manufactured by Frontier Carbon Co.) on the oxide semiconductor layer are in a mass ratio of 5: 4. Spin-coat (800 rpm, 60 s) the 1.8% by mass chlorobenzene solution mixed in step 1, wipe off and remove unnecessary portions, and then heat at 150 degrees for 10 minutes to form an organic semiconductor layer (organic photoelectric conversion layer) with a thickness of 100 nm. Filmed.

<Film formation of hole transport layer>
Next, H. on the organic semiconductor layer. C. Baytron P4083 (PEDOT: PEDOT / PSS) manufactured by Starck was spin-coated (4000 rpm, 60 s) and heated at 150 degrees for 10 minutes to form a 40 nm hole transport layer.

<Counter electrode film formation>
Next, as an Ag electrode layer on the conductive polymer layer, a silver nanoparticle paste dispersion (L-Ag1T manufactured by ULVAC Material Co., Ltd.) is screen-printed to form a 1 cm wide line so as to be orthogonal to the transparent conductive layer pattern. Were printed, and the electrode layer was formed by heat-drying for 10 minutes at 120 degrees, and the organic photoelectric conversion element 1 was obtained.

  The obtained organic photoelectric device 1 was put in the glove box again, and then sealed with an aluminum foil having a thickness of 30 μm using a sealant (manufactured by Nagase ChemteX Corporation, UV RESIN XNR5570-B1). After performing the above, it was taken out into the atmosphere and the photoelectric conversion efficiency was measured.

  Photoelectric conversion element A-8 showed 1.5 times the efficiency compared with photoelectric conversion element B-1.

DESCRIPTION OF SYMBOLS 10 Board | substrate 11 1st electrode 12 2nd electrode 13 Organic functional layer 14 1st conductive layer 15 2nd conductive layer

Claims (6)

A transparent conductor having a transparent conductive layer containing carbon nanotubes on a transparent substrate,
The transparent conductive layer contains at least one π-conjugated compound selected from a porphyrin compound, a phthalocyanine compound, and a graphene compound,
The average transmittance at a spectral wavelength of 400 to 700 nm is 70% or more ,
2 The sheet resistance value at 50 ° C. and 50% RH is less than 10Ω / □ ,
Below the arithmetic average roughness Ra of 10nm of the transparent conductive layer surface, and the ten-point average roughness Rz Ri der less 40 nm,
Transparent conductor in which the concentration of carbon nanotubes in the transparent conductive layer is characterized in der Rukoto least 75 wt%. The transparent conductive layer, transparent conductor of claim 1 Symbol placement, characterized by further comprising a conductive polymer containing layer. The transparent conductor according to claim 2, wherein the conductive polymer-containing layer further contains a hydroxyl group-containing nonconductive polymer. A transparent conductor having a transparent conductive layer having a carbon nanotube-containing layer and a conductive polymer-containing layer on a transparent substrate,
The carbon nanotube-containing layer contains at least one π-conjugated compound selected from a porphyrin compound, a phthalocyanine compound, and a graphene compound,
The conductive polymer-containing layer further contains a hydroxyl group-containing nonconductive polymer,
The average transmittance at a spectral wavelength of 400 to 700 nm is 70% or more,
The sheet resistance value at 25 ° C. and 50% RH is less than 10Ω / □,
An arithmetic average roughness Ra of the surface of the transparent conductive layer is 10 nm or less, and a ten-point average roughness Rz is 40 nm or less.   5. An organic EL element, wherein at least an organic phosphorescent light emitting layer is provided on the transparent conductive layer of the transparent conductor according to any one of claims 1 to 4.   An organic photoelectric conversion element, wherein at least an organic power generation layer is provided on the transparent conductive layer of the transparent conductor according to any one of claims 1 to 4.