JP2001167630A - Electrolyte composition, photoelectric transducer and photoelectrochemical cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric transducer exhibiting durability and photoelectric conversion characteristics, as well as a photoelectrochemical cell comprising the photoelectric transducer. SOLUTION: Disclosed herein are an electrolyte composition containing a compound represented by the following formula 1, and a photoelectric transducer and a photoelectrochemical cell: where Q represents an atomic group capable of forming a 5- or 6-membered ring aromatic cation together with a nitrogen atom, R001 represents L001-A01 (A01 represents a substituent when L001 represents a linkage, or A01 represents a hydrogen atom or a substituent when L001 represents a divalent linking group), n01 represents an integer of 0 or 1 or more which is a number less than a maximum number of the R001 which can be present on the group Q, R002 represents L002-L003-A02 (L002 represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group, L003 represents a divalent linking group, and A02 represents a hydrogen atom or a substituent), X- represents an anion, and at least one of A01 and A02 is a substituent having a pKa of 3 to 15, of a conjugate acid of a compound consisting of hydrogen bonded thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolyte composition having excellent durability and charge transport ability, a photoelectric conversion device using such an electrolyte composition, and a photoelectrochemical cell comprising the photoelectric conversion device. Further, the present invention relates to novel imidazolium compounds and pyridinium compounds that can be used for the electrolyte composition.

[0002]

2. Description of the Related Art Conventionally, a liquid electrolyte obtained by dissolving an electrolyte salt in a solvent has been used as an electrolyte for electrochemical devices such as batteries, capacitors, sensors, display devices, and recording devices. However, an electrochemical device using such a liquid electrolyte sometimes leaks during long-term use or storage, and thus lacks reliability.

[0003] Nature, 353, 737-740, 1991
U.S. Pat.No. 4,492,721 discloses a photoelectric conversion element using a fine particle semiconductor sensitized by a dye and a photoelectrochemical cell using the same, but also in these, a liquid electrolyte is used for the charge transfer layer. Therefore, there is a concern that the electrolyte solution may leak or deplete during long-term use or storage, resulting in a significant decrease in photoelectric conversion efficiency or a failure to function as an element.

[0004] Under such circumstances, WO 93/20565 discloses a photoelectric conversion element using a solid electrolyte. Also, The Chemical Society of Japan, 7, 484 pages (1997), JP-A-7-2881142, S
olidState Ionics, 89, 263 (1986) and JP-A-9-27352
No. proposed a photoelectric conversion element including a solid electrolyte using a crosslinked polyethylene oxide polymer compound. However, photoelectric conversion elements using these solid electrolytes have insufficient photoelectric conversion characteristics, particularly short-circuit current density, and have insufficient durability.

[0005] In addition, a method of using a pyridinium salt, an imidazolium salt, a triazolium salt or the like as an electrolyte has been disclosed in order to prevent leakage and depletion of an electrolyte solution and to improve durability of a photoelectric conversion element (WO95 / 2005). No. 18456, JP 8-25
9543, Electrochemistry, Vol. 65, No. 11, p. 923 (1997)
etc). These salts are in the molten state at room temperature and are called room temperature molten salts. In this method, a solvent for dissolving the electrolyte, such as water or an organic solvent, is not necessary or requires a small amount, and thus the durability of the battery is improved. However, photoelectric conversion elements using these room temperature molten salts have low open-circuit voltage and poor photoelectric conversion efficiency.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electrolyte composition having excellent durability and charge transport ability, and a photoelectric conversion exhibiting excellent durability and photoelectric conversion characteristics due to the use of this electrolyte composition. It is an object of the present invention to provide an element and a photoelectrochemical cell comprising such a photoelectric conversion element. Another object of the present invention is to provide novel imidazolium compounds and pyridinium compounds that can be used in the electrolyte composition.

[0007]

Means for Solving the Problems As a result of intensive studies in view of the above-mentioned object, the present inventor has obtained the following general formula (1):

Embedded image (However, Q represents an atomic group capable of forming a 5- or 6-membered aromatic cation together with a nitrogen atom, and R ₀₀₁ represents L ₀₀₁ -A ₀₁ (L
₀₀₁ represents a bond or a divalent linking group, A ₀₁ when the L ₀₀₁ is a bond represents a substituent, A ₀₁ when the L ₀₀₁ is a divalent linking group
Represents a hydrogen atom or a substituent. ) Represent, may be the same as or different from each other, n01 is 0 or 1 or more Q represents an integer less than or equal to the maximum value of the number of presence capable R ₀₀₁ on, R ₀₀₂ is L
₀₀₂ -L ₀₀₃ -A ₀₂ (L ₀₀₂ represents a substituted or unsubstituted alkylene group, or a substituted or unsubstituted alkenylene group;
₀₀₃ represents a bond or a divalent linking group, A ₀₂ represents a hydrogen atom or a substituent. ) Represents, X ^- represents an anion, R ₀₀₁ and
Two or more of R ₀₀₂ may be linked to each other to form a ring structure, and at least one of A ₀₁ and A ₀₂ has a pKa of a conjugate acid of a compound obtained by adding hydrogen thereto of 3 to 15; Is a substituent. The present inventors have found that an electrolyte composition containing the compound represented by the formula (1) exhibits excellent durability and charge transport ability, and have reached the present invention.

The photoelectric conversion device of the present invention has a conductive layer, a photosensitive layer, a charge transfer layer, and a counter electrode, and the charge transfer layer contains the above-mentioned electrolyte composition. Further, a photoelectrochemical cell of the present invention comprises the above-mentioned photoelectric conversion element.

In the present invention, by satisfying the following conditions, an electrolyte composition, a photoelectric conversion element and a photoelectrochemical cell having more excellent photoelectric conversion characteristics and durability can be obtained.

(1) The constituent atom of Q is preferably selected from the group consisting of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom and a sulfur atom.

(2) The 5- or 6-membered aromatic cation formed by Q together with the nitrogen atom is preferably an imidazolium cation or a pyridinium cation.

(3) The compound represented by the general formula (1) further comprises the following general formula (2):

Embedded image (However, R ₀₀₃ represents L ₀₀₄ -L ₀₀₅ -A ₀₃ (L ₀₀₄ represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group, L ₀₀₅ represents a bond or a divalent linking group, ₀₃
Represents a hydrogen atom or a substituent. ), Which may be the same or different, and n02 represents an integer of 0 to 3,
₀₀₄ represents a hydrogen atom or _{L 006 -L 007 -A 04 (L} 006 represents a substituted or unsubstituted alkylene group, or a substituted or unsubstituted alkenylene group, L ₀₀₇ represents a bond or a divalent linking group, A ₀₄
Represents a hydrogen atom or a substituent. ), And R ₀₀₅ is L ₀₀₈ −
L ₀₀₉ -A ₀₅ (L ₀₀₈ represents a substituted or unsubstituted alkylene group, or a substituted or unsubstituted alkenylene group, L ₀₀₉ represents a bond or a divalent linking group, the A _{0 5} represents a hydrogen atom or a substituent . representing) represent, X ^- represents an anion, may form two or more connected to each other to form a ring structure of R ₀₀₃ to R _005,
At least one of A _{03 to} A ₀₅ is a substituent in which the pKa of the conjugate acid of the compound obtained by adding hydrogen thereto is 3 to 15. ) Or the following general formula (3):

Embedded image (However, R ₀₀₆ represents L ₀₁₀ -L ₀₁₁ -A ₀₆ (L ₀₁₀ represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group, L ₀₁₁ represents a bond or a divalent linking group, ₀₆
Represents a hydrogen atom or a substituent. ), Which may be the same or different, and n03 represents an integer of 0 to 5,
₀₀₇ represents L ₀₁₂ -L ₀₁₃ -A ₀₇ (L ₀₁₂ represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group, L ₀₁₃ represents a bond or a divalent linking group, and A ₀₇ represents a hydrogen atom or a substituted group) represents, X ^-. represents an anion, R
Two or more of ₀₀₆ and R ₀₀₇ may be linked to each other to form a ring structure, and at least one of A ₀₆ and A ₀₇ is
The pKa of the conjugate acid of the compound obtained by adding hydrogen thereto is 3 to 1
5 is a substituent. ) Is preferred.

(4) The substituent having a pKa of 3 to 15 of the conjugate acid of the compound obtained by adding hydrogen thereto is preferably an imidazolyl group or a pyridyl group.

(5) The solvent content of the electrolyte composition is preferably not more than 10% by mass of the whole electrolyte composition.

[0015] (6) X ^- is iodide ion, NCS ^-, BF ₄ ^-,
(CF ₃ SO ₂ ) ₂ N ⁻ , or the following general formulas (AN-1) and (AN-2):

[Formula 10] (However, R ₀₁₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a perfluoroalkyl group, or a substituted or unsubstituted aryl group, and R ₀₁₄ represents a substituted or unsubstituted alkyl group, a perfluoroalkyl group, or Represents a substituted or unsubstituted aryl group).

(7) The electrolyte composition preferably contains an iodine salt and / or iodine in addition to the compound represented by the general formula (1).

(8) In the photoelectric conversion element, the photosensitive layer preferably contains a fine particle semiconductor sensitized by a dye. The fine particle semiconductor is preferably composed of metal chalcogenide fine particles, and the metal chalcogenide fine particles preferably include titanium oxide fine particles. The dye is preferably a metal complex dye and / or a polymethine dye.

Further, in the electrolyte composition of the present invention,
The following general formula (4):

[Formula 11] (However, R ₀₀₈ is L ₀₁₄ -A ₀₈ (L ₀₁₄ is an alkylene group, -O
- or a divalent linking group them by combining one or more thereof, A ₀₈ represents a hydrogen atom or a substituent. ), Which may be the same or different, and n04 is 0
And R ₀₀₉ represents a hydrogen atom or L ₀₁₅ -A ₀₉ (L
₀₁₅ represents an alkylene group, -O- or a divalent linking group them by combining one or more thereof, A ₀₉ represents a hydrogen atom or a substituent. ), And R ₀₁₀ is L ₀₁₆ −A ₁₀ (L ₀₁₆
Represents an alkylene group, —O—, or a divalent linking group formed by combining one or more of them, and A ₁₀ represents a hydrogen atom or a substituent. ) Represents a, X ^- represents an anion, A ₀₈
At least one of the to A ₁₀ are, it is a substituent having a pKa of 3-15 conjugate acid of a compound obtained by adding hydrogen. A) a novel imidazolium compound represented by the following general formula (5):

Embedded image (However, R ₀₁₁ is L ₀₁₇ -A ₁₁ (L ₀₁₇ is an alkylene group, -O
-Or a divalent linking group obtained by combining one or more of these, and A ₁₁ represents a hydrogen atom or a substituent. ), Which may be the same or different, and n05 is 0
And R ₀₁₂ represents L ₀₁₈ -A ₁₂ (L ₀₁₈ represents an alkylene group, —O— or a divalent linking group formed by combining one or more of them, and A ₁₂ represents a hydrogen atom or a substituent . a representative) represents, X ^- represents an anion, at least one of a ₁₁ and a ₁₂ are, it is a substituent having a pKa of 3-15 conjugate acid of a compound obtained by adding hydrogen. )) Can be suitably used.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [1] Electrolyte composition The electrolyte composition of the present invention is used for a reaction medium such as a chemical reaction and metal plating, a CCD (charge-coupled device) camera, various photoelectric conversion elements, and a battery. However, it is preferably used for a lithium secondary battery or a photoelectrochemical battery using a semiconductor. Hereinafter, each component of the electrolyte composition of the present invention will be described in detail.

(A) Compound Represented by General Formula (1) The electrolyte composition of the present invention has the following general formula (1):

Embedded image And a compound represented by This compound is preferably a low-melting salt, a so-called molten salt, and more preferably a compound that is liquid at normal temperature (around 25 ° C.), a so-called room temperature molten salt. The melting point of the compound represented by the general formula (1) is preferably 100 ° C. or lower, more preferably 80 ° C. or lower, and particularly preferably 60 ° C. or lower.

When the compound represented by the general formula (1) is a molten salt at room temperature, this compound can often be used as an electrolyte with little use of a solvent, and can often be used alone as an electrolyte. Even if it is solid at normal temperature (around 25 ° C.), it can be made into a liquid state by adding a small amount of an organic solvent, water, etc., and used as an electrolyte. Also, a method of dissolving by heating and dissolving on the electrode without adding anything, a method of dissolving on the electrode using a low boiling point solvent (methanol, acetonitrile, methylene chloride, etc.), and then removing the solvent by heating. For example, it can be incorporated in the photoelectric conversion element.

In the general formula (1), Q represents an atomic group capable of forming a 5- or 6-membered aromatic cation together with a nitrogen atom.
Q is preferably composed of one or more atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen and sulfur. The 5-membered ring formed by Q is preferably an oxazole ring, a thiazole ring, an imidazole ring, a pyrazole ring, an isoxazole ring, a thiadiazole ring, an oxadiazole ring or a triazole ring,
It is more preferably an oxazole ring, a thiazole ring or an imidazole ring, and particularly preferably an imidazole ring. The 6-membered ring formed by Q is preferably a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring or a triazine ring, and more preferably a pyridine ring.

R₀₀₁Is L₀₀₁−A₀₁(L₀₀₁Is a bond or divalent ream
Represents a group, L₀₀₁A represents a bond ₀₁Represents a substituent
Then L₀₀₁A represents a divalent linking group₀₁Is a hydrogen atom or
Represents a substituent. ), Which are the same but different
Is also good. R₀₀₁N01 representing the number of is 0, or 1 or more exists on Q
Possible R₀₀₁Represents an integer less than or equal to the maximum value of

When L ₀₀₁ represents a divalent linking group, examples thereof include an alkylene group, an alkenylene group, an arylene group,
—O—, —S—, —CO—, —NR′— (R ′ is a hydrogen atom or an alkyl group), —SO ₂ —, and a divalent linking group formed by combining two or more of these.

When A ₀₁ is a substituent, examples thereof include an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an amino group, a guanidino group, a cyano group and a halogen atom. A ₀₁ may further have a substituent, and the substituent is an alkyl group (methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, 2-
Carboxyethyl group, a benzyl group), an alkoxy group (methoxy group, an ethoxy _{group, - (OCH 2 CH 2)} n -OCH 3 (n is an integer of 1 to _{20), - (OCH 2 CH 2} ) n -OCH 2 CH ₃ (n is an integer of 1 to 20), an amino group (dimethylamino group, diethylamino group, etc.), an amide group (acetylamino group, benzoylamino group, etc.), a carbamoyl group (N, N-dimethylcarbamoyl group, It is preferably a halogen atom (eg, chlorine atom, bromine atom, iodine atom) or an alkylthio group (eg, methylthio group, ethylthio group).

R ₀₀₂ represents L ₀₀₂ -L ₀₀₃ -A ₀₂ (L ₀₀₂ represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group; L ₀₀₃ represents a bond or a divalent linking group;
₀₂ represents a hydrogen atom or a substituent. ).

Examples of _L002 include a methylene group, an ethylene group, a propylene group, a vinylene group and a propenylene group. L ₀₀₂ is preferably a methylene group, an ethylene group or a propylene group.

L₀₀₃When represents a divalent linking group,
Are alkylene, alkenylene, arylene,
-O-, -S-, -CO-, -NR'- (R 'is a hydrogen atom or
Alkyl group), -SO_Two-Combine two or more of these
And the like. L₀₀₃Is-(OCH_TwoCH_Two)
_n−, − (OCH_TwoCH_Two)_n−CH_Two−, − (OCH_TwoCH_Two)_n−O−, − (OC
H _TwoCH_TwoCH_Two)_n−, − (OCH_TwoCH_TwoCH_Two)_n-O-, -O-, -CO
-, -NHCO-, -CONH-, -OCO-, -COO-, -OCOO
−, −SO_Two-Or-OSO_Two-Is preferable, and-(OCH_Two
CH_Two)_n−, − (OCH_TwoCH_Two)_n−CH_Two−, − (OCH_TwoCH_Two)_n-O-,
− (OCH_TwoCH_TwoCH_Two)_n−, − (OCH_TwoCH_TwoCH_Two)_nAt -O- or -O-
It is particularly preferred. Note that n is an integer of 1 to 20 respectively.
Is a number.

[0029] When A ₀₂ is a substituent, the examples alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an amino group, a guanidino group, a cyano group and a halogen atom. Among them, _A02 is preferably an alkyl group, an aryl group, a heterocyclic group, an amino group, a guanidino group or a cyano group, more preferably a nitrogen-containing heterocyclic group.
A ₀₂ may further have a substituent, preferred examples of the substituent include the same as the preferred examples of the substituent on the A _01.

The compound represented by the general formula (1)
Two or more of ₀₀₁ and _R002 may be connected to each other to form a ring structure. This ring structure is preferably a 5- to 7-membered ring, more preferably a 5- to 6-membered ring. This compound may form a multimer via R ₀₀₁ and / or R ₀₀₂ . The formed multimer is preferably a dimer to a tetramer, and more preferably a dimer.

At least one of A ₀₁ and A ₀₂ is a substituent in which a pKa of the conjugate acid of the compound obtained by adding hydrogen thereto is 3 or more. The conjugate acid preferably has a pKa of 3 to 15, more preferably 4 to 12. Such substituents include amino groups (dimethylamino group, diethylamino group, anilino group, etc.), nitrogen-containing heterocyclic groups (morpholino group, quinuclidinyl group, piperazinyl group, piperidino group, pyrrolidino group, imidazolyl group, 2-methylimidazolyl group) Group, quinolyl group, acridinyl group, pyridyl group, 2-
Methylpyridyl group, diazabicycloundecenyl group, etc.)
Alternatively, it is preferably a guanidino group (such as a trimethylguanidino group), more preferably a nitrogen-containing heterocyclic group, and particularly preferably a substituted or unsubstituted imidazolyl group, or a substituted or unsubstituted pyridyl group.

The above imidazolyl group and pyridyl group are substituted
When it has a group, the substituent is an alkyl group (methyl group,
Ethyl, propyl, isopropyl, cyclopropyl
Butyl, 2-carboxyethyl, benzyl
Etc.), alkoxy group (methoxy group, ethoxy group,-(OCH
_TwoCH_Two)_n−OCH_Three(N is an integer of 1 to 20),-(OCH_TwoCH_Two)_n−OCH
_TwoCH_Three(N is an integer of 1 to 20), an amino group (dimethylamine
Amino group, diethylamino group, etc.), amide group (acetyl
Amino group, benzoylamino group, etc.), carbamoyl group (N,
N-dimethylcarbamoyl group, N-phenylcarbamoyl group
Etc.), halogen atoms (chlorine, bromine, iodine)
Etc.) or alkylthio group (methylthio group, ethylthio group
Etc.).

[0033] In the general formula (1), X ^- represents an anion. X ^- include preferred examples are halide ions (I ^-, Cl ^-, B
r ^{-, _{etc.), NCS -, BF 4 -}} , PF 6 -, ClO 4 -, (CF 3 SO 2) 2 N -, (CF 3
^{_{CF 2 SO 2) 2 N -}} , Ph 4 B -, (CF 3 SO 2) 3 C -, the following general formula (AN-1)
And (AN-2):

Embedded imageAnd the like. X^-
Is I^-, NCS^-, BF_Four ^-, (CF _ThreeSO_Two)_TwoN^-Or general formula (AN-1)
And an anion represented by any of (AN-2)
Is more preferred.

In the general formula (AN-1), R ₀₁₃ is a hydrogen atom,
A substituted or unsubstituted alkyl group (preferably having 1 carbon atom)
To 10, may be linear or branched, or may be cyclic, such as methyl, ethylpropyl, butyl, isopropyl, pentyl, hexyl, octyl, 2 -Ethylhexyl group, t-octyl group, decyl group, cyclohexyl group, cyclopentyl group, etc., perfluoroalkyl group (preferably having 1 to 10 carbon atoms, for example, trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, etc.) ) Or a substituted or unsubstituted aryl group (preferably having 6 to 12 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group). R ₀₁₃ is more preferably an alkyl group having 1 to 10 carbon atoms or a perfluoroalkyl group having 1 to 10 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 10 carbon atoms.

R ₀₁₄ represents a substituted or unsubstituted alkyl group (preferably having 1 to 10 carbon atoms, which may be linear, branched or cyclic, such as methyl, Ethylpropyl, butyl, isopropyl, pentyl, hexyl, octyl, 2-ethylhexyl, t-
An octyl group, a decyl group, a cyclohexyl group, a cyclopentyl group, etc.), a perfluoroalkyl group (preferably having 1 to 10 carbon atoms, such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, etc.), or a substituted or unsubstituted group. Substituted aryl group (preferably having 6 to 12 carbon atoms, for example, phenyl group, tolyl group, naphthyl group, etc.)
Represents R ₀₁₄ is more preferably an alkyl group having 1 to 7 carbon atoms, and particularly preferably an alkyl group having 1 to 5 carbon atoms.

When R ₀₁₃ is a substituted alkyl group or an aryl group, preferred examples of the substituent include a halogen atom (such as fluorine, chlorine, bromine and iodine) and an alkoxy group (a methoxy group, an ethoxy group, − (OCH ₂ CH ₂ ) _n −OCH ₃
(N is an integer of 1 to _{20), - (OCH 2 CH 2} ) n -OCH 2 CH 3 (n is an integer of 1 to 20), etc.), a cyano group, an alkoxycarbonyl group (an ethoxycarbonyl group, methoxyethoxy group ), Carbonic ester group (ethoxycarbonyloxy group, etc.), amide group (acetylamino group, benzoylamino group, etc.), carbamoyl group (N, N-dimethylcarbamoyl group, N-phenylcarbamoyl group, etc.), phosphonyl group (diethyl Phosphonyl group, etc.), heterocyclic group (pyridyl group, imidazolyl group, furanyl group, oxazolidinonyl group, etc.),
Aryloxy group (phenoxy group, etc.), alkylthio group (methylthio group, ethylthio group, etc.), acyl group (acetyl group, propionyl group, benzoyl group, etc.), sulfonyl group (methanesulfonyl group, benzenesulfonyl group, etc.),
Acyloxy group (acetoxy group, benzoyloxy group, etc.), sulfonyloxy group (methanesulfonyloxy group, toluenesulfonyloxy group, etc.), aryl group (phenyl group, tolyl group, etc.), aryloxy group (phenoxy group, etc.), alkenyl group ( Vinyl group, 1-propenyl group, etc.), alkyl group (methyl group, ethyl group, propyl group,
Isopropyl, cyclopropyl, butyl, 2-carboxyethyl, benzyl, etc.). Among them, a halogen atom and an alkoxy group are more preferable.

When R ₀₁₄ is an alkyl group or an aryl group having a substituent, preferred examples of the substituent include an alkoxy group (a methoxy group, an ethoxy group, and-(OCH ₂ CH ₂ ) _n-
OCH ₃ (n is an integer of 1 to _{20), - (OCH 2 CH 2} ) n -OCH 2 CH
₃ (n is an integer of 1 to 20), cyano group, alkoxycarbonyl group (ethoxycarbonyl group, methoxyethoxycarbonyl group, etc.), carbonate group (ethoxycarbonyloxy group, etc.), amide group (acetylamino group, benzoyl Amino group), carbamoyl group (N, N-dimethylcarbamoyl group, N-phenylcarbamoyl group, etc.), phosphonyl group (diethylphosphonyl group, etc.), heterocyclic group (pyridyl group, imidazolyl group, furanyl group, oxazolidy Nonyl group), aryloxy group (phenoxy group, etc.), alkylthio group (methylthio group, ethylthio group, etc.), acyl group (acetyl group, propionyl group, benzoyl group, etc.), sulfonyl group (methanesulfonyl group, benzenesulfonyl group, etc.) , Acyloxy group (acetoxy group, benzoyloxy group, etc.), sulfonyl Oxy group (methanesulfonyloxy group, toluenesulfonyloxy group, etc.), aryl group (phenyl group, tolyl group, etc.), aryloxy group (phenoxy group, etc.), alkenyl group (vinyl group, 1-propenyl group, etc.), alkyl group ( Methyl group, ethyl group, propyl group,
Isopropyl, cyclopropyl, butyl, 2-carboxyethyl, benzyl, etc.). Among them, an alkoxy group is more preferable.

The anion represented by any one of formulas (AN-1) and (AN-2) may form a multimer through R _013, or R _{0 14.} The formed multimer is preferably a dimer to a tetramer, and more preferably a dimer.

The compound represented by the general formula (1) further includes a compound represented by the following general formula (2):

Embedded image Or the following general formula (3):

Embedded image Is preferably represented by

In the general formula (2), R₀₀₃Is L₀₀₄−L₀₀₅−A₀₃
And each may be the same or different, and R₀₀₃of
N02 representing a number is an integer of 0 to 3. R₀₀₄Is a hydrogen atom or
Is L_{00 6}−L₀₀₇−A₀₄And R₀₀₅Is L₀₀₈−L₀₀₉−A₀₅The table
You. In general formula (3), R ₀₀₆Is L₀₁₀−L₀₁₁−A₀₆To
Represents, each may be the same or different, R₀₀₆Number of
Is an integer of 0 to 5. R₀₀₇Is L₀₁₂−L₀₁₃−A
₀₇Represents

The above L ₀₀₄ , L ₀₀₆ , L ₀₀₈ , L ₀₁₀ and L ₀₁₂ are
Each independently represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group, and examples thereof include the same as those of _L002 described above. Also,
L ₀₀₅ , L ₀₀₇ , L ₀₀₉ , L _011, and L ₀₁₃ each independently represent a bond or a divalent linking group, and preferable examples of the divalent linking group include the same as those described above for _L003 .

A _{03 to} A ₀₇ each independently represent a hydrogen atom or a substituent. When A _{03 to} A ₀₇ are substituents, examples thereof are the same as those of A ₀₂ above. These may further have a substituent, and preferable examples of the substituent are the same as those of the substituent on _A01 .

In the general formula (2), two or more of R _{003 to} R ₀₀₅ , and in the general formula (3), two or more of R ₀₀₆ and R ₀₀₇ may be connected to each other to form a ring structure. Good. This ring structure is preferably a 5- to 7-membered ring, more preferably a 5- to 6-membered ring. Further, the compound represented by the general formula (2) or (3) may form a multimer via R _{1 to} R ₃ , or R ₄ and / or R ₅ , respectively. The formed multimer is preferably a dimer to a tetramer, and more preferably a dimer.

[0044] At least one of the general formula (2) in the A ₀₃ to A _05, and at least one of A _{0 6} and A ₀₇ in the general formula (3) is it compounds obtained by adding hydrogen Is a substituent having a pKa of 3 or more. PKa of the conjugate acid
Is preferably 3 to 15, more preferably 4 to 12. Preferred embodiments of such substituents are described above.
This is the same as in the case of _A01 and _A02 . Further, in the general formula (2) and (3), X ^- represents an anion. X ^- are the same as the like ^- X in the general formula (1) as preferred examples.

In the electrolyte composition of the present invention,
The following general formula (4):

Embedded image A novel imidazolium compound represented by the following general formula (5):

Embedded image A novel pyridinium compound represented by the following formula (1) can be preferably used.

[0046] In the general formula (4), R ₀₀₈ represents L ₀₁₄ -A _08, which may be the same or different, n04 indicating the number of R ₀₀₈ represents an integer of 0 to 3, R ₀₀₉ is hydrogen Atom or L
It represents ₀₁₅ -A _09, R ₀₁₀ represents L ₀₁₆ -A _10. In the general formula (5), R ₀₁₁ represents L ₀₁₇ -A ₁₁ , which may be the same or different, n05 representing the number of R ₀₁₁ is an integer of 0 to 5, and R ₀₁₂ is L ₀₁₈ -A Represents ₁₂ .

L _{014 to} L ₀₁₈ each independently represent an alkylene group, —O—, or a divalent linking group formed by combining one or more alkylene groups and —O—, and a preferred example is — ( CH ₂ ) _m −, − (OCH ₂ CH ₂ ) _n −, − (OCH ₂ C
H ₂ ) _n -CH ₂ -,-(OCH ₂ CH ₂ CH ₂ ) _n -,-(CH ₂ ) _m- (OCH ₂ C
H ₂ ) _n −, − (CH ₂ ) _m − (OCH ₂ CH ₂ ) _n −CH ₂ −, − (CH ₂ ) _m − (OC
_{H 2 CH 2 CH 2) n} - , and the like. Here, m and n are integers of 1 to 20, respectively.

A _{08 to} A ₁₂ each independently represent a hydrogen atom or a substituent. When A _{08 to} A ₁₂ are substituents, examples thereof are the same as those of A ₀₂ above. These may have a substituent include the same as the preferred examples of the substituent on the A ₀₁ Preferred examples of the substituent.

[0049] At least one of the general formula (4) A ₀₈ ~A ₁₀ in, and at least one of the general formula (5) A _{1 1} and A ₁₂ in the thereto compounds obtained by adding hydrogen Is a substituent having a pKa of 3 or more. PKa of the conjugate acid
Is preferably 3 to 15, more preferably 4 to 12. Preferred examples of such a substituent include the same as those in the case of _A01 and _A02 described above. Further, in the general formula (4) and (5), X ^- represents an anion.
X ^- are the same as the like ^- X in the general formula (1) as preferred examples.

Hereinafter, specific examples of the compound represented by formula (1) of the present invention will be shown, but the present invention is not limited thereto.

[0051]

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[0052]

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[0053]

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[0054]

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(B) Iodine Salt and / or Iodine The electrolyte composition of the present invention preferably contains an iodine salt and / or iodine. When the compound represented by the general formula (1) is not an iodine salt, see WO 95/18456,
No. 59543, Electrochemistry, Vol. 65, No. 11, p. 923 (1997) and the like, pyridinium salts, imidazolium salts,
It is preferable to use a known iodine salt such as a triazolium salt in combination. When the compound represented by the general formula (1) is an iodine salt, a salt other than the iodine salt may be used in combination.

When the compound represented by the general formula (1) is mixed with another salt, the content of the compound represented by the general formula (1) is 10% by mass or more based on the whole electrolyte composition. Is more preferable, and more preferably 20 to 95% by mass. Further, the content of the iodine salt is preferably at least 10% by mass, more preferably from 50 to 95% by mass, based on the whole electrolyte composition.

When iodine is added to the electrolyte composition, the content of iodine is preferably from 0.1 to 20% by mass, more preferably from 0.5 to 5% by mass, based on the whole of the electrolyte composition.

The preferred iodine salt used in combination with the compound represented by the general formula (1) includes the following general formula (Y-
a), (Yb) and (Yc):

Embedded image And the like.

In the general formula (Ya), Q _y1 is 5 together with a nitrogen atom.
Or an atomic group capable of forming a 6-membered aromatic cation. Q _y1 is preferably composed of one or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom and a sulfur atom.

The 5-membered ring formed by Q _y1 is preferably an oxazole ring, a thiazole ring, an imidazole ring, a pyrazole ring, an isoxazole ring, a thiadiazole ring, an oxadiazole ring or a triazole ring. It is more preferably a ring or an imidazole ring, particularly preferably an oxazole ring or an imidazole ring. The 6-membered ring formed by Q _y1 is preferably a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring or a triazine ring, and more preferably a pyridine ring.

In the general formula (Yb), A _y1 represents a nitrogen atom or a phosphorus atom.

R in the general formulas (Ya), (Yb) and (Yc)
_{y1 to Ry6} each independently represent a substituted or unsubstituted alkyl group (preferably having 1 to 24 carbon atoms, which may be linear, branched, or cyclic; for example, methyl Group, ethyl group, propyl group, isopropyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, t-
Octyl, decyl, dodecyl, tetradecyl,
2-hexyldecyl group, octadecyl group, cyclohexyl group, cyclopentyl group, etc.) or a substituted or unsubstituted alkenyl group (preferably having 2 to 24 carbon atoms, which may be linear or branched, For example, a vinyl group or an allyl group), more preferably an alkyl group having 2 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms, and particularly preferably an alkyl group having 2 to 6 carbon atoms. . However, in the general formula (Yb), or three of R _y1 to R _{y 4} is not an alkenyl group at the same time.

In addition, two or more of R _{y1 to} R _{y4 in} the general formula (Yb) may be linked to each other to form a non-aromatic ring containing A _y1. Two or more of _{y1 to Ry6} may be connected to each other to form a ring structure.

Q in the general formulas (Ya), (Yb) and (Yc)
_y1 and R _y1 to R _y6 may have a substituent, examples of preferred substituents, a halogen atom (F, Cl, Br, I
), A cyano group, an alkoxy group (such as a methoxy group and an ethoxy group), an aryloxy group (such as a phenoxy group), an alkylthio group (such as a methylthio group and an ethylthio group), an alkoxycarbonyl group (such as an ethoxycarbonyl group), and a carbonate group ( Ethoxycarbonyloxy group, etc.), acyl group (acetyl group, propionyl group, benzoyl group, etc.), sulfonyl group (methanesulfonyl group, benzenesulfonyl group, etc.), acyloxy group (acetoxy group, benzoyloxy group, etc.), sulfonyloxy group ( Methanesulfonyloxy group, toluenesulfonyloxy group, etc.), phosphonyl group (diethylphosphonyl group, etc.), amide group (acetylamino group, benzoylamino group, etc.), carbamoyl group (N, N-
Dimethylcarbamoyl group), alkyl group (methyl group,
Ethyl group, propyl group, isopropyl group, cyclopropyl group, butyl group, 2-carboxyethyl group, benzyl group, etc., aryl group (phenyl group, toluyl group, etc.), heterocyclic group (pyridyl group, imidazolyl group, furanyl group) etc),
Alkenyl groups (vinyl group, 1-propenyl group, etc.) and the like.

According to the general formula (Y-a), (Y-b) or (Y-c)
The compound represented by_y1Or R_y1~ R _y6Multimer through
May be formed.

(C) Solvent The electrolyte composition of the present invention may contain a solvent. The amount of the solvent to be used is preferably 50% by mass or less, more preferably 30% by mass or less, and particularly preferably 10% by mass or less, based on the whole electrolyte composition.

As the solvent, those which can exhibit excellent ionic conductivity because of low viscosity and high ion mobility, high dielectric constant and effective carrier concentration, or both are preferable. Examples of such solvents include carbonate compounds (such as ethylene carbonate and propylene carbonate), heterocyclic compounds (such as 3-methyl-2-oxazolidinone), ether compounds (such as dioxane and diethyl ether), and chain ethers (such as ethylene glycol dialkyl ether). , Propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, etc.), alcohols (methanol, ethanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, etc.) , Polyhydric alcohols (ethylene glycol, propylene glycol, polyethylene glycol , Polypropylene glycol, glycerin, etc.), nitrile compounds (acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, biscyanoethyl ether, etc.), esters (carboxylates, phosphates, phosphonates, etc.), Aprotic polar solvent (dimethyl sulfoxide (DMS
O), sulfolane, etc.), water and the like. These solvents may be used as a mixture of two or more kinds.

(D) Others The electrolyte composition of the present invention may be gelled (solidified) by a technique such as addition of a polymer, addition of an oil gelling agent, polymerization containing a polyfunctional monomer, or crosslinking reaction of a polymer. Can also.

When gelling by adding a polymer,
Polymer Electrolyte Reviews-1 and 2 (JR MacCallu
m and CA Vincent, ELSEVIER APPLIED SCIENCE)
Can be used, and it is preferable to use polyacrylonitrile or polyvinylidene fluoride.

When gelation is carried out by adding an oil gelling agent, J. Chem. Soc. Japan, Ind. Chem. Soc., 46779
(1943), J. Am. Chem. Soc., 111, 5542 (1989), J. Ch.
em. Soc., Chem. Commun., 390 (1993), Angew. Chem. I
Ent., 35, 1949 (1996), Chem. Lett., 885,
(1996), J. Chem. Soc., Chem. Commun., 545, (1997).
And the like, and it is preferable to use a compound having an amide structure.

When the gel electrolyte is formed by polymerization of polyfunctional monomers, a solution is prepared from the polyfunctional monomers, a polymerization initiator, an electrolyte and a solvent, and a casting method, a coating method,
A method in which a sol-like electrolyte layer is formed on an electrode supporting a dye by a method such as an immersion method or an impregnation method and then gelled by radical polymerization is preferable. The polyfunctional monomer is preferably a compound having two or more ethylenically unsaturated groups, such as divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, and triethylene glycol diacrylate. Preferred are ethylene glycol dimethacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, and the like.

The gel electrolyte may be formed by polymerization of a mixture containing a monofunctional monomer in addition to the above polyfunctional monomers. Monofunctional monomers include acrylic acid or α-alkylacrylic acid (acrylic acid, methacrylic acid, itaconic acid, etc.), or esters or amides thereof (N-isopropylacrylamide, Nn-butylacrylamide,
Nt-butylacrylamide, N, N-dimethylacrylamide, N-methylmethacrylamide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, acrylamidopropyltrimethylammonium chloride, methacrylamide, diacetone acrylamide, N-methylolacrylamide, N -Methylol methacrylamide,
Methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, n-propyl acrylate, isopropyl acrylate, 2-hydroxypropyl acrylate, 2-methyl-2-nitropropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, t-pentyl Acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-methoxyethoxyethyl acrylate, 2,2,2-trifluoroethyl acrylate, 2,2-dimethylbutyl acrylate, 3-methoxybutyl acrylate, ethyl carbitol acrylate , Phenoxyethyl acrylate, n-pentyl acrylate, 3-pentyl acrylate, octafluoropentyl acrylate, n-hexyl acrylate, cyclohexyl acrylate Cyclopentyl acrylate, cetyl acrylate, benzyl acrylate, n- octyl acrylate, 2-ethylhexyl acrylate, 4-methyl-2-propyl pentyl acrylate,
Heptadecafluorodecyl acrylate, n-octadecyl acrylate, methyl methacrylate, 2-methoxyethoxyethyl methacrylate, ethylene glycol ethyl carbonate methacrylate, 2,2,2-trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, hexafluoropropyl methacrylate, hydroxyethyl Methacrylate, 2-hydroxypropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, t-pentyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, benzyl methacrylate, heptadecafluorodecyl methacrylate, n-octadecyl Methacrylate, 2-isobornyl methacrylate, 2-norbornyl methyl meth Acrylate, 5-norbornen-2-ylmethyl methacrylate, 3-methyl-2-norbonylmethyl methacrylate, dimethylaminoethyl methacrylate, etc.), vinyl esters (vinyl acetate, etc.),
Maleic acid or fumaric acid or esters derived therefrom (dimethyl maleate, dibutyl maleate,
Diethyl fumarate, etc.), sodium salt of p-styrenesulfonic acid, acrylonitrile, methacrylonitrile, dienes (butadiene, cyclopentadiene, isoprene, etc.), aromatic vinyl compounds (styrene, p-chlorostyrene, t-butylstyrene, α-methylstyrene, sodium styrenesulfonate, etc.), N-vinylformamide, N-
Vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, vinylsulfonic acid, sodium vinylsulfonate, sodium allylsulfonate, sodium methacrylsulfonate, vinylidene fluoride, vinylidene chloride, vinyl alkyl ether (Such as methyl vinyl ether), ethylene,
Propylene, 1-butene, isobutene, N-phenylmaleimide and the like can be used.

The weight composition of the polyfunctional monomer in the total amount of the monomers is preferably 0.5 to 70% by mass, more preferably 1.0 to 50% by mass.

The above-mentioned monomers are described in “Experimental Method of Polymer Synthesis” by Takayuki Otsu and Masayoshi Kinoshita (Chemical Doujinshi) and Takayuki Otsu “Course Polymerization Reaction Theory 1 Radical Polymerization (I)” (Chemical Doujinshi). It can be polymerized by radical polymerization, which is a general polymer synthesis method. The monomer for gel electrolyte used in the present invention can be subjected to radical polymerization by heating, light or electron beam, or electrochemically, but is preferably subjected to radical polymerization by heating. In this case, preferably used polymerization initiators are 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), and dimethyl 2,2′-azobis (2-methyl Azo initiators such as propionate) and dimethyl 2,2′-azobisisobutyrate; and peroxide initiators such as lauryl peroxide, benzoyl peroxide, and t-butyl peroctoate. A preferable addition amount of the polymerization initiator is 0.01 to 20% by mass based on the total amount of the monomers, more preferably
0.1 to 10% by mass.

The weight composition range of the monomer in the gel electrolyte is preferably from 0.5 to 70% by mass, more preferably from 1.0 to 50% by mass.

When the electrolyte is gelled by the crosslinking reaction of the polymer, it is preferable to use a polymer containing a crosslinkable reactive group and a crosslinking agent together. In this case, a preferred reactive group is a nitrogen-containing heterocycle such as a pyridine ring, an imidazole ring, a thiazole ring, an oxazole ring, a triazole ring, a morpholine ring, a piperidine ring, and a piperazine ring. A compound (electrophile) having two or more functional groups capable of attacking, for example, 2
Functional or higher alkyl halides, aralkyl halides, sulfonic esters, acid anhydrides, acid chlorides, isocyanates and the like.

The electrolyte of the present invention includes metal iodide (Li
I, NaI, KI, CsI, CaI ₂ etc.), metal bromide (LiBr, NaB
r, KBr, CsBr, CaBr _2, etc.), quaternary ammonium bromine salt (tetraalkylammonium bromide, pyridinium bromide, etc.), metal complexes (ferrocyanate - ferricyanate, ferrocene - ferricinium ion, etc.), sulfur compounds (Sodium polysulfide, alkyl thiol-alkyl disulfide, etc.), viologen dyes,
Hydroquinone-quinone and the like can be added. These may be used as a mixture.

Further, according to the present invention, J. Am. Ceram. Soc.,
80, (12), 3157-3171 (1997)
Basic compounds such as butylpyridine, 2-picoline and 2,6-lutidine can also be added. A preferred concentration range when adding a basic compound is 0.05 to 2M.

The water content in the charge transfer layer is preferably at most 10,000 ppm, more preferably at most 2,000 ppm, particularly preferably at most 100 ppm.

[2] Photoelectric Conversion Element The photoelectric conversion element of the present invention has the above-mentioned electrolyte composition in the charge transfer layer. Preferably, as shown in FIG.
The conductive layer 10, the photosensitive layer 20, the charge transfer layer 30, and the counter electrode conductive layer 40 were stacked in this order, and the photosensitive layer 20 was filled in the gap between the semiconductor fine particles 21 sensitized by the dye 22 and the semiconductor fine particles 21. And an electrolyte 23. The electrolyte 23 is a charge transfer layer
It consists of the same components as the material used for 30. Further, a substrate 50 may be provided on the conductive layer 10 side and / or the counter electrode conductive layer 40 side in order to impart strength to the photoelectric conversion element. Hereinafter, in the present invention, a layer composed of the conductive layer 10 and the optional substrate 50 is referred to as a “conductive support”, and a layer composed of the counter electrode conductive layer 40 and the optional substrate 50 is referred to as a “counter electrode”. A photoelectrochemical cell in which the photoelectric conversion element is connected to an external circuit to perform a work is provided. The conductive layer 10, the counter electrode conductive layer 40, and the substrate 50 in FIG.
May be a transparent conductive layer 10a, a transparent counter electrode conductive layer 40a, and a transparent substrate 50a, respectively.

In the photoelectric conversion device of the present invention shown in FIG. 1, light incident on the photosensitive layer 20 containing the semiconductor fine particles 21 sensitized by the dye 22 excites the dye 22 and the like, and the excited dye
High-energy electrons in 22 and the like are transferred to the conduction band of the semiconductor fine particles 21 and further reach the conductive layer 10 by diffusion. At this time, molecules such as the dye 22 are oxidized. In the photoelectrochemical cell, the electrons in the conductive layer 10 return to an oxidant such as the dye 22 through the counter electrode conductive layer 40 and the charge transfer layer 30 while working in an external circuit, and the dye 22 is regenerated. The photosensitive layer 20 functions as a negative electrode. At the boundary of each layer (for example, the boundary between the conductive layer 10 and the photosensitive layer 20, the boundary between the photosensitive layer 20 and the charge transfer layer 30, the boundary between the charge transfer layer 30 and the counter electrode conductive layer 40, etc.), They may be mutually diffused and mixed. Hereinafter, each layer will be described in detail.

(A) Conductive Support The conductive support comprises (1) a single layer of a conductive layer, or (2) two layers of a conductive layer and a substrate. A substrate is not necessarily required if a conductive layer that maintains sufficient strength and sealing properties is used.

In the case of (1), a conductive layer having sufficient strength, such as metal, and having conductivity is used as the conductive layer.

In the case of (2), a substrate having a conductive layer containing a conductive agent on the photosensitive layer side can be used. Preferred conductive agents are metals (for example, platinum, gold, silver, copper, aluminum, rhodium, indium, etc.), carbon, or conductive metal oxides (indium-tin composite oxide, tin oxide doped with fluorine, etc.). Is mentioned. The thickness of the conductive layer is preferably about 0.02 to 10 μm.

The lower the surface resistance of the conductive support, the better. The preferred range of the surface resistance is 100 Ω / □ or less, more preferably 40 Ω / □ or less. The lower limit of the surface resistance is not particularly limited, but is usually about 0.1Ω / □.

When light is irradiated from the conductive support side, the conductive support is preferably substantially transparent.
Substantially transparent means that the light transmittance is 10% or more, preferably 50% or more, and particularly preferably 70% or more.

The transparent conductive support is preferably formed by forming a transparent conductive layer made of a conductive metal oxide on the surface of a transparent substrate such as glass or plastic by coating or vapor deposition. Of these, conductive glass in which a conductive layer made of tin dioxide doped with fluorine is deposited on a transparent substrate made of low-cost soda-lime float glass is preferable. For a low-cost and flexible photoelectric conversion element or solar cell, a transparent polymer film provided with a conductive layer is preferably used. Materials for the transparent polymer film include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and syndioctatic polystyrene (SP
S), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PAr), polysulfone (PSF), polyestersulfone (PES), polyetherimide (PEI), cyclic polyolefin, brominated phenoxy, and the like. In order to ensure sufficient transparency, the amount of the conductive metal oxide applied is preferably 0.01 to 100 g per 1 m ² of a glass or plastic support.

It is preferable to use a metal lead for the purpose of lowering the resistance of the transparent conductive support. The material of the metal lead is preferably a metal such as aluminum, copper, silver, gold, platinum and nickel, and particularly preferably aluminum and silver. The metal lead is preferably provided on a transparent substrate by vapor deposition, sputtering or the like, and a transparent conductive layer made of tin oxide doped with fluorine or an ITO film is preferably provided thereon. It is also preferable to provide a metal lead on the transparent conductive layer after providing the transparent conductive layer on the transparent substrate. The decrease in the amount of incident light due to the installation of the metal leads is preferably within 10%, more preferably 1 to 5%.

(B) Photosensitive Layer In a photosensitive layer containing semiconductor fine particles sensitized by a dye, the semiconductor fine particles act as a so-called photoreceptor, absorb light to separate electric charges, and generate electrons and holes. In the dye-sensitized semiconductor fine particles, light absorption and thereby generation of electrons and holes mainly occur in the dye, and the semiconductor fine particles have a role of receiving and transmitting the electrons.

(1) Semiconductor Fine Particles Semiconductor fine particles include a simple semiconductor such as silicon or germanium, a III-V compound semiconductor, a metal chalcogenide (eg, oxide, sulfide, selenide, etc.), or a perovskite structure. Compounds (for example, strontium titanate, calcium titanate, sodium titanate, barium titanate, potassium niobate, etc.) can be used.

Preferred metal chalcogenides include titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium or tantalum oxide, cadmium, zinc, lead and silver. , Antimony or bismuth sulfide, cadmium or lead selenide, cadmium telluride and the like. Other compound semiconductors include phosphides such as zinc, gallium, indium and cadmium, selenides of gallium-arsenic or copper-indium, and sulfides of copper-indium.

Preferred examples of the semiconductor used in the present invention include Si, TiO ₂ , SnO ₂ , Fe ₂ O ₃ , WO ₃ , ZnO, Nb ₂ O ₅ , CdS, Z
nS, PbS, Bi ₂ S ₃ , CdSe, CdTe, GaP, InP, GaAs, CuIn
S ₂ , CuInSe ₂ or the like, more preferably TiO ₂ , ZnO, Sn
O ₂ , Fe ₂ O ₃ , WO ₃ , Nb ₂ O ₅ , CdS, PbS, CdSe, InP, GaAs,
CuInS ₂ or CuInSe ₂ , particularly preferably TiO ₂ or Nb ₂
An O _5, and most preferably TiO _2.

The semiconductor used in the present invention may be single crystal or polycrystal. From the viewpoint of conversion efficiency, a single crystal is preferable,
Polycrystal is preferred from the viewpoints of production cost, securing of raw materials, energy payback time and the like.

The particle size of the semiconductor fine particles is generally on the order of nm to μm, but the average particle size of the primary particles obtained from the diameter when the projected area is converted into a circle is preferably from 5 to 200 nm, and from 8 to 200 nm. 100 nm is more preferred. The average particle size of the semiconductor fine particles (secondary particles) in the dispersion is preferably 0.01 to 100 μm.

Two or more types of fine particles having different particle size distributions may be mixed. In this case, the average size of the small particles is 5 nm.
It is preferred that: For the purpose of improving the light capture rate by scattering incident light, semiconductor particles having a large particle size, for example, about 300 nm may be mixed.

As methods for producing semiconductor fine particles, Sakuhana Shizuo's "Sol-Gel Method Science" Agne Shofusha (1998) and Technical Information Association "Sol-Gel Method Thin Film Coating Technology" (1995 ), Tadao Sugimoto, "Synthesis of Monodisperse Particles and Size Morphology Control by New Synthetic Gel-Sol Method", Materia, Vol. 35, No. 9, 1012-1018.
The gel-sol method described on page (1996) is preferred. Also De
Also preferred is a method developed by Gussa to produce oxides by high temperature hydrolysis of chlorides in oxyhydrogen salts.

When the semiconductor fine particles are titanium oxide, the sol-gel method, the gel-sol method, and the high-temperature hydrolysis method in a chloride oxyhydrogen salt are all preferable. Applied Technology "Gihodo Publishing (1997)
The sulfuric acid method and the chlorine method described in (1) can also be used. Furthermore, as a sol-gel method, Barb et al.
American Ceramic Society, Vol. 80, No. 12
No. 3,1577-1317 (1997), and Burnside et al., Chemical Materials, Vol. 10, No. 9, 24.
The method described on pages 19 to 2425 is also preferred.

(2) Semiconductor fine particle layer In order to coat the semiconductor fine particles on the conductive support, in addition to the method of applying a dispersion or colloid solution of the semiconductor fine particles on the conductive support, the above-mentioned sol-gel is used. A method can also be used. In consideration of mass production of photoelectric conversion elements, physical properties of semiconductor fine particle liquid, flexibility of a conductive support, and the like, a wet film forming method is relatively advantageous. As a wet film forming method, a coating method and a printing method are typical.

As a method for preparing a dispersion of semiconductor fine particles, in addition to the above-mentioned sol-gel method, a method of grinding in a mortar, a method of dispersing while pulverizing using a mill, or a solvent for synthesizing a semiconductor. A method of precipitating fine particles in the solution and using it as it is, may be mentioned.

Examples of the dispersion medium include water and various organic solvents (eg, methanol, ethanol, isopropyl alcohol, dichloromethane, acetone, acetonitrile, ethyl acetate, etc.). At the time of dispersion, a polymer, a surfactant, an acid, a chelating agent or the like may be used as a dispersing aid, if necessary.

The application method includes a roller method and a dipping method as an application system, an air knife method and a blade method as a metering system.
-4589, the wire bar method, US Patent 268
The slide hopper method, extrusion method, curtain method, and the like described in Nos. 1294, 2761419, and 2761791 are preferable. As a general-purpose machine, a spin method or a spray method is also preferable. As the wet printing method, intaglio printing, rubber printing, screen printing, and the like are preferable, including three major printing methods of letterpress, offset and gravure. From these, a preferable film forming method is selected according to the liquid viscosity and the wet thickness.

The viscosity of the dispersion of semiconductor fine particles greatly depends on the type and dispersibility of the semiconductor fine particles, the type of solvent used, and additives such as a surfactant and a binder. For a high viscosity liquid (for example, 0.01 to 500 Poise), an extrusion method, a casting method, a screen printing method, or the like is preferable. For a low-viscosity liquid (for example, 0.1 Poise or less), a slide hopper method, a wire bar method or a spin method is preferable, and a uniform film can be formed. If a certain amount of coating is used, application by the extrusion method is possible even in the case of a low-viscosity liquid. As described above, a wet film forming method may be appropriately selected according to the viscosity of the coating solution, the coating amount, the support, the coating speed, and the like.

The layer of the semiconductor fine particles is not limited to a single layer, but a multi-layer coating of a dispersion of semiconductor fine particles having different particle diameters, or a coating layer containing semiconductor fine particles of different types (or different binders and additives) may be used. It can also be applied. Multilayer coating is effective even when the film thickness is insufficient by one coating. An extrusion method or a slide hopper method is suitable for multilayer coating. In the case of multi-layer coating, multi-layer coating may be performed at the same time, or several to dozens of times may be sequentially applied. Furthermore, a screen printing method can also be preferably used in the case of successive coating.

In general, as the thickness of the semiconductor fine particle layer (same as the thickness of the photosensitive layer) becomes larger, the amount of dye carried per unit projected area increases, so that the light capture rate increases, but the diffusion distance of generated electrons increases. Therefore, the loss due to charge recombination also increases. Therefore, the preferred thickness of the semiconductor fine particle layer is
It is 0.1-100 μm. When used in a photoelectrochemical cell, the thickness of the semiconductor fine particle layer is preferably 1 to 30 μm, and 2 to 25 μm.
Is more preferred. The coating amount of the semiconductor fine particles per m ² of the support is preferably 0.5 to 400 g, more preferably 5 to 100 g.

After applying the semiconductor fine particles on the conductive support, the semiconductor fine particles are brought into electronic contact with each other,
Heat treatment is preferably performed to improve the strength of the coating film and the adhesion to the support. A preferred heating temperature range is from 40 ° C to less than 700 ° C, more preferably from 100 ° C to 600 ° C. The heating time is about 10 minutes to 10 hours. When a support having a low melting point or softening point such as a polymer film is used, high-temperature treatment is not preferable because it causes deterioration of the support. It is preferable that the temperature be as low as possible from the viewpoint of cost. The lowering of the temperature can be attained by the above-mentioned combined use of small semiconductor particles of 5 nm or less, heat treatment in the presence of a mineral acid, and the like.

For the purpose of increasing the surface area of the semiconductor fine particles after the heat treatment, increasing the purity in the vicinity of the semiconductor fine particles, and increasing the efficiency of injecting electrons from the dye into the semiconductor particles, for example, chemical plating using an aqueous solution of titanium tetrachloride or trichloride. Electrochemical plating using an aqueous titanium solution may be performed.

The semiconductor fine particles preferably have a large surface area so that many dyes can be adsorbed. Therefore, the surface area in a state where the layer of semiconductor fine particles is coated on the support is preferably 10 times or more the projected area,
Further, it is preferably 100 times or more. The upper limit is not particularly limited, but is usually about 1000 times.

(3) Dye The dye used in the photosensitive layer is preferably a metal complex dye, a phthalocyanine dye or a methine dye. Two or more dyes can be mixed in order to widen the wavelength range of photoelectric conversion as much as possible and to increase the conversion efficiency. The dyes to be mixed and their proportions can be selected so as to match the wavelength range and intensity distribution of the desired light source.

The dye preferably has a suitable interlocking group for the surface of the semiconductor fine particles. Preferred linking groups include a COOH group, an OH group,
SO ₃ H group, a cyano group, -P (O) (OH) 2 group, -OP (O) (OH) 2 group,
Or chelating groups having π conductivity, such as oximes, dioximes, hydroxyquinolines, salicylates and α-keto enolates. Above all, COOH group, -P
Particularly preferred are (O) (OH) ₂ groups and -OP (O) (OH) ₂ groups. These groups may form a salt with an alkali metal or the like, or may form an inner salt. In the case of a polymethine dye, if the methine chain contains an acidic group as in the case of forming a squarylium ring or a croconium ring, this portion may be used as a bonding group.

Hereinafter, preferred dyes used in the photosensitive layer will be specifically described.

(A) Metal complex dye When the dye is a metal complex dye, the metal atom is ruthenium.
Ru is preferred. Ruthenium complex dyes include:
For example, U.S. Pat.Nos. 4,492,721, 4,684,537, 5,084,365
No. 5,350,644, No. 5463057, No. 5,525,440, JP-A-7
-249790, Japanese Translation of PCT International Publication No. 10-504512, and the complex dyes described in World Patent No. 98/50393.

Further, the ruthenium complex dye used in the present invention is preferably represented by the following general formula (I): (A ₁ ) _p Ru (Ba) (Bb) (Bc) (I) In the general formula (I), A ₁ is C
l, expressed _{SCN, H 2 O, Br,} I, CN, a ligand selected from the group consisting of NCO and SeCN, p is an integer of 0 to 3, preferably 2. Ba, Bb and Bc are each independently the following formulas B-1 to B-8:

Embedded image Represents an organic ligand selected from the compounds represented by
In the formulas B-1 to B-8, R ₁₁ represents a substituent, and specific examples include a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, and a substituted or unsubstituted alkyl group having 7 to 12 carbon atoms. A substituted aralkyl group, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, an acidic group such as a carboxylic acid group or a phosphoric acid group (which may form a salt), and the like. The alkyl part of the aralkyl group may be linear or branched, and the aryl group and the aryl part of the aralkyl group may be monocyclic or polycyclic (condensed ring, ring assembly). Ba, Bb and Bc
May be the same or different.

Preferred specific examples of the metal complex dye are shown below, but the present invention is not limited thereto.

[0114]

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[0115]

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[0116]

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(B) Methine Dye The methine dye used in the photosensitive layer in the present invention is preferably a dye represented by the following formula (II), (III), (IV) or (V).

[0118] 1. Dye represented by general formula (II)

Embedded image Represents in the general formula (II), R ₂₁ and R ₂₅ are each independently a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, R ₂₂
To R ₂₄ each independently represent a hydrogen atom or a substituent, R ₂₁
~ R ₂₅ may combine with each other to form a ring, L ₁₁ and L
₁₂ each independently represents a nitrogen atom, oxygen atom, sulfur atom, selenium atom or tellurium atom, n1 and n3 each independently represent an integer of 0 to 2, and n2 represents an integer of 1 to 6. The dye may have a counterion depending on the charge on the entire molecule.

The above alkyl group, aryl group and heterocyclic group may have a substituent. The alkyl group may be linear or branched, and the aryl group and the heterocyclic group may be monocyclic or polycyclic (condensed ring, ring assembly). The ring formed by R _{21 to} R ₂₅ may have a substituent, and may be a single ring or a condensed ring.

[0120] 2. Dye represented by general formula (III)

Embedded image In the general formula (III), Z _a represents a non-metallic atomic group necessary to form a nitrogen-containing heterocyclic ring, R ₃₁ represents an alkyl group or an aryl group. Q _a compound represented by the general formula (III) represents a methine group or a polymethine group necessary to act as a methine dye may form multimers through Q _a. X ₃ represents a counter ion, n4 is an integer of 0.

[0121] nitrogen-containing heterocyclic ring formed by the Z _a may have a substituent, may be a condensed ring may be a single ring. The alkyl group and the aryl group may have a substituent, the alkyl group may be linear or branched, and the aryl group may be monocyclic or polycyclic (condensed ring, ring assembly).

Among the dyes represented by the general formula (III), the following general formulas (III-a) to (III-d):

Embedded image (However, R _{41 to} R ₄₅ , R _{51 to} R ₅₄ , R _{61 to} R ₆₃ , and R _{71 to} R
₇₃ each independently represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, L ₂₁ , L ₂₂ , L ₃₁ , L ₃₂ , L _{41 to} L ₄₅ and L _{51 to} L ₅₆ each independently represent an oxygen atom, Represents a sulfur atom, a selenium atom, a tellurium atom, -CRR'- or -NR- (R and R 'represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, which may be the same or different). , L ₃₃ is O
^{-, S -, Se -,} Te - represents a R ^- or N. _{Y 11, Y 12, Y 21} , Y 22,
Y ₃₁ and Y ₄₁ each independently represent a substituent, n5, n6 and
n7 independently represents an integer of 1 to 6. ) Are more preferred.

The compounds represented by the general formulas (III-a) to (III-d) may have a counter ion depending on the charge of the whole molecule, and may have the above-mentioned alkyl group, aryl group and heterocyclic group. May have a substituent, the alkyl group may be linear or branched, and the aryl group and the heterocyclic group may be monocyclic or polycyclic (condensed ring, ring assembly).

Specific examples of the above polymethine dyes include:
Organ by M.Okawara, T. Kitao, T.Hirashima, M.Matsuoka
It is described in detail in ic Colorants (Elsevier) and the like.

[0125] 3. Dye represented by general formula (IV)

Embedded image In the general formula (IV), Q _b represents an atomic group necessary for forming a nitrogen-containing heterocycle of 5 or 6-membered, Z _b represents an atomic group necessary to form a 3-9 membered ring _{, L 61, L 62, L} 6 3, L 64
And L ₆₅ each independently represent a methine group optionally having a substituent, n 8 is an integer of 0 to 4, n 9 is 0 or 1, R ₈₁ represents a substituent, and X ₄ is It represents a counter ion when a counter ion is necessary for summing.

The ring formed by Q _b may be condensed, and may have a substituent. Preferred examples of the nitrogen-containing heterocycle include a benzothiazole ring, a benzoxazole ring, a benzoselenazole ring, a benzotellurazole ring, a 2-quinoline ring, a 4-quinoline ring, a benzimidazole ring, a thiazoline ring, an indolenine ring, and an oxalate. Diazole ring, thiazole ring, and imidazole ring, more preferably benzothiazole ring, benzoxazole ring, benzimidazole ring, benzoselenazole ring,
2-quinoline ring, 4-quinoline ring, indolenine ring,
Particularly preferred are a benzothiazole ring, a benzoxazole ring, a 2-quinoline ring, a 4-quinoline ring and an indolenine ring.

Examples of the substituent on the nitrogen-containing hetero ring include:
Carboxyl group, phosphonyl group, sulfonyl group, halogen atom (F, Cl, Br, I etc.), cyano group, alkoxy group (methoxy group, ethoxy group, methoxyethoxy group etc.),
Aryloxy group (phenoxy group etc.), alkyl group (methyl group, ethyl group, cyclopropyl group, cyclohexyl group, trifluoromethyl group, methoxyethyl group, allyl group, benzyl etc.), alkylthio group (methylthio group, ethylthio group And the like, an alkenyl group (vinyl group, 1-propenyl group, etc.), an aryl group, a heterocyclic group (phenyl group, thienyl group, toluyl group, chlorophenyl group, etc.).

Z _b is constituted by an atom selected from a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a hydrogen atom.
The ring formed by Z _b is preferably a ring whose skeleton is formed by 4 to 6 carbons, and more preferably
(A)-(E):

Embedded image And most preferably (a).

Examples of the substituent which L ₆₁ , L ₆₂ , L ₆₃ , L ₆₄ and L ₆₅ each independently optionally have include a substituted or unsubstituted alkyl group (preferably having 1 to 12 carbon atoms, more preferably Has 1 to 7 atoms, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclopropyl group,
Butyl group, 2-carboxyethyl group, benzyl group, etc., substituted or unsubstituted aryl group (preferably having 6 carbon atoms,
8 or 10, more preferably 6 or 8 carbon atoms, such as phenyl, toluyl, chlorophenyl, o-carboxyphenyl, etc., heterocyclic (pyridyl, thienyl, furanyl, barbi) Tool acid), halogen atom (chlorine atom, bromine atom, etc.), alkoxy group (methoxy group, ethoxy group, etc.), amino group (preferably having 1 to 12 carbon atoms, more preferably having 6 to 12 carbon atoms) And examples thereof include a diphenylamino group, a methylphenylamino group, a 4-acetylpiperazin-1-yl group and the like, and an oxo group. These substituents may combine with each other to form a ring such as a cyclopentene ring, a cyclohexene ring, or a squarylium ring, or may form a ring with an auxochrome. N8 is an integer of 0 to 4, preferably 0 to 3
It is. N9 is 0 or 1.

The substituent R ₈₁ is preferably an aromatic group (which may have a substituent) or an aliphatic group (which may have a substituent). The number of carbon atoms of the aromatic group is preferably 1 to 1
6, more preferably 5-6. The number of carbon atoms of the aliphatic group is preferably 1 to 10, more preferably 1 to 6.
Examples of the unsubstituted aliphatic group and aromatic group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a phenyl group, and a naphthyl group.

[0131] Whether a dye is either a cationic or anionic, or has a net ionic charge depends on its auxochrome and substituents, the charge of the whole molecule is neutralized by a counter ion X ₄ . Typical cations are inorganic or organic ammonium ion (tetraalkylammonium ion, pyridinium ion, etc.) as counter-ions X ₄ is and alkali metal ions, while the anions be either inorganic or organic anion Also, halide ion (fluoride ion, chloride ion, bromide ion, iodide ion, etc.), substituted arylsulfonate ion (p-toluenesulfonate ion, p-chlorobenzenesulfonate ion, etc.), aryldisulfonate ion (1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, etc.), alkyl sulfate ion (methyl sulfate ion, etc.), sulfate ion, thiocyanate ion, perchloric acid Ion, tetrafluoroborate ion, picrate ion, acetate ion And trifluoromethanesulfonic acid ions.

Further, as the charge-balancing counter ion, an ionic polymer or another dye having a charge opposite to that of the dye may be used, or a metal complex such as bisbenzene-1,2-dithiolatonickel (III) may be used. Ions may be used.

4. Dye represented by general formula (V)

Embedded image In the general formula (V), Q _c represents at least 4 or more functional aromatic group, L ₇₁ and L ₇₂ are each independently a sulfur atom, a selenium atom or -CRR '- (wherein, R and R' are each independently Represents a hydrogen atom or an alkyl group, which may be the same or different, and may be the same or different, and are preferably each independently a sulfur atom or -CRR'-, more preferably -CRR'- It is. R ₉₁ and R ₉₂ each independently represent an alkyl group or an aromatic group, and Y ₅₁ and Y ₅₂ each independently represent a group of non-metallic atoms necessary to form a polymethine dye. X ₅ represents a counter ion.

[0134] Examples of the aromatic group Q _c, benzene, naphthalene, anthracene, those derived from an aromatic hydrocarbon phenanthrene or anthraquinone, carbazole, pyridine, quinoline, thiophene, furan, xanthene, etc. thianthrene Examples thereof include those derived from an aromatic hetero ring, and these may have a substituent other than the connecting portion. Q _c is preferably an aromatic hydrocarbon-derived group, more preferably a benzene or naphthalene-derived group.

[0135] Although the Y ₅₁ and Y ₅₂ it is possible to form any methine dye, preferred are cyanine dyes,
Merocyanine dyes, rhodacyanine dyes, trinuclear merocyanine dyes, allopolar dyes, hemicyanine dyes, styryl dyes, and the like. Cyanine dyes include those in which the substituent on the methine chain forming the dye forms a squarium ring or a croconium ring. For details of these dyes, see "Heterocyclic Compounds-Cyani
ne Dyes and Related Compounds ", John Wiley & Sons
, New York, London, 1964, DMSturmer
By Heterocyclic Compounds-Special Topics in Heter
ocyclic Chemistry ", Chapter 18, Section 14, pages 482 to 515 and the like. Further, cyanine dyes, merocyanine dyes and rhodacyanine dyes are described in US Pat. No. 5,340,694,
Those shown in (XI), (XII) and (XIII) on pages 21-22 are preferred. Also preferably it has a squarylium ring in at least one of the methine chain moiety of the polymethine dye formed by Y ₅₁ and Y _52, which has both are more preferred.

R ₉₁ and R ₉₂ are an aromatic group or an aliphatic group, and these may have a substituent. The number of carbon atoms of the aromatic group is preferably 5 to 16, more preferably 5 to 6. The number of carbon atoms of the aliphatic group is preferably 1 to 10, more preferably 1 to 6. Examples of the unsubstituted aliphatic group and aromatic group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a phenyl group, and a naphthyl group.

It is preferable that at least one of R ₉₁ , R ₉₂ , Y ₅₁ and Y ₅₂ has an acidic group. Here, the acidic group is a substituent having a dissociable proton, and examples thereof include a carboxylic acid group, a phosphonic acid group, a sulfonic acid group, and a boric acid group, and a carboxylic acid group is preferable. Further, the proton on such an acidic group may be dissociated.

Specific examples (1) to (43) and S-1 to S-42 of the polymethine dyes represented by formulas (II) to (V) are shown below, but the present invention is not limited to these. Not something.

[0139]

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[0140]

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[0141]

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[0142]

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[0143]

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[0144]

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[0145]

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[0146]

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[0147]

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[0148]

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[0149]

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[0150]

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[0151]

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[0152]

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[0153]

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[0154]

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[0155]

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[0156]

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[0157]

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[0158]

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[0159]

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The compounds represented by the general formulas (II) and (III) are described in "Heterocyclic Compounds-Cyanine" by FM Harmer.
Dyes and Related Compounds, ”John Wiley & Sons
, New York, London, 1964, DM Sturme
r, Heterocyclic Compounds-Special Topics in Hete
rocyclic Chemistry ", Chapter 18, Section 14, Chapters 482-515
Page, John Wiley & Sons, New York, London, 1
977, `` Rodd's Chemistry of Carbon Compounds '',
2nd. Ed., Vol. IV, part B, Chapter 15, pages 369-422, E
It can be synthesized by the method described in lsevier Science Publishing Company Inc., New York, 1977, UK Patent No. 1,077,611, and the like.

The compound represented by the formula (IV) is
The compound can be synthesized with reference to the description of nd Pigments, Vol. 21, pages 227 to 234 and the like. The compound represented by the formula (V) is described in Ukrainskii Khimicheskii Zhurnal, No. 40
Vol. 3, No. 253-258, Dyes and Pigments, No. 21
Pp. 227-234 and the references cited therein.

(4) Adsorption of Dye on Semiconductor Fine Particles The dye is adsorbed on the semiconductor fine particles by dipping a conductive support having a well-dried semiconductor fine particle layer in a dye solution or by dissolving the dye solution in a semiconductor solution. A method of applying to the fine particle layer can be used. In the former case, a dipping method, a dipping method, a roller method, an air knife method, or the like can be used. In the case of the immersion method, the dye may be adsorbed at room temperature,
It may be carried out by heating and refluxing as described in JP-A-7-249790. In addition, as the latter coating method, a wire bar method, a slide hopper method, an extrusion method,
There are a curtain method, a spin method, a spray method and the like, and a printing method includes letterpress, offset, gravure, screen printing and the like. The solvent can be appropriately selected according to the solubility of the dye. For example, alcohols (methanol, ethanol, t-butanol, benzyl alcohol, etc.), nitriles (acetonitrile, propionitrile, 3-methoxypropionitrile, etc.), nitromethane, halogenated hydrocarbons (dichloromethane, dichloroethane, chloroform,
Chlorobenzene, etc.), ethers (diethyl ether,
Tetrahydrofuran), dimethylsulfoxide, amides (N, N-dimethylformamide, N, N-dimethylacetamide, etc.), N-methylpyrrolidone, 1,3-dimethylimidazolidinone, 3-methyloxazolidinone, esters ( Ethyl acetate, butyl acetate, etc.), carbonates (diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), ketones (acetone, 2-butanone, cyclohexanone, etc.), hydrocarbons (hexane, petroleum ether, benzene, toluene, etc.) And a mixed solvent thereof.

As for the viscosity of the solution of the dye, similarly to the formation of the semiconductor fine particle layer, a high viscosity liquid (for example, 0.01 to 500
In the case of se), various printing methods other than the extrusion method are suitable, and in the case of a low-viscosity liquid (for example, 0.1 Poise or less), the slide hopper method, the wire bar method, or the spin method is suitable. It is possible.

As described above, the viscosity of the coating solution of the dye, the coating amount,
The method for adsorbing the dye may be appropriately selected according to the conductive support, the coating speed, and the like. The time required for dye adsorption after coating should be as short as possible in consideration of mass production.

Since the presence of unadsorbed dye causes disturbance of device performance, it is preferable to remove the dye by washing immediately after adsorption. Using a wet cleaning tank, polar solvents such as acetonitrile,
It is preferable to perform washing with an organic solvent such as an alcohol solvent. Further, in order to increase the adsorption amount of the dye, it is preferable to perform a heat treatment before the adsorption. After the heat treatment, do not return to room temperature to avoid water adsorbing on the surface of the semiconductor fine particles.
Preferably, the dye is adsorbed quickly between 40 and 80 ° C.

The total amount of the dye used is preferably 0.01 to 100 mmol per unit surface area (1 m ² ) of the conductive support. The amount of dye adsorbed on the semiconductor fine particles is 1 g of the semiconductor fine particles.
It is preferably 0.01 to 1 mmol per unit. By using such a dye adsorption amount, a sufficient sensitizing effect in a semiconductor can be obtained. On the other hand, if the amount of the dye is too small, the sensitizing effect becomes insufficient, and if the amount of the dye is too large, the dye not adhering to the semiconductor floats and causes a reduction in the sensitizing effect.

In order to widen the wavelength range of photoelectric conversion as much as possible and to increase the conversion efficiency, two or more dyes can be mixed. In this case, it is preferable to select the dyes to be mixed and their proportions so as to match the wavelength range and the intensity distribution of the light source.

For the purpose of reducing the interaction between dyes such as association, a colorless compound may be co-adsorbed on the semiconductor fine particles. Examples of the hydrophobic compound to be co-adsorbed include a steroid compound having a carboxyl group (for example, chenodeoxycholic acid). Further, an ultraviolet absorber can be used in combination.

For the purpose of promoting the removal of excess dye, the surface of the semiconductor fine particles may be treated with amines after the dye is adsorbed. Preferred amines are pyridine,
4-t-butylpyridine, polyvinylpyridine and the like. When these are liquids, they may be used as they are, or may be used after being dissolved in an organic solvent.

(C) Charge transfer layer The charge transfer layer is a layer having a function of replenishing an oxidized dye with electrons. Although the electrolyte composition of the present invention is used for the charge transfer layer, a solid electrolyte or a hole transport material may be used in combination.

To form a charge transfer layer comprising the electrolyte composition of the present invention, an electrolyte solution is applied on the photosensitive layer by a casting method, a coating method, an immersion method, an impregnation method, etc., and then, if necessary, a heating reaction. What is necessary is just to crosslink.

When the electrolyte layer is formed by a coating method,
Additives such as coatability improvers (leveling agents, etc.) to the coating solution consisting of molten salt etc. to prepare a uniform electrolyte solution,
This is applied to spin coating, dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, and US Patent No. 26
Extrusion coating method using hopper described in 81294, U.S. Pat.Nos. 2,761,418, 3,508,947, 2,761
Application by a method such as the multilayer simultaneous application method described in No. 791,
Thereafter, if necessary, heating is performed to form the charge transfer layer of the present invention. The heating temperature is appropriately selected depending on the heat-resistant temperature of the dye, but is preferably 10 to 150 ° C.
More preferably, it is 10 to 100 ° C. The heating time depends on the heating temperature and the like, but is about 5 minutes to 72 hours.

According to a preferred embodiment, as shown in FIG. 1, a solution containing more electrolyte than an amount that completely fills the voids in the photosensitive layer 20 is applied, so that the obtained electrolyte layer substantially has a conductive support. From the boundary with the body conductive layer 10
It can be said that it exists between the boundaries of 40. Here, assuming that the electrolyte layer existing between the boundary with the photosensitive layer 20 containing the dye-sensitized semiconductor and the boundary with the counter electrode 40 is the charge transfer layer 30, the thickness is preferably 0.001 to 200 μm, and 0.1 to 200 μm. ~ 100
μm is more preferable, and 0.1 to 50 μm is particularly preferable. If the charge transfer layer 30 is thinner than 0.001 μm, the semiconductor fine particles 21 in the photosensitive layer may come into contact with the counter electrode conductive layer 40. If the charge transfer layer 30 is thicker than 200 μm, the charge transfer distance becomes too large, and the resistance of the element increases. The thickness of the photosensitive layer 20 + the charge transfer layer 30 (substantially equal to the thickness of the electrolyte composition) is preferably from 0.1 to 300 μm, and more preferably from 1 to 130 μm.
Is more preferable, and 2 to 75 μm is particularly preferable.

When iodine or the like is introduced into the electrolyte in order to generate a redox couple, the method of adding iodine to the above-described electrolyte solution, after forming the charge transfer layer, place this in an airtight container together with iodine or the like and diffuse it into the electrolyte. It can be introduced by a method or the like. In addition, it is also possible to apply or deposit iodine or the like on a counter electrode to be described later and to introduce it into the charge transfer layer when assembling the photoelectric conversion element.

(D) Counter electrode When the photoelectric conversion element is a photoelectrochemical cell, the counter electrode functions as a positive electrode of the photoelectrochemical cell. The counter electrode may have a single-layer structure of a counter electrode conductive layer made of a conductive material, or may be composed of a counter electrode conductive layer and a support substrate, similarly to the above-described conductive support. Examples of the conductive material used for the counter electrode conductive layer include metal (for example, platinum, gold, silver, copper, aluminum, rhodium, indium, and the like), carbon, and conductive metal oxide (indium-tin composite oxide, tin oxide with fluorine). And the like). An example of a preferable support substrate for the counter electrode is glass or plastic, to which the above-described conductive agent is applied or vapor-deposited. The thickness of the counter electrode conductive layer is not particularly limited, but is preferably 3 nm to 10 μm. When the counter electrode conductive layer is made of metal, its thickness is preferably 5 μm or less, more preferably 5 nm to 3 μm.
Range.

Since light may be irradiated from one or both of the conductive support and the counter electrode, at least one of the conductive support and the counter electrode must be substantially transparent in order for the light to reach the photosensitive layer. I just want it. From the viewpoint of improving the power generation efficiency, it is preferable that the conductive support is made transparent and light is incident from the conductive support side. In this case, the counter electrode preferably has a property of reflecting light. As such a counter electrode, glass or plastic on which a metal or a conductive oxide is deposited, or a metal thin film can be used.

The procedure for providing the counter electrode is as follows: (a) when the charge transfer layer is formed and then formed thereon; and (b) when the counter electrode is arranged on the layer of the dye-sensitized semiconductor fine particles via a spacer. There are two cases in which the space is filled with an electrolyte solution. In the case of (a), a conductive material is applied directly on the charge transfer layer,
Plating or vapor deposition (PVD, CVD) or attaching the conductive layer side of the substrate having the conductive layer. In the case of (b), a counter electrode is assembled and fixed via a spacer on the dye-sensitized semiconductor fine particle layer, the open end of the obtained assembly is immersed in an electrolyte solution, and capillary action or reduced pressure is used. An electrolyte solution is made to penetrate into the gap between the dye-sensitized semiconductor fine particle layer and the counter electrode. Further, similarly to the case of the conductive support, it is preferable to use a metal lead for the purpose of reducing the resistance of the counter electrode, particularly when the counter electrode is transparent. In addition, the preferable material and the installation method of the metal lead, the decrease of the incident light amount by the installation of the metal lead, and the like are the same as those of the conductive support.

(E) Other Layers A functional layer such as a protective layer or an anti-reflection layer may be provided on one or both of the conductive support serving as an electrode and the counter electrode. When such a functional layer is formed in multiple layers, a simultaneous multilayer coating method or a sequential coating method can be used, but from the viewpoint of productivity, the simultaneous multilayer coating method is preferable. In the simultaneous multilayer coating method,
In consideration of productivity and uniformity of a coating film, a slide hopper method or an extrusion method is suitable. In forming these functional layers, an evaporation method, a sticking method, or the like can be used depending on the material. In addition, in order to prevent a short circuit between the counter electrode and the conductive support, a dense semiconductor thin film layer may be previously provided between the conductive support and the photosensitive layer as an undercoat layer. Preferred as the undercoat layer are TiO ₂ , Sn
O ₂ , Fe ₂ O ₃ , WO ₃ , ZnO, Nb ₂ O ₅ , more preferably
TiO ₂ . Primer layer is Electrochimi. Acta 40, 643-6
52 (1995) can be applied by the spray pyrolysis method. The preferred thickness of the undercoat layer is
It is 5 to 1000 nm or less, more preferably 10 to 500 nm.

(F) Specific Example of Internal Structure of Photoelectric Conversion Element As described above, the internal structure of the photoelectric conversion element can take various forms according to the purpose. When roughly divided into two, a structure in which light can enter from both sides and a structure in which light can be entered only from one side are possible. 2 to 8 exemplify an internal structure of a photoelectric conversion element which can be preferably applied to the present invention.

FIG. 2 shows the transparent conductive layer 10 a and the transparent counter electrode conductive layer 4.
The photosensitive layer 20 and the charge transfer layer 30 are interposed between the photosensitive layer 20a and the light transfer layer 0a, and have a structure in which light enters from both sides.
FIG. 3 shows that a metal lead 11 is partially provided on a transparent substrate 50a, a transparent conductive layer 10a is further provided, an undercoat layer 60, a photosensitive layer 20, a charge transfer layer 30, and a counter electrode conductive layer 40 are provided in this order and further supported. The substrate 50 is arranged, and has a structure in which light is incident from the conductive layer side. FIG. 4 further includes a conductive layer 10 on a support substrate 50, and a photosensitive layer 20 provided through an undercoat layer 60.
Further, the charge transfer layer 30 and the transparent counter electrode conductive layer 40a are provided, and the transparent substrate 50a, in which the metal leads 11 are partially provided, is
This is a structure in which light is incident from the counter electrode side, with one side being placed inside. FIG. 5 shows that a transparent conductive layer 10a and a transparent counter electrode conductive layer 40a are respectively provided on two transparent substrates 50a partially provided with metal leads 11, and an undercoat layer 60, a photosensitive layer 20, and a charge transfer layer 30 are provided therebetween. And light is incident from both sides. FIG. 6 shows that the transparent conductive layer 10a is provided on the transparent substrate 50a, and the photosensitive layer 20 is provided through the undercoat layer 60.
Provided, further provided a charge transfer layer 30 and a counter electrode conductive layer 40,
A support substrate 50 is disposed thereon, and has a structure in which light is incident from the conductive layer side. FIG. 7 shows that the conductive layer 10 is provided on the support substrate 50, the photosensitive layer 20 is provided via the undercoat layer 60, the charge transfer layer 30 and the transparent counter electrode conductive layer 40a are further provided, and the transparent substrate 50a is disposed thereon. This is a structure in which light is incident from the counter electrode side. FIG. 8 has a transparent conductive layer 10a on a transparent substrate 50a, and the photosensitive layer 20 is provided with an undercoat layer 60 interposed therebetween.
Further, a charge transfer layer 30 and a transparent counter electrode conductive layer 40a are provided, and a transparent substrate 50a is disposed thereon, so that light is incident from both sides.

[3] Photoelectrochemical Battery The photoelectrochemical battery of the present invention is such that the above-mentioned photoelectric conversion element works in an external circuit. It is preferable that the side surface of the photoelectrochemical cell is sealed with a polymer, an adhesive, or the like in order to prevent deterioration of components and volatilization of the contents. The external circuit itself connected to the conductive support and the counter electrode via a lead may be a known one.

[4] Dye-Sensitized Solar Cell When the photoelectric conversion device of the present invention is applied to a so-called solar cell, the structure inside the cell is basically the same as the structure of the above-described photoelectric conversion device. Hereinafter, a module structure of a solar cell using the photoelectric conversion element of the present invention will be described.

The dye-sensitized solar cell of the present invention can have a module structure basically similar to a conventional solar cell module. The solar cell module generally has a structure in which cells are formed on a supporting substrate such as a metal and a ceramic, and the cells are covered with a filling resin or a protective glass or the like, and light is taken in from the opposite side of the supporting substrate. It is also possible to adopt a structure in which a transparent material such as tempered glass is used for the support substrate, a cell is formed thereon, and light is taken in from the transparent support substrate side. Specifically, a module structure called a superstrate type, a substrate type, or a potting type, a substrate-integrated module structure used in an amorphous silicon solar cell, and the like are known. The module structure of the dye-sensitized solar cell of the present invention can be appropriately selected depending on the purpose of use, the place of use, and the environment.

In a typical superstrate type or substrate type module, cells are arranged at fixed intervals between supporting substrates which are transparent on one or both sides and have been subjected to antireflection treatment, and adjacent cells are made of metal leads or flexible. It is connected by wiring or the like, and a current collecting electrode is arranged on the outer edge, so that generated power is taken out to the outside. Between the substrate and the cell, various kinds of plastic materials such as ethylene vinyl acetate (EVA) may be used in the form of a film or a filling resin, depending on the purpose, in order to protect the cell and improve current collection efficiency. Also, when used in places where it is not necessary to cover the surface with a hard material, such as places where there is little external impact, the surface protective layer is made of a transparent plastic film, or the above-mentioned resin is cured to cure the protective function. It is possible to eliminate the support substrate on one side. The periphery of the support substrate is fixed in a sandwich shape with a metal frame in order to secure the internal sealing and the rigidity of the module, and the space between the support substrate and the frame is hermetically sealed with a sealing material. When a flexible material is used for the cell itself, the supporting substrate, the filling material, and the sealing material, a solar cell can be formed on a curved surface.

In the super straight type solar cell module, for example, while a front substrate sent from a substrate supply device is conveyed by a belt conveyor or the like, a cell is formed thereon with a sealing material-cell connection lead wire, a back surface sealing. After laminating sequentially with materials and the like, a back substrate or a back cover can be placed, and a frame can be set on the outer edge to produce.

On the other hand, in the case of the substrate type, while the support substrate sent out from the substrate supply device is conveyed by a belt conveyor or the like, the cells are sequentially stacked thereon together with the inter-cell connection lead wire, the sealing material, and the like. It can be manufactured by placing a front cover and setting a frame on the periphery.

FIG. 9 shows an example of a structure in which the photoelectric conversion element of the present invention is made into a module integrated with a substrate. FIG. 9 shows that a transparent conductive layer 10a is provided on one surface of a transparent substrate 50a, on which a photosensitive layer 20 containing dye-adsorbed TiO ₂ and a charge transfer layer 30 are further provided.
Further, the cell provided with the metal counter electrode conductive layer 40 is modularized, and the structure is such that the antireflection layer 70 is provided on the other surface of the substrate 50a. In the case of such a structure, it is preferable to increase the area ratio of the photosensitive layer 20 (the area ratio when viewed from the substrate 50a which is the light incident surface) in order to increase the utilization efficiency of incident light.

In the case of the module having the structure shown in FIG. 9, selective plating, selective etching, and CVD are performed so that the transparent conductive layer, the photosensitive layer, the charge transfer layer, the counter electrode, and the like are three-dimensionally arranged at regular intervals on the substrate. , PVD and other semiconductor process technologies, or laser scribing after pattern coating or wide coating, plasma CVM (Solar Energy Materials and SolarC)
ells, 48, pp. 373-381), and a desired module structure can be obtained by patterning by a mechanical method such as grinding.

The other members and steps will be described below in detail.

Examples of the sealing material include liquid EVA (ethylene vinyl acetate), depending on the purpose of imparting weather resistance, imparting electrical insulation, improving light-collecting efficiency, and improving cell protection (impact resistance).
Various materials such as a film-like EVA and a mixture of a vinylidene fluoride copolymer and an acrylic resin can be used. It is preferable to use a sealing material having high weather resistance and high moisture resistance between the outer edge of the module and the frame surrounding the periphery. In addition, the strength and light transmittance can be increased by mixing a transparent filler into the sealing material.

When the sealing material is fixed on the cell, a method suitable for the physical properties of the material is used. Various methods such as roll coating, bar coating, spray coating, screen printing, etc. are possible for film-shaped materials, such as heat adhesion after roll pressurization, and heat adhesion after vacuum pressurization, and for liquid or paste-like materials. is there.

When a flexible material such as PET or PEN is used as the support substrate, a roll-shaped support is drawn out to form a cell thereon, and then the sealing layer is continuously laminated by the above method. Can be highly productive.

In order to increase the power generation efficiency, the surface of the substrate (generally tempered glass) on the light intake side of the module is subjected to an anti-reflection treatment. As the anti-reflection treatment method,
There are a method of laminating an antireflection film and a method of coating an antireflection layer.

By treating the surface of the cell by a method such as grooving or texturing, it is possible to increase the utilization efficiency of incident light.

In order to increase the power generation efficiency, it is most important that the light is taken into the module without loss. However, the light that has passed through the photoelectric conversion layer and has reached the inside thereof is reflected to improve the efficiency toward the photoelectric conversion layer side. It is also important to return well. As a method of increasing the reflectance of light, after mirror-polishing the support substrate surface, a method of depositing or plating Ag or Al, etc., an alloy layer such as Al-Mg or Al-Ti at the bottom layer of the cell as a reflective layer. There are a method of providing a texture structure and a method of forming a texture structure in the lowermost layer by annealing.

In order to increase the power generation efficiency, it is important to reduce the connection resistance between cells in order to suppress the internal voltage drop. As a method of connecting the cells, wire bonding and connection using a conductive flexible sheet are generally used.However, a method of fixing the cells using a conductive adhesive tape or a conductive adhesive and simultaneously electrically connecting the cells, There is also a method of pattern-coating a conductive hot melt at a desired position.

In the case of a solar cell using a flexible support such as a polymer film, cells are sequentially formed by the above-described method while feeding a roll-shaped support, and cut into a desired size. The battery body can be manufactured by sealing with a material having a property.
Also, Solar Energy Materials and Solar Cells, 48,
A module structure called “SCAF” described in p383-391 can also be used. Further, a solar cell using a flexible support can be used by being adhered and fixed to a curved glass or the like.

As described in detail above, solar cells having various shapes and functions can be manufactured according to the purpose and environment of use.

[0199]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

[0200] 1. Synthesis Example of Compound Represented by General Formula (1) The compound represented by the general formula (1) of the present invention was synthesized using the following compounds a to d. The structure of the synthesized compound is ¹ H
-Confirmed by NMR. The water content of the synthesized compound was measured by the Karl Fischer method, and the viscosity was measured using a B-type viscometer (manufactured by Tokimec Co., Ltd.).

[0201]

Embedded image

(A) Synthesis of (1-a) 5.58 g of compound a and 3.7 g of N-methylimidazole were dissolved in 15 ml of ethyl acetate and reacted at room temperature for 48 hours. After removing the ethyl acetate phase by decantation, it was dried under reduced pressure and heated to obtain 1.8 g of a crude product containing compound b. 1.8 g of this crude product and 3.0 g of sodium iodide were mixed in 20 ml of acetonitrile and reacted under heating and reflux for 5 hours. After completion of the reaction, the precipitate was removed by filtration, the solvent was distilled off under reduced pressure, and the residue was purified by a silica gel column to obtain 1.0 g of (1-a).
The water content of the obtained (1-a) was 0.3%, and the viscosity at 25 ° C. was η = 832 cp or more.

(B) Synthesis of (1-b) 1.8 g of the above crude product containing compound b and 2.0 g of N-lithiotrifluoromethanesulfonimide were placed in 20 ml of water at room temperature for 30 minutes.
Stirred for minutes. This is extracted with methylene chloride and concentrated to 1.
7 g of (1-b) were obtained as an oil. This is further heated at 50 ° C and 5m
The water content of the compound (1-b) obtained by drying under the condition of mHg for 5 hours was 0.15%, and the viscosity at 25 ° C. was η = 355 cp.

(C) Synthesis of (1-c) 3.15 g of (1-a) and 1.95 g of silver tetrafluoroborate were added in 25 m
1 in water. Next, the precipitate was filtered using celite, the water was concentrated, and dried under the conditions of 50 ° C. and 5 mmHg for 5 hours to obtain 1.8 g of (1-c). The water content of the obtained (1-c) was 0.2%, and the viscosity at 25 ° C. was η = 1100 cp.

(D) Synthesis of (4-a) 2.2 g of 65% oily sodium hydride was suspended in 50 ml of DMF, and at 0 ° C., 3.4 g of imidazole was added in portions. After the addition was completed, a solution in which 10.7 g of the compound c was dissolved in 10 ml of DMF was added and reacted at room temperature for 24 hours. After completion of the reaction, the solvent was distilled off under reduced pressure, and the residue was purified by a silica gel column (eluent: methylene chloride / methanol = 10/1) to obtain 9.8 g of compound d.

Subsequently, 2.5 g of compound d and 0.63 ml of methyl iodide were dissolved in 10 ml of ethyl acetate and reacted at room temperature for 24 hours. After completion of the reaction, the solvent was distilled off under reduced pressure, and a silica gel column (eluent: methylene chloride / methanol = 4/1)
And dried under the conditions of 50 ° C and 1 mmHg for 5 hours.
1.82 g of (4-a) was obtained. The water content of the obtained (4-a) was 0.3
%, And the viscosity at 25 ° C. was η = 2000 cp or more.

(E) Synthesis of (4-b) 1.8 g of (4-a) and 1.33 g of N-lithiotrifluoromethanesulfonimide were stirred in 20 ml of water at room temperature for 1 hour.
The reaction solution was extracted with methylene chloride, concentrated, and dried under the conditions of 50 ° C. and 5 mmHg for 5 hours to obtain 1.6 g of (4-b) as an oil. The water content of the obtained (4-b) was 0.2%, and the viscosity at 25 ° C. was η = 333 cp.

(F) Synthesis of (4-c) 2.0 g of (4-a) and 1.0 g of silver tetrafluoroborate in 20 ml
In water. Next, the precipitate was filtered using celite, the water was concentrated, and dried under the conditions of 50 ° C. and 5 mmHg for 5 hours to obtain 1.3 g of (4-c) as an oil. Obtained (4-c)
Had a water content of 0.2% and a viscosity at 25 ° C. of η = 2000 cp.

(G) Synthesis of (4-d) 2.0 g of (4-a) and 0.86 g of silver thiocyanate were mixed in 80 ml of water. This was stirred for 48 hours and the precipitate was filtered using celite. The water of the obtained solution was concentrated, purified by a silica gel column, and dried under the conditions of 50 ° C. and 5 mmHg for 5 hours to obtain 0.6 g of (4-d) as an oil. The water content of the obtained (4-d) is 0.3%, and the viscosity at 25 ° C. is η = 20.
It was more than 00cp.

(H) Synthesis of (4-e) 3.87 g of (4-a) and 2.3 g of silver trifluoroacetate were mixed in 20 ml of water, and the precipitate was filtered using celite. The water of the obtained solution was concentrated and purified by a silica gel column, and then dried at 50 ° C. and 5 mmHg for 5 hours to obtain 1.4 g of (4-e) as an oil. The water content of the obtained (4-e) was 0.5%, and the viscosity at 25 ° C. was η = 2000 cp or more.

(I) Synthesis of (4-f) 2.0 g of (4-a) and 1.05 g of silver methanesulfonate were mixed in 20 ml of water, and the precipitate was filtered using celite. The water of the obtained solution was concentrated, purified by a silica gel column, and dried at 50 ° C. and 5 mmHg for 5 hours to obtain 1.3 g of (4-f) as an oil. The water content of the obtained (4-f) was 0.5%, and the viscosity at 25 ° C. was η = 2000 cp or more.

(J) Synthesis of Compound Represented by Other General Formula (1) Compounds represented by the general formula (1) of the present invention other than those described above can be easily synthesized in the same manner as the above compound.

[0213] 2. Preparation of Photoelectrochemical Cell (A) Preparation of Titanium Dioxide Dispersion Solution Inner volume of 20 coated with Teflon (registered trademark)
In a 0 ml stainless steel container, 15 g of titanium dioxide particles (Degussa P-25, manufactured by Nippon Aerosil Co., Ltd.), 45 g of water, 1 g of a dispersant (Triton X-100, manufactured by Aldrich), and zirconia beads having a diameter of 0.5 mm (Nikkato) 30 g) and 1500 using a sand grinder mill (made by Imex)
The dispersion treatment was performed at rpm for 2 hours. Zirconia beads were removed from the obtained dispersion by filtration. The average particle size of the titanium dioxide fine particles in the obtained dispersion was 2.5 μm. The particle size was measured with a master sizer manufactured by MALVERN.

(B) Preparation of TiO ₂ Electrode Adsorbing Dye Conductive glass having a tin oxide layer doped with fluorine (TCO glass-U manufactured by Asahi Glass Co., Ltd. cut into a size of 20 mm × 20 mm, The above dispersion was applied to the conductive surface side having a surface resistance of about 30Ω / □ using a glass rod. The application amount of the semiconductor fine particles was 20 g / m ² . At that time, an adhesive tape was stretched on a part (3 mm from the end) on the conductive surface side to form a spacer, and glass was lined up so that the adhesive tape came to both ends, and eight pieces were applied at a time. After application, the adhesive tape was peeled off and air-dried at room temperature for one day. Next, this glass was placed in an electric furnace (muffle furnace FP-32 type, manufactured by Yamato Scientific Co., Ltd.) and fired at 450 ° C. for 30 minutes to obtain a TiO ₂ electrode. After taking out the electrode and cooling it, an ethanol solution of the dye shown in Table 1 (3 × 10 ⁻⁴ mol /
l) for 3 hours. Dye-stained TiO ₂ electrode with 4-t-
After being immersed in butylpyridine for 15 minutes, it was washed with ethanol and dried naturally. The amount of dye applied depends on the type of dye,
Selected from a range of appropriate 0.1 to 10 mmol / m ^2.

(C) Preparation of photoelectrochemical cell The dye-sensitized TiO ₂ electrode substrate (20 mm × 20
mm) was overlaid with platinum-evaporated glass of the same size. Next, using a capillary phenomenon to penetrate the electrolyte composition into the gap between the two glasses, the electrolyte is introduced into the TiO ₂ electrode,
A conductive support layer made of conductive glass (a conductive layer 10a is provided on a transparent glass substrate 50a) shown in FIG. 1,
A photoelectrochemical cell in which a photosensitive layer 20 of dye-sensitized TiO ₂ , a charge transfer layer 30, a counter electrode conductive layer 40 made of platinum, and a transparent substrate 50a made of glass were laminated in this order and sealed with an epoxy-based sealant was produced.
However, when the viscosity of the electrolyte composition is high and it is difficult to use the capillary phenomenon to impregnate the electrolyte composition,
After heating the electrolyte composition to 50 ° C. and applying it to a TiO ₂ electrode, the electrode was placed under reduced pressure. After the electrolyte composition permeated sufficiently and the air in the electrode had escaped, platinum-deposited glass (counter electrode) )
Were overlapped to produce a photoelectrochemical cell in the same manner.

The above-mentioned steps were performed by changing the electrolyte composition and the dye, and photoelectrochemical cells of Examples 1 to 30 and Comparative Examples 1 to 15 were produced. Table 1 shows the composition of the electrolyte composition used for each photoelectrochemical cell, the thickness of the obtained photosensitive layer, and the dye used. BCE in Table 1 represents biscyanoethyl ether. The electrolyte salt of the present invention used in the examples,
The pKa of the conjugate acid of the compound obtained by adding hydrogen thereto is 3 to 1
5 substituents. Such substituents are (1-a) to (1-
f) and (15-c) are pyridyl groups (pKa of the conjugate acid of the compound obtained by adding hydrogen: 5), and (2-b), (2-c),
(3-d), (3-e), (4-c) to (4-f) and (5-c) are α-picolyl groups (same pKa: 6), and (7-c) Is a 2-methylimidazolyl group (pKa: 8), and (13-c) is an imidazolyl group (pKa: 7). The structures of the compounds (Y-1) to (Y-8) other than the compound of the present invention used in the electrolyte compositions of Examples and Comparative Examples are shown below.

[0219]

[Table 1]

[0218]

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[0219] 3. Measurement of photoelectric conversion efficiency AM light of 500 W xenon lamp (Ushio Electric Co., Ltd.)
Simulated sunlight without ultraviolet rays was generated by passing through a 1.5 filter (manufactured by Oriel) and a sharp cut filter (Kenko L-42). The intensity of this light was 72 mW / cm ² . This simulated sunlight was irradiated at 55 ° C. on each of the produced photoelectrochemical cells, and the generated electricity was measured with a current / voltage measuring device (Keithley SMU238 type). The open-circuit voltage (Voc), short-circuit current density (Jsc), form factor (FF), conversion efficiency (η) and 80
Table 2 shows the rate of decrease in conversion efficiency after storage in a dark place.

[0220]

[Table 2]

From Table 2, it can be seen that the photoelectrochemical cells containing a large amount of organic solvent in the electrolyte (Examples 1 and 2, Comparative Examples 1 to 4) were significantly deteriorated after storage in a dark place. The photoelectrochemical cell of Example 2 was prepared using Comparative Examples 1, 3 and 4 using a conventional imidazolium salt and a basic compound (Y-2).
It can be seen that the rate of decrease in the conversion efficiency is improved as compared with the photoelectrochemical cell of Comparative Example 2 in which is used in combination. Further, in order to suppress the rate of decrease in conversion efficiency to within 10%, the solvent content of the electrolyte composition is limited to 10% by mass, and it can be seen that it is more preferable not to use a solvent. In a photoelectrochemical cell using an electrolyte composition having a solvent content of 10% by mass or less,
Photoelectrochemical cells using only the existing imidazolium salt as the electrolyte (Comparative Examples 6 to 10) and photoelectrochemical cells using this together with the existing basic compound (Y-2) (Comparative Examples 11 to 15)
In this case, the open-circuit voltage and the conversion efficiency are low, and the rate of decrease in the conversion efficiency is equal to or lower than that of the photoelectrochemical cell of the present invention. On the other hand, it can be seen that in the photoelectrochemical cell using the electrolyte composition of the present invention, the open-circuit voltage is high, and the conversion efficiency is accordingly improved. Conversion efficiency is improved by combination with a salt having an oxyethylene group (Examples 16 to 19).
Further, when the photosensitive layer is made thinner, the short-circuit current density is reduced accordingly (Example 5: 6.5 μm, Example 27: 4.8 μm).
m, Example 28: 3.3 μm), the results of Examples 29 and 30 show that the photoelectric conversion efficiency is improved by combining a dye having a high light absorption.

[0222]

As described in detail above, the electrolyte composition of the present invention is excellent in durability and charge transport ability, and a photoelectric conversion element using this electrolyte composition has excellent photoelectric conversion characteristics, Characteristic deterioration is small. A photoelectrochemical cell comprising such a photoelectric conversion element is extremely effective as a solar cell.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 2 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 3 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 4 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 5 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 6 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 7 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 8 is a partial sectional view showing the structure of a preferred photoelectric conversion element of the present invention.

FIG. 9 is a partial cross-sectional view illustrating an example of the structure of a substrate-integrated solar cell module using the photoelectric conversion element of the present invention.

[Explanation of symbols]

 10 conductive layer 10a transparent conductive layer 11 metal lead 20 photosensitive layer 21 fine semiconductor particles 22 dye 23 electrolyte 30 charge transfer layer 40 ..Counter electrode conductive layer 40a ... Transparent counter electrode conductive layer 50 ... Substrate 50a ... Transparent substrate 60 ... Undercoat layer 70 ... Anti-reflective layer

Claims (18)

[Claims] 1. The following general formula (1):(However, Q is a 5- or 6-membered aromatic compound together with a nitrogen atom.
Represents an atomic group capable of forming thione, R₀₀₁Is L₀₀₁−A₀₁(L₀₀₁Represents a bond or a divalent linking group;
₀₀₁A represents a bond ₀₁Represents a substituent, L₀₀₁Is divalent
A when representing a group₀₁Represents a hydrogen atom or a substituent. )
And each may be the same or different, and n01 is 0, or 1 or more R that can exist on Q₀₀₁Maximum number of
Represents the following integer, R₀₀₂Is L₀₀₂−L₀₀₃−A₀₂(L₀₀₂Is a substituted or unsubstituted al
Shows a kylene group or a substituted or unsubstituted alkenylene group.
Then L₀₀₃Represents a bond or a divalent linking group;₀₂Is a hydrogen atom
Or a substituent. ), And X^-Represents an anion; R₀₀₁And R₀₀₂Two or more are linked together to form a ring structure
May be formed, A₀₁And A₀₂At least one of which has hydrogen added to it
A conjugate acid having a pKa of 3 to 15
is there. )
Electrolyte composition. 2. The electrolyte composition according to claim 1, wherein the constituent atom of Q is selected from the group consisting of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom, and a sulfur atom. . 3. The electrolyte composition according to claim 1, wherein the 5- or 6-membered aromatic cation in which Q forms together with a nitrogen atom is an imidazolium cation or a pyridinium cation. Composition. 4. The electrolyte composition according to claim 1, wherein the compound represented by the general formula (1) is represented by the following general formula (2): (However, R ₀₀₃ represents L ₀₀₄ -L ₀₀₅ -A ₀₃ (L ₀₀₄ represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group, L ₀₀₅ represents a bond or a divalent linking group, ₀₃
Represents a hydrogen atom or a substituent. ) Represent, may be the same as or different from each other, n02 represents an integer of 0 to 3, R ₀₀₄ is a hydrogen atom or _{L 006 -L 007 -A 04 (L} 006 represents a substituted or unsubstituted alkylene group, or L ₀₀₇ represents a substituted or unsubstituted alkenylene group; L ₀₀₇ represents a bond or a divalent linking group;
₀₄ represents a hydrogen atom or a substituent. R ₀₀₅ represents L ₀₀₈ -L ₀₀₉ -A ₀₅ (L ₀₀₈ represents a substituted or unsubstituted alkylene group, or a substituted or unsubstituted alkenylene group, L ₀₀₉ represents a bond or a divalent linking group, a ₀₅ represents a) represents a hydrogen atom or a substituent, X ^-. represents an anion, it may form two or more connected to each other to form a ring structure of R ₀₀₃ ~R _005, a ₀₃ ~A _At least one of ₀₅ is a substituent in which the pKa of the conjugate acid of the compound obtained by adding hydrogen thereto is 3 to 15. An electrolyte composition represented by the formula: 5. The electrolyte composition according to claim 1, wherein the compound represented by the general formula (1) is represented by the following general formula (3): (However, R ₀₀₆ represents L ₀₁₀ -L ₀₁₁ -A ₀₆ (L ₀₁₀ represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenylene group, L ₀₁₁ represents a bond or a divalent linking group, ₀₆
Represents a hydrogen atom or a substituent. ) Represents, which may be the same or different, n03 represents an integer of 0 to 5, R ₀₀₇ is _{L 012 -L 013 -A 07 (L} 012 represents a substituted or unsubstituted alkylene group, or a substituted or unsubstituted a substituted alkenylene group, L ₀₁₃ represents a bond or a divalent linking group, a ₀₇ represents a represents) a hydrogen atom or a substituent, X ^-. represents an anion, two of R ₀₀₆ and R ₀₀₇ The above may combine with each other to form a ring structure, and at least one of A ₀₆ and A ₀₇ is a substituent having a pKa of 3 to 15 of a conjugate acid of a compound obtained by adding hydrogen thereto. . An electrolyte composition represented by the formula: 6. The electrolyte composition according to claim 1, wherein the conjugate acid of the compound obtained by adding hydrogen thereto has a pKa of 3 to 15 which is an imidazolyl group or a pyridyl group. An electrolyte composition comprising: 7. The electrolyte composition according to claim 1, wherein the content of the solvent is not more than 10% by mass of the whole electrolyte composition. 8. The electrolyte composition according to claim 1, wherein X ⁻ is an iodide ion, NCS ⁻ , B
F ₄ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , or the following general formulas (AN-1) and (AN-
2): embedded image (However, R ₀₁₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a perfluoroalkyl group, or a substituted or unsubstituted aryl group, and R ₀₁₄ represents a substituted or unsubstituted alkyl group, a perfluoroalkyl group, or Or a substituted or unsubstituted aryl group). 9. The electrolyte composition according to claim 1, further comprising an iodine salt and / or iodine in addition to the compound represented by the general formula (1). object. 10. The electrolyte composition according to claim 1, wherein the electrolyte composition is used for a photoelectrochemical cell. 11. A photoelectric conversion device having a conductive layer, a photosensitive layer, a charge transfer layer, and a counter electrode, wherein the charge transfer layer contains the electrolyte composition according to claim 1. Photoelectric conversion element. 12. The photoelectric conversion device according to claim 11, wherein the photosensitive layer contains a fine particle semiconductor sensitized by a dye. 13. The photoelectric conversion device according to claim 12, wherein the fine particle semiconductor is composed of metal chalcogenide fine particles. 14. The photoelectric conversion device according to claim 13, wherein the metal chalcogenide fine particles include titanium oxide fine particles. 15. The photoelectric conversion device according to claim 12, wherein the dye is a metal complex dye and / or a polymethine dye. A photoelectrochemical cell comprising the photoelectric conversion element according to any one of claims 11 to 15. 17. The following general formula (4): (However, R ₀₀₈ is L ₀₁₄ -A ₀₈ (L ₀₁₄ is an alkylene group, -O
- or a divalent linking group them by combining one or more thereof, A ₀₈ represents a hydrogen atom or a substituent. ) Represents, which may be the same or different, n04 represents an integer of 0 to 3, R ₀₀₉ is a hydrogen atom or L ₀₁₅ -A ₀₉ (L ₀₁₅ represents an alkylene group,
—O— or a divalent linking group obtained by combining one or more of them, and A ₀₉ represents a hydrogen atom or a substituent. R ₀₁₀ represents L ₀₁₆ -A ₁₀ (L ₀₁₆ represents an alkylene group, —O—, or a divalent linking group formed by combining at least one of them, and A ₁₀ represents a hydrogen atom or a substituent. ) represents, X ^- represents an anion, at least one of a ₀₈ to a ₁₀ is, it is a substituent having a pKa of 3-15 conjugate acid of a compound obtained by adding hydrogen. ). An imidazolium compound represented by the formula: 18. The following general formula (5): (However, R ₀₁₁ is L ₀₁₇ -A ₁₁ (L ₀₁₇ is an alkylene group, -O
-Or a divalent linking group obtained by combining one or more of these, and A ₁₁ represents a hydrogen atom or a substituent. ) Represent, may be the same as or different from each other, n05 represents an integer of 0 to 5, R ₀₁₂ is L ₀₁₈ -A ₁₂ (L ₀₁₈ represents an alkylene group, -O-, or a combination thereof one or more respective consisting represents a divalent linking group, a ₁₂ represents a represents) a hydrogen atom or a substituent, X ^-. represents an anion, at least one of a ₁₁ and a ₁₂ are, it compounds obtained by adding hydrogen Is a substituent having a pKa of 3 to 15. A pyridinium compound represented by the formula: