JP2005150278A - Electrode and functional element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a functional element having a sufficient characteristic for suppressing the deactivation of an element excitation state since the disappearance of the element excitation state on a granular interface deteriorates the characteristic of the functional element when the electrode material of the functional element is formed of an assembly of particulates. <P>SOLUTION: An electrode including a semiconductor having a nanotube structure and the functional element using the electrode are installed. The electrode is formed of an oxide including a transition metal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrode including a semiconductor having a nanotube structure as a constituent element and a functional element using the same.

  In a functional element such as a conventional electro-optical element or photoelectrochemical element, a functional electrode in which a semiconductor is formed on a substrate with a conductive film is used. A semiconductor responds to external stimuli such as heat, light, and temperature, and electrons and phonons or their composites are generated depending on the environment. When the semiconductor layer is composed of semiconductor fine particles when propagating through the semiconductor, the elementary excited state may be deactivated due to scattering of the fine particles between the particles. Therefore, it is an important issue to reduce scattering of fine particles in the agglomeration.

  For example, titanium oxide is most frequently used as a semiconductor material in a dye-sensitized solar cell (see, for example, Non-Patent Document 1). This solar cell uses a functional electrode in which titanium oxide particles of about several tens of nanometers are formed on a transparent conductive substrate and a dye is adsorbed thereon. It has been reported that in this functional electrode, the light conversion efficiency greatly depends on the structure of the titanium oxide layer such as the particle shape of titanium oxide and the bonding state between the particles. The portion where the titanium oxide particles are bonded becomes an obstacle for photogenerated electrons to move through the titanium oxide layer toward the transparent conductive substrate. For this reason, sufficient effect cannot be acquired with respect to making a titanium oxide layer thick, adsorb | sucking many pigment | dyes, and improving sunlight utilization efficiency. In order to improve this point, attempts have been made to control the structure of the titanium oxide particles themselves constituting the titanium oxide layer (see, for example, Non-Patent Documents 2 to 9). However, it is difficult to accurately control the structure of the particles themselves, and at the same time, improving productivity is also an issue.

B. O'Regan, M. Gratzel, “Nature” (UK), 1991, 353, p. 737 M. Adachi, Yusuke Murata, Makoto Harada, Susumu Yoshikawa, “Chemistry Letters” (USA), 2000, p. 942 W. M. S. Won, Esther S. Jeng, Jackie Y. Ying, “Nano Letters” (USA), 2001, Vol. 1, p. 637 M. Ohtaki, et al., "Journal of American Chemical Sciety" (USA), 1998, 120, p. 6832 M. Yata, M. Mihara, S. Mouri, M. Kuroki, T. Kijima, "Advanced Materials", (USA) 2002, volume 14, p. 309 N. Ulagappan, C. N. R. Rao, “Chemical Communications” (UK), 1996, p. 1685 W. Zhao, Y. Sun, Q. Ma, Y. Fang, “Chinese Journal of Catalysis” (China), 1999 , 20, p. 375 D. M. Antonelli, “Microporous and Mesoporous Materials” (USA), 1999, 30, p. 315 H. Imai, Yuko Takei, Kazuhiko Shimizu, Manabu Matsuda, Hiroshi Hirashima, "Journal of Materials Chemistry" (UK) ), 1999, vol. 9, p. 2971

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electrode manufactured using a semiconductor having a nanotube structure that can be easily structurally controlled. Another object is to provide a functional element such as a highly efficient photoelectrochemical element using the electrode.

  As a result of intensive research to solve the conventional problems as described above, the present inventors formed a semiconductor having a target nanotube structure along the template, and then peeled off the template to control the structure. The inventors have found that a semiconductor having a nanotube structure can be taken out, and that the intended functional electrode can be produced by using the semiconductor having the nanotube structure, and the present invention has been completed.

That is, the present invention relates to an electrode including a semiconductor having a nanotube structure.
The semiconductor includes an oxide containing a transition metal, a Group 2B to Group 7B element in the periodic table, an alloy containing the element, an oxide of those elements, or a unit including a molecular structure having an electron donating property and electron acceptance. It is preferable that it consists of a high molecular compound comprised at least from the unit containing the molecular structure which has property.
The nanotube structure is preferably formed by a template, and the template is preferably formed by an anodized porous material obtained by anodizing a metal in an electrolytic solution.

The present invention also relates to a functional element using the electrode.
The functional element preferably has photoelectric conversion characteristics.
The functional element has a configuration in which an electrode including a semiconductor having a nanotube structure made of titanium oxide adsorbed with a dye, a counter electrode on which a platinum or carbon material is formed, and an electrolyte solution containing iodine ions therebetween. It is preferable.

Hereinafter, the present invention will be described in detail.
The electrode of the present invention includes a substrate and a semiconductor layer made of a semiconductor having a nanotube structure formed on the substrate (hereinafter also referred to as a semiconductor nanotube).
It does not specifically limit as a board | substrate, A material, thickness, a dimension, a shape, etc. can be suitably selected according to the objective. The substrate may or may not be conductive, and in addition to metals such as gold and platinum, for example, colorless or colored glass, meshed glass, glass blocks, and the like are used. Further, it may be a colorless or colored resin having transparency. Specific examples of these resins include polyesters such as polyethylene terephthalate, polyamide, polysulfone, polyether sulfone, polyether ether ketone, polyphenylene sulfide, polycarbonate, polyimide, polymethyl methacrylate, polystyrene, cellulose triacetate, and polymethyl. Examples include pentene. As the substrate used for the electrode of the present invention, a transparent conductive substrate is particularly preferable. In addition, the board | substrate in this invention has a smooth surface at normal temperature, The surface may be a plane or a curved surface, and may deform | transform by stress. In order to impart conductivity to the substrate, a conductive film made of a metal thin film or metal oxide such as gold, silver, chromium, copper, or tungsten may be disposed on the surface. Examples of the metal oxide include Indium Tin Oxide (ITO (In ₂ O ₃ : Sn)) obtained by doping a metal oxide such as tin or zinc with a small amount of other metal elements, or Fluorine doped Tin Oxide (FTO (SnO ₂ )). : F)), Aluminum doped Zinc Oxide (AZO (ZnO: Al)) and the like are preferably used.

  The thickness of the conductive film is usually 10 nm to 10 μm, preferably 100 nm to 2 μm, and the surface resistance (resistivity) is usually 0.5 to 500 Ω / sq, preferably 2 to 50 Ω / sq. These conductive films can be formed on a substrate by a known method such as a vacuum deposition method, an ion plating method, a CVD method, an electron beam vacuum deposition method, or a sputtering method.

In the present invention, the nanotube structure has a hollow shape, and the outer shape of the cross section of the tube has a circular shape, an elliptical shape, a polygonal shape, etc., and the length is usually 0.01 μm to 2000 μm, preferably 0. 1 μm to 1500 μm, more preferably 1 μm to 1000 μm, the tube cross-section thickness is usually 5 nm to 200 nm, preferably 10 nm to 100 nm, and the outer diameter or major axis of the tube cross-section is usually 1 nm to 500 nm, preferably 10 nm to 300 nm.
The nanotube structure can be confirmed by electron microscope observation.

Semiconductor nanotubes can be produced by directly synthesizing by any of the solid phase method, liquid phase method, and vapor phase method, and by depositing or synthesizing a semiconductor material on the mold surface by vapor deposition or sputtering. Is mentioned.
When forming semiconductor nanotubes on the template surface, the template may be any molecule that forms micelles in a solution such as a surfactant, such as a template formed in an aqueous solution containing sodium dodecyl sulfate and urea. Can be mentioned.
The material formed on the template may be a molecule containing a metal element such as a metal alkoxide, and examples thereof include TiCl ₄ , Ti (SO ₄ ) _2, and Ti (OiPr) ₄ .

Further, as another method, for example, a method called a liquid phase microparticle growth method described in Non-Patent Documents 10 and 11 below, an electrophoresis method described in Non-Patent Documents 13 to 15, and a method described in Non-Patent Documents 12 to 14 It can also be produced by various methods such as an electrodeposition method and a pressure method described in Non-Patent Document 15.
(1) Non-Patent Document 10: Shigehito Deki, three others, “Chemistry Letters”, 1996, Vol. 433 (2) Non-patent Document 11: Kazuhiko Shimizu, three others "Thin Solid Films" (UK), 1999, 351, p. 220
(3) Non-Patent Document 12: Tsutomu Miyasaka, 4 others, “Chemistry Letters”, 2003, p. 1250
(4) Non-Patent Document 13: S. Karuppuchamy, 5 others, “Chemistry Letters”, 2001, p. P. 78 (5) Non-Patent Document 14: D. Schlettwein, 3 others, “Journal of Electroanalytical Chemistry” (USA), 2000, 481, p. 42 (6) Non-Patent Document 15: H. Lindstrom, 4 others, “Journal of Photochemical and Photobiological A Chemistry” (UK), 2001, 145, p. 107

  Furthermore, an anodized porous material can be used as a method for producing a higher-performance semiconductor nanotube. For example, as shown in Non-Patent Document 16 below, using a highly ordered nanoporous alumina as a template, a highly regular semiconductor layer is produced in the pores by using the above-described method for producing a semiconductor layer. You can also. Further, as described in Non-Patent Documents 17 and 18 below, a highly ordered nanoporous alumina is used as a template, and another template material is filled in the pores, and then the template prepared first is removed to obtain a new template. A semiconductor layer having photoelectric conversion characteristics can be manufactured using a target semiconductor material. Examples include a method of removing the template after forming these semiconductor materials to obtain semiconductor nanotubes (for example, Non-Patent Documents 17 to 19 below).

(1) Non-Patent Document 16: Hideki Masuda, Kenji Fukuda, "Science", (USA), 1995, 268, p. 1466
(2) Non-Patent Document 17: Patrick Hoyer, Hideki Masuda, "Journal of Material Science Letters", (Netherlands), 1996, Vol. 15, p. . 1228
(3) Non-Patent Document 18: Patrick Hoyer, “Langmuir” (UK), 1996, Vol. 12, p. 1411
(4) Non-Patent Document 19: S.-Z. Chu, three others, “Chemistry of Materials” (USA), 2002, 14, p. 266

As a method for forming a film on a mold, the methods described in the following non-patent documents 20 to 23 such as a sputtering method, an MOCVD method, and a PLD method can be used.
(1) Non-Patent Document 20: M. Komabayashi, two others, “Japan Journal of Applied Physics”, 1990, Vol. 29 (2) Non-Patent Document 21 : ZX Liu, two others, “Thin Solid Films” (UK), 2001, 381, p. 262
(3) Non-Patent Document 22: Y. Maeda, three others, “Proceedings of MRS” (USA), 2000, 607, p. 315
(4) Non-Patent Document 23: M. Libezny, 6 others, “Proc. Of the 13th European Photovoltaics Solar Energy Conference) ", (France), 1995, p. 1326

Further, when a metal, semiconductor, or insulator material is laminated on the mold surface, an optimum value is selected for the thickness depending on the type of material and the intended function. For example, when a superlattice structure such as Si or SiO described in Non-Patent Documents 24 and 25 is required, the thickness of these layers is preferably 1 to 10 nm, and more preferably 3 to 7 nm.
(1) Non-Patent Document 24: J. Nelson, “Quantum-well structures for photovoltaics energy conversion MH Francombe and JL Vossen eds.,” Heterojunction and quantum-well infrared detector), (USA), Academic Press, 1995, p. 311
(2) Non-Patent Document 25: MA Green, “Third Generation Photovoltaics: Ultra High Efficiency at Low Cost, Progress Generation Photovoltaics: Ultra-high efficiency at low cost, Progress in Photovoltaics), (Germany), Springer, 2001, Vol. 9, p. 257

  The arrangement pattern of the semiconductor layer on the substrate or the conductive film on the substrate is not particularly limited, and may be arranged on the entire surface of the substrate, or a part of the substrate, for example, a mesh shape, a stripe shape, or the like. You may arrange as. The thickness of the semiconductor layer is not particularly limited, but is usually 0.1 μm to 1000 μm, preferably 1 μm to 500 μm, and more preferably 1 μm to 100 μm. In addition, the shape of the template when the nanotube structure is formed using the template is appropriately selected according to the purpose, but a tube having an outer shape of a circle, an ellipse, or a polygon is preferably used.

  In the present invention, the semiconductor forming the semiconductor layer is not necessarily composed of only a single semiconductor material. For example, the structure of the semiconductor material A and the semiconductor material B as shown in FIG. Further, for example, when a bonding surface of at least two kinds of materials having different carrier characteristics such as a photoelectric conversion element, a thermoelectric element, and a thermophotovoltaic element is important as a functional element, the semiconductor material A and the semiconductor in FIG. Examples of the material B include combinations having different characteristics such as p-type and n-type semiconductors. Alternatively, a compound semiconductor can be obtained by performing heat treatment after alternately laminating at least two kinds of metals, semiconductors, and insulators on the mold surface by sputtering or the like.

In addition, the semiconductor layer in the present invention may be composed of only a semiconductor material, but may contain other optional components as long as the object of the present invention is not impaired.
For example, a binder for improving the bonding state between the semiconductor particles can be preferably used. The binder is not particularly limited as long as it is inactive to the electrolyte after curing and does not electrolyze. For example, the polymer solid electrolyte, epoxy resin, acrylic resin, melamine resin, silicone resin, polytetrafluoroethylene, polytetrafluoroethylene Styrol, carboxymethyl cellulose, polyvinylidene fluoride, or derivatives or mixtures thereof are used. When these binders are used, the mixing ratio of the semiconductor material / binder (mass ratio) is usually 10/90 to 90/10, preferably 20/80 to 80/20. Alternatively, in order to obtain a paste that enables a process for forming a semiconductor layer of a desired shape by the printing method, doctor blade method, etc., a binder or a second layer such as polyethylene glycol to impart a thickening effect. It is also possible to add three components. These optional components are preferably substances that can be removed when heat treatment or pressure treatment is performed to form a semiconductor layer.
Other optional components include fine metal particles that do not corrode by the electrolyte and conductive oxide semiconductors such as ITO, FTO, and AZO.

  The method for forming the semiconductor layer is not particularly limited, and a known method can be employed. For example, when a binder is used, generally, the semiconductor material and the binder are mixed to form a paste, and then screen printing, flat printing, gravure printing, intaglio printing, flexographic printing, letterpress printing, and special printing are performed on the substrate surface. It can be manufactured by a doctor blade method, a method in which a groove is formed in advance on a substrate, a paste in which a semiconductor material and a binder are mixed is filled in the groove, and then the excess paste is removed with a spatula or the like. After disposing the paste on the substrate surface, the conductivity and adhesion may be improved by heating or the like. In addition to an oven, a muffle furnace, an electric furnace, infrared heating or the like may be used for heating. The firing temperature varies depending on the paste used and the substrate material, but is preferably 50 ° C to 700 ° C, more preferably 100 ° C to 600 ° C, and still more preferably 200 ° C to 500 ° C. Moreover, you may bake in nitrogen atmosphere as needed.

The semiconductor having a nanotube structure used in the present invention is selected from materials exhibiting functions that can be used as electrodes of functional elements.
For example, an oxide containing a transition metal can be given. These materials include Nb ₂ O ₅ , TiO ₂ , WO ₃ , V ₂ O ₅ , Ta ₂ O ₅ , MoO ₃ , RhO ₂ , NiO, FeO ₂ , Cr ₂ O ₃ , IrO ₂ , SrTiO ₃ , MX. ₃ series compounds (M = Co, Rh, Ir; X = P, As, Sb), RM ₄ X ₁₂ (M = Fe, Ru, Os; R = La, Ce, Pr, Nd, Eu), NaCo ₂ O ₄ etc. can be illustrated.

In addition, examples include materials selected from Si, Ge, an alloy or an oxide containing Group 2B to Group 7B elements of the periodic table, and Group 2B to Group 7B elements of the periodic table. These _{materials, ZnO, SiO 2, Si,} CdS, Fe 1-x M x Si 2 (x = 0~1, M = Co, Mn, Cr), GaInAsP, GaAs, InP, GaSb, GaInAs, Ge , SiGe, CdTe, CuInGaSSe, CuInGaSe 2, (ZnO) m In 2 O 3 (m = 4~7,9,11), Ba 1-x Sr x PbO 3 (x = 0~1), Ni 1-x LiO (x = 0~1), Cd 3 TeO 6, Cd 3 - x A x TeO 6 -δ (x = 0~1, δ = 0~0.8), Zn 1-x Al x O (x = 0-1), Bi ₂ Te _{3 and the} like. _{Further, Gd 3 Mg 7, YH x} (x = 0~3), Y-Mg, Ni-Mg, etc. S _m -Mg _(m = 0~3) alloy exhibiting metal-semiconductor transition behavior of and the like.
The semiconductor used in the present invention may be single crystal or polycrystalline. In particular, in the case of titanium oxide, anatase type, rutile type, brookite type, etc. are mainly used as the crystal system, but anatase type is preferred.

  Furthermore, conjugated organic substances such as polyphenylene vinylene (PPV) and polythiophene, organic substances in which conjugated substances are bonded by non-conjugated chains, molecules having electron donating properties, molecules having electron accepting properties, and electron donating properties Examples thereof include a polymer compound (block copolymer) composed at least of a unit including a molecular structure and a unit including a molecular structure having an electron accepting property.

  The molecular structure having the electron donating property means a structure having a small ionization potential, a property of supplying electrons to other molecules and easily becoming positive ions, and a molecular structure having an electron accepting property. Refers to a structure having a high electron affinity and a property of receiving an electron from another molecule and easily becoming a negative ionic state. In the block copolymer, a unit containing a molecular structure having electron donating properties (polymer unit) and a unit containing a molecular structure having electron accepting properties (polymer unit) are used in combination. The donating property is naturally determined by the relative relationship between the compounds used, and a combination of compounds satisfying these properties is appropriately selected.

  The molecular structure having an electron-donating property is not particularly limited as long as it has an electron-donating property in the molecular structure part, but a poly or oligoarylene vinylene structure, a poly or oligoaniline linked structure, a poly or oligothiophene linked structure, Examples thereof include a poly or oligopyrrole linking structure, a poly or oligoamine linking structure, a phthalocyanine structure, and a naphthalocyanine structure.

Further, the molecular structure having electron accepting property is not particularly limited as long as it has electron accepting property, but a poly or oligoarylene vinylene structure containing an electron withdrawing group such as cyano group, electron withdrawing such as cyano group, etc. Poly or oligothiophene structure containing a functional group, poly or oligopyrrole structure containing an electron withdrawing group such as cyano group, poly or oligophenylquinoline, viologen structure, polycyclic aromatic structure such as perylene, fullerene Examples include the structure.
Specific examples of the electron accepting molecular structure include those represented by the following formulas (1) to (4), and examples of the electron donating molecular structure include those represented by the following formulas (5) to (11). be able to.

In the general formulas (1) to (11), R ¹ and R ^{4 to} R ⁸ may be the same or different and are each independently a linear and branched alkyl group having 1 to 10 carbon atoms, an alkenyl group, An alkoxyl group or an aryl group having 6 to 12 carbon atoms, an aralkyl group, or an aryloxy group is shown.
R ² and R ³ may be the same or different, and each independently represents a linear and branched alkyl group or alkenyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms.
In addition, when several R < ¹ > -R < ⁸ > exists in the same structural formula, they may be the same or different.

  Examples of the alkyl group include methyl group, ethyl group, propyl group, i-propyl group, butyl group, s-butyl group, t-butyl group, pentyl group, isopentyl group, neopentyl group, t-pentyl group, and hexyl. Group, isohexyl group, heptyl group, octyl group, nonyl group, decyl group and the like. Examples of the alkenyl group include vinyl group, allyl group, isopropenyl group, butyryl group, pentylenyl group, hexenyl group and the like. As the group, methoxy group, ethoxy group, propoxy group, i-propoxy group, butoxy group, s-butoxy group, t-butoxy group, pentoxy group, isopentoxy group, neopentyloxy group, t-pentyloxy group, hexyloxy Group, isohexyloxy group, heptyloxy group, octyloxy group, nonyloxy group Group, decyloxy group and the like, as aryl group, phenyl group, xylyl group, tolyl group, cumenyl group, naphthyl group and the like, as aralkyl group, benzyl group, trimethyl group and the like as aryloxy group, A phenoxy group, a tolyloxy group, etc. are mentioned.

In the general formulas (1) to (11), X ⁻ and Y ⁻ may be the same or different, and each independently represents a halogen anion, ClO ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CH ₃ COO ^−. , CH ₃ (C ₆ H ₄ ) SO ₃ ^— represents a counter anion. M and n each independently represent an integer of 1 to 1000, preferably 2 to 500.

  The copolymer having these structures may be either a copolymer having these structures in the main chain or a copolymer having these structures in the side chain, but preferably these structures are in the main chain. It is desirable to have a copolymer.

Moreover, as these structures, it is essential to have either an electron-accepting property or an electron-donating property, and further, these structures have a carrier mobility. It is desirable that Whether or not these structures have carrier mobility can be easily determined by a conventional method. For example, it can be discriminated by producing a homopolymer mostly composed of these structures and measuring the carrier mobility by the time-of-flight method (for example, Jpn. J. Appl. Phys., Vol. 38). , pp.L1188 (1999) measurement examples). Usually, the carrier mobility of ^{10 -7 ~10 3 cm 2 / V} · s, preferably desirably of about ^{10 -6 ~10cm 2 / V · s} .

  A thin film formed from a block copolymer forms a microphase separation structure composed of an electron donating phase and an electron accepting phase by self-organization. The microphase separation structure referred to here is an electron donating phase. Or the thing which has the phase-separation structure whose domain size of each phase which consists of an electron-accepting phase is about several nanometers-several hundred nanometers. The domain size can be measured with an electron microscope or a scanning probe microscope. Furthermore, in a thin film formed from a block copolymer, the domain size of the microphase separation structure is preferably within 10 times the exciton diffusion length. The exciton diffusion length is the distance that excitons diffuse while the amount of excitons generated by light absorption becomes 1 / e. The value can be obtained by measuring the photoluminescent quenching of a polymer or oligomer comprising each unit constituting the block copolymer as a function of its film thickness. The measured exciton diffusion length takes different values between the electron donating phase and the electron accepting phase, but generally takes a value of about several tens of nm.

  More specific examples of the block copolymer that can be used in the present invention include the following general formulas (12) to (20).

  In general formulas (12) to (20), A and A ′ represent molecular groups containing a molecular structure having electron accepting properties, and D and D ′ represent molecular groups containing a molecular structure having electron donating properties. Moreover, as n, m, l, and p in the formulas (12) to (20), in each case, n is usually an integer in the range of 2 to 10000, preferably 3 to 5000, and more preferably 4 to 2000. M is an integer in the range of usually 2 to 10000, preferably 3 to 5000, and more preferably 4 to 2000. l is an integer in the range of usually 2 to 10,000, preferably 3 to 5000, more preferably 4 to 2000. p is usually an integer in the range of 2 to 10000, preferably 3 to 5000, and more preferably 4 to 2000. R represents a polymer residue. Specific examples of the block copolymers represented by the general formulas (12) to (20) are not particularly limited, but examples include the following general formulas (21) to (37).

In the general formulas (21) to (37), R ¹⁰ and R ¹¹ may be the same or different, and each independently represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ⁹ and R ¹² are Each independently represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 12 carbon atoms, or an alkylene group having 1 to 10 carbon atoms containing an oxygen atom or a nitrogen atom, or an arylene group having 6 to 12 carbon atoms. . Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and an isopropylene group. Examples of the arylene group include a phenylene group and a tolylene group.

Moreover, as n, m, l, and p in the formulas (21) to (37),
n is usually an integer in the range of 2 to 10000, preferably 3 to 5000, more preferably 4 to 2000, and m is an integer in the range of 2 to 10000, preferably 3 to 5000, more preferably 4 to 2000. Yes, l is usually an integer in the range of 2 to 10000, preferably 3 to 5000, more preferably 4 to 2000, and p is usually 2 to 10000, preferably 3 to 5000, more preferably 4 to 2000. It is an integer.

The molecular terminals of these copolymers vary depending on the production method, but are usually hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkenyl group, an alkoxyl group, or an aryl group having 6 to 12 carbon atoms, an aralkyl group, and an aryloxy group. Such as hydrocarbons.
These copolymers can be easily obtained by a known method. The production method thereof is not particularly limited. For example, a condensation polymerization reaction of a dihalogen compound having an electron-accepting structure or an electron-donating structure with a strong base, or an electron-accepting structure or electron donating. And a method of radical polymerization, anionic polymerization, and cationic polymerization of a monomer compound having a structure having a property and having various polymerizable groups.

The functional element of the present invention is characterized by using an electrode including a semiconductor having a nanotube structure obtained as described above.
In the present invention, the functional element is a general term for elements that generate electricity, change color or transmittance, or cause a chemical reaction, for example, by stimulation of light, electricity, temperature, gas, or the like. . Specifically, an electrochromic element, a photochromic element, a gasochromic element, a photoelectric conversion element, a thermoelectric conversion element, a Thermophotovoltaic element, and the like can be typically given.
Such a functional element basically includes a transparent conductive substrate, an electrode made of a semiconductor layer formed on the substrate, and a counter electrode, and the electrode made of the semiconductor layer and the counter electrode may be in direct contact with each other. And the electrolyte layer may be arrange | positioned between both. The distance between the electrodes is usually 0.1 μm or more, preferably 1 μm or more, and usually 1 mm or less, preferably 0.5 mm or less. Examples of these functional elements include those having a structure as shown in FIG.

The electrolyte layer is not particularly limited and may be either a liquid system or a solid system, and preferably exhibits a reversible electrochemical redox characteristic.
The electrolyte has an ionic conductivity of usually 1 × 10 ⁻⁷ S / cm or more, preferably 1 × 10 ⁻⁶ S / cm or more, more preferably 1 × 10 ⁻⁵ S / cm or more at room temperature. desirable. The ionic conductivity can be obtained by a general method such as a complex impedance method.
As the electrolyte, the oxidant has a diffusion coefficient of 1 × 10 ⁻⁹ cm ² / s or more, preferably 1 × 10 ⁻⁸ cm ² / s or more, more preferably 1 × 10 ⁻⁷ cm ² / s or more. What is shown is desirable. The diffusion coefficient is an index indicating ion conductivity, and can be obtained by a general method such as constant potential current characteristic measurement or cyclic voltammogram measurement.

  The thickness of the electrolyte layer is not particularly limited, but is preferably 1 μm or more, more preferably 10 μm or more, and preferably 3 mm or less, more preferably 1 mm or less.

The liquid electrolyte is not particularly limited. Usually, a solvent, a substance exhibiting reversible electrochemical redox characteristics (soluble in a solvent), and, if necessary, a supporting electrolyte as a basic component Composed.
Any solvent can be used as long as it is generally used in electrochemical cells and batteries. Specifically, acetic anhydride, methanol, ethanol, tetrahydrofuran, propylene carbonate, nitromethane, acetonitrile, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoamide, ethylene carbonate, dimethoxyethane, γ-butyrolactone, γ-valerolactone, sulfolane, dimethoxy Ethane, propiononitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, dimethylacetamide, methylpyrrolidinone, dimethyl sulfoxide, dioxolane, sulfolane, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, ethyldimethyl phosphate, tributyl phosphate, phosphorus Tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, phosphoric acid Tridecyl, tris phosphate (trifluoromethyl), tris phosphate (pentafluoroethyl), triphenyl polyethylene glycol phosphate, polyethylene glycol, and the like can be used. In particular, propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone, sulfolane, dioxolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, adiponitrile, methoxyacetonitrile, methoxypropionitrile, dimethylacetamide, methylpyrrolidinone, dimethylsulfoxide , Dioxolane, sulfolane, trimethyl phosphate and triethyl phosphate are preferred.

  Moreover, room temperature molten salts can also be used as a solvent. Here, the room temperature molten salt is a salt made of an ion pair that is melted at room temperature (that is, in a liquid state) consisting of only an ion pair that does not contain a solvent component, and usually has a melting point of 20 ° C. or less. A salt composed of an ion pair that is in a liquid state at a temperature in excess of ° C.

Examples of the room temperature molten salt include the following.

(Here, R represents an alkyl group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, and X ⁻ represents a halogen ion or SCN ⁻ ).

(Wherein R1 and R2 each represent an alkyl group having 1 to 10 carbon atoms (preferably a methyl group or an ethyl group) or an aralkyl group having 7 to 20 carbon atoms, preferably 7 to 13 carbon atoms (preferably a benzyl group). And may be the same as or different from each other, and X ⁻ represents a halogen ion or SCN ⁻ .)

(Here, R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group having 1 or more carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms (such as a phenyl group). Or a methoxymethyl group or the like, which may be the same or different from each other, and X ⁻ represents a halogen ion or SCN ⁻ .)

  The solvent may be used alone or in combination of two or more.

In addition, examples of substances that exhibit reversible electrochemical oxidation-reduction characteristics include what are commonly referred to as so-called redox materials, but the type is not particularly limited. Examples of such substances include ferrocene, p-benzoquinone, 7,7,8,8-tetracyanoquinodimethane, N, N, N ′, N′-tetramethyl-p-phenylenediamine, tetrathiafulvalene, thi Anthracene, p-toluylamine, etc. can be mentioned. Further, LiI, NaI, KI, CsI , CaI 2, 4 quaternary imidazolium iodide salt, iodine tetraalkylammonium Motoshio, Br ₂ and LiBr, NaBr, KBr, CsBr, and metal bromides, such as CaBr ₂ and the like, In addition, Br ₂ and tetraalkylammonium bromide, bipyridinium bromide, bromine salts, complex salts such as ferrocyanic acid-ferricyanate, sodium polysulfide, alkylthiol-alkyldisulfides, hydroquinone-quinones, viologen dyes and the like can be mentioned. .

As the redox material, only one of an oxidant and a reductant may be used, or the oxidant and the reductant may be mixed and added at an appropriate molar ratio. Further, these redox pairs may be added so as to show electrochemical responsiveness. Materials exhibiting such properties include halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N _{^{-, PF 6 -, AsF 6}} -, CH 3 COO -, CH 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - , such as ferrocenium having a counter anion selected from metallocenium of In addition to salts, halogens such as iodine, bromine and chlorine can also be used.

Another example of a substance exhibiting reversible electrochemical redox characteristics is a salt having a counter anion (X ⁻ ) selected from halogen ions and SCN ⁻ . Specifically, (CH ₃ ) ₄ N ⁺ X ⁻ , (C ₂ H ₅ ) ₄ N ⁺ X ⁻ , (n−C ₄ H ₉ ) ₄ N ⁺ X ⁻ ,

Quaternary ammonium salts such as (CH ₃ ) ₄ P ⁺ X ⁻ , (C ₂ H ₅ ) ₄ P ⁺ X ⁻ , (C ₃ H ₇ ) ₄ P ⁺ X ⁻ , (C ₄ H ₉ ) ₄ P ⁺ Examples thereof include phosphonium salts such as X ⁻ .
Of course, a mixture of these can also be used suitably.

In addition, redox room temperature molten salts can also be used as substances exhibiting reversible electrochemical redox properties. Here, the redox ambient temperature molten salt is a salt composed of ion pairs that are melted at room temperature (that is, in a liquid state) consisting only of ion pairs that do not contain a solvent component, and usually has a melting point of 20 ° C. or less. A salt composed of an ion pair that is in a liquid state at a temperature exceeding 20 ° C. and capable of performing a reversible electrochemical redox reaction.
The redox room temperature molten salt can be used alone or in combination of two or more.

Examples of redox room temperature molten salts include the following.

(Here, R represents an alkyl group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms. X ⁻ represents a counter anion, specifically a halogen ion or SCN ⁻ or the like.)

(Where R1 and R2 are each independently an alkyl group having 1 to 10 carbon atoms (preferably a methyl group or an ethyl group) or an aralkyl group having 7 to 20 carbon atoms, preferably 7 to 13 carbon atoms (preferably benzyl). And X ⁻ represents a counter anion, specifically a halogen ion or SCN ⁻ ).

(Here, R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group having 1 or more carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms (such as a phenyl group). Or a methoxymethyl group, etc., which may be the same or different from each other, and X ⁻ represents a counter anion, specifically a halogen ion or SCN ⁻ .

  The amount of the substance exhibiting reversible electrochemical redox characteristics is not particularly limited as long as it dissolves in the solvent, but is usually 1% by mass to 50% by mass, preferably 3% with respect to the solvent. It is desirable that it is mass%-30 mass%.

Further, as the supporting electrolyte added as necessary, salts, acids, alkalis, and room temperature molten salts that are usually used in the field of electrochemistry or the field of batteries can be used.
The salt is not particularly limited, and examples thereof include inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, cyclic quaternary ammonium salts, and quaternary phosphonium salts. preferable.

Specific examples of the salts include ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ and AsF ₆ ^−. Li salt, Na salt, or K salt having a counter anion selected from CH ₃ COO ⁻ , CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , and (C ₂ F ₅ SO ₂ ) ₃ C ⁻ . Also, ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , CH ₃ COO ⁻ A quaternary ammonium salt having a counter anion selected from CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , and (C ₂ F ₅ SO ₂ ) ₃ C ⁻ , specifically, (CH ₃ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBF ₄ , (n-C ₄ H ₉ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBr, (C ₂ H ₅ ) ₄ NClO ₄ , (n-C ₄ H ₉ ) ₄ NClO ₄ , CH ₃ (C ₂ H ₅ ) ₃ NBF ₄ , (CH ₃ ) ₂ (C ₂ H ₅ ) ₂ NBF ₄ , (CH ₃ ) ₄ NSO ₃ CF ₃ , (C ₂ H ₅ ) ₄ NSO ₃ CF ₃ , (n-C ₄ H ₉ ) ₄ NSO ₃ CF ₃ ,

Etc. Also, ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , CH ₃ COO ⁻ , A phosphonium salt having a counter anion selected from CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , and (C ₂ F ₅ SO ₂ ) ₃ C ⁻ , specifically, (CH ₃ ) ₄ PBF ₄ , (C _{2 H 5) 4 PBF 4,} (C 3 H 7) 4 PBF 4, include _{(C 4 H 9) 4 PBF} 4 and the like.
Moreover, these mixtures can also be used suitably.

The acids are not particularly limited, and inorganic acids and organic acids can be used. Specifically, sulfuric acid, hydrochloric acid, phosphoric acids, sulfonic acids, carboxylic acids and the like can be used.
The alkalis are not particularly limited, and any of sodium hydroxide, potassium hydroxide, lithium hydroxide and the like can be used.

The room temperature molten salt is not particularly limited, but the room temperature molten salt in the present invention is a salt made of an ion pair that is melted at room temperature (that is, a liquid form) consisting of only an ion pair that does not contain a solvent component. In general, it indicates a salt composed of an ion pair having a melting point of 20 ° C. or lower and being liquid at a temperature exceeding 20 ° C.
The room temperature molten salt can be used alone or in combination of two or more.

Examples of the room temperature molten salt include the following.

(Wherein R represents an alkyl group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms. X ⁻ represents ClO ₄ ⁻ , BF ₄ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) represents a counter anion selected from ₂ N ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , CH ₃ COO ⁻ , CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , and (C ₂ F ₅ SO ₂ ) ₃ C ⁻ .)

(Wherein R1 and R2 each represent an alkyl group having 1 to 10 carbon atoms (preferably a methyl group or an ethyl group) or an aralkyl group having 7 to 20 carbon atoms, preferably 7 to 13 carbon atoms (preferably a benzyl group). X ⁻ may be ClO ₄ ⁻ , BF ₄ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ , (It represents a counter anion selected from AsF ₆ ⁻ , CH ₃ COO ⁻ , CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , and (C ₂ F ₅ SO ₂ ) ₃ C ⁻ ).

(Here, R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group having 1 or more carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms (such as a phenyl group). Or a methoxymethyl group, etc., which may be the same or different from each other, and X ⁻ is ClO ₄ ⁻ , BF ₄ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ^{_{-, PF 6 -, AsF 6}} -, CH 3 COO -, CH 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - represents a counter anion selected from).

  The amount of the supporting electrolyte used is not particularly limited and is arbitrary, but is usually 0.1% by mass or more, preferably 1% by mass or more, more preferably 10% by mass or more, and 70% by mass in the electrolyte. Hereinafter, it can be contained in an amount of preferably 60% by mass or less, more preferably 50% by mass or less.

  In addition, the electrolyte may be a liquid type as described above, but a polymer solid electrolyte (ion conductive film) is particularly preferable in the present invention from the viewpoint that all solidification is possible. As the polymer solid electrolyte, it is particularly preferable that (a) the polymer matrix (component (a)) contains at least (c) a substance (component (c)) exhibiting reversible electrochemical redox characteristics. If desired, those further containing (b) a plasticizer (component (b)) may be mentioned. In addition to these, other optional components such as (d) the above-mentioned supporting electrolyte and (e) a room temperature molten salt may be further contained as desired. As an ion conductive film, the said component (b), a component (b) and a component (c), or a further arbitrary component is hold | maintained in a polymer matrix, and a solid state or a gel state is formed.

  The material that can be used as the polymer matrix is not particularly limited as long as a solid state or a gel state is formed by the polymer matrix alone, or by the addition of a plasticizer, the addition of a supporting electrolyte, or the addition of a plasticizer and a supporting electrolyte. In general, so-called polymer compounds that are generally used can be used.

  Examples of the polymer compound exhibiting characteristics as the polymer matrix include hexafluoropropylene, tetrafluoroethylene, trifluoroethylene, ethylene, propylene, acrylonitrile, vinylidene chloride, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, and methyl methacrylate. And polymer compounds obtained by polymerizing or copolymerizing monomers such as styrene and vinylidene fluoride. These polymer compounds may be used alone or in combination. Among these, a polyvinylidene fluoride polymer compound is particularly preferable.

Examples of the polyvinylidene fluoride polymer compound include a homopolymer of vinylidene fluoride, or a copolymer of vinylidene fluoride and another polymerizable monomer, preferably a radical polymerizable monomer. Specific examples of other polymerizable monomers copolymerized with vinylidene fluoride (hereinafter referred to as copolymerizable monomers) include hexafluoropropylene, tetrafluoroethylene, trifluoroethylene, ethylene, propylene, acrylonitrile, vinylidene chloride. Acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, styrene and the like can be exemplified.
These copolymerizable monomers can be used in an amount of 1 to 50 mol%, preferably 1 to 25 mol%, based on the total amount of monomers.

  As the copolymerizable monomer, hexafluoropropylene is preferably used. In the present invention, in particular, it can be preferably used as an ion conductive film using a vinylidene fluoride-hexafluoropropylene copolymer obtained by copolymerizing 1 to 25 mol% of hexafluoropropylene with vinylidene fluoride as a polymer matrix. Two or more kinds of vinylidene fluoride-hexafluoropropylene copolymers having different copolymerization ratios may be mixed and used.

  Further, two or more of these copolymerizable monomers can be used for copolymerization with vinylidene fluoride. For example, copolymerization with combinations of vinylidene fluoride + hexafluoropropylene + tetrafluoroethylene, vinylidene fluoride + hexafluoropropylene + acrylic acid, vinylidene fluoride + tetrafluoroethylene + ethylene, vinylidene fluoride + tetrafluoroethylene + propylene, etc. The copolymer obtained by making it also can be used.

  Furthermore, as a polymer matrix, polyvinylidene fluoride polymer compound, polyacrylic acid polymer compound, polyacrylate polymer compound, polymethacrylic acid polymer compound, polymethacrylate polymer compound, polyacrylonitrile polymer One or more polymer compounds selected from a compound and a polyether polymer compound can be mixed and used. Alternatively, one or more kinds of copolymers obtained by copolymerizing two or more kinds of monomers of the above-described polymer compound with a polyvinylidene fluoride polymer compound may be used. In this case, the blending ratio of the homopolymer or copolymer is usually preferably 200 parts by mass or less with respect to 100 parts by mass of the polyvinylidene fluoride polymer compound.

  The weight-average molecular weight of the polyvinylidene fluoride polymer compound used here is preferably 10,000 to 2,000,000, preferably 100,000 to 1,000,000. it can.

  The plasticizer (component (b)) acts as a solvent for substances exhibiting reversible electrochemical redox properties. Any plasticizer can be used as long as it can be generally used as an electrolyte solvent in an electrochemical cell or battery, and specific examples thereof include various solvents exemplified in liquid electrolytes. In particular, propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone, sulfolane, dioxolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, adiponitrile, methoxyacetonitrile, dimethylacetamide, methylpyrrolidinone, dimethyl sulfoxide, dioxolane, sulfolane, Trimethyl phosphate and triethyl phosphate are preferred. Also, room temperature molten salts used in liquid electrolytes can be used. The solvent may be used alone or in combination of two or more.

  The amount of the plasticizer (component (b)) used is not particularly limited, but is usually 20% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, and 98% by mass in the ion conductive material. It can be contained in an amount of not more than mass%, preferably not more than 95 mass%, more preferably not more than 90 mass%.

Component (c) is a compound that can perform a reversible electrochemical redox reaction, and includes what is usually referred to as a redox material.
The type of the compound is not particularly limited. For example, ferrocene, p-benzoquinone, 7,7,8,8-tetracyanoquinodimethane, N, N, N ′, N′-tetra Methyl-p-phenylenediamine, tetrathiafulvalene, anthracene, p-toluylamine and the like can be used. Further, LiI, NaI, KI, CsI, CaI ₂ , quaternary imidazolium iodine salt, tetraalkylammonium iodine salt, Br ₂ and LiBr, NaBr, KBr, CsBr, CaBr ₂ and other metal bromides are listed.

Further, Br ₂ and tetraalkylammonium bromide, bipyridinium bromide, bromine salts, complex salts such as ferrocyanic acid-ferricyanate, sodium polysulfide, alkylthiol-alkyldisulfides, hydroquinone-quinones, viologens, and the like can be used. As the redox material, only one of an oxidant and a reductant may be used, or the oxidant and the reductant may be mixed and added at an appropriate molar ratio.

Examples of the component (c) include a salt having a counter anion (X ⁻ ) selected from halogen ions and SCN ⁻ . As the cation, as a quaternary ammonium salt, specifically, (CH ₃ ) ₄ NX ⁻ , (C ₂ H ₅ ) ₄ NX ⁻ , (n-C ₄ H ₉ ) ₄ NX ⁻ ,

Etc. A phosphonium salt having a counter anion (X ⁻ ), specifically, (CH ₃ ) ₄ PX ⁻ , (C ₂ H ₅ ) ₄ PX ⁻ , (C ₃ H ₇ ) ₄ PX ⁻ , (C ₄ H ₉ ) ₄ PX- ^{and the} like.
Of course, a mixture of these can also be used suitably.
In addition, in the case of these compounds, it is preferable to use together with a normal component (b).
Moreover, the redox normal temperature molten salt used for liquid electrolytes can also be used as a component (c).

  There is no particular limitation on the amount of the substance exhibiting reversible electrochemical oxidation-reduction characteristics (component (c)), usually 0.1% by mass or more, preferably 1% by mass or more in the polymer solid electrolyte. The amount is preferably 10% by mass or more and 70% by mass or less, preferably 60% by mass or less, and more preferably 50% by mass or less.

When component (c) is used in combination with component (b), it is desirable that component (c) has a mixing ratio that dissolves in component (b) and does not cause precipitation even when a polymer solid electrolyte is obtained. Preferably, component (c) / component (b) is in the range of 0.01 to 0.5, more preferably 0.03 to 0.3 in terms of mass ratio.
For component (a), the mass ratio of component (a) / (component (b) + component (c)) is preferably 1/20 to 1/1, more preferably 1/10 to 1/2. It is desirable to be in the range.

The amount of the supporting electrolyte (component (d)) used in the polymer solid electrolyte is not particularly limited and is arbitrary, but is usually 0.1% by mass or more, preferably 1% by mass or more in the polymer solid electrolyte. More preferably, it is 10% by mass or more and 70% by mass or less, preferably 60% by mass or less, and more preferably 50% by mass or less.
The polymer solid electrolyte may further contain other components. Examples of other components include ultraviolet absorbers and amine compounds. Although it does not specifically limit as a ultraviolet absorber which can be used, Organic UV absorbers, such as a compound which has a benzotriazole skeleton and a compound which has a benzophenone skeleton, are mentioned as a typical thing.

As the compound having a benzotriazole skeleton, for example, a compound represented by the following general formula (38) is preferably exemplified.

In the general formula (38), R ⁸¹ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Examples of the halogen atom include fluorine, chlorine, bromine and iodine. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group, and a cyclohexyl group. The substitution position of R ⁸¹ is the 4-position or 5-position of the benzotriazole skeleton, but the halogen atom and the alkyl group are usually located at the 4-position. R ⁸² represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group, and a cyclohexyl group. R ⁸³ represents an alkylene group or alkylidene group having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, and a propylene group. Examples of the alkylidene group include an ethylidene group and a propylidene group.

  Specific examples of the compound represented by the general formula (38) include 3- (5-chloro-2H-benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy-benzenepropanoic acid. 3- (2H-benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy-benzeneethanoic acid, 3- (2H-benzotriazol-2-yl) -4-hydroxybenzene Ethanoic acid, 3- (5-methyl-2H-benzotriazol-2-yl) -5- (1-methylethyl) -4-hydroxybenzenepropanoic acid, 2- (2′-hydroxy-5′-methylphenyl) Benzotriazole, 2- (2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl) phenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5'-di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 3- (5-chloro-2H- Benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy-benzenepropanoic acid octyl ester and the like.

Preferred examples of the compound having a benzophenone skeleton include compounds represented by the following general formulas (39) to (41).

In the general formulas (39) to (41), R ⁹² , R ⁹³ , R ⁹⁵ , R ⁹⁶ , R ⁹⁸ , and R ⁹⁹ are the same or different from each other, and are a hydroxyl group, 1 to 10 carbon atoms, Preferably 1-6 alkyl groups or alkoxy groups are shown. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, a butyl group, a t-butyl group, and a cyclohexyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an i-propoxy group, and a butoxy group.
R ⁹¹ , R ⁹⁴ , and R ^{97 each} represents an alkylene group or alkylidene group having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, and a propylene group. Examples of the alkylidene group include an ethylidene group and a propylidene group.
p1, p2, p3, q1, q2, and q3 each independently represent an integer of 0 to 3.

  Preferable examples of the compound having a benzophenone skeleton represented by the general formulas (39) to (41) include 2-hydroxy-4-methoxybenzophenone-5-carboxylic acid and 2,2′-dihydroxy-4-methoxybenzophenone. -5-carboxylic acid, 4- (2-hydroxybenzoyl) -3-hydroxybenzenepropanoic acid, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfone Acid, 2-hydroxy-4-n-octoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4-methoxy -2'-carboxybenzophenone and the like.

Of course, two or more of these can be used in combination.
The use of the ultraviolet absorber is optional, and the amount used is not particularly limited, but when used, it is 0.1% by mass or more, preferably 1% by mass or more in the electrolyte. It is desirable to make it contain in the quantity of 20 mass% or less, Preferably the range of 10 mass% or less.

  The amine compound that can be contained in the polymer solid electrolyte is not particularly limited, and various aliphatic amines and aromatic amines are used. For example, pyridine derivatives, bipyridine derivatives, quinoline derivatives, and the like are representative. Can be mentioned. By adding these amine compounds, an improvement in open circuit voltage is expected. Specific examples of these compounds include 4-t-butyl-pyridine, quinoline, isoquinoline and the like.

  In addition, these polymer solid electrolytes can be obtained by forming a mixture of the components (a) to (c) and optional components blended as desired into a film by a known method. The molding method in this case is not particularly limited, and examples thereof include extrusion molding, a method obtained in a film state by a casting method, a spin coating method, a dip coating method, an injection method, and an impregnation method.

Extrusion molding can be performed by a conventional method, and after the mixture is melted by heating, film molding is performed.
Regarding the casting method, the mixture can be formed into a film by further adjusting the viscosity with an appropriate diluent, applying the mixture with a normal coater used in the casting method, and drying. As the coater, a doctor coater, a blade coater, a rod coater, a knife coater, a reverse roll coater, a gravure coater, a spray coater, and a curtain coater can be used, and they can be selectively used depending on the viscosity and the film thickness.
As for the spin coating method, the mixture can be formed into a film by further adjusting the viscosity with an appropriate diluent, applying the mixture with a commercially available spin coater, and drying.
As for the dip coating method, a film can be formed by adjusting the viscosity of the mixture with an appropriate diluent to prepare a mixture solution, pulling up an appropriate base from the mixture solution, and drying.

In the present invention, various dyes can be adsorbed or contained in the semiconductor layer for the purpose of improving the light absorption efficiency of the semiconductor layer.
The dye that can be used in the present invention is not particularly limited as long as it is a dye that improves the light absorption efficiency of the semiconductor layer. Usually, one or more of various metal complex dyes and organic dyes are used. Can be used. In addition, in order to impart adsorptivity to the semiconductor layer, a functional group such as a carboxyl group, a hydroxyl group, a sulfonyl group, a phosphonyl group, a carboxylalkyl group, a hydroxyalkyl group, a sulfonylalkyl group, or a phosphonylalkyl group is included in the dye molecule. Those having a group are preferably used.
As the metal complex dye, ruthenium, osmium, iron, cobalt, zinc complex, metal phthalocyanine, chlorophyll and the like can be used.
Examples of the metal complex dye used in the present invention include the following.

(Dye 1)

Here, X ₁ represents a monovalent anion, but the two X ₁ may be independent or cross-linked. Examples of X ₁ include the following.

(Dye 2)

Here, X represents a monovalent anion. For example, the following is exemplified.

Y is a monovalent anion, which is a halogen ion, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ^−. PF ₆ ⁻ , AsF ₆ ⁻ , CH ₃ COO ⁻ , CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ^{− and the} like.

(Dye 3)

Here, Z is an atomic group having an unshared electron pair, and the two Zs may be independent or bridged. For example, the following is exemplified.

Y is a monovalent anion, which is a halogen ion, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ^−. PF ₆ ⁻ , AsF ₆ ⁻ , CH ₃ COO ⁻ , CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ^{− and the} like.

(Dye 4)

As the organic dye, a cyanine dye, a hemicyanine dye, a merocyanine dye, a xanthene dye, a triphenylmethane dye, or a metal-free phthalocyanine dye can be used.
Examples of the organic dye used in the present invention are as follows.

  As a method for adsorbing the dye to the semiconductor layer, a solution in which the dye is dissolved in a solvent is applied on the semiconductor layer by spray coating or spin coating and then dried. In this case, the substrate may be heated to an appropriate temperature. Alternatively, a method in which a semiconductor layer is immersed in a solution and adsorbed can be used. The immersion time is not particularly limited as long as the dye is sufficiently adsorbed, but is preferably 1 to 30 hours, particularly preferably 5 to 20 hours. Moreover, you may heat a solvent and a board | substrate when immersing as needed. Preferably, the concentration of the dye in the case of a solution is about 1 to 1000 mM / L, preferably about 10 to 500 mM / L.

  The solvent to be used is not particularly limited as long as it does not dissolve the dye and does not dissolve the semiconductor layer, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and t-butanol. Nitrile solvents such as alcohol, acetonitrile, propionitrile, methoxypropionitrile, glutaronitrile, benzene, toluene, o-xylene, m-xylene, p-xylene, pentane, heptane, hexane, cyclohexane, heptane, acetone, Methyl ethyl ketone, diethyl ketone, 2-butanone, diethyl ether, tetrahydrofuran, ethylene carbonate, propylene carbonate, nitromethane, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoamide, dimethoxy ester , Γ-butyrolactone, γ-valerolactone, sulfolane, dimethoxyethane, adiponitrile, methoxyacetonitrile, dimethylacetamide, methylpyrrolidinone, dimethylsulfoxide, dioxolane, sulfolane, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, ethyl phosphate Dimethyl, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, tris phosphate (trifluoromethyl), tris phosphate (pentafluoroethyl), Triphenyl polyethylene glycol phosphate, polyethylene glycol and the like can be used.

  By using the semiconductor having the nanotube structure of the present invention as an electrode, it is possible to suppress the deactivation of the elementary excited state at the interface, which was a conventional problem, and to obtain a functional element having good characteristics. it can.

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

[Example 1]
Ti (OiPr) ₄ and acetylacetone (ACA) are mixed 1: 1 to prepare Ti (OiPr) ₄ ACA. Ti (OiPr) ₄ ACA, sodium dodecyl sulfate, urea and H ₂ O were mixed so that each molar ratio was 1: 2: 30: 60. This mixed solution was stirred in an oven at 80 ° C. for 95 hours. Thereafter, washing with water was performed 5 times. This aqueous solution was centrifuged and the solid content was taken out and dried in an oven at 80 ° C. As shown in FIG. 3, it was confirmed that the powder obtained by X-ray diffraction was anatase TiO ₂ .
Furthermore, 0.4 ml of acetic acid was added to 25 g of this titania semiconductor nanotube (anatase type TiO ₂ ), 20 ml of water was further added, zirconia beads (20 grains having a diameter of 6 mm) were added, and the mixture was stirred for 3 hours. Thereafter, 2 ml of a 5-fold diluted surfactant (Triton manufactured by Sigma Chemical Co.) was added, defoamed with a defoaming kneader, beads were separated, and a titania semiconductor nanotube paste was obtained.
The paste containing the titania semiconductor nanotubes was bar-coated on a 3 cm square SnO ₂ : F glass (transparent conductive glass having a SnO ₂ : F film formed on a glass substrate) having a surface resistance of 12 Ω / sq and dried. At the time of bar coating, a scotch tape was attached to the side 5 mm of the transparent conductive glass so that the film thickness was uniform. The coated substrate was baked at 500 ° C. for 30 minutes. When the thickness of the titania semiconductor nanotube layer after firing was measured with a stylus type thickness meter, it was found to be 12 μm. This was immersed in a ruthenium dye / ethanol solution (3.0 × 10 ⁻⁴ mol / L) represented by the following formula (42) for 15 hours to form a dye layer. A counter electrode in which a Pt film was formed in a film thickness of 30 nm on the obtained substrate and a 3 cm square SnO ₂ : F glass (transparent conductive glass having a SnO ₂ : F film formed on a glass substrate) having a surface resistance of 12 Ω / sq. In the meantime, a propylene carbonate solution containing 0.3 mol / L lithium iodide and 0.03 mol / L iodine was impregnated by capillary action, and the periphery was sealed with an epoxy adhesive. A lead wire was connected to the conductive layer portion of the transparent conductive substrate and the counter electrode.
When the cell thus obtained was irradiated with pseudo-sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, good photoelectric conversion characteristics (conversion efficiency 5.2%) were obtained. The results are shown in Table 1.

[Example 2]
TiCl ₄ , sodium dodecyl sulfate, urea and H ₂ O were mixed so that each molar ratio was 1: 2: 30: 60. This mixed solution was stirred in an oven at 80 ° C. for 95 hours. Thereafter, washing with water was performed 5 times. This aqueous solution was centrifuged and the solid content was taken out and dried in an oven at 80 ° C. As shown in FIG. 3, it was confirmed that the powder obtained by X-ray diffraction was anatase TiO ₂ .
Furthermore, 0.4 ml of acetic acid was added to 25 g of the titania semiconductor nanotubes, 20 ml of water was further added, zirconia beads (20 grains having a diameter of 6 mm) were added, and the mixture was stirred for 3 hours. Thereafter, 2 ml of a 5-fold diluted surfactant (Triton manufactured by Sigma Chemical Co.) was added, defoamed with a defoaming kneader, beads were separated, and a titania semiconductor nanotube paste was obtained.
The paste containing the titania semiconductor nanotubes was bar-coated on a 3 cm square SnO ₂ : F glass (transparent conductive glass having a SnO ₂ : F film formed on a glass substrate) having a surface resistance of 12 Ω / sq and dried. At the time of bar coating, a scotch tape was attached to the side 5 mm of the transparent conductive glass so that the film thickness was uniform. The coated substrate was baked at 500 ° C. for 30 minutes. When the thickness of the titania semiconductor nanotube layer after firing was measured with a stylus type thickness meter, it was found to be 12 μm. This was immersed in a ruthenium dye / ethanol solution (3.0 × 10 ⁻⁴ mol / L) represented by the formula (42) for 15 hours to form a dye layer. The obtained substrate and the counter electrode were combined, and a propylene carbonate solution containing 0.3 mol / L lithium iodide and 0.03 mol / L iodine was impregnated between them by capillary action, and the periphery was sealed with an epoxy adhesive. did. A lead wire was connected to the conductive layer portion of the transparent conductive substrate and the counter electrode.
When the cell thus obtained was irradiated with simulated sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, good photoelectric conversion characteristics (conversion efficiency 5.3%) were obtained. The results are shown in Table 1.

[Example 3]
Ti (SO ₄ ) ₂ , sodium dodecyl sulfate, urea and H ₂ O were mixed so that each molar ratio was 1: 2: 30: 60. This mixed solution was stirred in an oven at 80 ° C. for 95 hours. Thereafter, washing with water was performed 5 times. This aqueous solution was centrifuged and the solid content was taken out and dried in an oven at 80 ° C. As shown in FIG. 3, it was confirmed that the powder obtained by X-ray diffraction was anatase TiO ₂ .
Furthermore, 0.4 ml of acetic acid was added to 25 g of the titania semiconductor nanotubes, 20 ml of water was further added, zirconia beads (20 grains having a diameter of 6 mm) were added, and the mixture was stirred for 3 hours. Thereafter, 2 ml of a 5-fold diluted surfactant (Triton manufactured by Sigma Chemical Co.) was added, defoamed with a defoaming kneader, beads were separated, and a titania semiconductor nanotube paste was obtained.
The paste containing the titania semiconductor nanotubes was bar-coated on a 3 cm square SnO ₂ : F glass (transparent conductive glass having a SnO ₂ : F film formed on a glass substrate) having a surface resistance of 12 Ω / sq and dried. At the time of bar coating, a scotch tape was attached to the side 5 mm of the transparent conductive glass so that the film thickness was uniform. The coated substrate was baked at 500 ° C. for 30 minutes. When the thickness of the titania semiconductor nanotube layer after firing was measured with a stylus type thickness meter, it was found to be 12 μm. This was immersed in a ruthenium dye / ethanol solution (3.0 × 10 ⁻⁴ mol / L) represented by the formula (42) for 15 hours to form a dye layer. The obtained substrate and the counter electrode were combined, and a propylene carbonate solution containing 0.3 mol / L lithium iodide and 0.03 mol / L iodine was impregnated between them by capillary action, and the periphery was sealed with an epoxy adhesive. did. A lead wire was connected to the conductive layer portion of the transparent conductive substrate and the counter electrode.
When the cell thus obtained was irradiated with simulated sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, good photoelectric conversion characteristics (conversion efficiency 5.3%) were obtained. The results are shown in Table 1.

[Example 4]
0.2 mol / L (NH ₄ ) ₂ [TiF ₆ ] and 0.4 mol / L H ₃ BO ₃ were mixed in the same amount at 30 ° C. Through-hole alumina (Whatman, anodsk) was immersed in this solution at 30 ° C. for 1 hour. After 1 hour, the through-hole alumina was taken out and immersed in a 0.1 mol / L nitric acid solution to completely dissolve the alumina, and then washed with water. As shown in FIG. 4, titania semiconductor nanotubes could be obtained.
To 25 g of the titania semiconductor nanotubes, 0.4 ml of acetic acid was added, 20 ml of water was further added, zirconia beads (20 grains having a diameter of 6 mm) were added, and the mixture was stirred for 3 hours. Thereafter, 2 ml of a 5-fold diluted surfactant (Triton manufactured by Sigma Chemical Co.) was added, defoamed with a defoaming kneader, beads were separated, and a titania semiconductor nanotube paste was obtained.
The paste containing the titania semiconductor nanotubes was bar-coated on a 3 cm square SnO ₂ : F glass (transparent conductive glass having a SnO ₂ : F film formed on a glass substrate) having a surface resistance of 12 Ω / sq and dried. At the time of bar coating, a scotch tape was attached to the side 5 mm of the transparent conductive glass so that the film thickness was uniform. The coated substrate was baked at 500 ° C. for 30 minutes. When the thickness of the titania semiconductor nanotube layer after firing was measured with a stylus type thickness meter, it was found to be 12 μm. This was immersed in a ruthenium dye / ethanol solution (3.0 × 10 ⁻⁴ mol / L) represented by the formula (42) for 15 hours to form a dye layer. The obtained substrate and the counter electrode were combined, and a propylene carbonate solution containing 0.3 mol / L lithium iodide and 0.03 mol / L iodine was impregnated by capillary action, and the periphery was sealed with an epoxy adhesive. A lead wire was connected to the conductive layer portion of the transparent conductive substrate and the counter electrode.
When the cell thus obtained was irradiated with pseudo-sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, good photoelectric conversion characteristics (conversion efficiency 5.1%) were obtained. The results are shown in Table 1.

[Example 5]
An aluminum substrate (manufactured by Toyo Aluminum Co., Ltd., purity 99.99%) is mixed with a sulfuric acid-phosphoric acid mixed solution (85% phosphoric acid 330 mL, concentrated sulfuric acid 75 mL, ethylene glycol 15 mL, water 80 mL) at 70 ° C. with aluminum as the anode and graphite. The cathode was subjected to constant current electrolytic treatment at 250 mA / cm ² for 5 minutes, then washed with water and dried. The aluminum substrate was used as an anode, graphite as a cathode, an anodizing treatment was performed in a 0.5 mol / L oxalic acid aqueous solution at a temperature of 16 ° C. and 40 V for 5 hours, and then a chromic acid-phosphoric acid mixed solution ( (6 g of chromium oxide, 20 g of phosphoric acid, 300 g of water) was immersed at 50 ° C. for 12 hours, washed with water and dried. This substrate was anodized for another hour under the same conditions as before. The obtained anodized substrate was subjected to a diameter expansion treatment in a 5% phosphoric acid aqueous solution for 40 minutes, and finally a highly ordered anodized porous alumina film having a film thickness of about 8 μm, a pitch of 100 nm, and a pore diameter of 75 nm was obtained.
The above anodized substrate is immersed in a mixed aqueous solution of 0.1 mol / L (NH ₄ ) ₂ TiF ₆ and 0.2 mol / L H ₃ BO ₃ at 30 ° C. for 5 minutes to form a fine anodized porous alumina film. After forming a titanium oxide film in the hole, it was baked at 550 ° C. for 30 minutes. Thereafter, the aluminum and alumina films were removed in an iodine / methanol mixed solution and a 1 mol / L nitric acid solution, respectively, to produce titanium oxide semiconductor nanotubes.
To 25 g of the titanium oxide semiconductor nanotubes, 0.4 ml of acetic acid was added, 20 ml of water was further added, zirconia beads (20 grains having a diameter of 6 mm) were added, and the mixture was stirred for 3 hours. Thereafter, 2 ml of a 5-fold diluted surfactant (Triton manufactured by Sigma Chemical Co.) was added, defoamed with a defoaming kneader, beads were separated, and a titania semiconductor nanotube paste was obtained.
Production and evaluation of the photoelectric conversion element were carried out by the method described in Example 4.
When the cell thus obtained was irradiated with pseudo-sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, good photoelectric conversion characteristics (conversion efficiency 5.4%) were obtained. The results are shown in Table 1.

[Example 6]
An aluminum substrate (manufactured by Toyo Aluminum Co., Ltd., purity 99.99%) is mixed with a sulfuric acid-phosphoric acid mixed solution (85% phosphoric acid 330 mL, concentrated sulfuric acid 75 mL, ethylene glycol 15 mL, water 80 mL) at 70 ° C. with aluminum as the anode and graphite. The cathode was subjected to constant current electrolytic treatment at 250 mA / cm ² for 5 minutes, then washed with water and dried. The aluminum substrate was used as an anode, graphite as a cathode, an anodizing treatment was performed in a 0.5 mol / L oxalic acid aqueous solution at a temperature of 16 ° C. and 40 V for 5 hours, and then a chromic acid-phosphoric acid mixed solution ( (6 g of chromium oxide, 20 g of phosphoric acid, 300 g of water) was immersed at 50 ° C. for 12 hours, washed with water and dried. This substrate was anodized for another hour under the same conditions as before. The obtained anodized substrate was subjected to a diameter expansion treatment in a 5% phosphoric acid aqueous solution for 40 minutes, and finally a highly ordered anodized porous alumina film having a film thickness of about 8 μm, a pitch of 100 nm, and a pore diameter of 75 nm was obtained.
The above anodized substrate is immersed in a mixed aqueous solution of 0.1 mol / L (NH ₄ ) ₂ TiF ₆ and 0.2 mol / L H ₃ BO ₃ at 30 ° C. for 5 minutes to form a fine anodized porous alumina film. After forming a titanium oxide film in the hole, it was baked at 550 ° C. for 30 minutes. Thereafter, the aluminum and alumina films were removed in an iodine / methanol mixed solution and a 1 mol / L nitric acid solution, respectively, to produce titanium oxide semiconductor nanotubes.
To 25 g of the titanium oxide semiconductor nanotubes, 0.4 ml of acetic acid was added, 20 ml of water was further added, zirconia beads (20 grains having a diameter of 6 mm) were added, and the mixture was stirred for 3 hours. Thereafter, 2 ml of a 5-fold diluted surfactant (Triton manufactured by Sigma Chemical Co.) was added, defoamed with a defoaming kneader, beads were separated, and a titania semiconductor nanotube paste was obtained.
The paste containing the titania semiconductor nanotubes was bar-coated on a 3 cm square SnO ₂ : F glass (transparent conductive glass having a SnO ₂ : F film formed on a glass substrate) having a surface resistance of 12 Ω / sq and dried. At the time of bar coating, a scotch tape was attached to the side 5 mm of the transparent conductive glass so that the film thickness was uniform. The coated substrate was baked at 500 ° C. for 30 minutes. When the thickness of the titania semiconductor nanotube layer after firing was measured with a stylus thickness meter, it was found to be 20 μm. This was immersed in a ruthenium dye / ethanol solution (3.0 × 10 ⁻⁴ mol / L) represented by the formula (42) for 15 hours to form a dye layer. The obtained substrate and the counter electrode were combined, and a propylene carbonate solution containing 0.3 mol / L lithium iodide and 0.03 mol / L iodine was impregnated by capillary action, and the periphery was sealed with an epoxy adhesive. A lead wire was connected to the conductive layer portion of the transparent conductive substrate and the counter electrode.
When the cell thus obtained was irradiated with pseudo-sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, good photoelectric conversion characteristics (conversion efficiency 6.5%) were obtained. The results are shown in Table 1.

[Example 7]
A precursor of polyphenylene vinylene (PPV) of the formula (43), which is an electron donor, was synthesized by stirring p-xylenebisdiethylsulfonium bromide in an alkaline aqueous solution at 5 ° C.

Here, R ⁴ is H.
A commercially available electron acceptor molecule (CN-PPV) having the structural formula of formula (44) was used.

Here, R ¹ is OC ₆ H ₁₃ .

An aluminum substrate (manufactured by Toyo Aluminum Co., Ltd., purity 99.99%) is mixed with a sulfuric acid-phosphoric acid mixed solution (85% phosphoric acid 330 mL, concentrated sulfuric acid 75 mL, ethylene glycol 15 mL, water 80 mL) at 70 ° C. with aluminum as the anode and graphite. The cathode was subjected to constant current electrolytic treatment at 250 mA / cm ² for 5 minutes, then washed with water and dried. The aluminum substrate was used as an anode, graphite as a cathode, an anodizing treatment was performed in a 0.5 mol / L oxalic acid aqueous solution at a temperature of 16 ° C. and 40 V for 5 hours, and then a chromic acid-phosphoric acid mixed solution ( (6 g of chromium oxide, 20 g of phosphoric acid, 300 g of water) was immersed at 50 ° C. for 12 hours, washed with water and dried. This substrate was anodized for another hour under the same conditions as before. The obtained anodized substrate was subjected to a diameter expansion treatment in a 5% phosphoric acid aqueous solution for 40 minutes, and finally a highly ordered anodized porous alumina film having a film thickness of about 8 μm, a pitch of 100 nm, and a pore diameter of 75 nm was obtained.
The obtained highly ordered anodized porous alumina film was immersed in a PPV precursor solution, and the PPV precursor solution was applied to the inner surface of the pores. Thereafter, the PPV film having a film thickness of 10 nm represented by the formula (43) was obtained on the inner surface of the pores by being left in an oven at 220 ° C. for 200 minutes in a nitrogen atmosphere. Then, it immersed in the chloroform solution of CN-PPV represented by Formula (44), the solution was filled in the pores, and then dried in an oven at 60 ° C. for 3 hours. Thus, the semiconductor nanotube which laminated | stacked PPV and CN-PPV in order on the pore internal surface was formed. On one surface of the porous alumina film containing the semiconductor nanotubes, 99.9999% aluminum pellets were formed to a thickness of 500 nm in an atmosphere of 10 ⁻³ Torr (0.133 Pa) by resistance heating vapor deposition. On the other side, Ar and O ₂ were flown into the film forming chamber at a ratio of 99: 1 as an In ₂ O ₃ target containing 10 mol% of Sn, and a film was formed to 400 nm at an operating pressure of 0.15 Pa.
A photoelectric conversion element was prepared by connecting a gold wire having a diameter of 50 μm to Sn: In ₂ O ₃ with silver paste on the both surfaces of this porous alumina film and Sn: In ₂ O ₃ . The cell thus obtained was irradiated with pseudo-sunlight (1 kW / m ² ) and the current-voltage characteristics were measured. As a result, a conversion efficiency of 1.1% was obtained.

[Example 8]
An aluminum substrate (manufactured by Toyo Aluminum Co., Ltd., purity 99.99%) is mixed with a sulfuric acid-phosphoric acid mixed solution (85% phosphoric acid 330 mL, concentrated sulfuric acid 75 mL, ethylene glycol 15 mL, water 80 mL) at 70 ° C. with aluminum as the anode and graphite. The cathode was subjected to constant current electrolytic treatment at 250 mA / cm ² for 5 minutes, then washed with water and dried. The aluminum substrate was used as an anode, graphite as a cathode, an anodizing treatment was performed in a 0.5 mol / L oxalic acid aqueous solution at a temperature of 16 ° C. and 40 V for 5 hours, and then a chromic acid-phosphoric acid mixed solution ( (6 g of chromium oxide, 20 g of phosphoric acid, 300 g of water) was immersed at 50 ° C. for 12 hours, washed with water and dried. This substrate was anodized for another hour under the same conditions as before. The obtained anodized substrate was subjected to a diameter expansion treatment in a 5% phosphoric acid aqueous solution for 40 minutes, and finally a highly ordered anodized porous alumina film having a film thickness of about 1 μm, a pitch of 100 nm, and a pore diameter of 75 nm was obtained.
A 200 nm Ni thin film was formed on the surface of the porous alumina by electroless plating. This substrate was mixed with copper naphthenate and indium naphthenate so that the molar ratio of copper and indium was 3: 5, and spin coated on the porous alumina surface on which the metal thin film was formed. Firing was performed under a nitrogen stream for 1 hour. Thereafter, porous alumina and selenium on which the copper-indium precursor thin film was formed were vacuum-sealed in a glass tube and heat-treated at 550 ° C. for 2 hours. Next, this substrate was spin-coated using a solution obtained by mixing copper naphthenate and indium naphthenate so that the molar ratio of copper to indium was 5: 4, and then for 1 hour under a nitrogen stream at 500 ° C. Baked. Thereafter, porous alumina and selenium on which the copper-indium precursor thin film was formed were vacuum-sealed in a glass tube and heat-treated at 550 ° C. for 2 hours. A transparent conductive film (ITO) was formed on porous alumina in which two different types of copper-indium-selenium (CIS) films thus obtained were laminated. This transparent conductive film was formed as an In ₂ O ₃ target containing 10 mol% of Sn by flowing Ar and O ₂ into the film forming chamber at a ratio of 99: 1 and forming a film with a working pressure of 0.15 Pa to 400 nm.
A gold wire having a diameter of 50 μm was connected to the porous Ni metal thin film and the ITO portion with a silver paste to produce a photoelectric conversion element. The element thus obtained is composed of a semiconductor nanotube material in which two different types of functional materials shown in FIG. 1 are laminated. When this element was irradiated with pseudo-sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, a conversion efficiency of 1.0% was obtained.

[Comparative Example 1]
A paste containing TiO ₂ fine particles (P25 manufactured by Nippon Aerosil Co., Ltd.) was prepared so as to have the same film thickness as that of the electrode made of the TiO ₂ semiconductor nanotube described in Example 1, and the electrode was prepared in the same manner as in Example 1. Was made.
The photoelectric conversion element was also produced in the same manner as in Example 1 except that the above electrode was used. When the characteristics of the device were evaluated, it was found that the conversion efficiency was lower as shown in Table 1 than when an electrode made of TiO ₂ semiconductor nanotubes was used.

[Comparative Example 2]
A paste containing TiO ₂ fine particles (P25 manufactured by Nippon Aerosil Co., Ltd.) was prepared so as to have the same film thickness as that of the electrode made of the TiO ₂ semiconductor nanotube described in Example 1, and the electrode was prepared in the same manner as in Example 6. Was made.
The photoelectric conversion element was also produced in the same manner as in Example 6 except that the above electrode was used. When the characteristics of the device were evaluated, it was found that the conversion efficiency was lower as shown in Table 1 than when an electrode made of TiO ₂ semiconductor nanotubes was used.

[Comparative Example 3]
As an In ₂ O ₃ target containing 10 mol% of Sn on a glass substrate, Ar and O ₂ were flowed in a deposition chamber at a ratio of 99: 1, and a film was formed to 400 nm at an operating pressure of 0.15 Pa.
On this substrate, PPV represented by the formula (43) used in Example 7 and CN-PPV represented by the formula (44) were alternately stacked by 4 μm. A 99.9999% aluminum pellet was formed thereon with a thickness of 500 nm by resistance heating vapor deposition in an atmosphere of 10 ⁻³ Torr (0.133 Pa).
A gold wire having a diameter of 50 μm was connected to the aluminum of this substrate and Sn: In ₂ O ₃ with a silver paste to produce a photoelectric conversion element. The cell thus obtained was irradiated with pseudo-sunlight (1 kW / m ² ) and the current-voltage characteristics were measured. As a result, a conversion efficiency of 0.17% was obtained.

[Comparative Example 4]
Naphthenic acid copper salt and naphthenic acid indium salt were mixed so that the molar ratio of copper to indium was 3: 5, and spin-coated on a substrate on which a Ni film was formed to 200 nm on a slide glass. Baked for 1 hour under. The film thickness after firing was 3 μm. Thereafter, porous alumina and selenium on which the copper-indium precursor thin film was formed were vacuum-sealed in a glass tube and heat-treated at 550 ° C. for 2 hours. Next, this substrate was spin-coated using a solution obtained by mixing copper naphthenate and indium naphthenate so that the molar ratio of copper to indium was 5: 4, and then for 1 hour under a nitrogen stream at 500 ° C. Baked. The film thickness after firing was 3 μm. Thereafter, the Ni film-formed glass substrate on which the copper-indium precursor thin film was formed and selenium were vacuum sealed in a glass tube and heat-treated at 550 ° C. for 2 hours. A transparent conductive film (ITO) was formed on porous alumina in which two different types of copper-indium-selenium (CIS) films thus obtained were laminated. This transparent conductive film was formed as an In ₂ O ₃ target containing 10 mol% of Sn by flowing Ar and O ₂ into the film forming chamber at a ratio of 99: 1 and forming a film with a working pressure of 0.15 Pa to 400 nm.
A gold wire having a diameter of 50 μm was connected to the Ni film-formed glass substrate and the ITO portion with a silver paste to produce a photoelectric conversion element. When this element was irradiated with pseudo sunlight (1 kW / m ² ) and the current-voltage characteristics were measured, a conversion efficiency of 0.07% was obtained. Although the conversion efficiency depends on the thickness of the copper-indium precursor thin film to be formed, the film thickness dependency could not be confirmed at 0.5 μm or more.

The block diagram of a semiconductor nanotube is shown. It is an example of the cross section of a photoelectric conversion element. 2 shows an X-ray diffraction pattern of a titania semiconductor nanotube. The SEM image of a titania semiconductor nanotube is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent conductive substrate 2 Counter electrode 3 Semiconductor layer 4 Electrolyte 5 Sealing material

Claims (9)

  An electrode including a semiconductor having a nanotube structure.   The electrode according to claim 1, wherein the semiconductor is made of an oxide containing a transition metal.   2. The electrode according to claim 1, wherein the semiconductor is made of a Group 2B to Group 7B element of the periodic table, an alloy containing the element, or an oxide of these elements.   2. The electrode according to claim 1, wherein the semiconductor is made of a polymer compound composed of at least a unit including a molecular structure having an electron donating property and a unit including a molecular structure having an electron accepting property.   2. The electrode according to claim 1, wherein a nanotube structure is formed by a template.   6. The electrode according to claim 5, wherein the mold is formed of an anodized porous material obtained by anodizing a metal in an electrolytic solution.   The functional element using the electrode of any one of Claims 1-6.   The functional element according to claim 7, wherein the functional element has photoelectric conversion characteristics. An electrode including a semiconductor having a nanotube structure made of titanium oxide adsorbed with a dye, a counter electrode on which a platinum or carbon material is formed, and an electrolyte solution containing iodine ions interposed therebetween Item 9. The functional element according to Item 7 or Item 8.