JP2006339199A - Photoelectric conversion element and its manufacturing method, and solar cell using the photoelectric conversion element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thoroughly solid-state photoelectric conversion element which exhibits proper photoelectric conversion characteristics and is superior in long-term stability and productivity, as well as to provide its manufacturing method, and to provide a solar cell that uses the photoelectric conversion element. <P>SOLUTION: An electron transport layer (for example, oxide semiconductor) is formed on a transparent electron collecting electrode, and a photosentitization compound is given to the electron transport layer. A solution, containing high polymer shown by general Formula (1), is used to coat and stack a hole transport layer by wet type film formation method, and a hole-collecting electrode is formed in contact with the Hall transport layer. The obtained photoelectric conversion element is used to form a solar cell. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion element, a method for producing the same, and a solar cell using the photoelectric conversion element.

  There are several types of solar cells, but most of them are diode type using silicon semiconductor junctions. These solar cells are currently expensive to manufacture, which is a factor that hinders their spread.

Recently, Graetzel et al. Of Swiss Lausanne University of Technology announced the possibility of cost reduction, and the expectation for practical use has increased (for example, Patent Document 1, Non-Patent Documents 1 and 2). reference.).
The structure of this high-efficiency solar cell includes a porous metal oxide semiconductor provided on a transparent conductive glass substrate, a dye adsorbed on the surface thereof, an electrolyte having a redox pair, and a counter electrode. Graetzel et al. Significantly improved the photoelectric conversion efficiency by making the metal oxide semiconductor electrode such as titanium oxide porous to increase the surface area and adsorbing a ruthenium complex as a dye with a single molecule.

However, since these solar cells use an electrolytic solution having a high vapor pressure such as acetonitrile, there is a problem in volatilization and leakage of the electrolytic solution. In order to compensate for this drawback, the following completely solid dye-sensitized solar cell has been announced.
(1) Using an inorganic semiconductor (for example, see Non-Patent Documents 3 and 4)
(2) A material using a low molecular organic hole transport material (see, for example, Patent Document 2 and Non-Patent Documents 5 and 6).
(3) Using a conductive polymer (for example, see Patent Document 3 and Non-Patent Document 7)

  In the solar cell of Non-Patent Document 3, copper iodide is used as a constituent material of the p-type semiconductor layer. However, there is a problem that the generated current decreases due to deterioration due to an increase in crystal grains of copper iodide. Therefore, in Non-Patent Document 4, although imidazolinium salt is added to suppress crystallization of copper iodide, it lacks long-term stability and further improvement in durability is required.

A solid type solar cell using the organic hole transport material described in Non-Patent Document 5 was reported by Hagen et al. And improved by Graetzel et al. (See Non-Patent Document 6).
However, the conversion efficiency is very low as compared with the liquid electrolyte, and the solid-type solar cell using the triphenylamine compound described in Patent Document 2 forms a charge transport layer by vacuum-depositing the triphenylamine compound. Yes. Therefore, the triphenylamine compound cannot reach the internal pores of the porous semiconductor, and only low conversion efficiency is obtained.

As a solid-type solar cell using a conductive polymer, Osaka University Yanagida et al. Reported a polypyrrole (see Non-Patent Document 7).
However, even in these cases, the conversion efficiency is low, and the solid-type solar cell using the polythiophene derivative described in Patent Document 3 is provided with a charge transfer layer using an electrolytic polymerization method on a porous titanium oxide electrode adsorbed with a dye. However, there is a problem that the pigment is desorbed from titanium oxide or the pigment is decomposed. Further, the polythiophene derivative has a very problem in durability.
As described above, none of the completely solid-state photoelectric conversion elements that have been studied so far have obtained satisfactory characteristics.
The present applicant has previously proposed a photovoltaic element containing a polymer material having a specific structure and an optical sensor provided with the photovoltaic element (see, for example, Patent Document 4), but the photoelectric conversion element of the present invention. Is different in operating principle and constituent materials.

Japanese Patent No. 2664194 Japanese Patent Laid-Open No. 11-144773 JP 2000-106223 A JP 2005-93572 A Nature, 353 (1991) 737 J. Am. Chem. Soc., 115 (1993) 6382 Semicond. Sci. Technol., 10 (1995) 1689 Electrochemistry, 70 (2002) 432 Synthetic Metals, 89 (1997) 215 Nature, 398 (1998) 583 Chem. Lett., (1997) 471

  The present invention solves the above-mentioned problems, and provides a completely solid-state photoelectric conversion element that exhibits excellent photoelectric conversion characteristics as compared with the prior art, has excellent long-term stability, and also has excellent productivity, and a method for manufacturing the same. The purpose is to do. Moreover, it aims at providing the solar cell using the said photoelectric conversion element.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by the inventions 1) to 20) described below, and have reached the present invention. Hereinafter, the present invention will be specifically described.

1) In a photoelectric conversion element in which an electron transport layer and a hole transport layer are provided between an electron collector electrode and a hole collector electrode, at least one of which is transparent,
The constituent material of the hole transport layer contains a polymer material represented by the following general formula (1).

In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, and Ar ² and Ar ³ each independently represents a substituted or unsubstituted monocyclic, non-fused polycyclic or fused polycyclic aromatic group. Represents a divalent group selected from group hydrocarbon groups. Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene.

  2) The photoelectric conversion element as described in 1) above, wherein the polymer material is a polymer material represented by the following general formula (2).

In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, R ⁷ , R ⁸ each independently represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group, and x and y each independently represents an integer of 0 to 4, R ⁷ , R ^{When a} plurality of ⁸ are present, they may be the same or different.

  3) The photoelectric conversion element as described in 1) above, wherein the polymer material is a polymer material represented by the following general formula (3).

In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ⁷ and R ⁸ are each independently a halogen atom, substituted or unsubstituted alkyl R ⁹ represents a group selected from a group, an alkoxy group or an alkylthio group, and R ⁹ represents a group selected from a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, an alkylthio group or an aryl group. z represents an integer of 0 to 5, x and y each independently represents an integer of 0 to 4, and when a plurality of R ⁷ , R ⁸ and R ⁹ are present, they may be the same or different.

  4) The photoelectric conversion element as described in 1) above, wherein the polymer material is a polymer material represented by the following general formula (4).

In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ⁷ , R ⁸ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are each represented by Independently represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group. v represents an integer of 0 to 3, w, x and y each independently represents an integer of 0 to 4, and when there are a plurality of R ⁷ , R ⁸ , R ¹⁰ and R ¹¹ , they may be the same or different. It may be different.

  5) The photoelectric conversion element as described in 1) above, wherein the polymer material is a polymer material represented by the following general formula (5).

In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group, and r, s, t and u each independently represents 0 4 represents an integer of 4, and when there are a plurality of R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ , they may be the same or different.

  6) The photoelectric conversion element as described in 1) above, wherein the polymer material is a polymer material represented by the following general formula (6).

In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are each independently halogen. Represents an atom, a substituted or unsubstituted group selected from an alkyl group, an alkoxy group, or an alkylthio group, q represents an integer of 0 to 5, and r, s, t, and u each independently represents an integer of 0 to 4 In the case where a plurality of R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are present, they may be the same or different.

  7) The polymer material represented by any one of the general formulas (1) to (6), which is a constituent material component of the hole transport layer, is also used as a constituent material of the hole collector electrode. The photoelectric conversion element according to any one of 1) to 6) above.

  8) The photoelectric conversion element as described in any one of 1) to 7) above, wherein the constituent material of the electron transport layer is an oxide semiconductor.

  9) The photoelectric conversion element as described in 8) above, wherein the oxide semiconductor is at least one selected from titanium oxide, zinc oxide, tin oxide, niobium oxide, and nickel oxide.

  10) The photoelectric conversion element as described in any one of 1) to 9) above, wherein a metal compound is further added as a constituent material of the hole transport layer.

  11) The photoelectric conversion element as described in 10) above, wherein the metal compound is at least one selected from a metal halide, a metal thiocyanide, or a metal amid.

  12) The photoelectric conversion element as described in any one of 1) to 9) above, wherein an ionic liquid comprising a room temperature molten salt is further added as a constituent material of the hole transport layer.

  13) The photoelectric conversion element as described in 12) above, wherein the ionic liquid is an imidazolinium compound.

  14) The photoelectric conversion element as described in any one of 1) to 13) above, wherein a photosensitizing compound is supported on the electron transport layer.

  15) The photoelectric conversion element as described in 14) above, wherein the photosensitizing compound is at least one selected from compounds represented by the following general formulas (7) to (11).

In the formula, R _{1 to} R _{4 and} R _{20 to} R ₂₂ may have a carboxyl group, a quaternary ammonium salt of a carboxyl group, an alkyl group having an acidic group, an alkenyl group having an acidic group, or a substituent. Represents an alkyl group, which may be the same or different. X ₁ represents a halogen atom, a cyano group, a thiocyanate group, or an isocyanate group. R _{23 to} R ₂₅ represent a hydrogen atom or an alkyl group. Ar ₇ represents a divalent vinylene group, a divalent arylene group which may have a substituent, or a divalent heterocyclic residue which may have a substituent. X ₂ and X ₃ represent a cyano group, a nitro group, a halogen atom, an alkylsulfonyl group which may have a substituent, or an arylsulfonyl group which may have a substituent. R ₂₇ and R ₃₀ represent a hydrogen atom or a quaternary ammonium salt. R ₂₈ and R ₂₉ represent an alkyl group which may have a substituent, an aryl group which may have a substituent, and a heterocyclic residue which may have a substituent. s represents the integer of 0-2. R ₃₁ and R ₃₂ represent an alkyl group which may have a substituent, an aryl group which may have a substituent, and a heterocyclic residue which may have a substituent. X ₄ represents an oxygen atom, a sulfur atom, or a selenium atom, and X ₅ represents an oxygen atom, a sulfur atom, or a rhodanine ring that may have a substituent. X ₆ represents a divalent substituent which forms a ring by bonding with a nitrogen atom and a benzene ring.

  16) The above-described 1) to 15), wherein the electron transport layer has a multilayer structure of a layer having a non-porous structure (hereinafter referred to as a layer having a dense structure) and a layer having a porous structure. The photoelectric conversion element in any one of.

  17) The layer having a porous structure has a nanoporous structure formed by baking semiconductor fine particles, and the roughness factor of the semiconductor fine particles inside the nanoporous structure is 20 or more. The photoelectric conversion element as described in 16).

  18) The photoelectric conversion element as described in any one of 1) to 17) above, wherein the thickness of the electron transport layer is from 100 nm to 100 μm.

19) In the method for producing a photoelectric conversion element comprising an electron transport layer and a hole transport layer provided between an electron collector electrode and a hole current collector electrode, at least one of which is transparent,
An electron transport layer is formed on the electron current collecting electrode, a photosensitizing compound is supported on the electron transport layer, and then wet film formation is performed using a solution containing a polymer material represented by the following general formula (1) A method for producing a photoelectric conversion element, comprising: applying and laminating a hole transport layer by a method, forming a hole collecting electrode in contact with the hole transport layer after performing a porous treatment.

In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, and Ar ² and Ar ³ each independently represents a substituted or unsubstituted monocyclic, non-fused polycyclic or fused polycyclic aromatic group. Represents a divalent group selected from group hydrocarbon groups. Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene.

  20) A solar cell using the photoelectric conversion element as described in any one of 1 to 18 above.

According to the configuration 1) of the present invention, there is provided a complete solid-state photoelectric conversion element having good productivity and excellent photoelectric conversion characteristics (for example, conversion efficiency) and excellent long-term stability and good cost performance. Is done.
Moreover, the polymer materials used for the hole transport layer are appropriately selected according to the configurations of 2) to 6), so that it is possible to provide a photoelectric conversion element that exhibits more excellent photoelectric conversion characteristics and has better cost performance. Become. Moreover, if it is the structure of said 7), it will become possible to provide the photoelectric conversion element which was further excellent in cost performance.
Further, when an oxide semiconductor is used for the electron transport layers in the above 8) and 9), a photoelectric conversion element that provides efficient electron transfer and further exhibits excellent photoelectric conversion characteristics such as conversion efficiency is provided.
Further, by adding an ionic liquid composed of a metal compound or a room temperature molten salt to the hole transport layers of 10) to 13) above, a photoelectric conversion element is provided in which electron transfer becomes efficient and further excellent photoelectric conversion characteristics are provided. The
And if it is set as the structure by which the photosensitizing compound was carry | supported by the electron carrying layer of said 14) and 15), the light absorption efficiency will increase and the photoelectric conversion element which shows higher conversion efficiency will be provided.
Furthermore, if the electron transport layer of 16) and 17) is a multilayer structure of a layer having a dense structure and a layer having a porous structure, the amount of the photosensitizing compound supported can be increased and the light capture rate can be increased. The photoelectric conversion element which can be improved and shows still higher conversion efficiency by the film thickness adjustment of said 18) is provided.
Moreover, according to the manufacturing method of said 19), the perfect solid type photoelectric conversion element excellent in the photoelectric conversion characteristic can be manufactured with sufficient productivity.
And if the photoelectric conversion element of said 1) -19) of this invention is used, the solar cell which shows the outstanding conversion efficiency will be provided. Such a solar cell can be used as a power source for various electronic devices such as a mobile phone, an electronic notebook, and electronic paper, and as an auxiliary power source for various rechargeable or dry cell type electric appliances.

The present invention will be described in detail below.
A photoelectric conversion element generally comprises an electron collector electrode, an electron acceptor / electron transport layer (hereinafter simply referred to as an electron transport layer), an electron donor / hole transport layer (hereinafter simply referred to as a hole transport layer), and a hole current collector electrode. Is done. The photoelectric conversion element of the present invention is characterized by using a hole transport material made of a specific polymer material as a constituent material of the hole transport layer. In addition, as one of the features, a polymer material that is a constituent material component of the hole transport layer can be used also for the hole collector electrode if necessary.

Preferred embodiments of the present invention will be described below with reference to the drawings.
The photoelectric conversion element in the present invention has, for example, a structure as shown in the schematic diagram of FIG.
In the photoelectric conversion element of FIG. 1, an electron transport layer (3a) having a dense structure on a transparent electron collecting electrode (2a) supported by a transparent support (substrate) (1a), a photosensitizing compound ( A granular electron transport layer (3b) having a porous structure carrying 5), a hole transport layer (4), a hole current collecting electrode (2b), and a substrate (1b) as a support are laminated. The electron transport layer (3) is constituted by (3a) and (3b). In addition, the block diagram of FIG. 1 shows one structural example of the photoelectric conversion element according to the present invention, and the present invention is not limited to this.

That is, in the photoelectric conversion element of the present invention, an electron transport layer and a hole transport layer are provided between an electron collector electrode and a hole collector electrode, at least one of which is transparent, and the constituent material of the hole transport layer is the above general formula. It contains the polymer material represented by any one of (1) to (6).
By using the polymer material as a hole transport layer, a completely solid photoelectric conversion element having excellent photoelectric conversion characteristics such as conversion efficiency and excellent long-term stability can be obtained. In addition, since the productivity is good, a photoelectric conversion element with good cost performance can be obtained.

Hereinafter, the polymer material which is a hole transport material contained in the hole transport layer, which is a feature of the present invention, will be described.
As described above, in general formula (1), Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, and Ar ² and Ar ³ are each independently substituted or unsubstituted, monocyclic, non-condensed polycyclic. Represents a divalent group selected from a cyclic or condensed polycyclic aromatic hydrocarbon group. Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene.

  That is, the polymer material may have a substituent on the aromatic ring, and examples of the substituent include an alkyl group, an alkoxy group, and an alkylthio group from the viewpoint of improving solubility. If the carbon number of these substituents increases, the solubility is further improved. Examples of suitable substituents include alkyl groups having 1 to 25 carbon atoms, alkoxy groups, and alkylthio groups. More preferable examples include an alkyl group having 2 to 18 carbon atoms, an alkoxy group, and an alkylthio group. A plurality of the same substituents may be introduced, or a plurality of different substituents may be introduced. In addition, these alkyl groups, alkoxy groups and alkylthio groups are further halogen atoms, cyano groups, phenyl groups, hydroxyl groups, carboxyl groups, or linear, branched or cyclic alkyl groups or alkoxy groups having 1 to 12 carbon atoms, It may contain a phenyl group substituted with an alkylthio group.

  Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, pentyl group, hexyl group, Heptyl, octyl, nonyl, decyl, 3,7-dimethyloctyl, 2-ethylhexyl, trifluoromethyl, 2-cyanoethyl, benzyl, 4-chlorobenzyl, 4-methylbenzyl, A cyclopentyl group, a cyclohexyl group, etc. can be mentioned as an example, As an alkoxy group and an alkylthio group, what made the alkoxy group and the alkylthio group by inserting an oxygen atom or a sulfur atom in the bond position of the said alkyl group is mentioned as an example. .

The substituted or unsubstituted aromatic hydrocarbon group Ar ¹ in the general formula (1) may be either a monocyclic group or a polycyclic group (a condensed polycyclic group or a non-condensed polycyclic group). Things can be mentioned. Examples include phenyl group, naphthyl group, pyrenyl group, fluorenyl group, azulenyl group, anthryl group, triphenylenyl group, chrycenyl group, biphenyl group, terphenyl group, etc. Examples of the cyclic or condensed polycyclic aromatic hydrocarbons Ar ² and Ar ³ include divalent groups of the above aromatic groups.

Moreover, these aromatic hydrocarbon groups may have a substituent shown below.
(1) Halogen atom, trifluoromethyl group, cyano group, nitro group.
(2) A linear or branched alkyl group or alkoxy group having 1 to 25 carbon atoms. These may be further substituted with a halogen atom, a cyano group, a phenyl group, a hydroxyl group, a carboxyl group, an alkoxy group, or an alkylthio group.
(3) Aryloxy group. (Examples include aryloxy groups having a phenyl group or a naphthyl group as the aryl group. These may contain a halogen atom as a substituent, and are a linear or branched alkyl group or alkoxy having 1 to 25 carbon atoms. A phenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, 4-methylphenoxy group, 4-methoxyphenoxy group, 4-chlorophenoxy group, 6 -A methyl-2-naphthyloxy group etc. are mentioned.
(4) An alkylthio group or an arylthio group. (Specific examples of the alkylthio group or arylthio group include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.)
(5) An alkyl-substituted amino group. (Specifically, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (p-tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And urolidyl group)
(6) Acyl group. (Specific examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, a malonyl group, and a benzoyl group.)

Of the polymers containing repeating units represented by the general formula (1), a more preferred first embodiment is represented by the following general formula (2).

In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, R ⁷ , R ⁸ each independently represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group, and x and y each independently represents an integer of 0 to 4, R ⁷ , R ^{When a} plurality of ⁸ are present, they may be the same or different.
Here, the substituent on the alkyl group, alkoxy group or alkylthio group is the same as in the general formula (1).

  Of the polymers containing repeating units represented by the general formula (1), a more preferred second embodiment is represented by the following general formula (3).

In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ⁷ and R ⁸ are each independently a halogen atom, substituted or unsubstituted alkyl R ⁹ represents a group selected from a group, an alkoxy group or an alkylthio group, and R ⁹ represents a group selected from a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, an alkylthio group or an aryl group. z represents an integer of 0 to 5, x and y each independently represents an integer of 0 to 4, and when a plurality of R ⁷ , R ⁸ and R ⁹ are present, they may be the same or different.
The substituent on the alkyl group, alkoxy group or alkylthio group is the same as in the general formula (1).

  Of the polymers containing repeating units represented by the general formula (1), a more preferred first embodiment is represented by the following general formula (4).

In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ⁷ , R ⁸ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are each represented by Independently represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group. v represents an integer of 0 to 3, w, x and y each independently represents an integer of 0 to 4, and when there are a plurality of R ⁷ , R ⁸ , R ¹⁰ and R ¹¹ , they may be the same or different. It may be different.
The substituent on the alkyl group, alkoxy group or alkylthio group is the same as in the general formula (1).

  Of the polymers containing repeating units represented by the general formula (1), a further preferred second embodiment is represented by the following general formula (5).

In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group, and r, s, t and u each independently represents 0 4 represents an integer of 4, and when there are a plurality of R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ , they may be the same or different.
The substituent on the alkyl group, alkoxy group or alkylthio group is the same as in the general formula (1).

  Of the polymers containing repeating units represented by the general formula (1), a further preferred third embodiment is represented by the following general formula (6).

In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are each independently halogen. Represents an atom, a substituted or unsubstituted group selected from an alkyl group, an alkoxy group, or an alkylthio group, q represents an integer of 0 to 5, and r, s, t, and u each independently represents an integer of 0 to 4 In the case where a plurality of R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are present, they may be the same or different. )
The substituent on the alkyl group, alkoxy group or alkylthio group is the same as in the general formula (1).

  Specific examples (compounds (I) to (XIX)) of the polymer material represented by the general formula (1) used in the present invention are listed below. It should be noted that these specific examples are not intended to limit the present invention, nor are they disclosed with the intention of limiting.

  The production method of the polymer material represented by the general formulas (1) to (6) includes, for example, Wittig-Horner reaction using aldehyde and phosphonate, Wittig reaction using aldehyde and phosphonium salt, vinyl substitution product and halide. The Heck reaction used, the Ullmann reaction using an amine and a halide, and the like can be used, and they can be produced by a known method. In particular, the Wittig-Horner reaction and the Wittig reaction are effective because of the simplicity of the reaction operation.

As an example, a method for producing a polymer material in the present invention using a Wittig-Horner reaction will be described.
As shown in the following reaction formula (F1), the polymer material used in the present invention includes a solution in which the phosphonic acid ester compound and the aldehyde compound are present stoichiometrically, and a base more than twice the molar amount thereof. By mixing these, the polymerization reaction proceeds and can be obtained.

In the production of polymeric materials used in the present invention, for example, an aryl amine moiety as A, or using a monomer combination of Ar ⁴ as B, or A as Ar ^4, B as monomers a combination of aryl amine sites May be used.

  The dialdehyde compound can be synthesized by various known reactions. As an example, a Vilsmeier reaction represented by the following reaction formula (F2);

Alternatively, the reaction of an aryllithium compound represented by the following reaction formula (F3) with a formylating agent such as DMF, N-formylmorpholine, N-formylpiperidine and the like;

Alternatively, a Gatterman reaction represented by the following reaction formula (F4);

Alternatively, various oxidation reactions of a hydroxymethyl compound represented by the following reaction formula (F5);

Can be cited as examples, and dialdehyde compounds can be synthesized using these reactions.

  The phosphonic acid diester compound can also be synthesized by various known reactions, but the Michaelis-Arbuzov reaction represented by the following reaction formula (F6) is particularly easy.

In addition, the specific manufacturing method of the said polymer material used by this invention is described in the Unexamined-Japanese-Patent No. 2004-18831.
The polymer material exhibits good solubility in various common organic solvents such as dichloromethane, tetrahydrofuran, chloroform, toluene, dichlorobenzene and xylene.

Moreover, in the photoelectric conversion element of this invention, you may add various additives to the polymeric material shown above. Additives include iodine, lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium iodide, copper iodide, iron iodide, silver iodide and other metal iodides, tetraalkylammonium iodide, Quaternary ammonium salts such as pyridinium iodide, metal bromides such as lithium bromide, sodium bromide, potassium bromide, cesium bromide and calcium bromide, quaternary ammonium compounds such as tetraalkylammonium bromide and pyridinium bromide Metal chlorides such as bromine salts, copper chloride and silver chloride, metal acetates such as copper acetate, silver acetate and palladium acetate, metal sulfides such as copper sulfate and zinc sulfate, ferrocyanate-ferricyanate, ferrocene -Sulfur compounds such as metal complexes such as ferricinium ions, sodium polysulfide, alkylthiol-alkyl disulfides Inorg. Chem. 35 (1996) such as viologen dye, hydroquinone, or the like, or 1,2-dimethyl-3-n-propylimidazolinium iodide, 1-methyl-3-n-hexylimidazolinium iodide, etc. Examples include ordinary temperature molten salts (ionic liquids) described in 1168, basic compounds such as pyridine, 4-t-butylpyridine, and benzimidazole, and lithium compounds such as lithium trifluoromethanesulfonylimide and lithium diisopropylimide.
Preferred in the above is an ionic liquid composed of a metal compound or a room temperature molten salt. Particularly preferred metal compounds include metal halides, thiocyanides or amidated metals. Moreover, an imidazolinium compound is mentioned as an ionic liquid which consists of especially preferable normal temperature molten salt.
By adding such an ionic liquid composed of a metal compound or a room temperature molten salt, the electron transfer becomes efficient, and a photoelectric conversion element exhibiting further excellent photoelectric conversion characteristics can be obtained.

  Further, for the purpose of improving the conductivity, an oxidizing agent for making a part of the polymer material a radical cation may be added. As the oxidizing agent, tris (4-bromophenyl) aminium hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluorate and the like are preferable. It is not necessary for all the polymers to be oxidized by the addition of the oxidizing agent, and only a part of the polymer needs to be oxidized. The added oxidizing agent may be taken out of the system after the addition or may not be taken out.

  The hole transport layer is formed on an electron transport layer carrying a photosensitizing compound described later. There is no restriction | limiting in particular in the preparation methods of a hole transport layer, The method of forming a thin film in vacuum, such as sputtering, and the wet film forming method are mentioned. In consideration of the manufacturing cost and the like, a wet film forming method is particularly preferable, and a method of coating on the electron transport layer is preferable. When this wet film-forming method is used, the coating method is not particularly limited and can be performed according to a known method. For example, dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, and wet printing methods such as letterpress, offset, gravure, intaglio, rubber plate, screen printing, etc. Can be used.

The hole collector electrode may be newly added after the hole transport layer is formed, or a polymer material used as a constituent material of the hole transport layer of the present invention may be used as the hole collector electrode.
As the hole current collecting electrode, the same one as an electron current collecting electrode described later can be usually used, and a support (the substrate (1b) shown in FIG. 1) is used in a configuration in which strength and sealability are sufficiently maintained. Is not necessarily required.
Specific examples of hole collecting electrode materials include metals such as platinum, gold, silver, copper, and aluminum, carbon compounds such as graphite, fullerene, and carbon nanotubes, indium tin oxide (hereinafter referred to as ITO), fluorine Examples thereof include conductive metal oxides such as doped tin oxide (hereinafter referred to as FTO), and conductive polymers such as polythiophene and polyaniline. There is no restriction | limiting in particular in the film thickness of a hole current collection electrode layer, and you may use individually or in mixture of 2 or more types.
The hole collecting electrode can be applied by a method such as coating, laminating, vapor deposition, CVD, and bonding on the hole transport layer as appropriate depending on the type of material used and the type of hole transport layer.

  In order to operate as a photoelectric conversion element, at least one of the hole collecting electrode and the later-described electron collecting electrode must be substantially transparent. In the photoelectric conversion element of the present invention, a method in which the electron collecting electrode side is transparent and sunlight is incident from the electron collecting electrode side is preferable. In this case, it is preferable to use a material that reflects light on the side of the hole collecting electrode, and a metal, glass, plastic, or metal thin film on which a conductive oxide is deposited is preferable. It is also effective to provide an antireflection layer on the sunlight incident side.

  The electron collector electrode used in the present invention is not particularly limited as long as it is a conductive material that is transparent to visible light, and a known one used for a normal photoelectric conversion element, a liquid crystal panel, or the like. Can be used. For example, ITO, FTO, etc. are mentioned. Of these, FTO is preferred. The thickness of the electron collector electrode is preferably 0.005 to 1 μm, and more preferably 0.01 to 0.1 μm. In addition, the electron collector electrode is preferably provided on a substrate made of a material transparent to visible light in order to maintain a certain hardness. For example, glass, a transparent plastic plate, a transparent plastic film, an inorganic transparent crystal, or the like is used. .

  A well-known one in which the electron collector electrode and the substrate are integrated can also be used, and examples thereof include FTO-coated glass, ITO-coated glass, and zinc oxide: aluminum-coated glass. In addition, a transparent electrode obtained by doping cations or anions with different valences into tin oxide or indium oxide, or a metal electrode having a structure capable of transmitting light, such as a mesh shape or a stripe shape, provided on a substrate such as a glass substrate Good. These may be used singly or as a mixture of two or more kinds or laminated ones.

  Moreover, a metal lead wire or the like may be used for the purpose of reducing the resistance of the substrate. Examples of the material of the metal lead wire include metals such as aluminum, copper, silver, gold, platinum, and nickel. For example, the metal lead wire may be provided on the substrate by vapor deposition, sputtering, pressure bonding, or the like, and ITO or FTO may be provided thereon.

  The photoelectric conversion element of this invention forms the thin film which consists of semiconductors as an electron carrying layer on said electron current collection electrode. This electron transport layer preferably has a laminated structure in which a dense electron transport layer is formed on an electron current collecting electrode, and a porous electron transport layer is further formed thereon. This dense electron transport layer is formed for the purpose of preventing electronic contact between the electron collector electrode and the hole transport layer. Therefore, if the electron final electrode and the hole transport layer are not in physical contact, pinholes, cracks, or the like may be formed. Moreover, although there is no restriction | limiting in the film thickness of this precise | minute electron carrying layer, 10 nm-1 micrometer are preferable and 20 nm-700 nm are more preferable.

That is, the electron transport layer in the present invention preferably has a multilayer structure of a layer having a dense structure and a layer having a porous structure.
The porous electron transport layer formed on the dense electron transport layer may be a single layer or multiple layers. As a method of forming a porous structure having a multilayer structure, it is possible to apply a multilayer coating of a dispersion of semiconductor fine particles having different particle diameters, or to apply different types of semiconductors and coating layers having different compositions of resins and additives. You can also Multi-layer coating is an effective means when the film thickness is insufficient with a single coating. In general, as the thickness of the electron transport layer increases, the amount of supported photosensitizing compound per unit projected area increases, so that the light capture rate increases. Loss due to recombination also increases. Therefore, the film thickness of the electron transport layer is preferably 100 nm to 100 μm.

The constituent material of the electron transport layer in the present invention is preferably a semiconductor. The semiconductor is not particularly limited, and a known semiconductor can be used.
Specifically, a single semiconductor such as silicon or germanium, a compound semiconductor typified by a metal chalcogenide, a compound having a perovskite structure, or the like can be given.
Metal chalcogenides include titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, or tantalum oxides, cadmium, zinc, lead, silver, antimony, bismuth. Sulfide, cadmium, lead selenide, cadmium telluride and the like. Other compound semiconductors are preferably phosphides such as zinc, gallium, indium, cadmium, gallium arsenide, copper-indium-selenide, copper-indium-sulfide, and the like. As the compound having a perovskite structure, strontium titanate, calcium titanate, sodium titanate, barium titanate, potassium niobate and the like are preferable.
Among these, an oxide semiconductor is preferable, and titanium oxide, zinc oxide, tin oxide, niobium oxide, and nickel oxide are particularly preferable, and they may be used alone or in combination of two or more. The crystal type of these semiconductors is not particularly limited, and may be single crystal, polycrystal, or amorphous.

  Although there is no restriction | limiting in particular in the particle size in the case of using the said semiconductor in a fine particle state, 1-100 nm is preferable and, as for the average particle diameter of a primary particle, 5-50 nm is more preferable. It is also possible to improve efficiency by mixing semiconductor fine particles having a larger average particle diameter and scattering incident light. In this case, the average particle size of the semiconductor is preferably 50 to 500 nm.

  There is no restriction | limiting in particular in the preparation methods of an electron carrying layer, The method of forming a thin film in vacuum, such as sputtering, and the wet film forming method are mentioned. In view of the manufacturing cost and the like, a wet film forming method is particularly preferable, and a method in which a paste in which semiconductor fine particle powder or sol is dispersed is prepared and applied onto an electron collecting electrode substrate is preferable. When this wet film-forming method is used, the coating method is not particularly limited and can be performed according to a known method. For example, dip method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, and wet printing methods such as relief printing, offset, gravure, intaglio printing, rubber printing, screen printing, etc. Can be used.

  When a dispersion is prepared by mechanical pulverization or using a mill, it is formed by dispersing at least semiconductor fine particles alone or a mixture of semiconductor fine particles and a resin in water or an organic solvent. As the resin used at this time, polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, acrylic acid ester, methacrylic acid ester, silicon resin, phenoxy resin, polysulfone resin, polyvinyl butyral resin, polyvinyl formal resin, Examples include polyester resin, cellulose ester resin, cellulose ether resin, urethane resin, phenol resin, epoxy resin, polycarbonate resin, polyarylate resin, polyamide resin, polyimide resin, and the like.

  Solvents for dispersing the semiconductor fine particles include alcohol solvents such as water, methanol, ethanol, and isopropyl alcohol, ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ethyl formate, ethyl acetate, and n-butyl acetate. Ester solvents, diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, or ether solvents such as dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, or amide solvents such as N-methyl-2-pyrrolidone , Dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodine Halogenated hydrocarbon solvents such as debenzene or 1-chloronaphthalene, n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, Examples thereof include hydrocarbon solvents such as m-xylene, p-xylene, ethylbenzene, and cumene. These can be used alone or as a mixed solvent of two or more.

  In order to prevent re-aggregation of particles, a dispersion of semiconductor particles or a paste of semiconductor particles obtained by a sol-gel method or the like, an acid such as acetylacetone, hydrochloric acid, nitric acid or acetic acid, or a surfactant such as Triton X-100 Chelating agents and the like can be added. It is also an effective means to add a thickener for the purpose of improving the film forming property. Examples of the thickener added at this time include polymers such as polyethylene glycol and polyvinyl alcohol, and thickeners such as ethyl cellulose.

  The semiconductor fine particles are preferably subjected to baking, microwave irradiation, press treatment or electron beam irradiation in order to bring the particles into electronic contact with each other after coating and to improve film strength and adhesion to the substrate. These treatments may be performed alone or in combination of two or more. In the case of firing, the range of the firing temperature is not particularly limited, but if the temperature is raised too much, the resistance of the substrate is increased and the substrate may melt, so 30 to 700 ° C is preferable, and 100 to 600 ° C is more preferable. Moreover, although there is no restriction | limiting in particular also in baking time, 10 minutes-10 hours are preferable. After firing, for example, chemical plating using titanium tetrachloride aqueous solution or electrochemical plating using titanium trichloride aqueous solution for the purpose of increasing the surface area of semiconductor fine particles or increasing the efficiency of electron injection from the photosensitizing compound to the semiconductor fine particles. Processing may be performed.

A film in which semiconductor fine particles having a diameter of several tens of nanometers are stacked by sintering or the like forms a porous state. This nanoporous structure has a very high surface area, which can be expressed using a roughness factor. This roughness factor is a numerical value representing the actual area inside the porous body relative to the area of the semiconductor fine particles applied to the substrate. Accordingly, the roughness factor is preferably as large as possible, but it is also related to the film thickness of the electron transport layer, and is preferably 20 or more in the present invention.
That is, the layer having a porous structure in the present invention preferably has a nanoporous structure formed by firing semiconductor fine particles, and the roughness factor of the semiconductor fine particles inside the nanoporous structure is preferably 20 or more.

Moreover, you may add a conductive support agent in order to reduce the impedance of an electron carrying layer. Microwave irradiation may be performed from the electron transport layer forming side or from the back side. Although there is no restriction | limiting in particular in irradiation time, It is preferable to carry out within 1 hour. The press treatment is preferably 100 kg / cm ² or more, more preferably 1000 kg / cm ² . There is no particular limitation on the pressing time, but it is preferably performed within 1 hour. Further, heat may be applied during the pressing process.

In order to further improve the light conversion efficiency, a photosensitizing compound may be supported (including physical adsorption and chemical bonding) on the electron transport layer. The photosensitizing compound is not particularly limited as long as it is a compound that is photoexcited by the excitation light used, and specific examples thereof include the following compounds.
The metal complex compounds described in JP 7-500630 A, JP 10-233238 A, JP 2000-26487 A, JP 2000-323191 A, JP 2001-59062 A, etc. JP-A-10-93118, JP-A-2002-164089, JP-A-2004-95450, Coumarin compounds described in JP-A-2004-95450, polyene compounds described in JP-A-2003-264010, JP Indoline type compounds described in JP-A-2004-63274, JP-A-2004-115636, JP-A-2004-200068, JP-A-2004-235052, JP-A-11-86916, JP-A-11-214730 JP, 2000-106224, JP 2001-7777 Cyanine dyes described in JP-A No. 2003-7359, JP-A No. 11-214731, JP-A No. 11-238905, JP-A No. 2001-52766, JP-A No. 2001-76775, 9-arylxanthene compounds described in JP-A No. 2003-7360, JP-A-10-92477, JP-A-11-273754, JP-A-11-273755, JP-A-2003-31273, etc. , JP-A-10-93118, JP-A-2003-31273, etc., triarylmethane compounds, JP-A-9-199744, JP-A-10-233238, JP-A-11-204821, The phthalocyanine compounds and porphyrin compounds described in JP-A-11-265738 It can be mentioned. In particular, it is preferable to use a metal complex compound, a coumarin compound, a polyene compound, and an indoline compound.
Furthermore, photosensitized compounds represented by the following general formulas (7) to (11) are more preferable.

In the formula, R _{1 to} R _{4 and} R _{20 to} R ₂₂ may have a carboxyl group, a quaternary ammonium salt of a carboxyl group, an alkyl group having an acidic group, an alkenyl group having an acidic group, or a substituent. Represents an alkyl group, which may be the same or different. X ₁ represents a halogen atom, a cyano group, a thiocyanate group, or an isocyanate group. R _{23 to} R ₂₅ represent a hydrogen atom or an alkyl group. Ar ₇ represents a divalent vinylene group, a divalent arylene group which may have a substituent, or a divalent heterocyclic residue which may have a substituent. X ₂ and X ₃ represent a cyano group, a nitro group, a halogen atom, an alkylsulfonyl group which may have a substituent, or an arylsulfonyl group which may have a substituent. R ₂₇ and R ₃₀ represent a hydrogen atom or a quaternary ammonium salt. R ₂₈ and R ₂₉ represent an alkyl group which may have a substituent, an aryl group which may have a substituent, and a heterocyclic residue which may have a substituent. s represents the integer of 0-2. R ₃₁ and R ₃₂ represent an alkyl group which may have a substituent, an aryl group which may have a substituent, and a heterocyclic residue which may have a substituent. X ₄ represents an oxygen atom, a sulfur atom, or a selenium atom, and X ₅ represents an oxygen atom, a sulfur atom, or a rhodanine ring that may have a substituent. X ₆ represents a divalent substituent which forms a ring by bonding with a nitrogen atom and a benzene ring.

  Specific examples of the photosensitizing compounds represented by the general formulas (7) to (11) include the following general formulas (12) to (54):

The carbon-carbon double bond in the specific examples may be either E-form or Z-form. Moreover, these pigment | dyes can be used as at least 1 type, or 2 or more types of mixture.

  As a method of adsorbing the photosensitizing compound to the electron transport layer, a method of immersing an electron current collecting electrode containing semiconductor fine particles in a photosensitizing compound solution or dispersion, or applying a solution or dispersion to the electron transport layer Thus, a method of adsorbing can be used. In the former case, dipping method, dipping method, roller method, air knife method, etc. can be used, and in the latter case, wire bar method, slide hopper method, extrusion method, curtain method, spin method, spray method, etc. Can be used.

  When adsorbing the photosensitizing compound, a condensing agent may be used in combination. The condensing agent is either a catalytic agent that seems to physically or chemically bind the photosensitizing compound to the inorganic surface, or a stoichiometric agent that favorably moves the chemical equilibrium. Also good. Furthermore, a thiol or a hydroxy compound may be added as a condensation aid.

  Solvents for dissolving or dispersing the photosensitizing compound are water, methanol, ethanol, alcohol solvents such as isopropyl alcohol, ketone solvents such as acetone, methyl ethyl ketone, or methyl isobutyl ketone, ethyl formate, ethyl acetate, or acetic acid. Ester solvents such as n-butyl, ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, or dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, or N-methyl-2-pyrrolidone Amido solvents, dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromoben Halogenated hydrocarbon solvents such as ethylene, iodobenzene or 1-chloronaphthalene, n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o Examples include hydrocarbon solvents such as -xylene, m-xylene, p-xylene, ethylbenzene, and cumene, and these can be used alone or as a mixture of two or more.

  The temperature at which the photosensitizing compound is adsorbed using these is preferably −50 ° C. or higher and 200 ° C. or lower. Further, this adsorption may be performed while stirring. Examples of the stirring method include, but are not limited to, a stirrer, a ball mill, a paint conditioner, a sand mill, an attritor, a disperser, and ultrasonic dispersion. The time required for adsorption is preferably 5 seconds or more and 1000 hours or less, more preferably 10 seconds or more and 500 hours or less, and further preferably 1 minute or more and 150 hours.

  As described above, in the photoelectric conversion element of the present invention, an electron transport layer is formed on an electron current collecting electrode, a photosensitizing compound is supported on the electron transport layer, and then the polymer represented by the general formula (1) A hole transport layer is applied and laminated by a wet film-forming method using a solution containing a material, and a hole current collecting electrode is formed in contact with the hole transport layer, whereby production can be performed with high productivity.

The photoelectric conversion element of the present invention can be applied to a solar cell and a power supply device using the solar cell.
As an application example, any device can be used as long as it has conventionally used a solar cell or a power supply device using the solar cell. For example, although it may be used for an electronic desk calculator or a solar cell for a wristwatch, examples of utilizing the characteristics of the photoelectric conversion element of the present invention include a power supply device such as a mobile phone, an electronic notebook, and electronic paper. It can also be used as an auxiliary power source for extending the continuous use time of a rechargeable or dry battery type electric appliance.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, embodiment of this invention is not limited to these Examples.

Example 1
Under the following conditions, a titanium oxide semiconductor electrode was produced, a photosensitizing compound was supported on the titanium oxide semiconductor, and a polymer compound (polymer 1) was synthesized. A photoelectric conversion element was produced using this.
<Production of titanium oxide semiconductor electrode>
Titanium tetra-n-propoxide 2 ml, acetic acid 4 ml, ion exchange water 1 ml, polyvinylpyrroline 0.8 g, 2-propanol 40 ml are mixed, spin-coated on an FTO glass substrate, dried at room temperature, and then in air at 450 ° C. For 1 hour. The electrode obtained by firing was spin-coated again using the same solution and fired in air at 450 ° C. for 1 hour.
Next, 3 g of titanium oxide (P-25 manufactured by Nippon Aerosil Co., Ltd.), 0.2 g of acetylacetone, and 0.3 g of surfactant (polyoxyethylene octylphenyl ether manufactured by Wako Pure Chemical Industries, Ltd.) together with 5.5 g of water and 1.0 g of ethanol are bead milled. Dispersion was carried out for 12 hours by treatment. 1.2 g of polyethylene glycol (# 20,000) was added to the obtained dispersion to prepare a paste. This paste was applied on the electrode obtained above so as to have a film thickness of 3 μm, dried at room temperature, and then fired in air at 500 ° C. for 1 hour.

<Support of photosensitizing compound on titanium oxide semiconductor>
The titanium oxide semiconductor electrode was replaced with an N719 dye [cis-bis (isothiocyanato) bis (2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium (II) -bis-tetra-n which is a ruthenium complex. -Butylammonium] in an acetonitrile / t-butanol (volume ratio 1: 1) mixed solution was allowed to stand in the dark at room temperature for 2 days to adsorb the dye.

<Synthesis of Polymer Compound (Polymer 1)>
A polymer compound (polymer 1) was synthesized according to the following reaction formula (F7).

That is, 0.852 g (2.70 mmol) of the above dialdehyde and 1.525 g (2.70 mmol) of diphosphonate were placed in a 100 ml four-necked flask, and nitrogen substitution was performed and 75 ml of tetrahydrofuran was added. To this solution, 6.75 ml (6.75 mmol) of a 1.0 mol · dm ⁻³ tetrahydrofuran solution of potassium t-butoxide was added dropwise and stirred at room temperature for 2 hours, and then diethyl benzylphosphonate and benzaldehyde were sequentially added, followed by further stirring for 2 hours. did. About 1 ml of acetic acid was added to terminate the reaction, and the solution was washed with water. After the solvent was distilled off under reduced pressure, purification by reprecipitation was performed using tetrahydrofuran and methanol to obtain 1.07 g of a polymer compound (polymer 1). The yield was 73%.
Elemental analysis value (calculated value); C: 84.25% (84.02%), H: 8.20% (7.93%), N: 2.33% (2.45%). The glass transition temperature determined from differential scanning calorimetry was 116.9 ° C. The number average molecular weight in terms of polystyrene measured by gel filtration chromatography (GPC) was 8500, and the weight average molecular weight was 20000.

[Production of photoelectric conversion element]
To a methylene chloride solution (solid content concentration 10%) of the polymer compound (polymer 1), trifluoromethanesulfonylimide lithium (27 mM), tris (4-bromophenyl) aminium (0.2 mM), 4-t-butylpyridine ( 0.11M) was added, and the obtained solution was introduced onto the titanium oxide semiconductor carrying the electrode-sensitized photosensitized compound prepared previously by a casting method. It was dried at room temperature for 30 minutes and then with a hot air dryer at 80 ° C. for 30 minutes. On top of this, gold was vacuum-deposited as a counter electrode to produce a photoelectric conversion element.

[Evaluation]
The photoelectric conversion characteristics of the photoelectric conversion element produced as described above were evaluated under simulated sunlight irradiation (AM1.5, 100 mW / cm ² ). As a result, the photoelectric conversion characteristics were as follows; an open circuit voltage = 0.85 V, a short circuit current density of 3.3 mA / cm ² , a form factor = 0.60, and a conversion efficiency = 1.68%.

(Example 2)
A photoelectric conversion element was produced in the same manner as in Example 1 except that the polymer material having the structural formula shown in the specific example (III) was used in place of the polymer 1 in Example 1.
The photoelectric conversion characteristics of the produced photoelectric conversion element under pseudo-sunlight irradiation (AM1.5, 100 mW / cm ² ) were evaluated in the same manner as in Example 1. As a result, the photoelectric conversion characteristics were as follows: open circuit voltage = 0.82V, short-circuit current density 3.5 mA / cm ² , form factor = 0.55, conversion efficiency = 1.58%.

(Example 3)
A photoelectric conversion element was produced in the same manner as in Example 1 except that the polymer material having the structural formula shown in the specific example (VII) was used in place of the polymer 1 in Example 1.
The photoelectric conversion characteristics of the produced photoelectric conversion element under pseudo-sunlight irradiation (AM1.5, 100 mW / cm ² ) were evaluated in the same manner as in Example 1. As a result, the photoelectric conversion characteristics were as follows; an open circuit voltage = 0.88 V, a short circuit current density of 3.7 mA / cm ² , a form factor = 0.62, and a conversion efficiency = 2.02%.

Example 4
A photoelectric conversion element was produced in the same manner as in Example 1 except that the polymer material having the structural formula shown in the specific example (XII) was used in place of the polymer 1 in Example 1.
The photoelectric conversion characteristics of the produced photoelectric conversion element under pseudo-sunlight irradiation (AM1.5, 100 mW / cm ² ) were evaluated in the same manner as in Example 1. As a result, the photoelectric conversion characteristics were as follows: open circuit voltage = 0.79 V, short-circuit current density 4.0 mA / cm ² , form factor = 0.57, conversion efficiency = 1.80%.

(Example 5)
A photoelectric conversion element was produced in the same manner as in Example 1 except that the polymer material having the structural formula shown in the specific example (XIV) was used in place of the polymer 1 in Example 1.
The photoelectric conversion characteristics of the produced photoelectric conversion element under pseudo-sunlight irradiation (AM1.5, 100 mW / cm ² ) were evaluated in the same manner as in Example 1. As a result, the photoelectric conversion characteristics were as follows; open circuit voltage = 0.84 V, short circuit current density 3.9 mA / cm ² , form factor = 0.60, conversion efficiency = 1.97%.

(Comparative Example 1)
A photoelectric conversion element was produced in the same manner as in Example 1 except that PEDOT-PSS was used in place of the polymer 1 in Example 1.
The photoelectric conversion characteristics of the produced photoelectric conversion element under pseudo-sunlight irradiation (AM1.5, 100 mW / cm ² ) were evaluated in the same manner as in Example 1. As a result, the photoelectric conversion characteristics were: open circuit voltage = 0.45V, short circuit current density 1.1 mA / cm ² , form factor = 0.48, conversion efficiency = 0.24%.

As is clear from the above results, the photoelectric conversion elements of the present invention containing the polymer material as a constituent material of the hole transport layer all exhibit superior photoelectric conversion characteristics as compared with the comparative example.
That is, the photoelectric conversion element of the present invention is excellent in productivity, and exhibits a completely solid type and high-performance photoelectric conversion characteristic. Therefore, the photoelectric conversion element can be used as a solar cell. It can be applied as a power source for electronic devices such as electronic notebooks and electronic papers, and as an auxiliary power source for rechargeable or dry-battery type electric appliances.

It is the schematic which shows one structural example of the structure of the photoelectric conversion element in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a board | substrate 1b board | substrate 2a electron current collection electrode 2b hole current collection electrode 3 electron transport layer 3a electron transport layer which consists of dense structure 3b granular electron transport layer which consists of porous structure 4 hole transport layer 5 photosensitizing compound

Claims (20)

In a photoelectric conversion element in which an electron transport layer and a hole transport layer are provided between an electron collector electrode and a hole current collector electrode, at least one of which is transparent,
The constituent material of the hole transport layer contains a polymer material represented by the following general formula (1).

(In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, and Ar ² and Ar ³ are each independently substituted or unsubstituted monocyclic, non-condensed polycyclic or condensed polycyclic Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene.) The photoelectric conversion element according to claim 1, wherein the polymer material is a polymer material represented by the following general formula (2).

(In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, Ar ⁴ represents a substituted or unsubstituted, benzene, thiophene, biphenyl, a divalent radical selected from anthracene or naphthalene, R ⁷ , R ⁸ each independently represents a halogen atom, a substituted or unsubstituted alkyl group, or an alkoxy group or an alkylthio group, and x and y each independently represents an integer of 0 to 4, R ⁷ , When there are a plurality of R ^{8 s} , they may be the same or different.) The photoelectric conversion element according to claim 1, wherein the polymer material is a polymer material represented by the following general formula (3).

(In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ⁷ and R ⁸ are each independently a halogen atom, substituted or unsubstituted, R ⁹ represents an alkyl group or a group selected from an alkoxy group or an alkylthio group, and R ⁹ represents a halogen atom, a substituted or unsubstituted group selected from an alkyl group, an alkoxy group, an alkylthio group, or an aryl group, and z is 0. And x and y each independently represents an integer of 0 to 4, and when there are a plurality of R ⁷ , R ⁸ and R ⁹ , they may be the same or different.) The photoelectric conversion element according to claim 1, wherein the polymer material is a polymer material represented by the following general formula (4).

(In the formula, Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ⁷ , R ⁸ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ are Each independently represents a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group or an alkylthio group, v represents an integer of 0 to 3, and w, x, and y each independently represents 0 to 4 And when there are a plurality of R ⁷ , R ⁸ , R ¹⁰ and R ¹¹ , they may be the same or different.) The photoelectric conversion element according to claim 1, wherein the polymer material is a polymer material represented by the following general formula (5).

(In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, Ar ⁴ represents a substituted or unsubstituted, benzene, thiophene, biphenyl, a divalent radical selected from anthracene or naphthalene, R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group, and r, s, t and u are each independently 0 Represents an integer of 1 to 4, and when there are a plurality of R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ , they may be the same or different.) The photoelectric conversion element according to claim 1, wherein the polymer material is a polymer material represented by the following general formula (6).

(Wherein Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene, and R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are each independently Represents a group selected from a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, or an alkylthio group, q represents an integer of 0 to 5, and r, s, t, and u each independently represents 0 to 4 Represents an integer, and when there are a plurality of R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ , they may be the same or different.)   The polymer material represented by any one of the general formulas (1) to (6), which is a constituent material component of the hole transport layer, is also used as a constituent material of a hole collecting electrode. The photoelectric conversion element in any one of 1-6.   The constituent material of the said electron carrying layer is an oxide semiconductor, The photoelectric conversion element in any one of Claims 1-7 characterized by the above-mentioned.   The photoelectric conversion element according to claim 8, wherein the oxide semiconductor is at least one selected from titanium oxide, zinc oxide, tin oxide, niobium oxide, and nickel oxide.   The photoelectric conversion element according to claim 1, wherein a metal compound is further added as a constituent material of the hole transport layer.   The photoelectric conversion element according to claim 10, wherein the metal compound is at least one selected from a metal halide, a metal thiocyanide, or a metal amid.   The photoelectric conversion element according to claim 1, further comprising an ionic liquid composed of a room temperature molten salt as a constituent material of the hole transport layer.   The photoelectric conversion element according to claim 12, wherein the ionic liquid is an imidazolinium compound.   The photoelectric conversion element according to claim 1, wherein a photosensitizing compound is supported on the electron transport layer. The photoelectric conversion element according to claim 14, wherein the photosensitizing compound is at least one selected from compounds represented by the following general formulas (7) to (11).

(In the formula, R _{1 to} R _{4 and} R _{20 to} R ₂₂ may have a carboxyl group, a quaternary ammonium salt of a carboxyl group, an alkyl group having an acidic group, an alkenyl group having an acidic group, or a substituent. X ₁ represents a halogen atom, a cyano group, a thiocyanate group, or an isocyanate group, R _{23 to} R ₂₅ represent a hydrogen atom or an alkyl group, and Ar ₇ represents an alkyl group. A divalent vinylene group, a divalent arylene group which may have a substituent, and a divalent heterocyclic residue which may have a substituent, wherein X ₂ and X ₃ are a cyano group; , A nitro group, a halogen atom, an optionally substituted alkylsulfonyl group, and an optionally substituted arylsulfonyl group, R ₂₇ and R ₃₀ represent a hydrogen atom or a quaternary ammonium salt. R ₂₈ and R ₂₉ may have a substituent. Represents an alkyl group, an aryl group which may have a substituent, or a heterocyclic residue which may have a substituent, s represents an integer of 0 to 2. R ₃₁ and R ₃₂ represent a substituent. X ₄ represents an oxygen atom, a sulfur atom, or a selenium atom, which may represent an alkyl group that may have a substituent, an aryl group that may have a substituent, or a heterocyclic residue that may have a substituent. represents, X ₅ represents an oxygen atom, a sulfur atom, substituted represents also good rhodanine ring .X ₆ is a divalent substituent which form a ring with the nitrogen atom and the benzene ring.)   The photoelectric conversion element according to claim 1, wherein the electron transport layer has a multilayer structure of a layer having a non-porous structure and a layer having a porous structure.   The layer having the porous structure has a nanoporous structure formed by firing semiconductor fine particles, and the roughness factor of the semiconductor fine particles in the nanoporous structure is 20 or more. The photoelectric conversion element described in 1.   The film thickness of the said electron carrying layer is 100 nm-100 micrometers, The photoelectric conversion element in any one of Claims 1-17 characterized by the above-mentioned. In the method for producing a photoelectric conversion element in which an electron transport layer and a hole transport layer are provided between an electron collector electrode and a hole current collector electrode, at least one of which is transparent,
An electron transport layer is formed on the electron current collecting electrode, a photosensitizing compound is supported on the electron transport layer, and then wet film formation is performed using a solution containing a polymer material represented by the following general formula (1) A method for producing a photoelectric conversion element, comprising: applying and laminating a hole transport layer by a method, forming a hole collecting electrode in contact with the hole transport layer after performing a porous treatment.

(In the formula, Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon group, and Ar ² and Ar ³ are each independently substituted or unsubstituted monocyclic, non-condensed polycyclic or condensed polycyclic Ar ⁴ represents a substituted or unsubstituted divalent group selected from benzene, thiophene, biphenyl, anthracene or naphthalene.) A solar cell using the photoelectric conversion element according to claim 1.

Images