JP2008277268A - Photoelectric conversion element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric conversion element capable of improving conversion efficiency. <P>SOLUTION: The photoelectric conversion element of dye-sensitized type is provided with an action electrode 10 and a counter electrode 20 as well as an electrolyte containing body 30, and a dye 14 is carried on a metal oxide semiconductor layer 12 of the action electrode 10. This dye 14 contains a cyanine dye having a benzil group and an indolenine skeleton. Thereby, crystallization of the dye on the surface of the metal oxide semiconductor layer 12 is suppressed in the action electrode 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion element using a dye.

  2. Description of the Related Art Conventionally, as a photoelectric conversion element such as a solar cell that converts light energy such as sunlight into electric energy, a dye-sensitized photoelectric conversion element that supports and sensitizes a dye on an electrode having an oxide semiconductor is known. This dye-sensitized photoelectric conversion element can be expected to have a theoretically high efficiency, and is considered to be very advantageous in terms of cost compared to a photoelectric conversion element using a silicon semiconductor that is generally spread. For this reason, it has been attracting attention as a next-generation photoelectric conversion element, and is being developed for practical use.

With respect to the dye used for the dye-sensitized photoelectric conversion element, a technique using an organic dye such as a cyanine dye is known for the purpose of improving conversion efficiency (see, for example, Patent Document 1). Moreover, it is thought that it is effective for the improvement of conversion efficiency because a pigment | dye molecule | numerator has an electron withdrawing group.
JP 2000-294303 A

  However, in the photoelectric conversion element using the conventional pigment | dye, sufficient conversion efficiency is not obtained and the further improvement is desired.

  This invention is made | formed in view of this problem, The objective is to provide the photoelectric conversion element which can improve conversion efficiency.

  The first photoelectric conversion element of the present invention includes an electrode having a dye and a carrier that supports the dye, and the dye includes an anchor group and a compound represented by Chemical Formula 1. . The anchor group is an electron-withdrawing group that can be chemically bonded to the carrier.

（Ｒ１およびＲ２は置換基であり、それぞれは互いに同一でもよいし異なってもよく、互いに結合して環状構造を形成してもよい。Ｒ３およびＲ４は置換基であり、それぞれは互いに同一でもよいし異なってもよく、互いに結合して環状構造を形成してもよい。Ｒ５およびＲ６は置換基であり、それぞれは互いに同一でもよいし異なってもよい。環Ａおよび環Ｂはベンゼン環またはナフタレン環である。Ｒ７およびＲ８は置換基であり、２以上のＲ７またはＲ８を有する場合、それぞれは互いに同一でもよいし異なってもよく、２以上のＲ７またはＲ８を隣接して有する場合、それぞれは互いに結合して環状構造を形成してもよい。ただし、Ｒ１、Ｒ２、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７およびＲ８からなる群のうちの少なくとも１つは環状または分岐構造を有する置換基である。なお、アンカー基は、Ｒ１、Ｒ２、Ｒ３、Ｒ４、Ｒ５、Ｒ６、Ｒ７およびＲ８からなる群のうちの少なくとも１つに含まれてもよい。ｍは０以上の整数である。ｎは０以上の整数である。）

(R1 and R2 are substituents, which may be the same or different from each other, and may be bonded to each other to form a cyclic structure. R3 and R4 are substituents, and each may be the same as each other. R5 and R6 are substituents, and each may be the same or different, and ring A and ring B may be a benzene ring or naphthalene. R7 and R8 are substituents, and when having two or more R7 or R8, each may be the same or different from each other, and when having two or more R7 or R8 adjacent to each other, each is They may combine with each other to form a cyclic structure, provided that at least one of the group consisting of R1, R2, R3, R4, R5, R6, R7 and R8 is cyclic. Is a substituent having a branched structure, wherein the anchor group may be contained in at least one of the group consisting of R1, R2, R3, R4, R5, R6, R7 and R8, where m is 0. (An integer greater than or equal to 0.)

  In the 1st photoelectric conversion element of this invention, since a pigment | dye contains the compound shown in Chemical formula 1 while having an anchor group, crystallization of the pigment | dye in the support body surface is suppressed. Thereby, the pigment | dye carry | supported by the support body surface absorbs light efficiently. The dye that has absorbed the light injects electrons into the carrier, whereby photoelectric conversion is performed.

  In the first photoelectric conversion element of the present invention, the substituent having a cyclic or branched structure shown in Chemical Formula 1 is preferably either an alkyl group having a cyclic or branched structure or an alkyl group having an aromatic ring, A benzyl group, a benzyl group derivative or a tertiary butyl group is preferred. Furthermore, it is preferable that at least one of the group consisting of R1, R2, R3 and R4 shown in Chemical Formula 1 is a substituent having the cyclic or branched structure described above. Thereby, the crystallization of the dye on the surface of the carrier is further suppressed.

  In the first photoelectric conversion element of the present invention, the anchor group may be a carboxylic acid group. Moreover, it is preferable that at least one of R5 and R6 shown in Chemical Formula 1 is a group having an anchor group. As a result, the dye is supported on the surface of the support, and the crystallization of the dye on the surface is further suppressed.

  Furthermore, in the 1st photoelectric conversion element of this invention, it is preferable that n shown to Chemical formula 1 is 3 or less. Moreover, it is preferable that a support body contains at least 1 sort (s) of a titanium oxide and a zinc oxide. Thereby, the pigment | dye carry | supported by the support body surface absorbs light, and the pigment | dye which absorbed light becomes easy to inject an electron with a support body.

  The 2nd photoelectric conversion element of this invention is equipped with the electrode which has a pigment | dye and the support body which carry | supports this pigment | dye, Comprising: A pigment | dye contains the compound represented by Chemical formula 2 while having an anchor group. .

（Ｒ１１およびＲ１２は置換基であり、それぞれは互いに同一でもよいし異なってもよく、互いに結合して環状構造を形成してもよい。Ｒ１３およびＲ１４は置換基であり、それぞれは互いに同一でもよいし異なってもよく、互いに結合して環状構造を形成してもよい。Ｒ１５およびＲ１６は置換基であり、それぞれは互いに同一でもよいし異なってもよい。環Ｃおよび環Ｄはベンゼン環またはナフタレン環である。Ｒ１７およびＲ１８は置換基であり、２以上のＲ１７またはＲ１８を有する場合、それぞれは互いに同一でもよいし異なってもよく、２以上のＲ１７またはＲ１８を隣接して有する場合、それぞれは互いに結合して環状構造を形成してもよい。ただし、Ｒ１１、Ｒ１２、Ｒ１３、Ｒ１４、Ｒ１５、Ｒ１６、Ｒ１７およびＲ１８からなる群のうちの少なくとも１つは環状または分岐構造を有する置換基である。Ｒ１９は水素基または置換基であり、２以上のＲ１９を有する場合、それぞれは互いに同一でもよいし異なってもよく、２以上のＲ１９を隣接して有する場合、それぞれは互いに結合して環状構造を形成してもよい。Ｒ２０は水素基、またはハロゲン基を除く置換基であり、２以上のＲ２０を有する場合、それぞれは互いに同一でもよいし異なってもよく、２以上のＲ２０を隣接して有する場合、それぞれは互いに結合して環状構造を形成してもよい。ただし、Ｒ１９およびＲ２０のうちの少なくとも１つは置換基である。なお、アンカー基は、Ｒ１１、Ｒ１２、Ｒ１３、Ｒ１４、Ｒ１５、Ｒ１６、Ｒ１７、Ｒ１８、Ｒ１９およびＲ２０からなる群のうちの少なくとも１つに含まれてもよい。ｘは０以上の整数である。ｙは０以上の整数である。）

(R11 and R12 are substituents, which may be the same or different from each other, and may be bonded to each other to form a cyclic structure. R13 and R14 are substituents, and each may be the same as each other. R15 and R16 are substituents, and each may be the same or different, and ring C and ring D may be a benzene ring or naphthalene. R17 and R18 are substituents, and when having two or more R17 or R18, each may be the same or different from each other, and when having two or more R17 or R18 adjacent to each other, each is They may combine with each other to form a cyclic structure, provided that R11, R12, R13, R14, R15, R16, R17 and R18. At least one of these groups is a substituent having a cyclic or branched structure, and R19 is a hydrogen group or a substituent, and when it has two or more R19, each may be the same or different. When two or more R19 are adjacent to each other, they may be bonded to each other to form a cyclic structure, and R20 is a substituent other than a hydrogen group or a halogen group, and when having two or more R20, Each may be the same as or different from each other, and when two or more R20 are adjacent to each other, each may be bonded to each other to form a cyclic structure, provided that at least one of R19 and R20 is The anchor group is a small group in the group consisting of R11, R12, R13, R14, R15, R16, R17, R18, R19 and R20. Good .x be included in Kutomo one is an integer of at least 0 .y is an integer of 0 or more.)

  In the 2nd photoelectric conversion element of this invention, since a pigment | dye contains the compound shown in Chemical formula 2 while having an anchor group, crystallization of the pigment | dye in the support body surface is suppressed. Thereby, the pigment | dye carry | supported by the support body surface absorbs light efficiently. The dye that has absorbed the light injects electrons into the carrier, whereby photoelectric conversion is performed.

  In the second photoelectric conversion device of the present invention, the substituent having a cyclic or branched structure shown in Chemical Formula 2 may be either an alkyl group having a cyclic or branched structure or an alkyl group having an aromatic ring, It may be a benzyl group or a tertiary butyl group. In addition, at least one of the group consisting of R11, R12, R13, and R14 shown in Chemical Formula 2 may be a substituent having the cyclic or branched structure described above.

  In the second photoelectric conversion element of the present invention, the anchor group may be a carboxylic acid group. Further, at least one of R15 and R16 shown in Chemical Formula 2 may be a group having an anchor group. Furthermore, y shown in Chemical Formula 2 may be 3 or less.

  Furthermore, in the 2nd photoelectric conversion element of this invention, it is preferable that a support body contains at least 1 sort (s) of a titanium oxide and a zinc oxide. Thereby, the pigment | dye carry | supported by the support body surface absorbs light, and the pigment | dye which absorbed light becomes easy to inject an electron with a support body.

  The third photoelectric conversion element of the present invention includes an electrode having a dye and a carrier that supports the dye, and the dye includes an anchor group and a compound represented by Chemical Formula 3. .

（Ｒ２１およびＲ２２は置換基であり、それぞれは互いに同一でもよいし異なってもよく、互いに結合して環状構造を形成してもよい。Ｒ２３およびＲ２４は置換基であり、それぞれは互いに同一でもよいし異なってもよく、互いに結合して環状構造を形成してもよい。Ｒ２５およびＲ２６は置換基であり、それぞれは互いに同一でもよいし異なってもよい。環Ｅおよび環Ｆはベンゼン環またはナフタレン環である。Ｒ２７およびＲ２８は置換基であり、２以上のＲ２７またはＲ２８を有する場合、それぞれは互いに同一でもよいし異なってもよく、２以上のＲ２７またはＲ２８を隣接して有する場合、それぞれは互いに結合して環状構造を形成してもよい。ただし、Ｒ２１、Ｒ２２、Ｒ２３、Ｒ２４、Ｒ２５、Ｒ２６、Ｒ２７およびＲ２８からなる群のうちの少なくとも１つは環状構造を有する置換基である。Ｒ２９は水素基または置換基であり、それぞれは互いに同一でもよいし異なってもよく、隣接したＲ２９が互いに結合して環状構造を形成してもよい。Ｒ３０は水素基またはハロゲン基であり、２以上のＲ３０を有する場合、それぞれは互いに同一でもよいし異なってもよい。ただし、Ｒ３０のうちの少なくとも１つはハロゲン基である。なお、アンカー基は、Ｒ２１、Ｒ２２、Ｒ２３、Ｒ２４、Ｒ２５、Ｒ２６、Ｒ２７、Ｒ２８およびＲ２９からなる群のうちの少なくとも１つに含まれてもよい。ｐは０以上の整数である。ｑは１以上の整数である。）

(R21 and R22 are substituents, which may be the same or different from each other, and may be bonded to each other to form a cyclic structure. R23 and R24 are substituents, and each may be the same as each other. And may be bonded to each other to form a cyclic structure, wherein R25 and R26 are substituents, and each may be the same as or different from each other, and ring E and ring F may be a benzene ring or naphthalene. R27 and R28 are substituents, and when having two or more R27 or R28, each may be the same or different from each other, and when having two or more R27 or R28 adjacent to each other, each is They may combine with each other to form a cyclic structure, provided that R21, R22, R23, R24, R25, R26, R27 and R28. At least one of the groups is a substituent having a cyclic structure, and R 29 is a hydrogen group or a substituent, and each may be the same or different, and adjacent R 29 are bonded to each other to form a cyclic group. R30 is a hydrogen group or a halogen group, and when it has two or more R30s, each may be the same as or different from each other, provided that at least one of R30 is a halogen group. The anchor group may be included in at least one of the group consisting of R21, R22, R23, R24, R25, R26, R27, R28, and R29, and p is an integer of 0 or more. Q is an integer of 1 or more.)

  In the 3rd photoelectric conversion element of this invention, since a pigment | dye contains the compound shown in Chemical formula 3 while having an anchor group, crystallization of the pigment | dye in the support body surface is suppressed. Thereby, the pigment | dye carry | supported by the support body surface absorbs light efficiently. The dye that has absorbed the light injects electrons into the carrier, whereby photoelectric conversion is performed.

  In the third photoelectric conversion device of the present invention, the substituent having the cyclic structure shown in Chemical Formula 3 may be either an alkyl group having a cyclic structure or an alkyl group having an aromatic ring, and is a benzyl group. May be. Further, at least one of the group consisting of R21, R22, R23 and R24 shown in Chemical Formula 3 may be a substituent having the above-described cyclic structure.

  In the third photoelectric conversion element of the present invention, the anchor group may be a carboxylic acid group. Further, at least one of R25 and R26 shown in Chemical Formula 3 may be a group having an anchor group. Furthermore, q shown in Chemical formula 3 may be 3 or less.

  Furthermore, in the 3rd photoelectric conversion element of this invention, it is preferable that a support body contains at least 1 sort (s) of a titanium oxide and a zinc oxide. Thereby, the pigment | dye carry | supported by the support body surface absorbs light, and the pigment | dye which absorbed light becomes easy to inject an electron with a support body.

  According to the first photoelectric conversion element of the present invention, since the dye includes an electrode having a dye and a carrier that supports the dye, and the dye includes an anchor group and the compound shown in Chemical Formula 1, the conversion efficiency Can be improved.

  In addition, a compound in which the substituent having a cyclic or branched structure shown in Chemical Formula 1 is either an alkyl group having a cyclic or branched structure or an alkyl group having an aromatic ring, or the substituent is a benzyl group or a benzyl group. If the dye contains a compound that is a derivative or a tertiary butyl group, or a compound in which at least one of the group consisting of R1, R2, R3, and R4 shown in Chemical Formula 1 is a substituent having a cyclic or branched structure Higher conversion efficiency can be obtained.

  Further, if the dye contains a compound in which at least one of R5 and R6 shown in Chemical formula 1 is a group having an anchor group, or a compound in which chemical formula n shown in Chemical formula 1 is 3 or less, the conversion efficiency is higher. Is obtained.

  Furthermore, if the support contains at least one of titanium oxide and zinc oxide, higher conversion efficiency can be obtained.

  According to the second photoelectric conversion element of the present invention, since the dye includes an electrode having a dye and a carrier that supports the dye, and the dye includes an anchor group and the compound shown in Chemical Formula 2, the conversion efficiency Can be improved.

  In addition, a compound in which the substituent having a cyclic or branched structure shown in Chemical Formula 2 is any of an alkyl group having a cyclic or branched structure and an alkyl group having an aromatic ring, or the substituent is a benzyl group or tertiary butyl. If the pigment contains a compound that is a group or a compound in which at least one of the group consisting of R11, R12, R13, and R14 shown in Chemical Formula 2 is a substituent having a cyclic or branched structure, high conversion efficiency is obtained. can get. Further, if the dye contains a compound having y of 3 or less shown in Chemical Formula 2, high conversion efficiency can be obtained.

  Furthermore, if the support contains at least one of titanium oxide and zinc oxide, higher conversion efficiency can be obtained.

  According to the third photoelectric conversion element of the present invention, since the dye includes an electrode having a dye and a carrier that supports the dye, and the dye includes an anchor group and the compound shown in Chemical Formula 3, the conversion efficiency Can be improved.

  Further, a compound in which the substituent having the cyclic structure shown in Chemical formula 3 is either an alkyl group having a cyclic structure or an alkyl group having an aromatic ring, a compound in which the substituent is a benzyl group, If the dye contains a compound in which at least one of the group consisting of R21, R22, R23 and R24 is a substituent having a cyclic structure, high conversion efficiency can be obtained. Further, if the compound represented by Chemical Formula 3 having q of 3 or less is contained in the pigment, high conversion efficiency can be obtained.

  Furthermore, if the support contains at least one of titanium oxide and zinc oxide, higher conversion efficiency can be obtained.

  Hereinafter, the best mode for carrying out the present invention (hereinafter simply referred to as an embodiment) will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 schematically shows a cross-sectional configuration of the photoelectric conversion element according to the first embodiment of the present invention, and FIG. 2 shows an extracted and enlarged main part of the photoelectric conversion element shown in FIG. It expresses. The photoelectric conversion element shown in FIGS. 1 and 2 is a main part of a so-called dye-sensitized solar cell. In this photoelectric conversion element, the working electrode 10 and the counter electrode 20 are arranged to face each other with the electrolyte-containing body 30 interposed therebetween, and at least one of the working electrode 10 and the counter electrode 20 is an electrode having optical transparency. It is.

  The working electrode 10 has, for example, a structure in which a metal oxide semiconductor layer 12 is provided on a conductive substrate 11 and a dye 14 is supported using the metal oxide semiconductor layer 12 as a carrier. The working electrode 10 functions as a negative electrode for the external circuit. For example, the conductive substrate 11 is obtained by providing a conductive layer 11B on the surface of an insulating substrate 11A.

  Examples of the material of the substrate 11A include insulating materials such as glass, plastic, and transparent polymer film. Examples of the transparent polymer film include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), syndioctane polyester (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), and polyarylate. (PAr), polysulfone (PSF), polyester sulfone (PES), polyetherimide (PEI), cyclic polyolefin, or brominated phenoxy.

As the conductive layer 11B, for example, conductive metal oxide thin film such as indium oxide, tin oxide, indium-tin composite oxide (ITO) or tin oxide doped with fluorine (FTO: F-SnO ₂ ), Examples thereof include metal thin films such as gold (Au), silver (Ag), and platinum (Pt), and those formed of a conductive polymer.

  In addition, the conductive substrate 11 may be configured to have a single-layer structure with, for example, a conductive material. In that case, examples of the material of the conductive substrate 11 include indium oxide, tin oxide, Examples thereof include conductive metal oxides such as indium-tin composite oxide or tin oxide doped with fluorine, metals such as gold, silver or platinum, and conductive polymers.

  The metal oxide semiconductor layer 12 is formed of, for example, a dense layer 12A and a porous layer 12B. A dense layer 12A is formed at the interface with the conductive substrate 11, and the dense layer 12A is preferably dense and has few voids, and more preferably in the form of a film. A porous layer 12B is formed on the surface in contact with the electrolyte-containing body 30, and the porous layer 12B preferably has a structure with many voids and a large surface area, and particularly has a structure in which porous fine particles are attached. More preferred. The metal oxide semiconductor layer 12 may be formed to have a film-like single layer structure, for example.

  Examples of the metal oxide semiconductor material include titanium oxide, zinc oxide, tin oxide, niobium oxide, indium oxide, zirconium oxide, tantalum oxide, vanadium oxide, yttrium oxide, aluminum oxide, and magnesium oxide. Among these, the metal oxide semiconductor material preferably contains at least one of titanium oxide and zinc oxide, and more preferably contains zinc oxide. This is because high conversion efficiency can be obtained. These metal oxide semiconductors may be used alone or in combination of two or more (mixed, mixed crystal, solid solution, etc.), for example, zinc oxide and tin oxide. Also, a combination of titanium oxide and niobium oxide can be used.

  The dye 14 supported on the metal oxide semiconductor layer 12 includes an anchor group and a compound represented by Chemical Formula 1 (hereinafter, simply referred to as a chemical compound represented by Chemical Formula 1). Since this compound is included, a compound having a substituent having a cyclic or branched structure having a large steric size is included. For this reason, crystallization on the surface of the carrier is suppressed, and excellent conversion efficiency is obtained.

The anchor group is an electron-withdrawing substituent that can be chemically bonded to the metal oxide semiconductor layer 12 and includes R1, R2, R3, R4, R5, R6, R7, and R8 shown in Chemical Formula 1. It may be included in at least one of the groups. Examples of the anchor group include a carboxylic acid group (—COOH), a phosphoric acid group (—PO ₃ H ₂ , —PO ₄ H ₂ ), a sulfonic acid group (—SO ₃ H), and a boric acid group (—B ( OH) ₂ ) or derivatives thereof. Among these, a carboxylic acid group is preferable. This is because higher conversion efficiency can be obtained. The anchor group is preferably introduced as at least one of R5 and R6 shown in Chemical Formula 1 via an alkylene group, for example. This is because a higher effect can be obtained.

Examples of the substituent having a cyclic or branched structure shown in Chemical Formula 1 include the following substituents. That is, examples of the substituent having a cyclic structure include a group having an aromatic ring or a group having a cycloalkane structure. Examples of the group having an aromatic ring, for example, -C ₆ H ₅ (phenyl group) or, -CH ₂ -C ₆ H ₅ (benzyl group) _{or, -CH 2 -CH 2 -C 6 H} 5 ( phenethyl group ), —CH ₂ —C ₆ H ₄ —CH ₃ which is a group in which a methyl group is introduced into the benzene ring of a benzyl group, —CH ₂ —C ₁₀ H ₇ which is a group having a naphthalene ring, or a group having a biphenyl skeleton And a derivative of a benzyl group such as —CH ₂ —C ₆ H ₄ —C ₆ H ₅ . Examples of the group having a cycloalkane structure include —C ₄ H ₇ (cyclobutanyl group), a group having a cyclobutanyl structure, —C ₆ H ₁₁ (cyclohexyl group), or a group having a cyclohexyl structure. Examples of the substituent having a branched structure include —CH (CH ₃ ) ₂ , —CH ₂ —CH (CH ₃ ) ₂ , —CH ₂ —CH ₂ —CH (CH ₃ ) ₂ , —CH ₂ —. _{CH (CH 3) (C 2} H 5), - C (CH 3) 3, -CH 2 -C (CH 3) 3, -C (CH 3) 2 -CH 2 -C (CH 3) 3 or such as _{-CH 2 -CH = C (CH 3} ) 2 and the like. As the substituent having a cyclic or branched structure, either an alkyl group having a cyclic or branched structure or an alkyl group having an aromatic ring is preferable, and a benzyl group, a derivative of benzyl group or a tertiary butyl group is more preferable. This is because higher conversion efficiency can be obtained. The substituent having a cyclic or branched structure is preferably introduced as at least one of the group consisting of R1, R2, R3 and R4 shown in Chemical formula 1. This is because higher conversion efficiency can be obtained. Needless to say, the substituent is not limited to the above-described substituent as long as the substituent has a cyclic or branched structure.

  N shown in Chemical formula 1 is preferably 3 or less. This is because it is difficult to obtain sufficient conversion efficiency when n is 4 or more. Among these, n is preferably 0 or more and 2 or less. As a result, higher conversion efficiency can be obtained, and a wide wavelength range from purple to red can be used as the sensitization wavelength (color variation).

  Examples of the compound represented by Chemical Formula 1 include a series of compounds represented by Chemical Formulas 4 to 11. These may be used independently and may be used in mixture of multiple types. Of these, the compounds shown in Chemical Formulas 4 to 8 are preferable. This is because high characteristics can be obtained.

  Needless to say, any compound having an anchor group and the structure shown in Chemical Formula 1 is not limited to the compounds shown in Chemical Formulas 4 to 11.

  The dye 14 may contain other dyes in addition to the compound shown in Chemical formula 1. The other dye is preferably a dye having an electron-withdrawing substituent that can be chemically bonded to the metal oxide semiconductor layer 12. Examples of other dyes include eosin Y, dibromofluorescein, fluorescein, rhodamine B, pyrogallol, dichlorofluorescein, erythrosine B (erythrocin is a registered trademark), fluorescin, mercurochrome, cyanine dye, merocyanine disazo dye, trisazo dye, Anthraquinone dyes, polycyclic quinone dyes, indigo dyes, diphenylmethane dyes, trimethylmethane dyes, quinoline dyes, benzophenone dyes, naphthoquinone dyes, perylene dyes, fluorenone dyes, squarylium dyes, azurenium dyes And organic dyes such as perinone dyes, quinacridone dyes, metal-free phthalocyanine dyes and metal-free porphyrin dyes.

  Examples of other dyes include organometallic complex compounds. For example, an ionic coordinate bond formed by a nitrogen anion and a metal cation in an aromatic heterocyclic ring, and a nitrogen atom or Organometallic complex compounds having both nonionic coordination bonds formed between chalcogen atoms and metal cations, ionic coordination bonds formed by oxygen anions or sulfur anions and metal cations, and nitrogen And organometallic complex compounds having both nonionic coordination bonds formed between an atom or chalcogen atom and a metal cation. Specifically, metal phthalocyanine dyes such as copper phthalocyanine and titanyl phthalocyanine, metal naphthalocyanine dyes, metal porphyrin dyes, bipyridyl ruthenium complexes, terpyridyl ruthenium complexes, phenanthroline ruthenium complexes, bicinchonirate ruthenium complexes, and azo ruthenium complexes Alternatively, a ruthenium complex such as a quinolinol ruthenium complex can be used.

  The counter electrode 20 is obtained, for example, by providing a conductive layer 22 on a conductive substrate 21. The counter electrode 20 functions as a positive electrode for an external circuit. Examples of the material of the conductive substrate 21 include the same material as that of the conductive substrate 11 of the working electrode 10. Examples of the conductive material used for the conductive layer 22 include metals such as platinum, gold, silver, copper (Cu), rhodium (Rh), ruthenium (Ru), aluminum (Al), magnesium (Mg), and indium (In). , Carbon (C), or a conductive polymer. These conductive materials may be used alone or in combination of two or more. Further, for example, an acrylic resin, a polyester resin, a phenol resin, an epoxy resin, cellulose, a melamine resin, a fluoroelastomer, or a polyimide resin may be used as a binder as necessary. The counter electrode 20 may have a single layer structure of the conductive layer 22, for example.

Examples of the electrolyte-containing body 30 include those containing a redox electrolyte. Examples of the redox electrolyte include I ⁻ / I ₃ ⁻ system, Br ⁻ / Br ₃ ⁻ system, and quinone / hydroquinone system. Such redox electrolytes are selected from, for example, cesium halides, quaternary alkylammonium halides, imidazolium halides, thiazolium halides, oxazolium halides, quinolinium halides, pyridinium halides. A combination of one or more of the above and a single halogen can be used. Specifically, cesium iodide and quaternary alkyl ammonium iodides such as tetraethylammonium iodide, tetrapropylammonium iodide, tetrabutylammonium iodide, tetrapentylammonium iodide, tetrahexylammonium iodide, tetraheptyl Ammonium iodide or trimethylphenylammonium iodide, imidazolium iodide as 3-methylimidazolium iodide or 1-propyl-2,3-dimethylimidazolium iodide, or thiazolium iodide as 3-ethyl 2-methyl-2-thiazolium iodide, 3-ethyl-5- (2-hydroxyethyl) -4-methylthiazolium iodide, 3-ethyl-2-methylbenzothiazolium iodide, Select from 3-ethyl-2-methyl-benzoxazolium iodide as oxazolium iodide, 1-ethyl-2-methylquinolinium iodide, and pyridinium iodide as quinolinium iodides A combination of one or more of the above and iodine, or a combination of quaternary alkyl ammonium bromide and bromine can be used. The electrolyte-containing body 30 may be a liquid electrolyte or a solid polymer electrolyte in which the electrolyte-containing body 30 is contained in a polymer material. As the solvent for the liquid electrolyte, an electrochemically inert solvent is used, and examples thereof include acetonitrile, propylene carbonate, and ethylene carbonate.

  The electrolyte-containing body 30 may be provided with a solid charge transfer layer such as a solid electrolyte instead of the redox electrolyte. The solid charge transfer layer includes, for example, a material in which carrier transfer in a solid is involved in electrical conduction. As this material, an electron transport material, a hole transport material, or the like is preferable.

  As the hole transport material, aromatic amines, triphenylene derivatives, and the like are preferable. For example, oligothiophene compounds, polypyrrole, polyacetylene or derivatives thereof, poly (p-phenylene) or derivatives thereof, and poly (p-phenylene vinylene). Alternatively, organic conductive polymers such as derivatives thereof, polythienylene vinylene or derivatives thereof, polythiophene or derivatives thereof, polyaniline or derivatives thereof, polytoluidine or derivatives thereof, and the like can be given.

  Further, as the hole transport material, for example, a p-type inorganic compound semiconductor may be used. The p-type inorganic compound semiconductor preferably has a band gap of 2 eV or more, and more preferably 2.5 eV or more. Further, the ionization potential of the p-type inorganic compound semiconductor needs to be smaller than the ionization potential of the working electrode 10 from the condition that the holes of the dye can be reduced. Although the preferable range of the ionization potential of the p-type inorganic compound semiconductor varies depending on the dye used, it is generally preferably in the range of 4.5 eV to 5.5 eV, and more preferably in the range of 4.7 eV to 5.3 eV. More preferably, it is within.

Examples of the p-type inorganic compound semiconductor include a compound semiconductor containing monovalent copper. Examples of the compound semiconductor containing monovalent copper, there _{CuI, CuSCN, CuInSe 2, Cu} (In, Ga) Se 2, CuGaSe 2, Cu 2 O, CuS, etc. _{CuGaS 2, CuInS 2, CuAlSe 2} . Examples of other p-type inorganic compound semiconductors include GaP, NiO, CoO, FeO, Bi ₂ O ₃ , MoO _{2, and} Cr ₂ O ₃ .

  As a method of forming such a solid charge transfer layer, for example, there is a method of forming a solid charge transfer layer directly on the working electrode 10, and then the counter electrode 20 may be formed and applied.

  A hole transport material containing an organic conductive polymer may be introduced into the electrode by a technique such as vacuum deposition, casting, coating, spin coating, dipping, electrolytic polymerization, or photoelectrolytic polymerization. Can do. Also in the case of an inorganic solid compound, it can be introduced into the electrode by a technique such as a casting method, a coating method, a spin coating method, a dipping method, or an electrolytic plating method.

  A part of the solid charge transfer layer (particularly, having a hole transport material) formed in this way partially penetrates into the gap of the porous structure of the metal oxide semiconductor layer 12 and is in direct contact with it. It is preferable to become.

  This photoelectric conversion element can be manufactured as follows, for example.

  First, for example, the working electrode 10 is produced by forming the metal oxide semiconductor layer 12 on the surface of the conductive substrate 11 on which the conductive layer 11B is formed and supporting the dye 14 on the metal oxide semiconductor layer 12. . When the metal oxide semiconductor layer 12 is formed, a metal oxide semiconductor powder is dispersed in a metal oxide semiconductor sol solution to form a metal oxide slurry, and the metal oxide slurry is formed into the conductive substrate 11. It is fired after being applied and dried. Further, the metal oxide semiconductor layer 12 may be formed by, for example, electrolytic deposition. The conductive substrate 11 on which the metal oxide semiconductor layer 12 is formed is immersed in a dye solution in which the dye 14 is dissolved in an organic solvent, and the dye 14 is supported.

  Next, for example, the counter electrode 20 is produced by forming the conductive layer 22 on one surface of the conductive substrate 21. The conductive layer 22 is formed, for example, by sputtering a conductive material.

  Subsequently, the surface of the working electrode 10 carrying the dye 14 and the surface of the counter electrode 20 on which the conductive layer 22 is formed are arranged so as to face each other while maintaining a predetermined distance. An electrolyte containing body 30 is injected between the working electrode 10 and the counter electrode 20 to seal the whole. Thus, the photoelectric conversion element shown in FIGS. 1 and 2 is completed.

  In this photoelectric conversion element, when light (sunlight or visible light equivalent to sunlight) is applied to the dye 14 carried on the working electrode 10, the dye 14 that absorbs and excites light to convert electrons into a metal oxide semiconductor. Inject into layer 12. As a result, a potential difference is generated between the counter electrode 20 and a current flows between the two electrodes for photoelectric conversion.

  According to the photoelectric conversion element in the first embodiment, the working electrode 10 including the dye 14 and the metal oxide semiconductor layer 12 that supports the dye 14 is provided. Since the compound shown is included, crystallization of the dye 14 on the surface of the metal oxide semiconductor layer 12 is suppressed. Thereby, compared with the case where the pigment | dye 14 contains the compound represented by Chemical formula 12, conversion efficiency can be improved.

  In addition, a compound in which the substituent having a cyclic or branched structure shown in Chemical Formula 1 is either an alkyl group having a cyclic or branched structure or an alkyl group having an aromatic ring, or the substituent is a benzyl group or a benzyl group. The dye 14 may contain a compound that is a derivative or a tertiary butyl group, or a compound in which at least one of the group consisting of R1, R2, R3, and R4 shown in Chemical Formula 1 is a substituent having a cyclic or branched structure. Thus, higher conversion efficiency can be obtained.

  Further, if the dye 14 contains a compound in which at least one of R5 and R6 shown in Chemical formula 1 is a group having an anchor group, or a compound in which chemical formula n shown in Chemical formula 1 is 3 or less, higher conversion is achieved. Efficiency is obtained.

  Furthermore, if at least one of titanium oxide and zinc oxide is included as a material for the metal oxide semiconductor, higher conversion efficiency can be obtained.

[Second Embodiment]
Next, a second embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the second embodiment, the dye 14 has an anchor group and the compound shown in Chemical Formula 2 (hereinafter simply referred to as the chemical formula 2), and the compound having the anchor group and shown in Chemical Formula 3 (hereinafter referred to as Chemical Formula 2). The compound has the same configuration as that of the first embodiment except that it contains at least one of the compounds shown in Chemical Formula 3), and is produced by the same procedure.

  Since the dye 14 contains the compound shown in Chemical Formula 2 or the compound shown in Chemical Formula 3, it contains a compound having a substituent having a cyclic or branched structure having a large steric size. For this reason, crystallization on the surface of the carrier is suppressed, and excellent conversion efficiency is obtained.

  The anchor group possessed by the compound represented by Chemical Formula 2 is the same as that possessed by the compound represented by Chemical Formula 1. This anchor group may be included in at least one of the group consisting of R11, R12, R13, R14, R15, R16, R17, R18, R19 and R20 shown in Chemical Formula 2. As this anchor group, a carboxylic acid group is preferred. This is because higher conversion efficiency can be obtained. In addition, the anchor group may be introduced as at least one of R15 and R16 shown in Chemical Formula 2 through an alkylene group, for example, and R19 or It may be introduced as R20.

  Examples of the substituent having a cyclic or branched structure shown in Chemical Formula 2 include those similar to the substituent having a cyclic or branched structure shown in Chemical Formula 1. As the substituent having a cyclic or branched structure, either an alkyl group having a cyclic or branched structure or an alkyl group having an aromatic ring is preferable, and a benzyl group, a derivative of benzyl group or a tertiary butyl group is more preferable. This is because higher conversion efficiency can be obtained. The substituent having a cyclic or branched structure is preferably introduced as at least one of the group consisting of R11, R12, R13 and R14 shown in Chemical Formula 2. This is because higher conversion efficiency can be obtained.

  R19 shown in Chemical Formula 2 is a hydrogen group (—H) or a substituent, and R20 is a hydrogen group or a substituent other than a halogen group, but at least one of R19 and R20 is a substituent. That is, the compound shown in Chemical Formula 2 is a derivative of the compound shown in Chemical Formula 1. Specifically, the chemical structure 1 has a structure in which part or all of the hydrogen in the methine chain connecting two indolenine skeletons is substituted. The kind of the substituent bonded to R19 is arbitrary, but it is preferably a cyclic structure in which two adjacent R19s are bonded to each other and include a methine chain as a part of the ring. Examples of the cyclic structure including the methine chain as a part of the ring include (1) cyclopentene structure represented by Chemical formula 13 or (2) cyclohexene structure. Of course, even when R19 has a cyclic structure including a methine chain as a part of the ring, a substituent may be further bonded to the cyclic structure. R19 may be a halogen group, and examples of the halogen group include a fluorine group, a chlorine group, a bromine group, and an iodine group. The kind of the substituent bonded to R20 is arbitrary, but similarly to R19, two adjacent R20s may be bonded to each other and may have a cyclic structure including a methine chain as a part of the ring. Even when it has a cyclic structure including a methine chain as a part of the ring, a substituent may be further bonded to the cyclic structure.

  Y shown in Chemical formula 2 is preferably 3 or less. This is because it is difficult to obtain sufficient conversion efficiency when y is 4 or more. Among these, y is preferably 0 or more and 2 or less. This is because higher conversion efficiency can be obtained, and a wide wavelength range from violet to red can be handled as a sensitization wavelength (color variation).

  Examples of the compound shown in Chemical Formula 2 include a series of compounds represented by Chemical Formula 14 and the like. These may be used independently and may be used in mixture of multiple types. Among these, the compound shown in Chemical formula 14 (1) is preferable. This is because high characteristics can be obtained.

  Needless to say, the compound is not limited to the compound shown in Chemical Formula 14 as long as it has an anchor group and the structure shown in Chemical Formula 2.

  The anchor group possessed by the compound represented by Chemical Formula 3 is the same as that possessed by the compound represented by Chemical Formula 1. This anchor group may be included in at least one of the group consisting of R21, R22, R23, R24, R25, R26, R27, R28 and R29 shown in Chemical Formula 3. As this anchor group, a carboxylic acid group is preferred. This is because higher conversion efficiency can be obtained. Further, the anchor group may be introduced as at least one of R25 and R26 shown in Chemical Formula 3 via an alkylene group or the like, for example.

  The compound shown in Chemical formula 3 has a substituent having a cyclic structure because it has a substituent having a cyclic structure having a large steric size, so that crystallization on the surface of the support is suppressed and excellent conversion is achieved. This is because efficiency is obtained, and a higher effect is obtained than when a substituent having a branched structure is used instead of the substituent having the cyclic structure. Examples of the substituent having a cyclic structure shown in Chemical Formula 3 include those similar to the substituent having a cyclic structure shown in Chemical Formula 1. As the substituent having a cyclic structure, either an alkyl group having a cyclic structure or an alkyl group having an aromatic ring is preferable, and a benzyl group or a derivative of a benzyl group is more preferable. This is because higher conversion efficiency can be obtained. The substituent having a cyclic structure is preferably introduced as at least one of the group consisting of R21, R22, R23 and R24 shown in Chemical formula 3. This is because higher conversion efficiency can be obtained.

  R29 shown in Chemical Formula 3 is a hydrogen group or a substituent, and R30 is a hydrogen group or a halogen group. At least one of R30 is, for example, a fluorine group, a chlorine group, a bromine group, or an iodine group. It is a halogen group. That is, the compound shown in Chemical formula 3 is a derivative of the compound shown in Chemical formula 1 like the compound shown in Chemical formula 2. The type of substituent bonded to R29 is arbitrary, but it is preferably a cyclic structure including a halogen group or a methine chain in which two adjacent R29s are bonded to each other as a part of the ring. Examples of the cyclic structure containing the methine chain as a part of the ring include the structure shown in Chemical Formula 13 above. Of course, even if R29 has a cyclic structure containing a methine chain as a part of the ring, a substituent may be further bonded to the cyclic structure.

  Q shown in Chemical formula 3 is preferably 1, 2 or 3. This is because it is difficult to obtain sufficient conversion efficiency when q is 4 or more. Among them, q is preferably 1 or 2. This is because higher conversion efficiency can be obtained, and a wide wavelength range from violet to red can be handled as a sensitization wavelength (color variation).

  Examples of the compound shown in Chemical Formula 3 include a compound represented by Chemical Formula 15 and the like.

  Needless to say, the compound is not limited to the compound shown in Chemical Formula 15 as long as it has an anchor group and the structure shown in Chemical Formula 3.

  In addition to the compound shown in Chemical Formula 2 and the compound shown in Chemical Formula 3, the dye 14 may contain the compound shown in Chemical Formula 1 or may contain other dyes. Good. The other dyes here are the same as the other dyes in the first embodiment.

  In this photoelectric conversion element, when light (sunlight or visible light equivalent to sunlight) is applied to the dye 14 carried on the working electrode 10, the dye 14 that absorbs and excites light to convert electrons into a metal oxide semiconductor. Inject into layer 12. As a result, a potential difference is generated between the counter electrode 20 and a current flows between the two electrodes for photoelectric conversion.

  According to the photoelectric conversion element in the second embodiment, the working electrode 10 having the dye 14 and the metal oxide semiconductor layer 12 that supports the dye 14 is provided, and the dye 14 has an anchor group and is converted to chemical formula 2. Since at least one of the compounds shown and the compound having an anchor group and shown in Chemical Formula 3 is included, crystallization of the dye 14 on the surface of the metal oxide semiconductor layer 12 is suppressed. Thereby, conversion efficiency can be improved compared with the case where the pigment | dye 14 contains the compound shown to Chemical formula 12, and the case where the compound shown to Chemical formula 16 is included.

  In addition, a compound in which the substituent having a cyclic or branched structure shown in Chemical Formula 2 is any of an alkyl group having a cyclic or branched structure and an alkyl group having an aromatic ring, or the substituent is a benzyl group or tertiary butyl. If the dye 14 contains a compound that is a group or a compound in which at least one of the group consisting of R11, R12, R13, and R14 shown in Chemical Formula 2 is a substituent having a cyclic or branched structure, high conversion efficiency Is obtained.

  Further, if the dye 14 contains a compound in which at least one of R15 and R16 shown in Chemical Formula 2 is a group having an anchor group, or a compound in which y is 3 or less shown in Chemical Formula 2, the conversion efficiency is high. Is obtained.

  Further, a compound in which the substituent having the cyclic structure shown in Chemical formula 3 is either an alkyl group having a cyclic structure or an alkyl group having an aromatic ring, a compound in which the substituent is a benzyl group, If the dye 14 contains a compound in which at least one of the group consisting of R21, R22, R23 and R24 is a substituent having a cyclic structure, high conversion efficiency can be obtained.

  In addition, if the dye 14 contains a compound in which at least one of R25 and R26 shown in Chemical Formula 3 is a group having an anchor group, or a compound in which q is 3 or less shown in Chemical Formula 2, the conversion efficiency is high. Is obtained.

  Furthermore, if at least one of titanium oxide and zinc oxide is included as a material for the metal oxide semiconductor, higher conversion efficiency can be obtained.

  Specific examples of the present invention will be described in detail.

(Example 1-1)
As specific examples of the photoelectric conversion element described in the above embodiment, a dye-sensitized solar cell using titanium oxide as a material for a metal oxide semiconductor and a dye-sensitized solar cell using zinc oxide are as follows. Produced by the procedure.

First, the working electrode 10 of the dye-sensitized solar cell using titanium oxide was produced. Titanium isopropoxide 125 cm ^3, was added with stirring to 0.1 mol / dm ³ aqueous solution of nitric acid 750 cm ^3, and 8 hours vigorously stirred at 80 ° C.. The obtained liquid was treated in an autoclave at 230 ° C. for 16 hours in a pressure vessel made of Teflon (registered trademark). After that, the sol solution containing the precipitate was resuspended by stirring. Next, the precipitate that was not resuspended was removed by suction filtration, and the sol solution was concentrated with an evaporator until the titanium oxide concentration became 11% by mass. One drop of Triton X-100 (Triton is a registered trademark) was added in order to improve paintability on the substrate. Next, titanium oxide powder P-25 was added to this titanium oxide sol solution so that the total content of titanium oxide would be 33% by mass, and dispersed by performing centrifugal agitation utilizing rotation and revolution for 1 hour. The liquid was adjusted to obtain a metal oxide slurry.

Next, a conductive substrate 11 made of a conductive glass substrate (F-SnO ₂ ) having a length of 2.0 cm, a width of 1.5 cm, and a thickness of 1.1 mm is surrounded by a square of 0.5 cm in length and 0.5 cm in width. A masking tape having a thickness of 70 μm was applied in this manner, and 3 cm ^{3 of} metal oxide slurry was applied to this portion so as to have a uniform thickness and dried, and then the masking tape was peeled off. Next, this substrate was baked at 500 ° C. in an electric furnace to form a metal oxide semiconductor layer 12 having a thickness of about 10 μm. The conductive substrate 11 on which the titanium oxide semiconductor layer is formed as the metal oxide semiconductor layer 12 is immersed in an anhydrous ethanol solution (3 × 10 ⁻⁴ mol / dm ³ ) of the compound shown in Chemical Formula 4 (1), Dye 14 was supported.

Next, a conductive layer having a thickness of 100 nm made of platinum by sputtering on one surface of a conductive substrate 21 made of 2.0 cm long × 1.5 cm wide × 1.1 mm thick conductive glass substrate (F—SnO ₂ ). The counter electrode 20 was produced by forming 22. Two holes (φ1 mm) for injecting the electrolyte containing body 30 were previously formed in the conductive substrate 21. Electrolyte inclusion 30, relative to acetonitrile, dimethyl hexyl imidazolium iodide (0.6 mol / dm ^3), lithium iodide (0.1 mol / dm ^3), iodine (0.05 mol / dm ^3), water ( The concentration was adjusted to 1 mol / dm ³ ).

  Next, the surface of the working electrode 10 carrying the dye 14 and the surface of the counter electrode 20 on which the conductive layer 22 was formed were bonded together with a spacer having a thickness of 50 μm in order to maintain a predetermined distance. At this time, the spacer was disposed so as to surround the metal oxide semiconductor layer 12. Next, an electrolyte-containing body 30 prepared from a hole opened in the counter electrode 20 was injected to obtain a dye-sensitized solar cell.

In addition, a dye-sensitized solar cell was produced by the same procedure as described above except that zinc oxide was used as the metal oxide semiconductor material as the working electrode 10. At that time, the working electrode 10 was produced by the following procedure. First, a metal oxide layer made of zinc oxide is deposited on a conductive substrate 11 made of a conductive glass substrate (F-SnO ₂ ) having a length of 2.0 cm, a width of 1.5 cm, and a thickness of 1.1 mm by electrolytic deposition. 12 was formed. For electrolytic deposition, 40 ml of electrolytic bath solution adjusted to have concentrations of eosin Y (30 μmol / dm ³ ), zinc chloride (5 mmol / dm ³ ) and potassium chloride (0.09 mol / dm ³ ) with respect to water. And a counter electrode made of a zinc plate and a reference electrode made of a silver / silver chloride electrode. First, after bubbling this electrolytic bath with oxygen for 15 minutes, the temperature was set to 70 ° C., and a film was formed on the surface of the conductive substrate 11 while bubbling constant potential electrolysis at a potential of −1.0 V for 60 minutes. The substrate was immersed in an aqueous potassium hydroxide solution (pH 11) without drying, and then washed with water to desorb eosin Y. Subsequently, the metal oxide semiconductor layer 12 was formed by drying at 150 ° C. for 30 minutes. Next, the working electrode 10 was produced by immersing in the absolute ethanol solution (5 mmol / dm ³ ) of the compound shown in Chemical Formula 4 (1) and supporting the dye 14.

(Examples 1-2 to 1-17)
In place of the compound shown in Chemical formula 4 (1) as a dye, Chemical formula 4 (2) (Example 1-2), Chemical formula 4 (3) (Example 1-3), Chemical formula 4 (4) (Example) 1-4), Chemical formula 5 (1) (Example 1-5), Chemical formula 5 (2) (Example 1-6), Chemical formula 5 (3) (Example 1-7), Chemical formula 5 (4) ( Example 1-8), Chemical formula 6 (1) (Example 1-9), Chemical formula 6 (2) (Example 1-10), Chemical formula 6 (3) (Example 1-11), Chemical formula 7 (1) (Example 1-12), Chemical formula 7 (2) (Example 1-13), Chemical formula 7 (3) (Example 1-14), Chemical formula 8 (1) (Example 1-15), Chemical formula 8 (2) A procedure similar to that in Example 1-1 was performed, except that the compound shown in (Example 1-16) or Chemical Formula 8 (3) (Example 1-17) was used.

(Comparative Examples 1-1 and 1-2)
Instead of the compound shown in Chemical formula 4 (1), the compound shown in Chemical formula 12 (1) (Comparative example 1-1) or Chemical formula 12 (2) (Comparative example 1-2) was used as the dye. Except for this, the same procedure as in Example 1-1 was performed.

  When the conversion efficiencies of the dye-sensitized solar cells of Examples 1-1 to 1-17 and Comparative Examples 1-1 and 1-2 were examined, the results shown in Table 1 were obtained.

The conversion efficiency was obtained by the following calculation method using an AM1.5 (1000 W / m ² ) solar simulator as the light source. First, the voltage of the dye-sensitized solar cell was swept with a source meter, and the response current was measured. As a result, a value obtained by multiplying the value obtained by dividing the maximum output, which is the product of voltage and current, by the light intensity per 1 cm ² and multiplying by 100 was defined as conversion efficiency (η:%). That is, the conversion efficiency is expressed by (maximum output / 1 light intensity per 1 cm ² ) × 100.

  As shown in Table 1, in Examples 1-1 to 1-17 in which the dye 14 includes the compounds shown in Chemical Formulas 4 to 8, the conversion efficiency is higher than that of Comparative Examples 1-1 and 1-2 in which the pigment 14 is not included. Became high. That is, when the dye 14 includes a compound represented by Chemical Formula 4 to Chemical Formula 8 having a substituent having a cyclic or branched structure, the pigment 14 includes a compound represented by Chemical Formula 12 having a linear substituent (Comparative Example). It was confirmed that the conversion efficiency was improved as compared with 1-1 and 1-2).

  Here, focusing on the anchor group, the conversion efficiency is that of Examples 1-1, 1-2, 1-4, 1-6, 1-7, 1-9 to 1-17 having a carboxylic acid group as the anchor group. It was higher than Examples 1-3, 1-5, and 1-8 having phosphoric acid groups, sulfonic acid groups, and boric acid groups. In addition, a comparison between Example 1-1 and Example 1-2 confirmed that higher conversion efficiency can be obtained if the anchor group is contained in R5 or R6 shown in Chemical Formula 1.

  When attention is paid to the structure of a substituent having a cyclic or branched structure, the substituent having a cyclic or branched structure is an alkyl group or aromatic having a cyclic or branched structure based on a comparison with Examples 1-1 to 1-17. It has been confirmed that a high conversion efficiency can be obtained with an alkyl group having a ring, and a higher conversion efficiency can be obtained with a tertiary butyl group, a benzyl group, or a derivative of a benzyl group. In addition, if the substituent is introduced as at least one of the group consisting of R1, R2, R3 and R4 shown in Chemical Formula 1, higher conversion efficiency can be obtained. confirmed. Furthermore, from the comparison of Examples 1-9 to 1-11 and the comparison of Examples 1-12 to 1-17, even when it has a group having a naphthalene ring or a group having a biphenyl structure, it has a benzyl group The conversion efficiency was almost the same, and the higher the number of benzyl groups, the higher the conversion efficiency.

  When attention is paid to n shown in Chemical Formula 1, the conversion efficiency is 2.5 to 3.4% in Example 1-4 where n = 0, and Examples 1-5 to 1-7 where n = 1. And 1-9 to 1-11, 0.7 to 5.9%, n = 1 to Examples 1-1 to 1-3 and 1-12 to 1-17, 0.6 to 3.4%, In Example 1-8 where n = 3, it was 0.2 to 0.4%. That is, the range of n in which sufficient conversion efficiency can be obtained is 0 or more and 3 or less, and it was confirmed that excellent conversion efficiency can be obtained at 0 or more and 2 or less. In particular, when the anchor group is a carboxylic acid group, it was confirmed that when n is 1, better conversion efficiency can be obtained.

  Furthermore, paying attention to the material of the metal oxide semiconductor, in Examples 1-1 to 1-17, the conversion efficiency was higher when zinc oxide was used than when titanium oxide was used.

  From this, it was confirmed that in the dye-sensitized solar cell, the dye 14 has an anchor group and contains the compound shown in Chemical Formula 1 so that the conversion efficiency can be improved. In this case, a high conversion efficiency can be obtained by changing the substituent having a cyclic or branched structure shown in Chemical Formula 1 to either an alkyl group having a cyclic or branched structure or an alkyl group having an aromatic ring. Among them, it was confirmed that higher conversion efficiency can be obtained by using a tertiary butyl group, a benzyl group or a benzyl group derivative. In addition, it was confirmed that higher conversion efficiency can be obtained by using at least one of the group consisting of R1, R2, R3 and R4 shown in Chemical Formula 1 as a substituent having a cyclic or branched structure. . Further, it was confirmed that when the anchor group was a carboxylic acid group, high conversion efficiency was obtained, and by using at least one of R5 and R6 as a group having an anchor group, high conversion efficiency was obtained. Furthermore, n shown in Chemical formula 1 is preferably 0 or more and 3 or less, and in particular, it was confirmed that higher conversion efficiency can be obtained when it is 0 or more and 2 or less. Furthermore, as a material for the metal oxide semiconductor, at least one of titanium oxide and zinc oxide is preferable. In particular, it was confirmed that higher conversion efficiency can be obtained by using zinc oxide.

(Examples 2-1 and 2-2)
Instead of the compound shown in Chemical formula 4 (1), the compound shown in Chemical formula 14 (1), which has an anchor group and is shown in Chemical formula 2 (Example 2-1), or an anchor group is used instead of the compound shown in Chemical formula 4 (1). The procedure similar to that of Example 1-1 was performed except that the compound (Example 2-2) represented by Chemical Formula 15 which is a compound represented by Chemical Formula 3 was used.

(Comparative Example 2)
The same procedure as in Example 2-2 was performed except that the compound shown in Chemical formula 16 was used instead of the compound shown in Chemical formula 15 as the dye.

  When the conversion efficiencies of the dye-sensitized solar cells of Examples 2-1 and 2-2 and Comparative Example 2 were examined in the same manner as in Example 1-1, the results shown in Table 2 were obtained. In Table 2, the results of Comparative Examples 1-1 and 1-2 are also shown.

  As shown in Table 2, when the compound shown in Chemical Formula 2 was used as the dye, the same result as that shown in Table 1 was obtained. That is, in Example 2-1 in which the dye 14 contains the compound shown in Chemical formula 14 (1), the conversion efficiency was higher than those in Comparative Examples 1-1 and 1-2 and Comparative Example 2 that did not contain the compound.

  Although not shown in the present Example, at least one of the group consisting of R11 to R14 shown in Chemical Formula 2 is a tertiary butyl group or a benzyl group, thereby having another cyclic or branched structure. It has been confirmed that higher conversion efficiency can be obtained than when the substituent is used. It was also confirmed that the conversion efficiency was improved by making the anchor group a carboxylic acid group, and that a higher conversion efficiency was obtained by making at least one of R15 and R16 a group having an anchor group. ing. Furthermore, y shown in Chemical formula 2 is preferably 0 or more and 3 or less, and it has been confirmed that higher conversion efficiency can be obtained by setting it to 0 or more and 2 or less.

  From this, in the dye-sensitized solar cell, it was confirmed that the conversion efficiency can be improved by including the compound shown in Chemical Formula 2 with the dye 14 having an anchor group. In particular, it was confirmed that higher conversion efficiency can be obtained by using zinc oxide as the material of the metal oxide semiconductor of the working electrode 10.

  In addition, when the compound shown in Chemical Formula 3 was used as the dye, the same results as those shown in Table 1 were obtained. That is, in Example 2-2 in which the dye 14 contains the compound shown in Chemical Formula 15, the conversion efficiency was higher than those in Comparative Examples 1-1 and 1-2 and Comparative Example 2 that did not contain the compound. From this result, the compound shown in Chemical formula 3 has a halogen group as R30, and when R29 has a cyclic structure containing a methine chain as a part of the ring, a substituted structure having a branched structure. It is considered that the crystallization of the dye 14 on the surface of the carrier is more effectively suppressed by having a substituent having a cyclic structure than the group.

  In addition, although not shown in the present Example, by making at least one of the group consisting of R21 to R24 shown in Chemical Formula 3 into a benzyl group, it is possible to make it a substituent having another cyclic structure. It has been confirmed that higher conversion efficiency can be obtained. It was also confirmed that conversion efficiency is improved by using an anchor group as a carboxylic acid group, and that higher conversion efficiency can be obtained by using at least one of R25 and R26 as a group having an anchor group. It was. Further, q shown in Chemical formula 3 is preferably 1 or more and 3 or less, and it is confirmed that higher conversion efficiency can be obtained by setting 1 or 2 among them.

  From this, in the dye-sensitized solar cell, it was confirmed that the conversion efficiency can be improved by including the compound represented by Chemical Formula 3 with the dye 14 having an anchor group. In particular, it was confirmed that higher conversion efficiency can be obtained by using zinc oxide as the material of the metal oxide semiconductor of the working electrode 10.

  The present invention has been described with reference to the embodiments and examples. However, the present invention is not limited to the embodiments described in the above embodiments and examples, and various modifications can be made. For example, the usage application of the photoelectric conversion element of the present invention is not necessarily limited to the usage already described, and may be other usages. Other applications include, for example, an optical sensor.

It is sectional drawing showing the structure of the photoelectric conversion element which concerns on one embodiment of this invention. It is sectional drawing which extracts and expands and shows the principal part of the photoelectric conversion element shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Working electrode, 11, 21 ... Conductive substrate, 11A ... Substrate, 11B ... Conductive layer, 12 ... Metal oxide semiconductor layer, 12A ... Dense layer, 12B ... Porous layer, 14 ... Dye, 20 ... Counter electrode, 22 ... conductive layer, 30 ... electrolyte-containing body.

Claims (24)

A photoelectric conversion element comprising an electrode having a dye and a carrier carrying the dye,
The said pigment | dye contains the compound represented by Chemical formula 1 while having an anchor group. The photoelectric conversion element characterized by the above-mentioned.

(R1, R2, R3, R4, R5, R6, R7 and R8 are substituents. Ring A and ring B are benzene rings or naphthalene rings, provided that R1, R2, R3, R4, R5, R6, (At least one of the group consisting of R7 and R8 is a substituent having a cyclic or branched structure. M and n are integers of 0 or more.)   2. The photoelectric conversion element according to claim 1, wherein the substituent having a cyclic or branched structure is any one of an alkyl group having a cyclic or branched structure and an alkyl group having an aromatic ring.   The at least one of the group consisting of R1, R2, R3, and R4 shown in the chemical formula 1 is the substituent having the cyclic or branched structure. Photoelectric conversion element.   The photoelectric conversion element according to any one of claims 1 to 3, wherein the substituent having a cyclic or branched structure is a benzyl group, a derivative of a benzyl group, or a tertiary butyl group.   The photoelectric conversion element according to claim 1, wherein the anchor group is a carboxylic acid group.   6. The photoelectric conversion element according to claim 1, wherein at least one of R 5 and R 6 shown in Chemical Formula 1 is a group having the anchor group.   7. The photoelectric conversion element according to claim 1, wherein n shown in the chemical formula 1 is 3 or less.   The photoelectric conversion element according to claim 1, wherein the carrier includes at least one of zinc oxide and titanium oxide. A photoelectric conversion element comprising an electrode having a dye and a carrier carrying the dye,
The said pigment | dye contains the compound represented by Chemical formula 2 while having an anchor group. The photoelectric conversion element characterized by the above-mentioned.

(R11, R12, R13, R14, R15, R16, R17 and R18 are substituents. Ring C and ring D are benzene rings or naphthalene rings, provided that R11, R12, R13, R14, R15, R16, At least one of the group consisting of R17 and R18 is a substituent having a cyclic or branched structure, R19 is a hydrogen group or a substituent, and may be bonded to each other to form a cyclic structure. A substituent other than a group or a halogen group, wherein at least one of R19 and R20 is a substituent, and x and y are integers of 0 or more.)   The photoelectric conversion element according to claim 9, wherein the substituent having a cyclic or branched structure is one of an alkyl group having a cyclic or branched structure and an alkyl group having an aromatic ring.   The at least one of the group consisting of R11, R12, R13, and R14 shown in the chemical formula 2 is the substituent having the cyclic or branched structure. Photoelectric conversion element.   The photoelectric conversion element according to claim 9, wherein the substituent having a cyclic or branched structure is a benzyl group or a tertiary butyl group.   The photoelectric conversion element according to claim 9, wherein the anchor group is a carboxylic acid group.   14. The photoelectric conversion device according to claim 9, wherein at least one of R 15 and R 16 shown in Chemical Formula 2 is a group having the anchor group.   The photoelectric conversion element according to claim 9, wherein y shown in Chemical Formula 2 is 3 or less.   16. The photoelectric conversion device according to claim 9, wherein the carrier includes at least one of zinc oxide and titanium oxide. A photoelectric conversion element comprising an electrode having a dye and a carrier carrying the dye,
The said pigment | dye contains the compound represented by Chemical formula 3 while having an anchor group. The photoelectric conversion element characterized by the above-mentioned.

(R21, R22, R23, R24, R25, R26, R27 and R28 are substituents. Ring E and ring F are benzene rings or naphthalene rings, provided that R21, R22, R23, R24, R25, R26, At least one of the group consisting of R27 and R28 is a substituent having a cyclic structure, R29 is a hydrogen group or a substituent, and may be bonded to each other to form a cyclic structure. A halogen group, provided that at least one of R30 is a halogen group, p is an integer of 0 or more, and q is an integer of 1 or more.)   The photoelectric conversion element according to claim 17, wherein the substituent having a cyclic structure is one of an alkyl group having a cyclic structure and an alkyl group having an aromatic ring.   The photoelectric conversion according to claim 17 or 18, wherein at least one of the group consisting of R21, R22, R23, and R24 shown in Chemical Formula 2 is a substituent having the cyclic structure. element.   The photoelectric conversion element according to any one of claims 17 to 19, wherein the substituent having a cyclic structure is a benzyl group.   21. The photoelectric conversion element according to claim 17, wherein the anchor group is a carboxylic acid group.   The photoelectric conversion element according to any one of claims 17 to 21, wherein at least one of R25 and R26 shown in Chemical Formula 3 is a group having the anchor group.   23. The photoelectric conversion element according to claim 17, wherein q shown in Chemical Formula 3 is 3 or less.   The photoelectric conversion device according to any one of claims 17 to 23, wherein the carrier includes at least one of zinc oxide and titanium oxide.

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