JPWO2018047498A1 - Photoelectric conversion device, dye-sensitized solar cell and dipyrromethene complex compound - Google Patents

Abstract

Provided are a photoelectric conversion element and a dye-sensitized solar cell exhibiting excellent photoelectric conversion efficiency, and a dipyrromethene complex compound suitably used for these. The photoelectric conversion device has a conductive support, a photosensitive layer containing an electrolyte, a charge transfer layer containing an electrolyte, and a counter electrode, and the photosensitive layer is represented by the following formula (1): Have the semiconductor particles supported. In the formula, M represents a metal atom or a metalloid atom. L1 represents a specific linking group such as an aromatic hydrocarbon ring group or an aromatic heterocyclic group. Anc1 represents an acidic group, and n represents an integer of 1 or more. R11 to R14 each represent a hydrogen atom or a substituent. R1 and R2 show a substituent. X1 and X2 each represent a specific group such as a halogen atom.

Description

  The present invention relates to a photoelectric conversion device, a dye-sensitized solar cell and a dipyrromethene complex compound.

  The photoelectric conversion element is used for various photo sensors, photoelectrochemical cells such as copying machines, solar cells, and the like. Various methods such as a method using a metal, a method using a semiconductor, a method using an organic pigment or a dye, or a method combining these methods have been put to practical use for this photoelectric conversion element. In particular, solar cells using non-depleting solar energy do not require fuel, and full-scale commercialization is expected as they use inexhaustible clean energy. Among them, silicon-based solar cells have been researched and developed since ancient times, and have been promoted in consideration of the policy considerations of each country. However, silicon is an inorganic material, and improvements in throughput and cost are naturally limited.

  Therefore, photoelectrochemical cells (also referred to as dye-sensitized solar cells) using dyes have been studied. For example, a dye-sensitized solar cell using a dye composed of a ruthenium complex is reported by Graetzel et al., Lausanne Institute of Technology, Switzerland. In addition, dye-sensitized solar cells using dyes other than dyes composed of ruthenium complexes have also been studied. For example, Non-Patent Document 1 proposes a dye-sensitized solar cell using a dipyrromethene complex compound in which a boron atom is bonded to a dipyrromethene skeleton formed by bonding two pyrrole rings with a methine group as a sensitizing dye. Specifically, this dipyrromethene complex compound introduced a triarylamino group by interposing an ethenylene group at positions 3 and 5 of the dipyrromethene skeleton (ring constituent carbon atoms adjacent to the ring constituent nitrogen atom of each pyrrole ring) It is a complex compound.

Dyes and Pigments, 128 (2016), p. 296-303

  Non-Patent Document 1 describes that short circuit current density and overall conversion efficiency can be improved by using the above dipyrromethene complex compound as a sensitizing dye of a dye-sensitized solar cell. ing.

  However, the performance required of the photoelectric conversion element and the dye-sensitized solar cell is higher, and further improvement of the photoelectric conversion efficiency is desired particularly under a low illuminance environment such as indoors.

  An object of the present invention is to provide a photoelectric conversion element and a dye-sensitized solar cell exhibiting excellent photoelectric conversion efficiency, and a dipyrromethene complex compound suitably used for these.

  The present inventors use a dipyrromethene complex compound in which a substituent is introduced at the 2- and 6-positions of the dipyrromethene skeleton as a sensitizing dye for a photoelectric conversion element and a dye-sensitized solar cell. It was found to show the conversion efficiency. The present invention has been further studied based on these findings and has been completed.

That is, the object of the present invention is achieved by the following means.
A photoelectric conversion element having a <1> conductive support, a photoreceptor layer containing an electrolyte, a charge transfer layer containing an electrolyte, and a counter electrode, wherein the photoreceptor layer is represented by the following formula (1): The photoelectric conversion element which has the semiconductor fine particle by which the dipyrromethene complex compound was carry | supported.

In the formula, M represents a metal atom or a metalloid atom. L ¹ represents an ethenylene group, an ethynylene group, an aromatic hydrocarbon ring group or an aromatic heterocyclic group, or a linking group formed by combining two or more of these groups. Anc ¹ represents an acidic group, and n represents an integer of 1 or more. R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a substituent. R ¹ and R ² each independently represent a substituent. X ¹ and X ² each independently represent a halogen atom, ethynyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group, heteroaryloxy group, alkylthio group, arylthio group or heteroarylthio group.

<2> ^{L 1} is, the photoelectric conversion element according to <1> which is represented by the following formula (L1-1) or formula (L1-2).

^Wherein, R 111 ^{to R 116} each independently represent a hydrogen atom or a substituent. A ^L represents an oxygen atom or a sulfur atom. The symbol * indicates a bond to Anc ¹ and ** indicates a bond to a methine carbon atom that bonds two pyrrole rings.

^{<3> R 13} and ^{R 14} are both photoelectric conversion device according to <1> or <2> of the following formula (R1).
Formula (R1) -L ^R1 -Ar ^R1
In the formula, L ^R1 represents a linking group represented by any one of the following formulas (R1-1) to (R1-4). Ar ^R1 represents an aryl group or a heteroaryl group.

^Wherein, R 21 ^{to R 28} each independently represent a hydrogen atom or a substituent. ^AR represents an oxygen atom or a sulfur atom. The symbol * represents a bond to the pyrrole ring, and ** represents a bond to Ar ^R1 .

<4> ^{R 1} and ^{R 2} are both, the photoelectric conversion device according to any one of <1> to <3> of the following formula (R2).
Formula (R2) -L ^R2- Anc ^R2
In formula, L ^R2 is synonymous with L ¹ of said Formula (1). Anc ^R2 is synonymous with Anc ¹ of the said Formula (1).
The dye-sensitized solar cell provided with the photoelectric conversion element as described in any one of <5> said <1>-<4>.

The dipyrromethene complex compound represented by <6> following formula (3).

In the formula, M represents a metal atom or a metalloid atom. L ¹ and L ^R2 each independently represent an ethenylene group, an ethynylene group, an aromatic hydrocarbon ring group or an aromatic heterocycle, or a linking group formed by combining two or more of these groups. Anc ¹ and Anc ^R2 each independently represent an acidic group. R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a substituent. X ¹ and X ² each independently represent a halogen atom, ethynyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group, heteroaryloxy group, alkylthio group, arylthio group or heteroarylthio group.

In the present specification, unless otherwise specified, the double bond may be either E-type or Z-type in the molecule, or a mixture thereof.
When there are a plurality of substituents, linking groups, ligands and the like (hereinafter referred to as substituents and the like) represented by a specific code or formula, or when a plurality of substituents and the like are simultaneously defined, no particular notice As long as it is, each substituent etc. may mutually be same or different. The same applies to the definition of the number of substituents and the like. In addition, when a plurality of substituents and the like are adjacent (especially, adjacent), they may be linked to each other to form a ring unless otherwise specified. In addition, unless otherwise specified, the ring, for example, an alicyclic ring, an aromatic ring or a hetero ring may be further condensed to form a condensed ring.

  In the present specification, the expression of a compound (including a complex and a dye) is used to mean including the salt thereof and the ion thereof as well as the compound itself. Moreover, it is a meaning including what changed a part of structure in the range which does not impair the effect of this invention. Furthermore, the compound which does not specify substitution or non-substitution is the meaning which may have arbitrary substituents in the range which does not impair the effect of this invention. The same applies to substituents, linking groups and ligands.

  Moreover, the numerical range represented using "-" in this specification means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

  The photoelectric conversion element and the dye-sensitized solar cell of the present invention exhibit excellent photoelectric conversion efficiency by supporting the dipyrromethene complex compound represented by the formula (1). Moreover, the dipyrromethene complex compound of this invention can raise the photoelectric conversion efficiency of a photoelectric conversion element and a dye-sensitized solar cell by using as a sensitizing dye.

FIG. 1 is a cross-sectional view schematically showing a system in which the photoelectric conversion element of the first aspect of the present invention is applied to a battery application, including an enlarged view of a circular portion in a layer. FIG. 2: is sectional drawing which showed typically the dye-sensitized solar cell which consists of a photoelectric conversion element of the 2nd aspect of this invention.

[Photoelectric conversion element and dye-sensitized solar cell]
The photoelectric conversion element of the present invention has a conductive support, a photoreceptor layer containing an electrolyte, a charge transfer layer containing an electrolyte, and a counter electrode (counter electrode). The photosensitive layer, the charge transfer layer and the counter electrode are provided in this order on the conductive support.

In the photoelectric conversion element of the present invention, the semiconductor fine particles forming the photoreceptor layer are also referred to as a dipyrromethene complex compound represented by Formula (1) described later as a sensitizing dye (dipyrromethene complex dye when used as a sensitizing dye). ). Here, the mode in which the dipyrromethene complex dye is supported on the surface of the semiconductor fine particle includes the mode in which the dipyrromethene complex dye is adsorbed on the surface of the semiconductor fine particle, the mode in which it is deposited on the surface of the semiconductor fine particle, and the mode in which these are mixed. Do. Adsorption includes chemisorption and physical adsorption, with chemisorption being preferred.
The dipyrromethene complex compound is preferably adsorbed to the semiconductor fine particle via an acidic group (also referred to as an adsorptive group) described later, and at this time, the acidic group releases a proton and becomes an dissociated anion or a salt thereof It may be About the counter ion when an acidic group becomes a salt, it is synonymous with what is mentioned later.
When the dipyrromethene complex compound is adsorbed to the semiconductor fine particle through the acidic group, this acidic group may be one or two or more.

  The configuration of the photoelectric conversion element of the present invention is not particularly limited except the configuration specified in the present invention, and a known configuration relating to the photoelectric conversion element can be adopted. The layers described above constituting the photoelectric conversion element of the present invention may be designed according to the purpose, and may be formed, for example, in a single layer or in multiple layers. Moreover, you may have layers other than the said each layer as needed.

The dye-sensitized solar cell of the present invention uses the photoelectric conversion element of the present invention.
Hereinafter, preferred embodiments of the photoelectric conversion element and the dye-sensitized solar cell of the present invention will be described.

A system 100 shown in FIG. 1 is an application of the photoelectric conversion element 10 of the first aspect of the present invention to a battery application that causes an operating means M (for example, an electric motor) to work in the external circuit 6.
The photoelectric conversion element 10 includes a conductive support 1, semiconductor fine particles 22 sensitized by supporting a dye (dipyrromethene complex dye) 21, a photosensitive layer 2 including an electrolyte between the semiconductor fine particles 22, and a positive electrode. It consists of a charge transfer layer 3 which is a hole transport layer and a counter electrode 4.
In the photoelectric conversion element 10, the photosensitive layer 2 is a semiconductor fine particle 22 on which the dipyrromethene complex dye represented by the formula (1) is adsorbed, and is also referred to as an oxide semiconductor electrode. The light receiving electrode 5 has a conductive support 1 and a photosensitive layer 2 and functions as a working electrode.

  In the system 100 to which the photoelectric conversion element 10 is applied, light incident on the photosensitive layer 2 excites the dipyrromethene complex dye 21. The excited dipyrromethene complex dye 21 has a high energy electron, and this electron is transferred from the dipyrromethene complex dye 21 to the conduction band of the semiconductor fine particle 22 and further reaches the conductive support 1 by diffusion. At this time, the dipyrromethene complex dye 21 is an oxidized form (cation). The electrons reaching the conductive support 1 work in the external circuit 6 and reach the oxidized product of the dipyrromethene complex dye 21 via the counter electrode 4 and the charge transfer layer 3, and the oxidized product is reduced. The system 100 functions as a solar cell by repeating such a cycle of excitation and electron transfer of the dipyrromethene complex dye.

The dye-sensitized solar cell 20 shown in FIG. 2 is constituted by the photoelectric conversion element of the second aspect of the present invention.
The photoelectric conversion element to be the dye-sensitized solar cell 20 is different from the photoelectric conversion element shown in FIG. 1 in the configuration of the conductive support 41 and the photosensitive layer 42 and the spacer S. Except the point, it is comprised similarly to the photoelectric conversion element 10 shown in FIG. That is, the conductive support 41 has a two-layer structure including the substrate 44 and the transparent conductive film 43 formed on the surface of the substrate 44. The photosensitive layer 42 has a two-layer structure of a semiconductor layer 45 and a light scattering layer 46 formed adjacent to the semiconductor layer 45. In the photoconductor layer 42, at least the dipyrromethene complex dye represented by the formula (1) is adsorbed to semiconductor fine particles forming the photoconductor layer 42, and is also referred to as an oxide semiconductor electrode. A spacer S is provided between the conductive support 41 and the counter electrode 48. In the dye-sensitized solar cell 20, 40 is a light receiving electrode, and 47 is a charge transfer layer.

  Similar to the system 100 to which the photoelectric conversion element 10 is applied, the dye-sensitized solar cell 20 functions as a solar cell when light is incident on the photosensitive layer 42.

  As described later, the photoelectric conversion element and the dye-sensitized solar cell of the present invention have lower illuminance even when irradiated with sunlight under fine weather (also referred to as under a high illuminance environment) and compared to sunlight under fine weather. It shows excellent photoelectric conversion efficiency even under low illuminance environment. The low illuminance environment is not particularly limited, and refers to, for example, an environment having an illuminance of 10,000 lux or less. As such a low illumination environment, for example, a low illumination sunlight environment such as cloudy weather or rainy weather, or a low illumination environment under illumination such as an indoor environment or a fluorescent lamp can be mentioned.

  The photoelectric conversion element and the dye-sensitized solar cell of the present invention are not limited to the above preferred embodiments, and the configurations and the like of the respective embodiments can be appropriately combined between the respective embodiments without departing from the spirit of the present invention.

  In the present invention, the materials and members used for the photoelectric conversion element or the dye-sensitized solar cell can be prepared by a conventional method. For example, U.S. Pat. No. 4,927,721, U.S. Pat. No. 4,684,537, U.S. Pat. No. 5,084,365, U.S. Pat. No. 5,350,644, U.S. Pat. No. 5,463,057 U.S. Pat. No. 5,525,440 U.S. Pat. Nos. 7,249,790, 2001-185244, 2001-210390, JP-A 2003-217688, JP-A 2004-220974, and JP-A 2008-135197 can be referred to.

<Dipyrromethene Complex Compound Represented by Formula (1)>
Next, the dipyrromethene complex compound used in the present invention will be described.
The dipyrromethene complex compound is represented by the following formula (1). The dipyrromethene complex compound having such a structure can impart high photoelectric conversion efficiency to the photoelectric conversion element and the dye-sensitized solar cell both in a high illuminance environment and in a low illuminance environment.

The details of the reason why the dipyrromethene complex compound represented by the formula (1) can impart the above-mentioned excellent performance to the photoelectric conversion element and the dye-sensitized solar cell are considered as follows, though it is not clear yet.
The dipyrromethene complex compound represented by Formula (1) has a substituent (R ¹ and R ² in Formula (1)) at the 2- and 6-positions of the dipyrromethene skeleton. Thereby, for example, in the adjacent dipyrromethene complex compounds, association formation or aggregation due to intermolecular interaction (for example, π-π stacking) generated between the adjacent dipyrromethene complex compounds due to steric repulsion etc. of the above-mentioned substituents It can be suppressed. This can suppress the deactivation (inefficient process) of the excited state. Therefore, it is considered that electrons generated by excitation of the dipyrromethene complex compound are efficiently injected into the semiconductor fine particles. Moreover, the light irradiated from illuminating devices, such as a light emitting diode (LED) other than sunlight, can be absorbed efficiently. As a result, it is considered that the photoelectric conversion efficiency is improved even in a low illuminance environment.

  In the present invention, the dipyrromethene complex dye represented by the formula (1) is any one of isomers such as an optical isomer, a geometric isomer, a bond isomer, an ionization isomer, etc. It may also be a mixture of these isomers.

  The dipyrromethene complex dye represented by Formula (1) may change to an oxidized state by a redox reaction with surrounding materials in a state of being incorporated in a photoelectric conversion device.

In formula (1), M represents a metal atom or a semimetal atom.
Examples of the metal atom include Mg, Al, Ga, Ru, Fe, Os, Cu, W, Cr, Mo, Ni, Pd, Pt, Co, Ir, Rh, Re, Mn, or Zn. Zn is preferred.
As a half metal atom, B, Si, Ge, As, Sb, or Te is mentioned, for example, Especially, B is preferable.
M may be one kind or two or more kinds.
In the state of being incorporated into the photoelectric conversion element, the valence number of M may change due to a redox reaction with surrounding materials.

In Formula (1), L ¹ represents an ethenylene group, an ethynylene group, an aromatic hydrocarbon ring group or an aromatic heterocyclic group, or a (conjugated) linking group formed by combining two or more of these groups.
The ethenylene group, ^{-CR L} = CR L - include a group represented by the. R ^L represents a hydrogen atom or a substituent, preferably a hydrogen atom. The substituent that can be taken as R ^L is not particularly limited, and a substituent selected from the substituent group T described later can be mentioned. This substituent may further have a substituent. When n to be described later is 2 or 3, this ethenylene group is a group obtained by removing one or two R ^L as a hydrogen atom.
The ethynylene group is a group represented by -C≡C-, in which case n described later is 1.
Examples of the aromatic hydrocarbon ring group include groups in which n hydrogen atoms have been further removed from the aryl group of the following Substituent Group T. The preferable range etc. in the aryl group of the following substituent group T are applied to the preferable range etc. in an aromatic hydrocarbon ring group.
Moreover, as the aromatic heterocyclic group, groups in which n hydrogen atoms are further removed from the aromatic heterocyclic group among the heterocyclic groups described in the following Substituent Group T can be mentioned. The preferable range etc. in the aromatic heterocyclic group of the following substituent group T are applied to the preferable range etc. in an aromatic heterocyclic group.

The linking group formed by combining two or more of an ethenylene group, an ethynylene group, an aromatic hydrocarbon ring group and an aromatic heterocyclic group preferably has a structure conjugated to the dipyrromethene skeleton in the above formula (1) . The groups to be combined may be the same or different groups as long as they are two or more groups selected from the above-mentioned groups. It is preferably a combination having at least one ethenylene group, an ethynylene group or an aromatic hydrocarbon ring group, and more preferably a combination of an ethenylene group and an aromatic hydrocarbon ring group.
The number of groups to be combined is not particularly limited, 2 to 4 is preferable, 2 to 3 is more preferable, and 2 is more preferable.

L ¹ is preferably an ethenylene group, an ethynylene group, an aromatic hydrocarbon ring group or an aromatic heterocyclic group, more preferably an aromatic hydrocarbon ring group or an aromatic heterocyclic group, and the following formula (L1-1) or formula The ring group (benzene ring group, thiophene ring group or furan ring group) represented by (L1-2) is more preferable, and the benzene ring group is particularly preferable.

In the formula, * represents a bond to Anc ¹ above, and ** represents a bond to a methine carbon atom that bonds two pyrrole rings in formula (1).
Each of R ^{111 to} R ¹¹⁶ independently represents a hydrogen atom or a substituent, with a hydrogen atom being preferred. The substituent that can be taken as R ^{111 to} R ¹¹⁶ is not particularly limited, and a substituent selected from the substituent group T described later can be mentioned. Among these, an alkyl group and an alkoxy group are preferable, and an alkyl group is more preferable. This substituent may further have a substituent.
A ^L represents an oxygen atom or a sulfur atom.

In the formula (1), Anc ¹ represents an acidic group.
In the present invention, the acidic group is a substituent having a dissociative proton and is a substituent having a pKa of 11 or less. The pKa of the acidic group is as described in J.I. Phys. Chem. A 2011, 115, p. It can obtain | require according to the "SMD / M05-2X / 6-31G ^* " method as described in 6641-6645. As an acidic group, for example, a carboxy group, a phosphonyl group (-PO (OH) ₂ ), a phosphoryl group (-O-PO (OH) ₂ ), a sulfo group (-SO ₃ H), a boric acid group, (phenolic And hydroxyl groups, thiophenol groups and sulfonamide groups.
The acidic group is preferably a carboxy group, a phosphonyl group, a sulfo group, a (phenolic) hydroxyl group or a thiophenol group, more preferably a carboxy group.

The acidic group may be an anion dissociated by releasing a proton when it is incorporated into the dipyrromethene complex compound represented by the formula (1), or may be a salt. The salt of the acidic group may be a metal salt or a nonmetal salt. It does not specifically limit as a counter ion when an acidic group turns into a salt, The following counter ion is mentioned.
The counter ion is not particularly limited, and examples thereof include inorganic or organic ammonium ions (for example, tetraalkyl ammonium ions, amidinium ions, guanidinium ions, pyridinium ions, etc.), phosphonium ions (for example, tetraalkyl phosphonium ions, alkyl Triphenyl phosphonium ions and the like), alkali metal ions (Li ions, Na ions, K ions and the like), alkaline earth metal ions, metal complex ions and the like can be mentioned. Among them, inorganic or organic ammonium ion or alkali metal ion is preferable, and tetraalkyl ammonium ion (tetraethyl ammonium ion, tetrabutyl ammonium ion, tetrahexyl ammonium ion, tetraoctyl ammonium ion, tetradecyl ammonium ion etc.) as organic ammonium ion Is more preferred.

In Formula (1), n is an integer of 1 or more. The upper limit is equal to (the number of hydrogen atoms in L ¹ + 1). n is preferably 1 or 2, and more preferably 1.
When n is an integer of 2 or more, the plurality of Anc ¹ may be the same or different.

R ^{11 to} R ¹⁴ each represent a hydrogen atom or a substituent, and preferably a substituent.
The substituent that can be taken as R ^{11 to} R ¹⁴ is not particularly limited, and examples thereof include one type of substituent selected from the substituent group T described later. Among them, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heteroaryl group is preferable, an alkyl group, an alkenyl group, an alkynyl group or an aryl group is more preferable, and an alkyl group, an alkenyl group or an aryl group is more preferable.

Above substituents can take as R ¹¹ to R ¹⁴ may further have a substituent. The substituent which may be further contained is not particularly limited, but a substituent selected from the substituent group T described later is preferable. That is, as a substituent which can be taken as R ^{11 to} R ¹⁴ , a substituent formed by combining two or more types of substituents selected from the substituent group T may be used. Here, a substituent formed by combining two or more types of substituents means a combined substituent obtained by substituting at least one of the hydrogen atoms of a certain substituent with another substituent.
Further, among the substituent group T, as the substituent which may be possessed, an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an amino group is preferable, and an alkyl group, an aryl group, an alkoxy group or an amino group is preferable. More preferable.
When R ^{11 to} R ¹⁴ further have a substituent, the number of the substituent further is not particularly limited as long as it is one or more, and for example, 1 to 6 is preferable, 1 to 4 is more preferable, 1 -3 are more preferable.

The substituent which can be taken as R ¹¹ and R ¹² is preferably one type of substituent selected from Substituent Group T, more preferably an alkyl group, an aryl group or a heteroaryl group, and still more preferably an alkyl group.
R ¹¹ and R ¹² may be the same or different and are preferably the same.

The substituent that can be taken as R ¹³ and R ¹⁴ may be one type of substituent selected from Substituent Group T, but a substituent formed by combining two or more types of substituents selected from Substituent Group T is preferable . More preferably, at least one of R ¹³ and R ¹⁴ is a group represented by the following formula (R1), and still more preferably, both R ¹³ and R ¹⁴ are a group represented by the following formula (R1) .
Formula (R1) -L ^R1 -Ar ^R1
In Formula (R1), L ^R1 represents a (conjugated) linking group represented by any of the following Formulas (R1-1) to (R1-4). Ar ^R1 represents an aryl group or a heteroaryl group.

In formulas (R1-1) to (R1-4), * represents a bond to the pyrrole ring in the above formula (1), and ** represents a bond to Ar ^R1 .

Each of R ^{21 to} R ²⁸ independently represents a hydrogen atom or a substituent, and a hydrogen atom is preferable for all of them.
Substituents can take as R ²¹ to R ²⁸ is not particularly limited, substituents selected from below substituents group T. Among them, an alkyl group is preferable. This substituent may further have a substituent.
In formula (R1-4), A represents an oxygen atom or a sulfur atom.
L ^R1, inter alia, preferably a connecting group represented by any of formulas (R1-1) ~ formula (R1-3), the linking group represented by the formula (R1-1) are more preferable.

Ar ^R1 represents an aryl group or a heteroaryl group, preferably an aryl group.
The aryl group which can be taken as Ar ^R1 is a group consisting of an aromatic hydrocarbon ring, and includes a monocyclic phenyl group and a fused polycyclic group. 6-30 are preferable, as for carbon number of an aryl group, 6-10 are more preferable, and 6 is especially preferable. Specific examples include phenyl or naphthyl.
The heteroaryl group that can be taken as Ar ^R1 may be monocyclic or polycyclic, and the preferable range in the aromatic heterocyclic group among the heterocyclic groups described in the following Substituent Group T is applied.

The aryl group and heteroaryl group that can be taken as Ar ^R1 may further have a substituent selected from Substituent Group T described later. Such substituent, R ¹¹ to R ¹⁴ are same as the substituents mentioned above which may have further. When the aryl group and the heteroaryl group have a substituent, the number is not particularly limited as long as it is one or more, and 1 to 3 are preferable.
When the substituent which the group may further have is a diarylamino group, the two aryl groups are preferably not bonded directly or through a carbon atom, an oxygen atom, a sulfur atom or a nitrogen atom.
The group represented by the above formula (R1) is not particularly limited, and examples thereof include alkyl or alkoxy substituted styryl, amino substituted styryl, di- (alkyl or alkoxy substituted aryl) amino substituted styryl, or an exemplified compound described later And the like.

R ¹¹ and R ¹² may be the same or different and are preferably the same.
R ¹³ and R ¹⁴ may be the same or different, and are preferably the same.
The substituent which can be taken as R ^{11 to} R ¹⁴ is preferably one having no acidic group.

R ¹ and R ² each represent a substituent. R ¹ and R ² may be the same or different, and are preferably the same.
The substituent that can be taken as R ¹ and R ² is not particularly limited, and examples thereof include one type of substituent selected from the substituent group T described later. Among them, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an amino group, an alkoxy group or a halogen atom is preferable, and an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heteroaryl group is more preferable. And alkyl, alkynyl and aryl groups are more preferred.

The above-mentioned substituent which can be taken as R ¹ and R ² may further have a substituent. The substituent which may be further contained is not particularly limited, and a substituent selected from the substituent group T described later is preferable. That is, as a substituent which can be taken as R ¹ and R ² , a bonded substituent may be formed by bonding two or more types of substituents selected from the substituent group T.
Further, among the substituent group T, as the substituent which may be possessed, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group or an acidic group is preferable, and an alkyl group, an aryl group, The heteroaryl group or the acidic group is more preferable, and the alkyl group or the acidic group is more preferable.
When R ¹ and R ² further have a substituent, the number of the substituent further is not particularly limited as long as it is one or more, and, for example, 1 to 3 is preferable.

R ¹ and R ² are preferably bonded substituents further having the above-mentioned acidic group. In this case, it is more preferable that at least one of R ¹ and R ² is a group represented by the following formula (R 2), and both of R ¹ and R ² are a group represented by the following formula (R 2) Is more preferred.
Formula (R2) -L ^R2- Anc ^R2
In formula (R2), L ^R2 has the same meaning as L ¹ described above. However, when L ^{R2 to} which Anc ^R2 is bonded is an aromatic hydrocarbon ring group (benzene ring group), the position of the aromatic hydrocarbon ring group to which Anc ^R2 is bonded is the dipyrromethene skeleton or another L on the skeleton side. binding portion of ^R2 with respect to (the formula (ring-constituting carbon atom indicated by ** in L1-1)), is preferably a meta position ^{(R 112} or ^{R 113} in formula (L1-1)).
Anc ^R2 has the same meaning as Anc ¹ described above, and preferred ones are also the same.
The group represented by the formula (R2) is not particularly limited, and is preferably an o-, m- or p-carboxyphenyl group or an o-, m- or p-sulfophenyl group, for example.
When at least one of R ¹ and R ² is a group represented by formula (R 2), the group represented by formula (R 2) may be the same as or different from L ¹ -Anc ¹ described above .

In Formula (1), X ¹ and X ² each independently represent a halogen atom, ethynyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group, heteroaryloxy group, alkylthio group, arylthio group or heteroaryl. It shows a ruthio group.
Among the above groups that can be taken as X ¹ and X ² , halogen atoms, aryl groups, alkoxy groups, aryloxy groups, alkylthio groups and arylthio groups each have a preferable range etc. for the corresponding group of the following substituent group T Applied. However, as described later, the alkoxy group and the alkylthio group which can be taken as X ¹ and X ² include a cycloalkyloxy group and a cycloalkylthio group, respectively.
The preferable range etc. in the aromatic heterocyclic group among the heterocyclic groups demonstrated by the following substituent group T are applied to the heteroaryl group which can be taken as X ¹ and X ² .
Heteroaryl groups in the heteroaryl group and heteroarylthio group may take as X ¹ and X ² are each as defined above heteroaryl groups can take as X ¹ and X ^2, it is preferable also the same.
The above-mentioned substituent which can be taken as X ¹ and X ² may further have a substituent. The substituent which may be further contained is not particularly limited, and a substituent selected from the substituent group T described later is preferable.

Each of X ¹ and X ² is preferably one having no acidic group, and among them, a halogen atom is preferable, and a fluorine atom is more preferable.
X ¹ and X ² may be the same or different, and are preferably the same.

The substituent that can be taken as R ¹ , R ² , R ^{11 to} R ¹⁴ , X ¹ and X ² , and the substituent that these substituents may further have are other substituents or linkages, respectively. It may combine with a group etc. to form a ring. The structure of the ring thus formed is not particularly limited.
However, if the substituent which may take as R ¹³ and R ¹⁴ are bonded together, do not form a porphyrin ring include dipyrromethene skeleton represented by the formula (1).

  It is preferable that the dipyrromethene complex compound represented by the said Formula (1) is represented by following formula (2) or (3).

The dipyrromethene complex compound represented by the following formula (2) is a compound in which both of the above R ¹³ and R ¹⁴ are a group represented by the above formula (R 1), and the above n is 1.

In formula (2), R ¹ , R ² , R ¹¹ , R ¹² , L ¹ , Anc ¹ , M, X ¹ and X ² are each as defined in the above formula (1), Preferred ones are also the same.
Each of L ^R1 and Ar ^R1 has the same meaning as that in the above formula (R1), and preferred ones are also the same. In Formula (2), two L ^R1 and two Ar ^R1 may be the same or different.

The dipyrromethene complex compound represented by the following formula (3) is a compound in which both of the above R ¹ and R ² are a group represented by the above formula (R 2), and the above n is 1.

In formula (3), R ^{11 to} R ¹⁴ , L ¹ , Anc ¹ , M, X ¹ and X ² are each as defined in the above formula (1), and preferred ones are also the same. .
Each of L ^R2 and Anc ^R2 has the same meaning as that in the above formula (R2), and preferred ones are also the same. In Formula (3), two L ^R2 and two An c ^{R 2} may be the same or different.

The dipyrromethene complex compound represented by the formula (1) is more preferably represented by the following formula (4).
In the dipyrromethene complex compound represented by the following formula (4), both of R ¹³ and R ¹⁴ are a group represented by the above-mentioned formula (R 1), and both of R ¹ and R ² are the above-mentioned formula It is a group represented by R2), wherein n is 1.

In formula (4), R ¹¹ , R ¹² , L ¹ , Anc ¹ , M, X ¹ and X ² are each as defined in the above formula (1), and preferred ones are also the same. .
L ^R1 and ^{Ar R1} are each the same meaning as ^{L R1} and ^{Ar R1} in the formula (R1), it is preferable also the same.
L ^R2 and Anc ^R2 are respectively synonymous with L ^R2 and Anc ^R2 in the above-mentioned formula (R2), and preferable ones are also the same.
In Formula (4), two L ^R1 , two Ar ^R1 , two L ^R2 and two Anc ^R2 may be the same or different.

  The dipyrromethene complex compound represented by the above-mentioned formula (1) can be synthesized by, for example, Non-Patent Document 1, known methods, synthesis examples in the examples, or methods according to these.

  In the dipyrromethene complex compound represented by the formula (1), the maximum absorption wavelength in the solution is preferably in the range of 300 to 900 nm, more preferably in the range of 350 to 800 nm, and particularly preferably in the range of 370 to 700 nm is there.

<Substituent group T>
In the present invention, preferable substituents include substituents selected from the following Substituent Group T.
Further, in the present specification, when only described as a substituent, this substituent group T is referred to, and when each group, for example, an alkyl group is only described, The preferred range in the corresponding group of this substituent group T is applied.
Furthermore, in the present specification, when an alkyl group is described as being distinguished from a cyclic (cyclo) alkyl group, the alkyl group is used to include a linear alkyl group and a branched alkyl group. On the other hand, when an alkyl group is not described as being distinguished from a cyclic alkyl group (in the case where it is simply described as an alkyl group), and unless otherwise specified, the alkyl group is a linear alkyl group or a branched alkyl group And cycloalkyl groups are used in the meaning. The same applies to a group containing a group capable of adopting a cyclic structure (alkyl group, alkenyl group, alkynyl group, etc.) (alkoxy, alkylthio group, alkenyloxy group etc.), and a compound containing a group capable of cyclic structure. is there. When the group can form a cyclic skeleton, the lower limit of the number of atoms of the group forming the cyclic skeleton is 3 or more regardless of the lower limit of the number of atoms specifically described below for the group capable of adopting this structure, Five or more are preferable.
In the following description of Substituent Group T, for example, in order to clarify a linear or branched group and a cyclic group, such as an alkyl group and a cycloalkyl group, they are separately described. There is also.

Groups included in Substituent Group T include the following groups.
Alkyl group (preferably having a carbon number of 1 to 20, more preferably 1 to 12), an alkenyl group (preferably having a carbon number of 2 to 20, more preferably 2 to 12), an alkynyl group (preferably having a carbon number of 2 to 20, Preferably, 2 to 12), cycloalkyl group (preferably having 3 to 20 carbon atoms), cycloalkenyl group (preferably having 5 to 20 carbon atoms), aryl group (preferably having 6 to 26 carbon atoms, more preferably 6 to 10) And heterocyclic group (having at least one oxygen atom, sulfur atom or nitrogen atom as a ring-constituting atom, preferably 2 to 20 carbon atoms. A 5- or 6-membered heterocyclic group is more preferred. The heterocyclic group includes an aromatic heterocyclic group (heteroaryl group) and an aliphatic heterocyclic group), an alkoxy group (preferably having a carbon number of 1 to 20, more preferably 1 to 12), a Kenyloxy group (preferably 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms), alkynyloxy group (preferably 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms), cycloalkyloxy group (preferably 3 carbon atoms) 20), an aryloxy group (preferably having a carbon number of 6 to 26), a heterocyclic oxy group (preferably having a carbon number of 2 to 20),

Alkoxycarbonyl group (preferably having a carbon number of 2 to 20), cycloalkoxycarbonyl group (preferably having a carbon number of 4 to 20), aryloxycarbonyl group (preferably having a carbon number of 6 to 20), amino group (preferably having a carbon number of 0 to 10) 20, (mono- or di-) alkylamino group, (mono- or di-) alkenylamino group, (mono- or di-) alkynylamino group, (mono- or di-) cycloalkylamino group, (mono -Or di-) cycloalkenyl amino group, (mono- or di-) arylamino group, (mono- or di-) heterocyclic amino group is included), sulfamoyl group (preferably having a carbon number of 0 to 20, alkyl And a sulfamoyl group of cycloalkyl or aryl is preferable), an acyl group (preferably having a carbon number of 1 to 20), an acyloxy group (preferably Having from 1 to 20 carbon atoms), a carbamoyl group (preferably with 1 to 20 carbon atoms, alkyl, a carbamoyl group of the cycloalkyl or aryl preferable.),

Acylamino group (preferably having a carbon number of 1 to 20), sulfonamide group (preferably having a carbon number of 0 to 20, preferably an alkyl, cycloalkyl or aryl sulfonamide group), alkylthio group (preferably having a carbon number of 1 to 20) , More preferably 1 to 12), cycloalkylthio group (preferably 3 to 20 carbon atoms), arylthio group (preferably 6 to 26 carbon atoms), alkyl, cycloalkyl or arylsulfonyl group (preferably 1 to 20 carbon atoms) ),

A silyl group (preferably a silyl group having 1 to 20 carbon atoms and substituted with alkyl, aryl, alkoxy and aryloxy is preferable), a silyloxy group (preferably having 1 to 20 carbon atoms, alkyl, aryl, alkoxy and aryloxy Siloxy groups are preferred), hydroxy groups, cyano groups, nitro groups, halogen atoms (eg, fluorine atom, chlorine atom, bromine atom or iodine atom), or the above-mentioned acidic group Anc ¹ .

  The substituent selected from Substituent group T is more preferably an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkoxycarbonyl group, a cycloalkoxycarbonyl Group, amino group, acylamino group, cyano group or halogen atom, particularly preferably alkyl group, alkenyl group, aryl group, heterocyclic group, alkoxy group, alkoxycarbonyl group, amino group, acylamino group or cyano group .

  The substituent selected from Substituent Group T also includes a group formed by combining a plurality of the above-mentioned groups unless otherwise specified. For example, when the compound or substituent or the like contains an alkyl group, an alkenyl group or the like, these may be substituted or unsubstituted. In addition, when the aryl group, the heterocyclic group and the like are contained, they may be monocyclic or fused ring, and may be substituted or unsubstituted.

Specific examples of the dipyrromethene complex compound represented by the formula (1) are shown below, but the present invention is not limited to these dipyrromethene complex compounds. In the following specific example, when it has two or more acidic groups, any of the acidic groups may be in the form of a salt, and the dipyrromethene complex compound and the acidic group are in the form of a salt. It may be a mixture with a dipyrromethene complex compound. In the following specific examples, ⁿ Bu represents a normal butyl group.

  Next, the preferable aspect of the main members of a photoelectric conversion element and a dye-sensitized solar cell is demonstrated.

<Conductive Support>
The conductive support is not particularly limited as long as it has conductivity and can support the photosensitive layer 2 and the like. The conductive support includes a conductive support 1 formed of a conductive material, for example, a metal described later, or a glass or plastic substrate 44 and a transparent conductive film 43 formed on the surface of the substrate 44. The conductive support body 41 which has is preferable.

Among them, the conductive support 41 having the transparent conductive film 43 of metal oxide on the surface of the substrate 44 is more preferable. Such a conductive support 41 can be obtained by applying a conductive metal oxide to the surface of the substrate 44 and depositing the transparent conductive film 43. As a board | substrate 44 formed with the plastics, the transparent polymer film as described in stage number 0153 of Unexamined-Japanese-Patent No. 2001-291534 is mentioned, for example. Moreover, as a material which forms the board | substrate 44, ceramic (Unexamined-Japanese-Patent No. 2005-135902) and electroconductive resin (Unexamined-Japanese-Patent No. 2001-160425) other than glass and a plastics can be used. As a metal oxide, tin oxide (TO) is preferable, and fluorine-doped tin oxide such as indium-tin oxide (tin-doped indium oxide; ITO) and fluorine-doped tin oxide (FTO) is particularly preferable. The coating amount of the metal oxide of this time, the surface area 1 m ² per 0.1~100g substrate 44 is preferable. When the conductive support 41 is used, light is preferably incident from the substrate 44 side.

The conductive supports 1 and 41 are preferably substantially transparent. “Substantially transparent” means that the transmittance of light (wavelength 300 to 1200 nm) is 10% or more, preferably 50% or more, and particularly preferably 80% or more .
The thickness of the conductive supports 1 and 41 is not particularly limited, and is preferably 0.05 μm to 10 mm, more preferably 0.1 μm to 5 mm, and particularly preferably 0.3 μm to 4 mm. .
When the transparent conductive film 43 is provided, the thickness of the transparent conductive film 43 is preferably 0.01 to 30 μm, more preferably 0.03 to 25 μm, and particularly preferably 0.05 to 20 μm. .

  The conductive supports 1 and 41 preferably have a metal oxide film made of a metal oxide on the surface thereof. As the metal oxide, the above-mentioned metal oxide for forming the transparent conductive film 43 and the metal oxide mentioned for the semiconductor fine particles described later can be used, and the metal oxide mentioned for the semiconductor fine particles is preferable. The metal oxide may be the same kind of metal oxide as the metal oxide mentioned in the above-mentioned metal oxide or the semiconductive fine particles forming the transparent conductive film 43, and even if it is a different kind of metal oxide Good. The metal oxide film is usually formed into a thin film, and preferably has a thickness of, for example, 0.01 to 100 nm. The formation method of the metal oxide film is not particularly limited, and the same method as the formation method of the layer formed by the semiconductor fine particles described later can be mentioned. For example, a metal oxide film can be formed by applying and heating (baking) a liquid containing a metal oxide or a precursor thereof (eg, a halide, an alkoxide).

  The conductive supports 1 and 41 may have a light management function on the surface. For example, the surface may have an antireflective film in which a high refractive film and a low refractive index oxide film described in JP-A 2003-123859 are alternately laminated, and described in JP-A 2002-260746. It may have a light guide function of

<Photoreceptor layer>
The configuration of the photosensitive layer is not particularly limited as long as it has the semiconductor fine particles 22 on which the dye 21 is supported and the electrolyte. Preferably, the photosensitive layer 2 and the photosensitive layer 42 can be mentioned.

-Semiconductor fine particles (layer formed by semiconductor fine particles)-
The semiconductor fine particles 22 are preferably fine particles of a metal chalcogenide (for example, an oxide, a sulfide, a selenide or the like) or a compound having a perovskite crystal structure. Metal chalcogenides preferably include oxides of titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium or tantalum, cadmium sulfide, cadmium selenide and the like. Preferred examples of the compound having a perovskite crystal structure include strontium titanate and calcium titanate. Among these, titanium oxide (titania), zinc oxide, tin oxide and tungsten oxide are particularly preferable.

  The crystal structure of titania includes anatase type, brookite type, and rutile type, with anatase type and brookite type being preferable. The titania nanotubes, nanowires, nanorods can be used alone or mixed with the titania particles.

  The particle size of the semiconductor fine particles 22 is an average particle size of 0.001 to 1 μm as a primary particle using a diameter when the projected area is converted to a circle, and 0.01 to 100 μm as an average particle size of a dispersion. Is preferred.

  The semiconductor fine particles 22 preferably have a large surface area so as to be capable of adsorbing many dyes 21. For example, in the state where the semiconductor fine particles 22 are coated on the conductive support 1 or 41, the surface area is preferably 10 times or more, more preferably 100 times or more the projected area. The upper limit is not particularly limited, and is usually about 5000 times. Generally, the larger the thickness of the layer (photosensitive material layer) formed by the semiconductor fine particles, the more the amount of dye 21 that can be carried per unit area increases, so the light absorption efficiency becomes higher, but the diffusion distance of generated electrons increases. The loss due to recombination also increases.

  The preferred thickness of the layer formed by the semiconductor fine particles is not unique depending on the application of the photoelectric conversion element, but typically 0.1 to 100 μm is preferable, 1 to 50 μm is more preferable, and 3 to 30 μm is still more preferable .

The layer of the semiconductor fine particles 22 can be formed, for example, by applying the semiconductor fine particles 22 to the conductive support 1 or 41 and then baking it at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours. Thereby, semiconductor fine particles can be adhered to each other, which is preferable.
Examples of the method of coating the semiconductor fine particles 22 on the conductive support 1 or 41 include a wet method, a dry method and other methods. Fine semiconductor particles 22, the coating amount of the surface area of 1 m ² per conductive support 0.5～500G, more 5~100g is preferred.
When using glass as a material of the electroconductive support body 1 or the board | substrate 44, 60-600 degreeC of film-forming temperature is preferable.

-Light scattering layer-
In the present invention, the photoreceptor layer may have a light scattering layer. This light scattering layer is different from the semiconductor layer 45 in that it has a function of scattering incident light.
In the dye-sensitized solar cell 20, the light scattering layer 46 preferably contains rod-like or plate-like metal oxide fine particles. As a metal oxide used for the light-scattering layer 46, the chalcogenide (oxide) of the said metal demonstrated as a compound which forms the said semiconductor fine particle is mentioned, for example. When the light scattering layer 46 is provided, the thickness of the light scattering layer is preferably 10 to 50% of the thickness of the photosensitive layer 42.
The light scattering layer 46 is preferably a light scattering layer described in JP-A-2002-289274, and the description of JP-A-2002-289274 is preferably incorporated into the present specification as it is.

-Metal oxide film-
In the present invention, the semiconductor fine particles forming the photosensitive layer (including those forming the semiconductor layer 45 and the light scattering layer 46) preferably have a metal oxide film on the surface thereof. As a metal oxide which forms a metal oxide film, the metal oxide mentioned by the said semiconductor fine particle can be used, and even if it is the same kind of metal oxide as the said semiconductor fine particle, it is a different kind of metal oxide May be This metal oxide film is usually formed into a thin film, and a thickness of, for example, 0.1 to 100 nm is preferable. In the present invention, when the semiconductor fine particles have a metal oxide film, the dipyrromethene complex compound is adsorbed to the semiconductor particles through the metal oxide film. The method of forming the metal oxide film is as described above.
In the present invention, it is also possible to have a metal oxide film on the surface of the conductive support and the surface of the semiconductor fine particle. In this case, each metal oxide film may be formed of the same type of metal oxide, or may be formed of different types of metal oxide.

-Dye-
In the photoelectric conversion element 10 and the dye-sensitized solar cell 20, the dipyrromethene complex dye represented by the above formula (1) is supported as a sensitizing dye. The dipyrromethene complex dye represented by the formula (1) is as described above.

  The semiconductor fine particles may carry other dyes in combination with the above-described dipyrromethene complex dyes. In the present invention, the dye that can be used in combination with the dipyrromethene complex dye is not particularly limited, and examples include Ru complex dye, squarylium cyanine dye, organic dye, porphyrin dye, and phthalocyanine dye. As a pigment | dye which can be used together, Ru complex pigment | dye, squarylium cyanine pigment | dye, or an organic pigment | dye is preferable.

The amount of the dye, can not be absolutely determined, surface area 1m preferably ² per 0.01 to 100 mmol of the conductive support 1 or 41, and more preferably 0.1 to 50 mmol, particularly preferably from 1 to 10 It is millimole. The amount of the dye adsorbed on the semiconductor fine particles is preferably 0.001 to 1 millimole, more preferably 0.1 to 0.5 millimole, per 1 g of the semiconductor fine particle. With such a dye amount, the sensitizing effect in the semiconductor fine particles can be sufficiently obtained.

  When the dipyrromethene complex dye represented by the formula (1) is used in combination with another dye, the ratio of the mass of the dipyrromethene complex dye represented by the formula (1) to the mass of the other dye is 95/5 to 10/90. 95/5 to 50/50 is more preferable, 95/5 to 60/40 is further preferable, 95/5 to 65/35 is particularly preferable, and 95/5 to 70/30 is most preferable.

-Electrolyte-
The photoreceptor layer contains an electrolyte. The electrolyte contained in the photosensitive layer is the same as the electrolyte contained in the charge transfer layer described later, and the preferable one is also the same. The electrolyte contained in the photoreceptor layer may be the same as or different from the electrolyte contained in the charge transfer layer, and is preferably the same.

-Coadsorbent-
In the present invention, the semiconductor fine particle preferably carries a co-adsorbent together with the dipyrromethene complex dye represented by the formula (1) or a dye optionally used in combination. As such a co-adsorbent, a co-adsorbent having one or more acidic groups (preferably, a carboxy group or a salt thereof) is preferable, and a compound having a fatty acid or a steroid skeleton can be mentioned.
The fatty acid may be saturated fatty acid or unsaturated fatty acid, and examples thereof include butanoic acid, hexanoic acid, octanoic acid, decanoic acid, hexadecanoic acid, dodecanoic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and the like. .
Examples of compounds having a steroid skeleton include cholic acid, glycocholic acid, chenodeoxycholic acid, hyocholic acid, deoxycholic acid, lithocholic acid, ursodeoxycholic acid and the like. Preferred are cholic acid, deoxycholic acid and chenodeoxycholic acid, and more preferred is deoxycholic acid.

  As a preferable co-adsorbent, compounds represented by the formula (CA) described in paragraphs 0125 to 0129 of JP-A 2014-82187 can be mentioned, and the description of paragraphs 0125 to 0129 of JP-A 2014-82187 Is preferably incorporated herein as it is.

  The above-mentioned co-adsorbent has an effect of suppressing inefficient association of the dipyrromethene complex dye and an effect of preventing reverse electron transfer from the surface of the semiconductor fine particle to the redox system in the electrolyte by adsorbing the semiconductor fine particle. The amount of the co-adsorbent used is not particularly limited, and is preferably 0.1 to 200 mol, more preferably 1 to 100 mol per mol of the dipyrromethene complex dye, from the viewpoint of exerting the above-mentioned effects effectively. The molar amount is particularly preferably 2 to 50 molar.

-Amine compound-
After the dye is supported on the semiconductor particles, the surface of the semiconductor particles may be treated with an amine compound. Pyridine compounds (for example, 4-t-butylpyridine, polyvinylpyridine) and the like can be mentioned as preferable amine compounds. In the case of a liquid, these may be used as it is, or may be used by dissolving in an organic solvent.

<Charge carrier layer>
The charge transfer layers 3 and 47 have a function of replenishing the oxidant of the dye 21 with electrons, and are provided between the light receiving electrode 5 or 40 and the counter electrode 4 or 48.
The charge transfer layers 3 and 47 contain an electrolyte. Here, the phrase "the charge transfer layer includes an electrolyte" means that the charge transfer layer includes only the electrolyte, and includes both the electrolyte and the material other than the electrolyte.
The charge transfer layers 3 and 47 may be in solid, liquid, gel or mixed state.

-Electrolyte-
Examples of the electrolyte include a liquid electrolyte in which a redox couple is dissolved in an organic solvent, a molten salt containing a redox couple, and a so-called gel electrolyte in which a liquid in which a redox couple is dissolved in an organic solvent is impregnated into a polymer matrix. . Among them, a liquid electrolyte is preferable in terms of photoelectric conversion efficiency.

  As a redox couple, for example, iodine and iodide (iodide salt, iodide ionic liquid is preferable, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, methylpropylimidazolium iodide are preferable) Combination, combination of alkyl viologen (eg methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoroborate) and its reduced form, combination of polyhydroxybenzene (eg hydroquinone, naphthohydroquinone etc) and its oxidized form, divalent Examples include combinations of trivalent iron complexes (for example, combinations of red blood salts and yellow blood salts), combinations of divalent and trivalent cobalt complexes, and the like. Among these, a combination of iodine and iodide, or a combination of divalent and trivalent cobalt complexes is preferred, and a combination of iodine and iodide is particularly preferred.

  The above-mentioned cobalt complex is preferably a complex represented by the formula (CC) described in paragraphs 0144 to 0156 of JP-A 2014-82189, and the description of paragraphs 0144 to 0156 of JP-A 2014-82189 is It is preferably incorporated herein as it is.

  When a combination of iodine and iodide is used as the electrolyte, it is preferable to further use an iodine salt of a 5- or 6-membered nitrogen-containing aromatic cation in combination.

The organic solvent used for the liquid electrolyte and the gel electrolyte is not particularly limited, and aprotic polar solvents (eg, acetonitrile, propylene carbonate, ethylene carbonate, dimethylformamide, dimethylsulfoxide, sulfolane, 1,3-dimethylimidazolinone, 3) -Methyl oxazolidinone etc. is preferable.
In particular, as the organic solvent used for the liquid electrolyte, nitrile compounds, ether compounds, ester compounds and the like are preferable, nitrile compounds are more preferable, and acetonitrile and methoxypropionitrile are particularly preferable.

  As the molten salt or gel electrolyte, those described in paragraph No. 0205 and paragraph No. 0208 to 0213 of JP-A-2014-139931 are preferable, and paragraph No. 0205 and paragraph No. 0208 to 0213 of JP-A-2014-139931. The description is preferably incorporated as such into the present specification.

  Electrolytes include, as additives, pyridine compounds such as 4-t-butylpyridine, aminopyridine compounds, benzimidazole compounds, aminotriazole compounds and aminothiazole compounds, imidazole compounds, aminotriazine compounds, urea compounds, amide compounds, pyrimidines It may contain a compound or a nitrogen-free heterocycle.

Further, in order to improve the photoelectric conversion efficiency, a method of controlling the water content of the electrolytic solution may be employed. As a preferable method of controlling the water, a method of controlling the concentration and a method of coexisting a dehydrating agent can be mentioned. It is preferable to adjust the water content (content rate) of the electrolytic solution to 0 to 0.1% by mass.
Iodine can also be used as an inclusion compound of iodine and cyclodextrin. In addition, cyclic amidine may be used, and an antioxidant, a hydrolysis inhibitor, a decomposition inhibitor, and zinc iodide may be added.

Instead of the above-described liquid electrolyte and pseudo-solid electrolyte, a solid charge transport material such as a p-type semiconductor or a hole transport material, for example, CuI or CuNCS can be used. Also, Nature, vol. 486, p. The electrolyte described in 487 (2012) or the like may be used. An organic hole transport material may be used as the solid charge transport material. The organic hole transport material is preferably a hole transport material that can be solution-coated and solid.
The hole transport material may be a low molecular weight compound or a high molecular weight compound, and a triarylamine compound, a polythiophene compound (eg, poly (3-hexylthiophene-2,5-diyl), polyethylenedioxythiophene (PEDOT)) And polyphenylene vinylene compounds, polyaniline compounds, polypyrrole compounds, and copolymers of these.

The triarylamine compound may be a low molecular weight compound or a high molecular weight compound.
As a triarylamine compound, the compound represented by a following formula (HT-1) is mentioned.

In formula (HT-1), R ^{A1 to} R ^A15 each represent a hydrogen atom or a substituent.
Examples of the substituent that can be taken as R ^{A1 to} R ^A15 include the substituents selected from the above-mentioned Substituent Group T, and even if adjacent substituents are linked via a single bond or a linking group to form a ring Good. From the viewpoint of heat resistance and ^durability, it is preferable that at least one of R A1 ^{to R A5} is an aryl ^group, that at least one of the at least one and ^R a ^R A1 ~R ^A5 A6 ~R ^A10 is an aryl group More preferable.

  The triarylamine compound preferably has a molecular weight of 400 or more and 1200 or less, more preferably 550 or more and 1100 or less, and 600 or more and 1000 or less, from the viewpoint of suppressing manufacturing variations of the photoelectric conversion element. More preferably, it is particularly preferably 600 or more and 900 or less.

  Specific examples of the compound represented by the above formula (HT-1) include 2,2 ′, 7,7′-tetrakis- (N, N-di-p-methoxyphenylamine) -9,9-spirobi Although fluorene (Spiro-OMeTAD), the compound etc. which are represented by the following (HTL-1)-(HTL-14), etc. are mentioned, this invention is not limited to these.

  As the above organic hole transport material, 2,2 ′, 7,7′-tetrakis- (N, N-di-p-methoxyphenylamine) -9,9-spirobifluorene, poly (3-hexylthiophene-2) Preferred are 5-diyl), 4- (diethylamino) benzaldehyde diphenyl hydrazone, polyethylene dioxythiophene and the like.

  The redox couple is preferably contained at a certain concentration because it becomes a carrier of electrons. The preferred concentration is 0.01 mol / L or more in total, more preferably 0.1 mol / L or more, and particularly preferably 0.3 mol / L or more. The upper limit in this case is not particularly limited, and is usually about 5 mol / L.

<Counter electrode>
The counter electrodes 4 and 48 preferably serve as the positive electrode of the dye-sensitized solar cell. The counter electrodes 4 and 48 may generally have the same configuration as the conductive support 1 or 41, but the substrate 44 is not necessarily required in the configuration where the strength is sufficiently maintained.
As a metal which forms a counter electrode, platinum (Pt), gold (Au), nickel (Ni), copper (Cu), silver (Ag), indium (In), ruthenium (Ru), palladium (Pd), for example Rhodium (Rh), iridium (Ir), osmium (Os), aluminum (Al) and the like can be mentioned.
As a structure of the counter electrodes 4 and 48, a structure having a high current collection effect is preferable. In order for light to reach the photosensitive layers 2 and 42, at least one of the conductive support 1 or 41 and the counter electrode 4 or 48 must be substantially transparent. In the dye-sensitized solar cell of the present invention, it is preferable that the conductive support 1 or 41 is transparent and sunlight be incident from the side of the conductive support 1 or 41. In this case, it is more preferable that the counter electrodes 4 and 48 have the property of reflecting light. As the counter electrodes 4 and 48 of the dye-sensitized solar cell, a glass or a plastic on which a metal or a conductive oxide is vapor-deposited is preferable, and a glass on which platinum is vapor-deposited is particularly preferable.
The film thickness of the counter electrode is not particularly limited, and is preferably 0.01 to 100 μm, more preferably 0.01 to 10 μm, and particularly preferably 0.01 to 1 μm.

<Other configuration>
Between the conductive support 1 or 41 and the photosensitive layer 2 or 42, in order to prevent reverse current due to direct contact between the electrolyte contained in the photosensitive layer 2 or 42 and the conductive support 1 or 41, It is preferable to form a short circuit prevention layer.
In addition, in order to prevent contact between the light receiving electrode 5 or 40 and the counter electrode 4 or 48, it is preferable to use a spacer S (see FIG. 2) and / or a separator.
Furthermore, in the photoelectric conversion element or the dye-sensitized solar cell, it is preferable to seal the side surface of the photoelectric conversion element or the dye-sensitized solar cell with a polymer, an adhesive or the like in order to prevent transpiration and the like of the components.

  The dye-sensitized solar cell of the present invention is configured using the above-described photoelectric conversion element. For example, as shown in FIG. 1, the conductive support of the photoelectric conversion element and the counter electrode can be connected by the external circuit 6 to make a dye-sensitized solar cell. The external circuit 6 may be a known one without particular limitation.

The photoelectric conversion element and the dye-sensitized solar cell carry the dipyrromethene complex compound represented by the above formula (1). This shows high photoelectric conversion efficiency.
This dipyrromethene complex compound usually exhibits yellow to blue. Therefore, although it also depends on the material of each layer, when the conductive support or the counter electrode is substantially transparent, the photoelectric conversion element and the dye-sensitized solar cell exhibit yellow to blue and have excellent designability.

[Manufacturing method of photoelectric conversion element and dye-sensitized solar cell]
The photoelectric conversion device and the dye-sensitized solar cell of the present invention are preferably produced using a dye solution containing the dipyrromethene complex compound represented by the above formula (1) and a solvent.

  In such a dye solution, the dipyrromethene complex compound represented by the above formula (1) is dissolved in a solvent, and may contain other components as necessary.

  Although the solvent of Unexamined-Japanese-Patent No. 2001-291534 can be mentioned as a solvent to be used, It does not specifically limit to this. In the present invention, organic solvents are preferred, and alcohol solvents, amide solvents, nitrile solvents, ketone solvents, hydrocarbon solvents and mixed solvents of two or more of these are more preferred. The mixed solvent is preferably a mixed solvent of an alcohol solvent and a solvent selected from an amide solvent, a nitrile solvent, a ketone solvent and a hydrocarbon solvent. More preferably, a mixed solvent of an alcohol solvent and an amide solvent, a mixed solvent of an alcohol solvent and a hydrocarbon solvent, or a mixed solvent of an alcohol solvent and a nitrile solvent, particularly preferably a mixed solvent of an alcohol solvent and an amide solvent, an alcohol solvent And a nitrile solvent mixed solvent. Specifically, a mixed solvent of at least one of methanol, ethanol, propanol and t-butanol with at least one of dimethylformamide and dimethylacetamide, or at least one of methanol, ethanol, propanol and t-butanol A mixed solvent with acetonitrile is preferred.

The dye solution preferably contains a co-adsorbent, and as the co-adsorbent, the above-described co-adsorbent is preferable.
Here, the dye solution is preferably a dye solution in which the concentration of the dipyrromethene complex dye or the co-adsorbent is adjusted so that this solution can be used as it is when producing a photoelectric conversion element or a dye-sensitized solar cell. The dye solution preferably contains 0.001 to 0.1% by mass of the dipyrromethene complex dye represented by the above formula (1). The amount of co-adsorbent used is as described above.

  The dye solution preferably has a low water content in terms of dye adsorption. For example, the water content is preferably adjusted to 0 to 0.1% by mass at least at the time of use. The water content can be adjusted in the usual manner, at least at the time of use.

In the present invention, it is preferable to prepare a photoreceptor layer by supporting the dipyrromethene complex dye represented by the formula (1) or the dye containing the same on the surface of the semiconductor fine particle using the above-mentioned dye solution. That is, the photosensitive layer is preferably formed by applying (including the dip method) the dye solution to semiconductor fine particles provided on the conductive support, and drying or curing the photosensitive dye layer.
The photoelectric conversion element of the present invention can be manufactured by further providing a charge transfer layer, a counter electrode, and the like to the light receiving electrode provided with the photosensitive layer thus produced.
Furthermore, an external circuit 6 can be connected to the conductive support 1 and the counter electrode 4 of the photoelectric conversion element produced as described above to produce a dye-sensitized solar cell.

  The present invention will be described in more detail based on the following examples, but the present invention is not limited thereto.

  The structures of the dipyrromethene complex compounds used in this example are shown below.

Hereinafter, the synthesis method of the dipyrromethene complex compound will be described in detail, but the starting material, the dye intermediate and the synthesis route are not limited thereto.
In the present invention, room temperature means 25 ° C.

Synthesis Example 1: Synthesis of Dipyrromethene Complex Compound D-54 A dipyrromethene complex compound D-54 was synthesized according to the method of the following scheme.

<Synthesis of Compound (2)>
8 g of the compound (1), 19.1 g of cesium carbonate and 80 mL of acetonitrile were placed in a three-necked flask, 10.7 mL of ethyl iodide was added dropwise while stirring at 90 ° C., and the mixture was heated under reflux for 2 hours. The reaction product obtained was allowed to cool to room temperature, ethyl acetate and distilled water were added, and a liquid separation operation was performed. The organic layer was concentrated under reduced pressure, and the concentrated residue was purified by silica gel column chromatography using ethyl acetate / hexane as an eluent to obtain 9 g of compound (2).

<Synthesis of Compound (3)>
1.14 g of 2,4-dimethylpyrrole, 1.07 g of compound (2) and 150 mL of methylene chloride were placed in a three-necked flask, and 100 mg of trifluoroacetic acid was added while stirring at room temperature under a nitrogen gas atmosphere. After confirming the disappearance of the compound (2) by TLC (thin layer chromatography), 1.48 g of chloranil was added to the reaction product, and the mixture was further stirred for 5 minutes. Next, 6.87 mL of diisopropylethylamine was added dropwise to the obtained mixture, and the mixture was further stirred for 15 minutes. Thereafter, 9.37 g of boron trifluoride etherate was added dropwise, followed by stirring for 30 minutes. The resulting reaction solution was added to 100 mL of a saturated aqueous solution of sodium hydrogen carbonate, stirred for 10 minutes, extracted with dichloromethane, and concentrated under reduced pressure. The concentrated residue is purified by silica gel column chromatography eluting with hexane / ethyl acetate = 9/1, then reprecipitated with 10 mL of methylene chloride / 30 mL of ethanol, and the obtained solid is filtered to obtain a compound (3 ) Was obtained.

<Synthesis of Compound (4)>
Using compound (3), 0.5 g of compound (4) was synthesized in the same manner as the method described in RSC Adv., 2013, 3, p. 9219-9222.

<Synthesis of Compound (6)>
0.5 g of compound (4), 0.3 g of compound (5), 0.127 g of S-Phos (2-dicyclohexylphosphino-2 ', 6'-dimethoxybiphenyl), 1.3 g of potassium triphosphate and cyclopentyl methyl ether 10 mL was charged into a three-necked flask, degassed under reduced pressure while stirring, and further purged with nitrogen gas (nitrogen gas atmosphere). Then, 17 mg of palladium acetate was added to the obtained mixture, and it heated and refluxed for 3 hours. The obtained reaction product was cooled to room temperature and purified by silica gel column chromatography using ethyl acetate / hexane as an eluent to obtain 0.3 g of compound (6).

<Synthesis of Compound (7)>
Compound (7) was synthesized using Compound (6) in the same manner as described in Org. Biomol. Chem., 2010, 8, p.

<Synthesis of Compound D-54>
0.2 g of Compound (7), 5 mL of tetrahydrofuran and 5 mL of methanol were placed in a three-necked flask, and while stirring, 0.3 mL of 3N sodium hydroxide was further added, and the mixture was stirred at room temperature for 5 hours. Thereafter, a 1 N methanol solution of trifluoromethanesulfonic acid was added dropwise to the resulting mixture until pH 3 was reached. Tetrahydrofuran and methanol were evaporated under reduced pressure to precipitate a solid. The solid was collected by filtration under reduced pressure, purified by silica gel column chromatography, and then vacuum dried to obtain 0.10 g of dipyrromethene complex compound D-54.

Synthesis Examples 2 to 7 Synthesis of Dipyrromethene Complex Compounds D-4, D-7, D-13, D-29, D-34, and D-56 According to the same synthesis method as in Synthesis Example 1, a dipyrromethene complex compound D-4 , D-7, D-13, D-29, D-34 and D-56, respectively.

  Each of the synthesized dipyrromethene complex compounds was confirmed from the MS measurement results in Table 1 below.

Example 1: Production of dye-sensitized solar cell Using the dipyrromethene complex compound synthesized in each synthesis example or the following comparative dye compound C1 respectively, the dye-sensitized solar cell 20 (light scattering shown in FIG. 2) according to the procedure shown below Layer 46 was unformed, 5 mm by 5 mm scale) was manufactured, and the following performance was evaluated. The results are shown in Table 2.

(Preparation of light receiving electrode precursor)
A conductive support 41 was produced by forming a fluorine-doped SnO ₂ conductive film (transparent conductive film 43, film thickness: 500 nm) on a glass substrate (substrate 44, thickness 4 mm). Then, the SnO ₂ conductive film, titania paste "18NR-T" a (Dyesol Inc.) was screen-printed, dried at 120 ° C.. Thereafter, the dried titania paste was fired at 500.degree. Thus, the semiconductor layer 45 (film thickness: 6 μm) was formed. Thus, the photosensitive layer 42 (the area of the light receiving surface: 5 mm × 5 mm, the film thickness: 6 μm, the light scattering layer 46 is not formed) was formed on the SnO ₂ conductive film. By the above operation, a light receiving electrode precursor not carrying the dipyrromethene complex compound was produced.

(Dye adsorption method)
Next, each dipyrromethene complex compound synthesized in the above synthesis example was supported on the photosensitive material layer 42 not carrying the dipyrromethene complex compound as follows. First, each of the above dipyrromethene complex compounds is dissolved in a 1: 1 (volume ratio) mixed solvent of t-butanol and acetonitrile so as to have a concentration of 2 × 10 ⁻⁴ mol / L, and further to the coadsorbent there. Each dye solution was prepared by adding 2 × 10 ⁻³ mol / L of deoxycholic acid as Next, the light receiving electrode precursor was immersed in each dye solution at 25 ° C. for 5 hours, pulled up from the dye solution, and then dried. Thus, the light receiving electrode 40 in which each dipyrromethene complex dye was supported on the light receiving electrode precursor was produced.

(Assembly of dye-sensitized solar cell)
As a counter electrode 48, a platinum electrode (Pt thin film thickness: 100 nm) having the same shape and size as the conductive support 41 described above was produced. In addition, as an electrolytic solution, iodine 0.001 M (mol / L), lithium iodide 0.1 M, 4-t-butylpyridine 0.5 M and 1,2-dimethyl-3-propyl imidazolium iodide 0.6 M The liquid electrolyte was prepared by dissolving in acetonitrile. Furthermore, Dupont's spacer S (trade name: “Surlyn”) having a shape matched to the size of the photosensitive layer 42 was prepared.
Each of the light receiving electrodes 40 manufactured as described above and the counter electrode 48 are made to face each other via the spacer S and thermocompression-bonded, and then the above-mentioned from the electrolyte solution inlet between the photosensitive layer 42 and the counter electrode 48 The liquid electrolyte was filled to form the charge transfer layer 47. The outer periphery of the battery thus prepared and the electrolyte injection port were sealed and cured using Nagase Chemteq resin XNR-5516 to manufacture each dye-sensitized solar cell (sample numbers 1 to 7). .

In the production of the above dye-sensitized solar cell, the dye growth for comparison is the same as the production of the above dye-sensitized solar cell except that the following dye compound C1 for comparison is used instead of the dipyrromethene complex compound. A solar cell (sample number c1) was manufactured.
Dye compound C1 is the dipyrromethene complex dye “ZH-b” described in Non-Patent Document 1.

<Evaluation of photoelectric conversion efficiency (low illuminance environment: indoor light)>
The cell characteristic test was done using each of the manufactured dye-sensitized solar cells.
The battery characteristic test was conducted using a white LED manufactured by Toshiba (model number: LDA8N-G-K / D / 60W). The illuminance adjustment (300 μW / cm ² (1000 lux)) was performed using an ND filter (ND1 to ND80) manufactured by Shibuya Optics Co., Ltd. The measurement of the adjusted illuminance was confirmed using a spectrometer USB4000 manufactured by Ocean Photonics. The current-voltage characteristic was measured using an IV tester to determine the photoelectric conversion efficiency (η).
The photoelectric conversion efficiencies (η) of the respective dye-sensitized solar cells of sample numbers 1 to 7 sufficiently functioned as a dye-sensitized solar cell under a low illuminance environment.
For each of the dye-sensitized solar cells (sample numbers 1 to 7) of each sample number, the obtained photoelectric conversion efficiency (η) is compared with the photoelectric conversion efficiency (η of the dye-sensitized solar cell (sample number c1) for comparison. _The following criteria were evaluated with respect to _c1 ).
In this evaluation, evaluations A and B are acceptable levels, preferably A.
The photoelectric conversion efficiency (η) is lower than the photoelectric conversion efficiency (η _c1 )
A: greater than 1.1 times B: greater than 1.0 times, less than 1.1 times C: less than 1.0 times

From the results of Table 2, the following was found.
The dye-sensitized solar cell (sample numbers 1 to 7) having semiconductor fine particles carrying the dipyrromethene complex compound represented by the formula (1) is superior to the dye-sensitized solar cell of sample number c1. The photoelectric conversion efficiency is shown.

DESCRIPTION OF SYMBOLS 41 41 conductive support body 2 42 photosensitive body layer 21 pigment 22 semiconductor fine particle 3 47 charge transfer body layer 4 48 counter electrode 5 40 light receiving electrode 6 circuit 10 photoelectric conversion element 100 photoelectric conversion element applied to battery application System M operating means (eg electric motor)
20 dye-sensitized solar cell 43 transparent conductive film 44 substrate 45 semiconductor layer 46 light scattering layer S spacer

Claims (6)

A photoelectric conversion element comprising a conductive support, a photoreceptor layer containing an electrolyte, a charge transfer layer containing an electrolyte, and a counter electrode, wherein the photoreceptor layer is represented by the following formula (1): The photoelectric conversion element which has a semiconductor fine particle in which the complex compound was carry | supported.

In the formula, M represents a metal atom or a metalloid atom.
L ¹ represents an ethenylene group, an ethynylene group, an aromatic hydrocarbon ring group or an aromatic heterocyclic group, or a linking group formed by combining two or more of these groups. Anc ¹ represents an acidic group, and n represents an integer of 1 or more.
R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a substituent.
R ¹ and R ² each independently represent a substituent.
X ¹ and X ² each independently represent a halogen atom, ethynyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group, heteroaryloxy group, alkylthio group, arylthio group or heteroarylthio group. The photoelectric conversion element according to claim 1, wherein L ¹ is represented by the following formula (L1-1) or the formula (L1-2).

^Wherein, R 111 ^{to R 116} each independently represent a hydrogen atom or a substituent. A ^L represents an oxygen atom or a sulfur atom. The symbol * indicates the binding site to the Anc ¹ and the symbol ** indicates the binding site to the methine carbon atom binding the two pyrrole rings. The photoelectric conversion element according to claim 1, wherein R ¹³ and R ¹⁴ are both represented by the following formula (R1).
Formula (R1) -L ^R1 -Ar ^R1
In the formula, L ^R1 represents a linking group represented by any one of the following formulas (R1-1) to (R1-4). Ar ^R1 represents an aryl group or a heteroaryl group.

^Wherein, R 21 ^{to R 28} each independently represent a hydrogen atom or a substituent. ^AR represents an oxygen atom or a sulfur atom. The symbol * represents a bond to the pyrrole ring, and ** represents a bond to Ar ^R1 . The photoelectric conversion element according to any one of claims 1 to 3, wherein both of R ¹ and R ² are represented by the following formula (R2).
Formula (R2) -L ^R2- Anc ^R2
In formula, L ^R2 is synonymous with L ¹ of said Formula (1). Anc ^R2 is synonymous with Anc ¹ of said Formula (1).   The dye-sensitized solar cell provided with the photoelectric conversion element of any one of Claims 1-4. The dipyrromethene complex compound represented by following formula (3).

In the formula, M represents a metal atom or a metalloid atom.
L ¹ and L ^R2 each independently represent an ethenylene group, an ethynylene group, an aromatic hydrocarbon ring group or an aromatic heterocycle, or a linking group formed by combining two or more of these groups. Anc ¹ and Anc ^R2 each independently represent an acidic group.
R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a substituent.
X ¹ and X ² each independently represent a halogen atom, ethynyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group, heteroaryloxy group, alkylthio group, arylthio group or heteroarylthio group.