JP6658727B2 - Photoelectric conversion element and organic thin-film solar cell - Google Patents

Description

  The present invention provides a photoelectric conversion element having a structure in which a base material, a cathode, an active layer, and an anode are arranged in this order, wherein the photoelectric conversion contains a polymer compound having a specific benzobisthiazole skeleton structural unit. Related to the element.

  Organic semiconductor compounds are one of the most important materials in the field of organic electronics, and can be classified into electron-donating p-type organic semiconductor compounds and electron-accepting n-type organic semiconductor compounds. Various elements can be manufactured by appropriately combining a p-type organic semiconductor compound and an n-type organic semiconductor compound. Such an element can be formed by, for example, an exciton (exciton) formed by recombination of electrons and holes. The method is applied to organic electroluminescence that emits light by the action of (2), organic thin-film solar cells that convert light into electric power, and organic thin-film transistors that control the amount of current and voltage.

  Among these, organic thin-film solar cells are useful for environmental preservation because they do not emit carbon dioxide into the atmosphere, and their demand is increasing because of their simple structure and easy production. However, the photoelectric conversion efficiency of the organic thin-film solar cell is not yet sufficient. The photoelectric conversion efficiency η is calculated by the product of the short circuit current density (Jsc), the open circuit voltage (Voc) and the fill factor (FF), “η = open circuit voltage (Voc) × short circuit current density (Jsc) × fill factor (FF)”. In order to increase the photoelectric conversion efficiency, it is necessary to improve not only the open circuit voltage (Voc) but also the short circuit current density (Jsc) and the fill factor (FF).

  The open circuit voltage (Voc) is proportional to the energy difference between the HOMO (highest occupied orbital) level of the p-type organic semiconductor compound and the LUMO (lowest unoccupied orbital) level of the n-type organic semiconductor compound. In order to improve (Voc), it is necessary to deepen (lower) the HOMO level of the p-type organic semiconductor.

  Further, the short-circuit current density (Jsc) is correlated with the amount of energy received by the organic semiconductor compound. To improve the short-circuit current density (Jsc) of the organic semiconductor compound, the short-circuit current density (Jsc) must be within the visible region to the near infrared region. It is necessary to absorb light in a wide wavelength range. Of the light that can be absorbed by the organic semiconductor compound, the wavelength of light having the lowest energy (longest wavelength) is the absorption edge wavelength, and the energy corresponding to this wavelength corresponds to the band gap energy. Therefore, in order to absorb light in a wider wavelength range, it is necessary to narrow the band gap (the energy difference between the HOMO level and the LUMO level of the p-type semiconductor).

  On the other hand, research on p-type organic semiconductor compounds has been actively conducted. For example, Non-Patent Document 1 discloses a copolymer of 4,4′-bis (2-ethylhexyl) dithieno [3,2-b; 2 ′, 3 ′,-d] silole and 2,1,3-benzothiadiazole. Coalescence has been proposed. However, the p-type organic semiconductor compound described in Non-Patent Document 1 may not have a sufficiently deep HOMO level in some cases.

  On the other hand, Patent Document 1 proposes a compound having a benzobisthiazole skeleton, but the conversion efficiency is not clear.

JP 2007-238530 A

Eiichiro Fukuchi and five others, "Evaluation using inverted organic thin-film solar cells using low-bandgap polymer PCBTBT and characteristic change due to oxidation," Solar Energy, 2012, 38, 53-58.

  An object of the present invention is to provide a photoelectric conversion element that exhibits high conversion efficiency. In addition, the capacity of the photoelectric conversion element depends on the type and combination of the organic semiconductor compound, the configuration of the photoelectric conversion element, and the like. In the organic semiconductor compound, since HOMO and open-circuit voltage are closely related, a more diverse skeleton. To provide a photoelectric conversion element using a polymer compound into which a polymer or a substituent can be introduced. In recent years, as shown in Non-Patent Document 1, attention has been focused on an inverted type component having an electrode (cathode) for collecting electrons on the substrate side due to its high stability, and it is necessary to study the element configuration. .

  In order to improve the conversion efficiency, that is, to improve the short-circuit current density (Jsc) while improving the open-circuit voltage (Voc), the present inventors have made it possible for a p-type organic semiconductor to absorb light in a wide wavelength range and at the same time to absorb HOMO. It has been found that it is useful to make the level deep enough. As a result of intensive studies focusing on the correlation between the conversion efficiency and the chemical structure of the p-type organic semiconductor compound, the use of an organic semiconductor polymer having a specific structure has a wide light absorption in the entire visible light region. At the same time, it has been found that since the HOMO level and the LUMO level can be adjusted to an appropriate range, the short circuit current density (Jsc) can be improved while the open circuit voltage (Voc) is improved. The inventors have found that the use of such an organic semiconductor polymer can easily cause charge separation between a p-type organic semiconductor and an n-type organic semiconductor, thereby completing the present invention.

  That is, the present invention relates to a photoelectric conversion element having a structure in which a base material, a cathode, an active layer, and an anode are arranged in this order, wherein a specific benzo compound represented by the formula (1) is added to the active layer. It is characterized by containing a polymer compound having a bisthiazole skeleton structural unit (hereinafter, may be referred to as “polymer compound (1)”).

[In equation (1),
T ¹ and T ² are each independently a thiophene ring optionally substituted with an alkoxy group, a thioalkoxy group, a hydrocarbon group or an organosilyl group, a thiazole optionally substituted with a hydrocarbon group or an organosilyl group. Represents a ring or a phenyl group which may be substituted with a hydrocarbon group, an alkoxy group, a thioalkoxy group, an organosilyl group, a halogen atom, or a trifluoromethyl group.
B ¹ and B ² represent a thiophene ring optionally substituted with a hydrocarbon group, a thiazole ring optionally substituted with a hydrocarbon group, or an ethynylene group. ]

In the formula (1), T ¹ and T ² are each preferably a group represented by any of the following formulas (t1) to (t5).

[In the formulas (t1) to (t5), R ^{13 to} R ¹⁴ each independently represent a hydrocarbon group having 6 to 30 carbon atoms. R ¹⁵ to R ¹⁶ are each independently a hydrocarbon group having 6 to 30 carbon atoms, ^{or,, * - Si (R 18} ) a group represented by _3. R ^{15 ′} represents a hydrogen atom, a hydrocarbon group having 6 to 30 carbon atoms, or a group represented by * —Si (R ¹⁸ ) ₃ . R ¹⁷ represents a halogen atom, a hydrocarbon group having 6 to 30 carbon atoms, * -OR ¹⁹ , * -SR ²⁰ , * -Si (R ¹⁸ ) ₃ , or * -CF ₃ . R ¹⁸ independently represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and a plurality of R ¹⁸ may be the same or different. R ^{19 to} R ²⁰ represent a hydrocarbon group having 6 to 30 carbon atoms. * Represents a bond bonded to the thiazole ring of benzobisthiazole. ]

In the formula (1), B ¹ and B ² are each preferably a group represented by any of the following formulas (b1) to (b3).

[In formulas (b1) to (b3),
R ²¹ , R ²² and R ^{21 ′} represent a hydrogen atom or a hydrocarbon group having 6 to 30 carbon atoms.
* Represents a bond, and particularly * on the left side represents a bond bonded to the benzene ring of the benzobisthiazole compound. ]

  The polymer compound (1) contained in the photoelectric conversion element of the present invention is preferably a donor-acceptor type semiconductor polymer.

  The active layer preferably further contains an n-type organic semiconductor compound, and the n-type semiconductor compound is preferably fullerene or a derivative thereof.

  The photoelectric conversion device of the present invention preferably has an electron transport layer between the cathode and the active layer, and preferably has a hole transport layer between the anode and the active layer. Preferably, the cathode is a transparent electrode, and the anode is a metal electrode.

The polymer compound (1) used in the present invention can form a plane cross-shaped skeleton by intramolecular SN interaction. As a result, since the π conjugation is extended to the plane cruciform skeleton, multi-band light absorption derived from a plurality of π-π ^* transitions is exhibited, and a wide range of light from the visible region to the near infrared region can be absorbed. As a result, both a high open circuit voltage (Voc) and a short circuit current density (Jsc) can be obtained, and a high photoelectric conversion efficiency η can be obtained. Further, it is possible to introduce various substituents as substituents into the benzobisthiazole skeleton constituting the polymer compound (1) used in the present invention, and the material has various effects on the characteristics of the photoelectric conversion element. (Crystallinity, film forming property, absorption wavelength) can be controlled. As an element configuration, an inverted-type element that collects electrons on the substrate side can be manufactured.

FIG. 1 shows an element structure of a photoelectric conversion element in which a base material, a cathode, an active layer, and an anode are arranged in this order.

  Hereinafter, embodiments of the present invention will be described in detail. The description of the constituent requirements described below is an example (representative example) of the embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist.

1. The photoelectric conversion element according to the present invention is a photoelectric conversion element having a structure in which a base material, a cathode, an active layer, and an anode are arranged in this order, and the active layer is represented by the formula (1). Contains a polymer compound having the represented benzobisthiazole structural unit.

  FIG. 1 shows a photoelectric conversion element (VII) according to an embodiment of the present invention. FIG. 1 shows a photoelectric conversion element used for a general organic thin-film solar cell, but the photoelectric conversion element according to the present invention is not limited to the configuration shown in FIG.

  The photoelectric conversion element (VII) has a structure in which a substrate (I), an electrode (cathode) (II), an active layer (IV), and an electrode (anode) (VI) are arranged in this order. It is preferable that the photoelectric conversion element (VII) further includes a buffer layer (electron transport layer) (III) and a buffer layer (hole transport layer) (V). That is, the photoelectric conversion element (VII) includes a substrate (I), a cathode (II), a buffer layer (electron transport layer) (III), an active layer (IV), and a buffer layer (hole transport layer) (V ) And the anode (VI) are preferably arranged in this order. However, the photoelectric conversion element according to the present invention may not have the electron transport layer (III) and the hole transport layer (V). Hereinafter, each of these units will be described.

1.1 Active layer (IV)
The active layer (IV) refers to a layer on which photoelectric conversion is performed, and usually includes a single or multiple p-type semiconductor compounds and a single or multiple n-type semiconductor compounds. Specific examples of the p-type semiconductor compound include, but are not limited to, a polymer compound (1) and an organic semiconductor compound (11) described below. In the present invention, it is necessary to use at least the polymer compound (1) as the p-type semiconductor compound. When the photoelectric conversion element (VII) receives light, the light is absorbed by the active layer (IV), and electricity is generated at the interface between the p-type semiconductor compound and the n-type semiconductor compound. It is taken out from the anode (VI). In the present invention, the polymer compound (1) is used as a p-type semiconductor compound.

  The thickness of the active layer (IV) is preferably at least 70 nm, more preferably at least 90 nm, and may be at least 100 nm, preferably at most 1,000 nm, more preferably at most 750 nm, further preferably at most 750 nm. It is 500 nm or less.

  When the thickness of the active layer (IV) is appropriately increased, improvement in the conversion efficiency of the photoelectric conversion element (VII) can be expected. It is also preferable that the thickness of the active layer (IV) is appropriately large in that a short circuit through the film can be prevented. It is preferable that the thickness of the active layer (IV) is appropriately small because the internal resistance becomes small, and the distance between the electrodes (II) and (VI) is not too large and the diffusion of electric charge is good. Furthermore, it is preferable that the film thickness of the active layer (IV) is in the above range, since reproducibility in a process for producing the active layer (IV) is improved.

  In general, the thicker the active layer, the longer the movement distance of the charge generated in the active layer to the electrode or the electron transporting layer or the hole transporting layer. Can be As described above, when the active layer (IV) is thick, the region where light can be absorbed increases, but the transport of charges generated by light absorption is difficult, so that the photoelectric conversion efficiency decreases. Therefore, it is preferable that the thickness of the active layer (IV) be in the above range from the viewpoints of securing voltage and improving conversion efficiency.

1.1.1 Layer Configuration of Active Layer The layer configuration of the active layer (IV) may be a thin-film stacked type in which a p-type semiconductor compound and an n-type semiconductor compound are stacked, or a p-type semiconductor compound and an n-type semiconductor compound. , A bulk heterojunction type having a layer in which is mixed. Above all, a bulk heterojunction type active layer is preferable in that the photoelectric conversion efficiency can be further improved.

Bulk heterojunction type active layer The bulk heterojunction type active layer has a layer (i layer) in which a p-type semiconductor compound and an n-type semiconductor compound are mixed. The i-layer has a structure in which a p-type semiconductor compound and an n-type semiconductor compound are phase-separated, carrier separation occurs at a phase interface, and generated carriers (holes and electrons) are transported to an electrode.

  Among the p-type semiconductor compounds included in the i-layer, a polymer compound (1) having a benzobisthiazole structural unit represented by the formula (1) (preferably, a benzobisthiazole structural unit represented by the formula (1)) And the proportion of the polymer compound (1-1) comprising the copolymer component (2) described later) is usually 50% by mass or more, preferably 70% by mass or more, more preferably 100% by mass of the p-type semiconductor compound. 90% by mass or more). Since the polymer compound (1) has properties suitable as a p-type semiconductor compound, it is particularly preferable that the p-type semiconductor compound contains only the polymer compound (1).

  The mass ratio of the p-type semiconductor compound to the n-type semiconductor compound in the i-layer (p-type semiconductor compound / n-type semiconductor compound) is 0 from the viewpoint of improving the photoelectric conversion efficiency by obtaining a good phase separation structure. 0.5 or more, more preferably 1 or more, while 4 or less, more preferably 3 or less, and particularly preferably 2 or less.

  The i-layer can be formed by any method including a coating method and an evaporation method (for example, a co-evaporation method), and it is preferable to use an application method because the i-layer can be formed more easily. Since the polymer compound (1) according to the present invention has solubility in a solvent, the polymer compound (1) is preferable in that it has excellent coating film formability. When the i-layer is formed by a coating method, a coating solution containing a p-type semiconductor compound and an n-type semiconductor compound is prepared, and this coating solution may be applied. The coating solution containing the p-type semiconductor compound and the n-type semiconductor compound may be prepared by preparing a solution containing the p-type semiconductor compound and a solution containing the n-type semiconductor compound, respectively, and then mixing them. It may be prepared by dissolving a compound and an n-type semiconductor compound.

  From the viewpoint of forming an active layer having a sufficient thickness, the total concentration of the p-type semiconductor compound and the n-type semiconductor compound in the coating solution is preferably 1.0% by mass or more based on the entire coating solution, From the viewpoint of sufficiently dissolving the semiconductor compound, the content is preferably 4.0% by mass or less based on the entire coating solution.

  As the coating method, any method can be used. For example, a spin coating method, an inkjet method, a doctor blade method, a drop casting method, a reverse roll coating method, a gravure coating method, a kiss coating method, a roll brushing method, a spray coating method Air knife coating method, wire bar bar coating method, pipe doctor method, impregnation / coating method, curtain coating method, flexo coating method, and the like. After the application of the coating liquid, a drying treatment by heating or the like may be performed.

  As the solvent of the coating solution, those capable of uniformly dissolving the p-type semiconductor compound and the n-type semiconductor compound are preferable, for example, aliphatic hydrocarbons such as hexane, heptane, octane, isooctane, nonane, and decane; toluene, xylene, Aromatic hydrocarbons such as mesitylene, cyclohexylbenzene, chlorobenzene or orthodichlorobenzene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, tetralin or decalin; methanol, ethanol or propanol; Lower alcohols such as anisole; aliphatic ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), cyclopentanone or cyclohexanone; acetophenone or Aromatic ketones such as ropiophenone; esters such as ethyl acetate, isopropyl acetate, butyl acetate or methyl lactate; halogen hydrocarbons such as chloroform, methylene chloride, dichloroethane, trichloroethane or trichloroethylene; ethyl ether, tetrahydrofuran, cyclopentyl methyl ether; Ethers such as dibutyl ether, diphenyl ether or dioxane; or amides such as dimethylformamide, N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI) or dimethylacetamide.

  Among them, preferred are aromatic hydrocarbons such as toluene, xylene, mesitylene, cyclohexylbenzene, chlorobenzene and orthodichlorobenzene; and alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, tetralin and decalin. Hydrogen; ketones such as acetone, methyl ethyl ketone, cyclopentanone or cyclohexanone; or ethers such as ethyl ether, tetrahydrofuran or dioxane.

  When a bulk heterojunction type active layer is formed by a coating method, an additive may be further added to a coating liquid containing a p-type semiconductor compound and an n-type semiconductor compound. The phase separation structure between the p-type semiconductor compound and the n-type semiconductor compound in the bulk heterojunction type active layer affects light absorption, exciton diffusion, exciton dissociation (carrier separation), carrier transport, and the like. It is considered that by optimizing the separation structure, good photoelectric conversion efficiency can be realized. When the coating liquid contains an additive having a high affinity for the p-type semiconductor compound or the n-type semiconductor compound, an active layer having a preferable phase separation structure can be obtained, and the photoelectric conversion efficiency can be improved.

  The additive is preferably solid or has a high boiling point in that the additive is less likely to be lost from the active layer (IV).

  Specifically, when the additive is a solid, the melting point (1 atm) of the additive is usually 35 ° C. or more, preferably 50 ° C. or more, more preferably 80 ° C. or more, and still more preferably 150 ° C. or more. Particularly preferably, it is 200 ° C. or higher, preferably 400 ° C. or lower, more preferably 350 ° C. or lower, and further preferably 300 ° C. or lower.

  When the additive is a liquid, the boiling point (1 atm) is 80 ° C or higher, more preferably 100 ° C or higher, particularly preferably 150 ° C or higher, preferably 300 ° C or lower, more preferably 250 ° C or lower, More preferably, it is 200 ° C. or lower.

  Examples of the additive include an aliphatic hydrocarbon compound having 10 to 20 carbon atoms which may have a substituent if it is a solid or an aromatic hydrocarbon having 10 to 20 carbon atoms which may have a substituent. Aromatic compounds having 10 to 20 carbon atoms are preferred. A specific example is a naphthalene compound, and a compound in which one or more and eight or less substituents are bonded to naphthalene is particularly preferable. Examples of the substituent bonded to naphthalene include a halogen atom, a hydroxyl group, a cyano group, an amino group, an amide group, a carbonyloxy group, a carboxy group, a carbonyl group, an oxycarbonyl group, a silyl group, an alkenyl group, an alkynyl group, and an alkoxy group. , An aryloxy group, an alkylthio group, an arylthio group or an aromatic group.

  If the additive is a liquid, an aliphatic hydrocarbon compound having 8 to 9 carbon atoms which may have a substituent or an aromatic compound having 8 to 9 carbon atoms which may have a substituent may be used. No. A specific example is a dihalogen hydrocarbon compound, and a compound in which one or more and eight or less substituents are bonded to octane is particularly preferable. Examples of the substituent bonded to octane include a halogen atom, a hydroxyl group, a mercapto group, a cyano group, an amino group, a carbamoyl group, a carbonyloxy group, a carboxyl group, a carbonyl group, or an aromatic group, and fluorine, chlorine, Halogen atoms such as bromine and iodine are preferred. Another example of the additive includes a benzene compound having 4 to 6 halogen atoms bonded thereto.

  The amount of the additive contained in the coating liquid containing the p-type semiconductor compound and the n-type semiconductor compound is preferably at least 0.1 vol / vol%, more preferably at least 0.5 vol / vol%, based on the whole coating liquid. preferable. Further, it is preferably 10% by volume / volume or less, more preferably 5% by volume / volume% or less based on the whole coating solution. When the amount of the additive is in this range, a preferable phase separation structure can be obtained.

1.1.2 P-type Semiconductor Compound The active layer (IV) contains at least the polymer compound (1) as a p-type semiconductor compound.

Polymer compound (1)
The polymer compound (hereinafter, sometimes referred to as “polymer compound (1)”) used in the photoelectric conversion element of the present invention is one kind of a p-type semiconductor compound and is a benzo compound represented by the formula (1). It has a bisthiazole structural unit (hereinafter, may be referred to as a “structural unit represented by the formula (1)”).

[In equation (1),
T ¹ and T ² are each independently a thiophene ring optionally substituted with an alkoxy group, a thioalkoxy group, a hydrocarbon group or an organosilyl group, a thiazole optionally substituted with a hydrocarbon group or an organosilyl group. Represents a ring or a phenyl group which may be substituted with a hydrocarbon group, an alkoxy group, a thioalkoxy group, an organosilyl group, a halogen atom, or a trifluoromethyl group.
B ¹ and B ² represent a thiophene ring optionally substituted with a hydrocarbon group, a thiazole ring optionally substituted with a hydrocarbon group, or an ethynylene group. ]

Since the polymer compound used in the present invention has the benzobisthiazole structural unit represented by the formula (1), the band gap can be narrowed while the HOMO level is deepened, which is advantageous for increasing the photoelectric conversion efficiency. It is. The polymer compound (1) is preferably a donor-acceptor semiconductor polymer obtained by copolymerizing a structural unit represented by the formula (1) and a copolymer component (2) described later. The donor-acceptor type semiconductor polymer means a high molecular compound in which donor units and acceptor units are alternately arranged. The donor unit means an electron-donating structural unit, and the acceptor unit means an electron-accepting structural unit. The donor-acceptor type semiconductor polymer is preferably a polymer compound in which a structural unit represented by the formula (1) and a copolymer component (2) described later are alternately arranged. With such a structure, it can be suitably used as a p-type semiconductor compound.
In this specification, an organosilyl group means a monovalent group in which one or more hydrocarbon groups are substituted on Si atoms, and the number of hydrocarbon groups substituted with Si atoms is two or more. The number is preferably three or less, and more preferably three.

In the benzobisthiazole structural unit represented by the formula (1), T ¹ and T ² may be the same or different from each other, but are preferably the same from the viewpoint of easy production.
In the benzobisthiazole structural unit represented by the formula (1), T ¹ and T ² are preferably groups represented by the following formulas (t1) to (t5). Specifically, the alkoxy group of T ¹ and T ² is preferably a group represented by the following formula (t1), and the thioalkoxy group is preferably a group represented by the following formula (t2). The thiophene ring optionally substituted with a group or an organosilyl group is preferably a group represented by the following formula (t3), and the thiazole ring optionally substituted with a hydrocarbon group or an organosilyl group includes The group represented by t4) is preferable. Examples of the phenyl group which may be substituted with a hydrocarbon group, an alkoxy group, a thioalkoxy group, an organosilyl group, a halogen atom, or a trifluoromethyl group include compounds represented by the following formula (t5) ) Is preferred. When T ¹ and T ² are groups represented by the following formulas (t1) to (t5), they can absorb short-wavelength light and have high planarity, so that π-π stacking is efficient. Is formed, so that the photoelectric conversion efficiency can be further improved.

[In the formulas (t1) to (t5), R ^{13 to} R ¹⁴ each independently represent a hydrocarbon group having 6 to 30 carbon atoms. R ¹⁵ to R ¹⁶ are each independently a hydrocarbon group having 6 to 30 carbon atoms, ^{or,, * - Si (R 18} ) a group represented by _3. R ^{15 ′} represents a hydrogen atom, a hydrocarbon group having 6 to 30 carbon atoms, or a group represented by * —Si (R ¹⁸ ) ₃ . R ¹⁷ represents a halogen atom, a hydrocarbon group having 6 to 30 carbon atoms, * -OR ¹⁹ , * -SR ²⁰ , * -Si (R ¹⁸ ) ₃ , or * -CF ₃ . R ¹⁸ independently represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and a plurality of R ¹⁸ may be the same or different. R ^{19 to} R ²⁰ represent a hydrocarbon group having 6 to 30 carbon atoms. * Represents a bond bonded to the thiazole ring of benzobisthiazole. ]

In the formulas (t1) to (t5), the hydrocarbon group having 6 to 30 carbon atoms represented by R ^{13 to} R ¹⁷ , R ^{19 to} R ²⁰ , and R ^{15 ′} is preferably a branched hydrocarbon group. And more preferably a branched saturated hydrocarbon group. The hydrocarbon group of R ^{13 to} R ¹⁷ , R ^{19 to} R ²⁰ , and R ^{15 ′} can increase the solubility in an organic solvent by having a branch, and the polymer compound of the present invention has appropriate crystallinity. Obtainable. The larger the carbon number of the hydrocarbon group of R ^{13 to} R ¹⁷ , R ^{19 to} R ²⁰ and R ^{15 ′} , the higher the solubility in an organic solvent can be. Therefore, the synthesis of a polymer compound becomes difficult. Therefore, the carbon number of the hydrocarbon group of R ^{13 to} R ¹⁷ , R ^{19 to} R ²⁰ , and R ^{15 ′} is preferably 8 to 25, more preferably 8 to 20, and further preferably 8 to 16. is there.

^{R 13 ~R 17, R 19 ~R} 20, the hydrocarbon group having 6 to 30 carbon atoms represented by R ^{15 ',} for example, C ₆ alkyl group such as n- hexyl group; such as n- heptyl C ₇ alkyl group: n-octyl group, 1-n-Buchirubuchiru group, 1-n-propyl pentyl group, 1-ethylhexyl group, a 2-ethylhexyl group, 3-ethylhexyl group, 4-ethylhexyl group, 1-methylheptyl group , 2-methylheptyl group, 6-methylheptyl group, a 2,4,4-trimethylpentyl group, 2,5-dimethyl-hexyl C ₈ alkyl group such group; n-nonyl group, 1-n-propyl-hexyl group, 2-n-propylhexyl group, 1-ethylheptyl group, 2-ethylheptyl group, 1-methyloctyl group, 2-methyloctyl group, 6-methyloctyl group, 2,3,3,4-tetramethylpen Le group, 3,5,5 C ₉ alkyl group such as trimethyl hexyl group; n-decyl group, 1-n-Penchirupenchiru group, 1-n-butyl hexyl group, 2-n-butyl hexyl group, 1- n- propyl-heptyl group, 1-ethyl-octyl group, 2-ethyl-octyl group, 1-methylnonyl group, 2-methylnonyl group, C ₁₀ alkyl group such as 3,7-dimethyl octyl group; n- undecyl group, 1-n - butyl heptyl group, 2-n-butyl-heptyl group, 1-n-propyl-octyl group, 2-n-propyl-octyl group, 1-Echirunoniru group, 2-Echirunoniru C ₁₁ alkyl group such group; n-dodecyl group, 1-n-pentylheptyl group, 2-n-pentylheptyl group, 1-n-butyloctyl group, 2-n-butyloctyl group, 1-n-propylnonyl group, 2-n-propylnonyl C ₁₂ alkyl group such as; n-tridecyl group, 1-n-pentyl-octyl group, 2-n-pentyl-octyl group, 1-n-Buchirunoniru group, 2-n-Buchirunoniru group, 1-methyl-dodecyl group, 2- A C ₁₃ alkyl group such as a methyl dodecyl group; n-tetradecyl group, 1-n-heptylheptyl group, 1-n-hexyloctyl group, 2-n-hexyloctyl group, 1-n-pentylnonyl group, 2-n - Penchirunoniru C ₁₄ alkyl group such group; n-pentadecyl group, 1-n-heptyl-octyl group, 1-n-hexyl-nonyl group, 2-n- C ₁₅ alkyl group such as hexyl nonyl group; n-hexadecyl group , 2-n-hexyl-decyl group, 1-n-octyl-octyl group, 1-n-Hepuchirunoniru group, C ₁₆ alkyl group such as 2-n-Hepuchirunoniru group; n-heptadecyl group, 1- - C ₁₇ alkyl group such as octyl nonyl group; n- octadecyl, C ₁₈ alkyl group such as 1-n- Nonirunoniru group; C ₁₉ alkyl group such as n- nonadecyl; n- eicosyl group, 2-n- octyl C ₂₃ alkyl group such as n- tricosyl;; C ₂₂ alkyl group such as n- docosyl group; C ₂₁ alkyl group such as n- heneicosyl group; C ₂₀ alkyl group such as dodecyl n- tetracosyl group, 2-n - C ₂₄ alkyl group such as decyl tetradecyl group; and the like. Preferably a C ₈ -C ₂₈ alkyl group, more preferably an alkyl group of C ₈ -C _26, more preferably a C ₈ -C ₂₆ branched alkyl group, even more preferably C ₈ -C _{It is a 24-} branched alkyl group. Particularly preferred are 2-ethylhexyl, 3,7-dimethyloctyl, 2-n-butyloctyl, 2-n-hexyldecyl, 2-n-octyldodecyl, and 2-n-decyltetradecyl. is there. When R ^{13 to} R ¹⁷ , R ^{19 to} R ²⁰ , and R ^{15 ′} are the above groups, the polymer compound of the present invention has improved solubility in an organic solvent and has appropriate crystallinity.

In the above formula (t1) ~ (t5), the group represented by * -Si (R ¹⁸⁾ ₃ of ^{R 15 ~R 17, R 15 '} , the number of carbon atoms of the aliphatic hydrocarbon group R ¹⁸ is preferably Is 1 to 18, more preferably 1 to 8. Examples of the aliphatic hydrocarbon group for R ¹⁸ include an alkyl group such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an isobutyl group, an octyl group, and an octadecyl group. The carbon number of the aromatic hydrocarbon group for R ¹⁸ is preferably 6 to 8, more preferably 6 to 7, and particularly preferably 6. Examples of the aromatic hydrocarbon group for R ¹⁸ include a phenyl group. Above all, R ¹⁸ is preferably an aliphatic hydrocarbon group, more preferably a branched aliphatic hydrocarbon group, and particularly preferably an isopropyl group. A plurality of R ¹⁸ may be the same or different, but are preferably the same. When R ^{15 to} R ¹⁷ and R ^{15 ′} are groups represented by * —Si (R ¹⁸ ) ₃ , the polymer compound of the present invention has improved solubility in an organic solvent.

In the above formula (t1) ~ (t5), the group represented by * -Si (R ¹⁸⁾ ₃ of ^{R 15 ~R 17, R 15 '} , specifically, trimethylsilyl group, triethylsilyl dimethylsilyl group, Alkylsilyl groups such as isopropyldimethylsilyl group, triisopropylsilyl group, tert-butyldimethylsilyl group, triethylsilyl group, triisobutylsilyl group, tripropylsilyl group, tributylsilyl group, dimethylphenylsilyl group and methyldiphenylsilyl group; Arylsilyl groups such as a triphenylsilyl group and a tert-butylchlorodiphenylsilyl group; and the like. Among them, an alkylsilyl group is preferable, and a trimethylsilyl group and a triisopropylsilyl group are particularly preferable.

In the above formula (t5), when R ¹⁷ is a halogen atom, any of fluorine, chlorine, bromine and iodine can be used. R ¹⁷ is preferably a halogen atom or * -CF ₃ .

R ^{15 ′} is a hydrogen atom, a hydrocarbon group having 6 to 30 carbon atoms exemplified as R ¹⁵ , or a group similar to the group represented by * —Si (R ¹⁸ ) ₃ , and is a hydrogen atom. Is preferred.

As the electron donating groups for T ¹ and T ² , groups represented by the formulas (t1), (t3), and (t5) are preferable from the viewpoint of excellent planarity of the entire structural unit represented by the formula (1). The groups represented by the formula (t3) are more preferable, and the groups represented by the following formulas (t3-1) to (t3-16) are particularly preferable. In the formula, * represents a bond.

As T ¹ and T ² , an electron donating group or an electron withdrawing group can be used. Examples of the electron donating group include groups represented by formulas (t1) to (t3).

[In formulas (t1) to (t3), * represents a bond, and R ^{13 to} R ¹⁵ and R ^{15 ′} represent the same groups as described above. * Represents a bond. ]

The group electron withdrawing that can be used as T ^1, T ^2, for example, a group represented by the formula (t4) ~ (t5).

[In the formulas (t4) to (t5), R ¹⁶ represents the same group as described above. R ¹⁷ represents a halogen atom, a hydrocarbon group having 6 to 30 carbon atoms, * -OR ¹⁹ , * -SR ²⁰ , * -Si (R ¹⁸ ) ₃ , or * -CF ₃ . * Represents a bond. ]

In the benzobisthiazole structural unit represented by the formula (1), B ¹ and B ² may be the same or different, but from the viewpoint of easy production, they are the same. Preferably, there is. In the structural unit represented by the formula (1), B ¹ and B ² are each preferably a group represented by any of the following formulas (b1) to (b3). When B ¹ and B ² are groups represented by the following formulas (b1) to (b3), the resulting polymer compound has good flatness and can further improve the photoelectric conversion efficiency.

[In the formulas (b1) to (b3), R ²¹ , R ²² and R ^{21 ′} represent a hydrogen atom or a hydrocarbon group having 6 to 30 carbon atoms.
* Represents a bond, and particularly * on the left side represents a bond bonded to the benzene ring of the benzobisthiazole compound. ]

Examples of the hydrocarbon group having 6 to 30 carbon atoms of R ²¹ , R ²² , and R ^{21 ′} include the hydrocarbon groups having 6 to 30 carbon atoms of R ^{13 to} R ¹⁷ , R ^{19 to} R ²⁰ , and R ^{15 ′} . A group can be preferably used.
It is preferable that R ²¹ , R ²² , and R ^{21 ′} be hydrogen atoms, because a donor-acceptor type semiconductor polymer can be easily formed. Further, it is preferable that R ²¹ , R ²² , and R ^{21 ′} be a hydrocarbon group having 6 to 30 carbon atoms because the photoelectric conversion efficiency may be further increased.

Further, in the benzobisthiazole structural unit represented by the formula (1), from the viewpoint of excellent planarity as a whole of the structural unit represented by the formula (1), and from the viewpoint of excellent planarity as a whole of the obtained polymer compound, As B ¹ and B ² , groups represented by formulas (b1) and (b2) are more preferable. When B ¹ and B ² are groups represented by the formulas (b1) and (b2), an interaction between an S atom and an N atom occurs in the benzobisthiazole structural unit (1), and the planarity is further improved. . Specifically, groups represented by the following formulas are preferred as B ¹ and B ² . In the formula, * represents a bond, and * on the left side binds to the benzene ring of benzobisthiazole.

  Examples of the structural unit represented by the formula (1) include structural units represented by the following formulas (1-1) to (1-48).

  It is preferable to use a copolymer component (2) (donor unit, acceptor unit) that forms a donor-acceptor type semiconductor polymer in combination with the structural unit represented by the formula (1). As the copolymer component (2), a conventionally known structural unit can be used. Specifically, the following structural units can be mentioned. Among them, structural units represented by the formulas (c1), (c3) to (c5), (c7), (c9), (c12), (c21), (c27), (c37), and (c42) are preferable. Structural units represented by the formulas (c1), (c5), (c9), (c21), (c37), and (c42) are more preferable.

[In formulas (c1) to (c43), R ^{30 to} R ⁷³ and R ^{75 to} R ⁷⁶ each independently represent a hydrogen atom or a hydrocarbon group having 4 to 30 carbon atoms, and R ⁷⁴ represents a hydrogen atom or Represents a hydrocarbon group having 4 to 30 carbon atoms. A ³⁰ and A ³¹ each independently represent the same group as T ¹ and T ^2, and j represents an integer of 1 to 4. ● represents a bond bonded to B ¹ or B ² of the structural unit represented by the formula (1). ]

The hydrocarbon group having 4 to 30 carbon atoms represented by R ³⁰ to R ^76, for example, C ₄ alkyl group such as n- butyl group; C ₅ alkyl group such as n- pentyl; n- hexyl C ₆ alkyl group; n-heptyl C ₇ alkyl group such as: n-octyl group, 1-n-Buchirubuchiru group, 1-n-propyl pentyl group, 1-ethylhexyl group, a 2-ethylhexyl group, 3-ethylhexyl group, 4-ethylhexyl group, 1-methylheptyl group, 2-methylheptyl group, 6-methylheptyl group, a 2,4,4-trimethylpentyl group, C ₈ alkyl group such as 2,5-dimethyl-hexyl; n -Nonyl group, 1-n-propylhexyl group, 2-n-propylhexyl group, 1-ethylheptyl group, 2-ethylheptyl group, 1-methyloctyl group, 2-methyloctyl group, 6-methyloctyl group Butyl group, 2,3,3,4- tetramethyl-pentyl group, 3,5,5 C ₉ alkyl group such as trimethyl hexyl group; n-decyl group, 1-n-Penchirupenchiru group, 1-n-Bed Such as a tylhexyl group, a 2-n-butylhexyl group, a 1-n-propylheptyl group, a 1-ethyloctyl group, a 2-ethyloctyl group, a 1-methylnonyl group, a 2-methylnonyl group, and a 3,7-dimethyloctyl group. C ₁₀ alkyl group; n-undecyl group, 1-n-butyl-heptyl group, 2-n-butyl-heptyl group, 1-n-propyl-octyl group, 2-n-propyl-octyl group, 1-Echirunoniru group, 2- Echirunoniru A C ₁₁ alkyl group such as a group; n-dodecyl group, 1-n-pentylheptyl group, 2-n-pentylheptyl group, 1-n-butyloctyl group, 2-n-butyloctyl group, 1-n - propyl nonyl group, 2-n-propyl-C ₁₂ alkyl group such as a nonyl group; n-tridecyl group, 1-n-pentyl-octyl group, 2-n-pentyl-octyl group, 1-n-Buchirunoniru group, 2-n - Buchirunoniru group, 1-methyl-dodecyl group, C ₁₃ alkyl group such as 2-methyl-dodecyl group; n-tetradecyl group, 1-n-heptyl-heptyl group, 1-n-hexyl-octyl group, 2-n-hexyl-octyl group , 1-n-Penchirunoniru group, C ₁₄ alkyl group such as 2-n-Penchirunoniru group; n-pentadecyl group, 1-n-heptyl-octyl group, 1-n-hexyl-nonyl group, 2-n-hexyl-nonyl C ₁₅ alkyl group such group; n-hexadecyl group, 2-n-hexyl-decyl group, 1-n-octyl-octyl group, 1-n-Hepuchirunoniru group, 2-n-Hepuchirunoniru group C ₁₆ alkyl group; n- octadecyl group, 1-n- Nonirunoniru C ₁₈ alkyl group such as a group;; n- heptadecyl group, 1-n- octyl C ₁₇ alkyl group such as nonyl n- nonadecyl C _19, such as a group alkyl group; n- eicosyl group, 2-n- octyl dodecyl group C ₂₀ alkyl group; n- etc. heneicosyl group C ₂₁ alkyl group; n- docosyl group C ₂₂ alkyl group; such as n- tricosyl C ₂₃ alkyl group; n-tetracosyl group, C ₂₄ alkyl group such as 2-n-decyl-tetradecyl group; and the like. Preferably a C ₈ -C ₂₈ alkyl group, more preferably a C ₈ -C ₂₆ alkyl group, more preferably a C ₈ -C ₂₆ branched alkyl group, even more preferably C ₈ -C ₂₄ A branched alkyl group, particularly preferably a 2-ethylhexyl group, a 3,7-dimethyloctyl group, a 2-n-butyloctyl group, a 2-n-hexyldecyl group, a 2-n-octyldodecyl group, It is an n-decyltetradecyl group. When R ^{30 to} R ⁷³ and R ^{75 to} R ⁷⁶ are the above groups, and R ⁷⁴ is a hydrogen atom or the above group, the polymer compound of the present invention has improved solubility in an organic solvent, It has crystallinity.

The groups represented by the above formulas (c1) to (c30) are groups acting as acceptor units, and the groups represented by the formulas (c32) to (c43) are groups acting as donor units. It is. The group represented by the formula (c31) may function as an acceptor unit or may function as a donor unit depending on the types of A ³⁰ and A ³¹ .

  The repeating ratio of the structural unit represented by the formula (1) in the polymer compound (1) used in the present invention is usually 1 mol% or more, preferably 5 mol% or more, more preferably 15 mol% or more, and still more preferably. Is at least 30 mol%, usually at most 99 mol%, preferably at most 95 mol%, more preferably at most 85 mol%, even more preferably at most 70 mol%.

  The proportion of the repeating unit of the copolymer component (2) in the polymer compound (1) is usually 1 mol% or more, preferably 5 mol% or more, more preferably 15 mol% or more, and still more preferably 30 mol% or more. Alternatively, it is usually 99 mol% or less, preferably 95 mol% or less, more preferably 85 mol% or less, and still more preferably 70 mol% or less.

In the polymer compound (1) according to the present invention, the arrangement state of the structural unit represented by the formula (1) of the repeating unit and the copolymer component (2) may be any of alternating, block and random. That is, the polymer compound (1) according to the present invention may be any of an alternating copolymer, a block copolymer, and a random copolymer. Preferably, they are arranged alternately.

  In the polymer compound (1), the structural unit represented by the formula (1) and the copolymer component (2) may each contain only one type. Further, two or more structural units represented by the formula (1) may be contained, and two or more copolymer components (2) may be contained. The number of types of the structural unit and the copolymer component (2) represented by the formula (1) is usually 8 or less, preferably 5 or less. Particularly preferably, it is a polymer compound (1) containing one kind of the structural unit represented by the formula (1) and one kind of the copolymer component (2) alternately, and most preferably the formula (1) ) Is a polymer compound (1) alternately containing only one type of the structural unit represented by the formula (1) and only one type of the copolymer component (2).

Preferred specific examples of the polymer compound (1) are shown below. However, the polymer compound (1) according to the present invention is not limited to the following examples. In the following specific examples, ^RT is n-octyl group, 2-ethylhexyl group, 3,7-dimethyloctyl group, 2-n-butyloctyl, 2-n-hexyldecyl group, 2-n-octyldodecyl group, Represents a 2-n-decyltetradecyl group or a triisopropylsilyl group. R ^{30 to} R ⁷³ and R ^{75 to} R ^{76 each} represent a hydrogen atom, an n-octyl group, a 2-ethylhexyl group, a 3,7-dimethyloctyl group, a 2-n-butyloctyl group, or a 2-n-hexyldecyl group. Table R ⁷⁴ represents a hydrogen atom, or an n-octyl group, a 2-ethylhexyl group, a 3,7-dimethyloctyl group, a 2-n-butyloctyl, a 2-n-hexyldecyl group, a 2-n-octyldodecyl group, Represents a 2-n-decyltetradecyl group or a triisopropylsilyl group. When the polymer compound (1) contains a plurality of types of repeating units, the ratio of the number of each repeating unit is arbitrary.

  The polymer compound (1) used in the present invention preferably has an absorption in a long wavelength region (preferably 600 nm or more, more preferably 650 nm or more). Further, a photoelectric conversion element using the polymer compound (1) exhibits a high open-circuit voltage (Voc) and exhibits high photoelectric conversion characteristics. When the polymer compound (1) is used as a p-type semiconductor compound and the fullerene compound is used as an n-type semiconductor compound, particularly high photoelectric conversion characteristics are exhibited. Further, the polymer compound (1) according to the present invention also has an advantage that the HOMO energy level is low and it is hard to be oxidized.

  In addition, since the polymer compound (1) exhibits high solubility in a solvent, there is an advantage that coating and film formation are easy. In addition, since the range of choices of the solvent when performing the coating film formation is widened, a solvent more suitable for the film formation can be selected, and the film quality of the formed active layer can be improved. This is also considered to be one reason that the photoelectric conversion element using the polymer compound (1) according to the present invention exhibits high photoelectric conversion characteristics.

  In general, the weight average molecular weight and the number average molecular weight of the polymer compound (1) of the present invention are preferably from 2,000 to 500,000, more preferably from 3,000 to 200,000. is there. The weight average molecular weight and the number average molecular weight of the polymer compound (1) of the present invention can be calculated based on a calibration curve prepared by using gel permeation chromatography and using polystyrene as a standard sample.

  The polymer compound (1) according to the present invention preferably has a light absorption maximum wavelength (λmax) of 400 nm or more, more preferably 450 nm or more, and usually 1200 nm or less, preferably 1000 nm or less, more preferably 900 nm or less. The half width is usually at least 10 nm, preferably at least 20 nm, and usually at most 300 nm. Further, the absorption wavelength region of the polymer compound (1) according to the present invention is preferably as close to the absorption wavelength region of sunlight.

  The solubility of the polymer compound (1) according to the present invention is preferably such that the solubility in chlorobenzene at 25 ° C. is usually 0.1% by mass or more, more preferably 0.4% by mass or more, further preferably 0.8% by mass or more. And usually 30% by mass or less, preferably 20% by mass. High solubility is preferred in that a thicker active layer can be formed.

  The polymer compound (1) according to the present invention preferably interacts between molecules. In the present invention, the interaction between molecules means that the distance between polymer chains is shortened by π-π stacking interaction between the molecules of the polymer compound. As the interaction becomes stronger, the polymer compound tends to show higher carrier mobility and / or crystallinity. That is, since charge transfer between molecules is likely to occur in a polymer compound that interacts between molecules, the p-type semiconductor compound (polymer compound (1)) in the active layer (IV) and the n-type semiconductor compound It is considered that holes generated at the interface can be efficiently transported to the anode (VI).

Method for Producing Polymer Compound (1) The method for producing the polymer compound (1) used in the present invention includes, for example, 2,6-diiodobenzo [1,2-d: 4,5-d ′] bisthiazole and Starting from one compound selected from the group consisting of 2,6-dibromobenzo [1,2-d: 4,5-d ′] bisthiazole as a starting material, a compound represented by formula (3):

[In the formula (3), T ¹ and T ² each independently represent an thiophene ring, a hydrocarbon group or an organosilyl group which may be substituted with an alkoxy group, a thioalkoxy group, a hydrocarbon group or an organosilyl group. Represents a thiazole ring which may be substituted, or a phenyl group which may be substituted with a hydrocarbon group, an alkoxy group, a thioalkoxy group, an organosilyl group, a halogen atom, or a trifluoromethyl group. ]

  A compound represented by the formula (4):

[In the formula (4), T ¹ and T ² each represent the same group as described above. X ¹ and X ² represent chlorine, bromine or iodine. ]

  A compound represented by the formula (5),

[In the formula (5), T ¹ and T ² represent the same groups as described above. B ¹ and B ² represent a thiophene ring optionally substituted with a hydrocarbon group, a thiazole ring optionally substituted with a hydrocarbon group, or an ethynylene group. ]
And a manufacturing method characterized by passing through.

  The method for producing the polymer compound (1) used in the present invention further comprises a compound represented by the formula (6):

[In the formula (6), T ¹ and T ² represent the same groups as described above. B ³ and B ⁴ represent the same groups as B ¹ and B ² . R ^{1 to} R ⁴ each independently represent an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, or an aryloxy group having 6 to 10 carbon atoms. M ¹ and M ² each independently represent a boron atom or a tin atom. R ¹ and R ² may form a ring together with M ¹ , and R ³ and R ⁴ may form a ring together with M ² . m and n each represent an integer of 1 or 2. When m and n are 2, a plurality of R ¹ and R ³ may be the same or different. ]
Is preferred.

The compound of the above formula (6) can be produced, for example, as follows.
First step: Formula (7) and / or Formula (8) in the presence of a 2,6-dihalogenated benzobisthiazole and a metal catalyst

[In the formulas (7) and (8), T ¹ and T ² each represent the same group as described above. R ^5, R ⁶ each independently represent a hydrogen atom or a * - represents the _{^{M 3 (R 7) k R}} 8. R ⁷ and R ⁸ each independently represent an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, or an aryloxy group having 6 to 10 carbon atoms. M ³ represents a boron atom or a tin atom. * Represents a bond. R ⁷ and R ⁸ may form a ring together with M ³ . k represents an integer of 1 or 2. When k is 2, a plurality of R ⁷ may be the same or different. ]
Reacting a compound represented by formula (3) to obtain a compound represented by formula (3)

Second step: a step of reacting a compound represented by the formula (3) with a base and a halogenating reagent to obtain a compound represented by the formula (4).

  Furthermore, the compound represented by the formula (6) can be obtained by including the following third step, fourth step and fifth step.

Third step: a compound represented by the formula (4) is reacted with a compound represented by the following formula (9) and / or the formula (10) in the presence of a metal catalyst to give a compound represented by the formula (5). Obtaining a compound.

[In the formulas (9) and (10), B ¹ and B ² each represent the same group as described above. R ^{9 to} R ¹² are each independently an aliphatic hydrocarbon group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 6 to 10 carbon atoms. Represents an aryloxy group. M ⁴ and M ⁵ represent a boron atom, a tin atom, or a silicon atom. R ⁹ and R ¹⁰ may form a ring together with M ⁴ , and R ¹¹ and R ¹² may form a ring together with M ⁵ . p represents an integer of 1 or 2. When p is 2, a plurality of R ⁹ may be the same or different. ]

Fourth step: a step of reacting a compound represented by the formula (5) with a base and a tin halide compound to obtain a compound represented by the formula (6).
In the present invention, a thiophene ring (preferably a group represented by the formula (b1)) in which B ¹ and B ² of the compound represented by the formula (5) may be substituted with a hydrocarbon group, or In the case of a thiazole ring (preferably a group represented by the formula (b2)) which may be substituted with a hydrocarbon group, the method preferably includes a fourth step.

Coupling reaction Further, the polymer compound (1) is combined with a donor-acceptor type by combining the structural unit represented by the formula (1) and the copolymer component (2) alternately by a coupling reaction. It can be produced as a polymer compound (donor-acceptor type semiconductor polymer).

  The coupling reaction can be performed by reacting the compound represented by the formula (6) with any of the compounds represented by the following formulas (C1) to (C43) in the presence of a metal catalyst. Structural units represented by the formulas (C1), (C3) to (C5), (C7), (C9), (C12), (C21), (C27), (C37), and (C42) are preferable. Structural units represented by (C1), (C5), (C9), (C21), (C37) and (C42) are more preferred.

[In the formulas (C1) to (C43), R ^{30 to} R ⁷³ and R ^{75 to} R ⁷⁶ each independently represent a hydrogen atom or a hydrocarbon group having 4 to 30 carbon atoms, and R ⁷⁴ represents a hydrogen atom. Alternatively, it represents a hydrocarbon group having 4 to 30 carbon atoms. A ³⁰ and A ³¹ each independently represent the same group as T ¹ and T ^2, and X represents a halogen atom. j represents an integer of 1 to 4. ]

Other p-type Semiconductor Compound The active layer (IV) contains at least the polymer compound (1) according to the present invention as a p-type semiconductor compound. However, it is also possible to mix and / or laminate a p-type semiconductor compound different from the polymer compound (1) with the polymer compound (1). As another p-type semiconductor compound that can be used in combination, for example, an organic semiconductor compound (11) can be mentioned. Hereinafter, the organic semiconductor compound (11) will be described. The organic semiconductor compound (11) may be a high-molecular organic semiconductor compound or a low-molecular organic semiconductor compound, but is preferably a high-molecular organic semiconductor compound.

Organic semiconductor compound (11)
Examples of the organic semiconductor compound (11) include conjugated copolymer semiconductor compounds such as polythiophene, polyfluorene, polyphenylenevinylene, polythienylenevinylene, polyacetylene, and polyaniline; and copolymer semiconductors such as oligothiophene substituted with an alkyl group or another substituent. And the like. Further, a copolymer semiconductor compound obtained by copolymerizing two or more types of monomer units is also included. Conjugated copolymers are described, for example, in Handbook of Conducting Polymers, 3rd Ed. (2 volumes), 2007; Polym. Sci. Part A: Polym. Chem. 2013, 51, 743-768; Am. Chem. Soc. 2009, 131, 13886-13887, Angew. Chem. Int. Ed. 2013, 52, 8341-8344, Adv. Mater. Copolymers and derivatives thereof described in known literatures such as 2009, 21, 2093-2097, and copolymers that can be synthesized by a combination of the described monomers can be used. The organic semiconductor compound (11) may be a single compound or a mixture of multiple compounds. Use of the organic semiconductor compound (11) can be expected to increase the amount of light absorbed by adding an absorption wavelength band.

  Specific examples of the organic semiconductor compound (11) include the following, but are not limited to the following.

  HOMO (highest occupied molecular orbital) of a p-type semiconductor compound (polymer compound (1) or a mixture of polymer compound (1) and another p-type semiconductor compound, preferably polymer compound (1)) ) The energy level can be selected according to the type of an n-type semiconductor compound described later. In particular, when a fullerene compound is used as an n-type semiconductor compound, the lower limit of the HOMO energy level of the p-type semiconductor compound is usually -7 eV or more, more preferably -6.5 eV or more, and particularly preferably -6.2 eV or more. is there. On the other hand, the upper limit of the HOMO energy level is usually -4.0 eV or less, more preferably -4.5 eV or less, and particularly preferably -5.1 eV or less. Since the HOMO energy level of the p-type semiconductor compound is appropriately increased, the characteristics as a p-type semiconductor are improved, and the HOMO energy level of the p-type semiconductor compound is moderately suppressed. The stability of the compound is improved, and the open circuit voltage (Voc) is also improved.

  The LUMO (lowest unoccupied molecular orbital) energy level of the p-type semiconductor compound can be selected according to the type of an n-type semiconductor compound described later. In particular, when a fullerene compound is used as an n-type semiconductor compound, the LUMO energy level of the p-type semiconductor compound is usually -4.5 eV or more, preferably -4.3 eV or more, and usually -2.5 eV or less, preferably -2.7 eV or less. Since the LUMO energy level of the p-type semiconductor is appropriately suppressed, the band gap can be adjusted, light energy of a long wavelength can be effectively absorbed, and the short-circuit current density can be improved. Since the LUMO energy level of the p-type semiconductor compound is appropriately increased, electron transfer to the n-type semiconductor compound is likely to occur, and the short-circuit current density is improved.

The method of calculating the LUMO energy level and the HOMO energy level includes a method of theoretically obtaining a calculated value and a method of actually measuring the calculated value. As a method of theoretically obtaining a calculated value, there are a semi-empirical molecular orbital method and a non-empirical molecular orbital method. Examples of the method of actually measuring include an ultraviolet-visible absorption spectrum measuring method and an ionization potential measured by an ultraviolet photoelectron analyzer ("AC-3", manufactured by Riken Keiki Co., Ltd.) under normal temperature and normal pressure.
Among them, AC-3 measurement is preferable, and the AC-3 measurement method is used in the present invention.

1.1.3 n-type semiconductor compound An n-type organic semiconductor compound is generally a π-electron conjugated compound having a lowest unoccupied orbital (LUMO) level of 3.5 to 4.5 eV. , Fullerenes or derivatives thereof, perfluoro compounds in which hydrogen atoms of a p-type organic semiconductor compound such as octazaporphyrin are substituted with fluorine atoms (for example, perfluoropentacene or perfluorophthalocyanine), naphthalenetetracarboxylic anhydride, naphthalenetetracarboxylic acid Examples thereof include aromatic carboxylic acid anhydrides such as acid diimide, perylene tetracarboxylic acid anhydride, and perylene tetracarboxylic acid diimide, and high molecular compounds containing imides thereof as a skeleton.

Among these n-type organic semiconductor compounds, fullerene or a derivative thereof is preferable because charge separation from a p-type semiconductor compound having the specific structural unit of the present invention (particularly, the polymer compound (1)) can be performed quickly and efficiently.
Examples of fullerenes and derivatives thereof include C60 fullerenes, C70 fullerenes, C76 fullerenes, C78 fullerenes, C84 fullerenes, C240 fullerenes, C540 fullerenes, mixed fullerenes, fullerene nanotubes, and some of which are hydrogen atoms, halogen atoms, substituted or unsubstituted. Examples include fullerene derivatives substituted by a substituted alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, cycloalkyl group, silyl group, ether group, thioether group, amino group, silyl group, and the like.

  As the fullerene derivative, phenyl-C61-butyrate, diphenyl-C62-bis (butyrate), phenyl-C71-butyrate, phenyl-C85-butyrate or thienyl-C61-butyrate are preferred. The carbon number of the alcohol moiety is preferably 1 to 30, more preferably 1 to 8, still more preferably 1 to 4, and most preferably 1.

  Examples of preferred fullerene derivatives include phenyl-C61-butyric acid methyl ester ([60] PCBM), phenyl-C61-butyric acid n-butyl ester ([60] PCBnB), and phenyl-C61-butyric acid isobutyl ester ([60] PCBiB). Phenyl-C61-butyric acid n-hexyl ester ([60] PCBH), phenyl-C61-butyric acid n-octyl ester ([60] PCBO), diphenyl-C62-bis (butyric acid methyl ester) (bis [60] PCBM) Phenyl-C71-butyric acid methyl ester ([70] PCBM), phenyl-C85-butyric acid methyl ester ([84] PCBM), thienyl-C61-butyric acid methyl ester ([60] ThCBM), C60 pyrrolidine tris acid, C60 pyrrolidine Tris acid ethyl ester, -Methylfuralopyrrolidine (MP-C60), (1,2-methanofullerene C60) -61-carboxylic acid, (1,2-methanofullerene C60) -61-carboxylic acid t-butyl ester, JP-A-2008-130889. No. 7,329,709 and the like, and fullerenes having a cyclic ether group.

1.2 Cathode (II), Anode (VI)
The cathode (II) and the anode (VI) have a function of collecting holes and electrons generated by light absorption. Therefore, it is preferable to use an electrode (II) (cathode) suitable for collecting electrons and an electrode (VI) (anode) suitable for collecting holes as the pair of electrodes. One of the pair of electrodes (preferably, the cathode (II)) only needs to be light-transmitting, and both may be light-transmitting. Translucent means that sunlight transmits at least 40%. In addition, it is preferable that the solar light transmittance of the transparent electrode having a light-transmitting property is 70% or more in order to allow the light to reach the active layer (IV) through the transparent electrode. The light transmittance can be measured with an ordinary spectrophotometer.

  The cathode (II) is an electrode generally made of a conductive material having a work function smaller than that of the anode, and having a function of smoothly extracting electrons generated in the active layer (IV).

  Examples of the material of the cathode (II) include conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium-zirconium oxide (IZO), titanium oxide, indium oxide, and zinc oxide. Materials; metals such as gold, platinum, silver, chromium or cobalt or alloys thereof. These substances are preferable because they have a small work function, and are further preferable because a conductive polymer material typified by PEDOT: PSS in which a polythiophene derivative is doped with polystyrenesulfonic acid can be stacked. In the case of laminating such a conductive polymer, since the work function of the conductive polymer material is large, even if the material has a small work function as described above, it is suitable for a cathode such as aluminum or magnesium. Metals can also be widely used.

  When the cathode (II) is a transparent electrode, a light-transmitting conductive metal oxide such as ITO, zinc oxide, or tin oxide is preferably used, and particularly preferably ITO is used.

  The thickness of the cathode (II) is usually at least 10 nm, preferably at least 20 nm, more preferably at least 50 nm, usually at most 10 μm, preferably at most 1 μm, more preferably at most 500 nm. When the thickness of the cathode (II) is appropriately large, the sheet resistance is suppressed, and when the thickness of the cathode (II) is appropriately small, light is efficiently converted into electricity without lowering the light transmittance. Can be. When the cathode (II) is a transparent electrode, it is necessary to select a film thickness that can achieve both light transmittance and sheet resistance.

  The sheet resistance of the cathode (II) is usually preferably 1 Ω / sq or more, usually 1000 Ω / sq or less, preferably 500 Ω / sq or less, more preferably 100 Ω / sq or less.

  Examples of the method for forming the cathode (II) include a vacuum film forming method such as an evaporation method or a sputtering method, and a wet coating method in which an ink containing nanoparticles or a precursor is applied to form a film.

  The anode (VI) is preferably an electrode made of a conductive material having a larger work function than that of the cathode, and having a function of smoothly extracting holes generated in the active layer (IV).

  Materials for the anode (VI) include, for example, metals such as platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, cesium, calcium or magnesium, and alloys thereof; Inorganic salts such as lithium oxide and cesium fluoride; and metal oxides such as nickel oxide, aluminum oxide, lithium oxide and cesium oxide. These materials are preferable because they are materials having a large work function. When an n-type semiconductor compound such as zinc oxide having conductivity is used as the material of the hole transport layer (V), a material having a small work function such as indium tin oxide (ITO) is used as the anode (VI). Can also be used as a material. From the viewpoint of electrode protection, the anode (VI) is preferably a metal electrode formed of a metal such as platinum, gold, silver, copper, iron, tin, aluminum, calcium, or indium, and an alloy using these metals.

  The thickness of the anode (VI) is usually at least 10 nm, preferably at least 20 nm, more preferably at least 50 nm, and usually at most 10 μm, preferably at most 1 μm, more preferably at most 500 nm. When the thickness of the anode (VI) is appropriately large, the sheet resistance is suppressed, and when the thickness of the anode (VI) is appropriately small, light can be efficiently converted into electricity without lowering the light transmittance. it can. When the anode (VI) is used as a transparent electrode, it is necessary to select a film thickness that achieves both light transmittance and sheet resistance.

  The sheet resistance of the anode (VI) is usually 1000 Ω / sq or less, preferably 500 Ω / sq or less, more preferably 100 Ω / sq or less. The lower limit is usually preferably 1 Ω / sq or more.

  Examples of the method for forming the anode (VI) include a vacuum film forming method such as a vapor deposition method or a sputtering method, and a wet coating method in which an ink containing nanoparticles or a precursor is applied to form a film.

  Further, the cathode (II) and the anode (VI) may have a laminated structure of two or more layers. In addition, by performing a surface treatment on the cathode (II) and the anode (VI), the characteristics (such as electric characteristics and wetting characteristics) may be improved.

1.3 Base material (I)
The photoelectric conversion element (VII) usually has a substrate (I) serving as a support. That is, the electrodes (II) and (VI) and the active layer (IV) are formed on the base material.

  The material of the substrate (I) is not particularly limited as long as the effects of the present invention are not significantly impaired. Preferable examples of the material of the substrate (I) include inorganic materials such as quartz, glass, sapphire, and titania; polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, and ethylene vinyl alcohol. Organic materials such as copolymers, fluororesin films, polyolefins such as vinyl chloride or polyethylene, cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene and epoxy resins; paper and synthetic paper Paper materials; composite materials such as stainless steel, titanium, aluminum, and other metals coated or laminated with a surface to impart insulation.

  Examples of the glass include soda glass, blue plate glass, and alkali-free glass. Of these, alkali-free glass is preferred among them because the amount of ions eluted from glass is small.

  As the shape of the base material (I), for example, a plate shape, a film shape, a sheet shape, or the like can be used. The film thickness of the substrate (I) is usually at least 5 μm, preferably at least 20 μm, and is usually at most 20 mm, preferably at most 10 mm. It is preferable that the thickness of the base material (I) is appropriately large because the possibility that the strength of the photoelectric conversion element is insufficient is reduced. It is preferable that the film thickness of the base material (I) is appropriately small because the cost is suppressed and the weight does not increase. When the material of the substrate (I) is glass, the film thickness is usually at least 0.01 mm, preferably at least 0.1 mm, and usually at most 1 cm, preferably at most 0.5 cm. It is preferable that the glass substrate (I) has a moderately large thickness because the mechanical strength increases and the glass substrate (I) hardly breaks. Further, it is preferable that the glass substrate (I) has an appropriately thin film thickness because the weight does not increase.

1.4 Buffer layer (III, V)
The photoelectric conversion element (VII) includes an active layer (IV), a cathode (II) (hereinafter, also referred to as “electrode (II)”), and an anode (VI) (hereinafter, also referred to as “electrode (VI)”). It is preferable to have buffer layers (III) and (V) between them. The buffer layer can be classified into a hole transport layer (V) and an electron transport layer (III). The provision of the buffer layer facilitates the movement of electrons or holes between the active layer (IV) and the cathode (II) or the anode (VI), and can prevent a short circuit between the electrodes. However, in the present invention, the buffer layers (III) and (V) may not be present.

  The hole transport layer (V) and the electron transport layer (III) are arranged so as to sandwich the active layer (IV) between the pair of electrodes (II) and (VI). That is, when the photoelectric conversion element (VII) according to the present invention includes both the hole transport layer (V) and the electron transport layer (III), the anode (VI), the hole transport layer (V), and the active layer (IV) , The electron transport layer (III), and the cathode (II) are arranged in this order. When the photoelectric conversion element (VII) according to the present invention includes the hole transport layer (V) and does not include the electron transport layer (III), the anode (VI), the hole transport layer (V), the active layer (IV), and The cathodes (II) are arranged in this order.

1.4.1 Electron transport layer (III)
The electron transport layer (III) is a layer for extracting electrons from the active layer (IV) to the cathode (II), and the material constituting the electron transport layer (V) is an electron transport layer for improving the efficiency of electron extraction. Is preferable, and an organic compound or an inorganic compound may be used, but an inorganic compound is preferable.

  Preferred examples of the inorganic compound material include a salt of an alkali metal such as lithium, sodium, potassium, and cesium, and a metal oxide. Among them, the alkali metal salt is preferably a fluoride salt such as lithium fluoride, sodium fluoride, potassium fluoride or cesium fluoride, and the metal oxide is preferably titanium oxide (TiOx) or zinc oxide (ZnO2). Metal oxides having n-type semiconductor characteristics as described in (1) and (2) above are preferable, and polyethyleneimine ethoxylate is preferable as the conductive polymer. More preferably, the inorganic compound material is a metal oxide having n-type semiconductor characteristics, such as titanium oxide (TiOx) or zinc oxide (ZnO). Particularly preferred are zinc oxide (ZnO) and polyethyleneimine ethoxylate. These may be used alone or may be laminated. Although the operating mechanism of such a material is unknown, it is conceivable that when combined with the cathode (II), the work function is reduced and the voltage applied inside the solar cell element is increased.

  The LUMO energy level of the material of the electron transporting layer (III) is usually -4.0 eV or more, preferably -3.9 eV or more, and is usually -1.9 eV or less, preferably -2.0 eV or less. It is preferable that the LUMO energy level of the material of the electron transport layer (III) is appropriately suppressed, since charge transfer can be promoted. It is preferable that the LUMO energy level of the material of the electron transport layer (III) is appropriately increased in that the reverse electron transfer to the n-type semiconductor compound can be prevented.

  The HOMO energy level of the material of the electron transporting layer (III) is usually -9.0 eV or more, preferably -8.0 eV or more, and is usually -5.0 eV or less, preferably -5.5 eV or less. It is preferable that the HOMO energy level of the material of the electron transport layer (III) is appropriately suppressed, since the movement of holes can be prevented. As a method of calculating the LUMO energy level and the HOMO energy level of the material of the electron transport layer (III), a cyclic voltammogram measurement method may be used.

  The thickness of the electron transporting layer (III) is usually 0.1 nm or more, preferably 0.5 nm or more, more preferably 1.0 nm or more, and usually 100 nm or less, preferably 70 nm or less, more preferably 50 nm or less, particularly Preferably it is 30 nm or less. When the thickness of the electron transport layer (III) is appropriately large, it functions as a buffer material. When the thickness of the electron transport layer (III) is appropriately small, electrons can be easily taken out, and photoelectric conversion is performed. Efficiency can be improved.

1.4.2 Hole transport layer (V)
The hole transporting layer (V) is a layer for extracting holes from the active layer (IV) to the anode (VI), and is a hole transporting material that can improve the efficiency of hole extraction. There is no particular limitation. Specifically, conductive polymers such as polythiophene, polypyrrole, polyacetylene, triphenylenediamine or polyaniline doped with sulfonic acid and / or iodine, polythiophene derivatives having a sulfonyl group as a substituent, and conductive organic compounds such as arylamine Examples thereof include compounds, metal oxides having p-type semiconductor characteristics such as molybdenum trioxide, vanadium pentoxide, and nickel oxide; Among them, preferred are conductive polymers doped with sulfonic acid. Poly (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) (PEDOT: PSS) obtained by doping polythiophene derivative with polystyrenesulfonic acid, molybdenum oxide And metal oxides such as vanadium oxide. Alternatively, a thin film of a metal such as gold, indium, silver, or palladium can be used. The thin film of a metal or the like may be formed alone, or may be used in combination with the above organic materials.

  The thickness of the hole transport layer (V) is usually 0.2 nm or more, preferably 0.5 nm or more, more preferably 1.0 nm or more, and usually 400 nm or less, preferably 200 nm or less, more preferably 100 nm or less, particularly Preferably it is 70 nm or less. When the thickness of the hole transport layer (V) is moderately large, it functions as a buffer material. When the thickness of the hole transport layer (V) is moderately thin, holes are easily taken out, and photoelectric conversion is performed. Conversion efficiency can be improved.

  The method for forming the electron transport layer (III) and the hole transport layer (V) is not limited. For example, when a material having sublimation property is used, it can be formed by a vacuum evaporation method or the like. When a material soluble in a solvent is used, for example, it can be formed by a wet coating method such as spin coating or inkjet. When a semiconductor compound is used for the electron transport layer (III), the precursor may be converted to a semiconductor compound after forming a layer containing a semiconductor compound precursor, similarly to the active layer (IV).

1.5 Manufacturing Method of Photoelectric Conversion Element The photoelectric conversion element (VII) can be prepared, for example, according to the following method, using a substrate (I), a cathode (II), an electron transport layer (III), an active layer (IV), and a hole transport layer. (V) and the anode (VI) are sequentially laminated. For example, a glass substrate (manufactured by Geomatec) on which an indium tin oxide (ITO) transparent conductive film (cathode) is patterned is subjected to ultrasonic cleaning with acetone, ultrasonic cleaning with ethanol, and then dried by nitrogen blowing, and UV-cured. Ozone treatment is performed to produce a substrate with a cathode. Next, a 0.5 M zinc acetate / 0.5 M aminoethanol / 2-methoxyethanol solution to be used as an electron transport layer was applied by a spin coater (3000 rpm, 40 seconds), and then annealed at 175 ° C. for 30 minutes to convert the electrons to zinc oxide. A transport layer can be formed. Thereafter, the active layer can be formed by carrying into a glove box, spin-coating a mixed solution of a donor material and an acceptor material under an inert gas atmosphere, and performing annealing or drying under reduced pressure on a hot plate. Next, molybdenum oxide is deposited under reduced pressure to form a hole transport layer. Finally, silver as an electrode is vapor-deposited to form an anode, whereby a photoelectric conversion element can be obtained.
Further, a photoelectric conversion element having a different structure, for example, a photoelectric conversion element not having at least one of the electron transport layer (III) and the hole transport layer (V) can be manufactured by the same method.

1.6 Photoelectric conversion characteristics The photoelectric conversion characteristics of the photoelectric conversion element (VII) can be obtained as follows. The photoelectric conversion element (VII) is irradiated with light of an AM 1.5 G condition at an irradiation intensity of 100 mW / cm ² by a solar simulator, and current-voltage characteristics are measured. From the obtained current-voltage curve, photoelectric conversion characteristics such as photoelectric conversion efficiency (PCE), short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), series resistance, and shunt resistance can be obtained.

2. Organic thin-film solar cell according to the present invention The photoelectric conversion element (VII) according to the present invention is preferably used as a solar cell, particularly a solar cell element of an organic thin-film solar cell. Thin-film solar cells are also included in the technical scope of the present invention.

  The use of the organic thin film solar cell according to the present invention is not limited, and can be used for any purpose. Examples of fields to which the organic thin-film solar cell according to the present invention can be applied include solar cells for building materials, solar cells for automobiles, solar cells for interiors, solar cells for railways, solar cells for ships, solar cells for airplanes, and spacecraft. Solar cells for home appliances, solar cells for home appliances, solar cells for mobile phones, solar cells for toys, and the like.

  The organic thin film solar cell according to the present invention may be used as it is, or may be used as a solar cell module by installing a solar cell on the substrate (I). As a specific example, when a building material plate is used as a base material, a solar cell panel can be manufactured as a solar cell module by providing a thin-film solar cell on the surface of the plate.

  This application claims the benefit of priority based on Japanese Patent Application No. 2015-029925 filed on February 18, 2015. The entire contents of the specification of Japanese Patent Application No. 2015-029925 filed on Feb. 18, 2015 are incorporated herein by reference.

  Hereinafter, the present invention will be described more specifically with reference to Examples. However, the present invention is not limited to the following Examples, and may be appropriately modified within a range that can conform to the purpose of the preceding and the following. It is, of course, possible to implement them, and all of them are included in the technical scope of the present invention. The measurement method used in the synthesis example is as follows.

NMR Spectrum Measurement The benzobisthiazole compound was subjected to NMR spectrum measurement using an NMR spectrum measurement device (“400MR” manufactured by Agilent (formerly Varian) and “AVANCE500” manufactured by Bruker).

  An example of the synthesis of the polymer compound (1) used in the present invention will be described below. The polymer compound (1) used in the present invention is not limited by the following synthesis examples as well as the synthesis method itself, and the synthesis method itself can be synthesized with appropriate modifications within a range that can be adapted to the gist described above and below. Of course it is possible. In the following, “parts” means “parts by mass” and “%” means “% by mass” unless otherwise specified.

Synthesis Example 1
Synthesis of 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] benzo [1,2-d; 4,5-d '] bisthiazole (DBTH-HDTH)

In a 300 mL flask, 2,6-diiodobenzo [1,2-d; 4,5-d '] bisthiazole (DBTH-DI, 5.2 g, 11.7 mmol), tributyl [5- (2-hexyldecyl) thiophene- 2-yl] stannane (HDT-Sn, 23.2 g, 38.6 mmol), tris (2-furyl) phosphine (443 mg, 1.87 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct ( 490 mg, 0.47 mol) and N, N-dimethylformamide (115 mL) were added and reacted at 120 ° C. for 23 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, added with water, extracted twice with chloroform, and the organic layer was washed with water and dried over anhydrous magnesium sulfate. Then, the crude product obtained by filtration and concentration was purified by column chromatography (silica gel, chloroform / hexane = 1/1) to give 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl. ] Benzo [1,2-d; 4,5-d '] bisthiazole (DBTH-HDTH) was obtained as a pale yellow solid (5.62 g, yield 60%).
¹ H-NMR measurement confirmed that the target compound was formed.

Synthesis Examples 2 to 6
As in Synthesis Example 1, 2,6-bis [5- (3,7-dimethyloctyl) thiophen-2-yl] benzo [1,2-d; 4,5-d ′] bisthiazole (DBTH-DMOTH ) (Synthesis Example 2), 2,6-bis [5- (2-ethylhexyl) thiophen-2-yl] benzo [1,2-d; 4,5-d '] bisthiazole (DBTH-EHTH) (synthesis) Example 3), 2,6-bis [5- (2-butyloctyl) thiophen-2-yl] benzo [1,2-d; 4,5-d ′] bisthiazole (DBTH-BOTH) (Synthesis Example 4) ), 2,6-bis [5- (2-decyltetradecyl) thiophen-2-yl] benzo [1,2-d; 4,5-d '] bisthiazole (DBTH-TDTH) (Synthesis Example 5) , 2,6-bis (5-triisopropylsilanylthiophene-2- Was obtained; [4,5-d '1,2-d] bisthiazole the (DBTH-TIPSTH) (Synthesis Example 6) - Le) benzo. The yield was 38-51%.

Synthesis Example 7
Of 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-diiodobenzo [1,2-d; 4,5-d '] bisthiazole (DI-DBTH-HDTH) Synthesis

In a 100 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] benzo [1,2-d; 4,5-d ′] bisthiazole (DBTH-HDTH, 4 g, 4.97 mmol) ) And tetrahydrofuran (80 mL) were added, and the mixture was cooled to -40 ° C, and lithium diisopropylamide (2 M solution, 5.5 mL, 10.9 mmol) was added dropwise, followed by stirring for 30 minutes. Then, after adding iodine (3.8 g, 14.9 mol), the mixture was reacted at room temperature for 2 hours. After completion of the reaction, 10% sodium bisulfite was added and the mixture was extracted with chloroform. The obtained organic layer was washed with saturated aqueous sodium hydrogen carbonate and then with saturated saline, and dried using anhydrous magnesium sulfate. Then, the crude product obtained by filtration and concentration was purified by column chromatography (silica gel, chloroform / hexane = 1/1) to give 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl. ] -4,8-diiodobenzo [1,2-d; 4,5-d '] bisthiazole (DI-DBTH-HDTH) (2.66 g) was obtained as a yellow solid (yield 51%).
¹ H-NMR measurement confirmed that the target compound was formed.

Synthesis Examples 8 to 12
As in Synthesis Example 7, 2,6-bis [5- (3,7-dimethyloctyl) thiophen-2-yl] -4,8-diiodobenzo [1,2-d; 4,5-d ′] bis Thiazole (DI-DBTH-DMOTH) (Synthesis Example 8), 2,6-bis [5- (2-ethylhexyl) thiophen-2-yl] -4,8-diiodobenzo [1,2-d; 4,5- d ′] Bisthiazole (DI-DBTH-EHTH) (Synthesis Example 9), 2,6-bis [5- (2-butyloctyl) thiophen-2-yl] -4,8-diiodobenzo [1,2-d 4,5-d '] bisthiazole (DI-DBTH-BOTH) (Synthesis Example 10), 2,6-bis [5- (2-decyltetradecyl) thiophen-2-yl] -4,8-diiodobenzo [1,2-d; 4,5-d '] bisthiazole (DI DBTH-TDTH) (Synthesis Example 11), 4,8-diiodo-2,6-bis- (5-triisopropylsilanylthiophen-2-yl) -benzo [1,2-d; 4,5-d ' ] Bisthiazole (DI-DBTH-TIPSTH) (Synthesis Example 12) was obtained. The yield was 36-70%.

Synthesis Example 13
2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-dithiophen-2-yl-benzo [1,2-d; 4,5-d '] bisthiazole (DTH -DBTH-HDTH)

In a 50 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-diiodobenzo [1,2-d; 4,5-d '] bisthiazole (DI-DBTH- HDTH, 1.1 g, 1.04 mmol), tributylthiophen-2-yl-stannane (830 μL, 2.60 mmol), tris (2-furyl) phosphine (40 mg, 0.17 mmol), tris (dibenzylideneacetone) dipalladium A (0) -chloroform adduct (45 mg, 0.04 mmol) and N, N-dimethylformamide (22 mL) were added, and the mixture was reacted at 80 ° C. for 19 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, added with water, extracted twice with chloroform, and the organic layer was washed with water and dried over anhydrous magnesium sulfate. Then, the crude product obtained by filtration and concentration was purified by column chromatography (silica gel, chloroform / hexane = 1/1 to chloroform) to give 2,6-bis [5- (2-hexyldecyl) thiophene-2. 1.01 g of -yl] -4,8-dithiophen-2-yl-benzo [1,2-d; 4,5-d '] bisthiazole (DTH-DBTH-HDTH) was obtained as a yellow solid ( Yield 100%).
¹ H-NMR measurement confirmed that the target compound was formed.

Synthesis Examples 14 to 16
As in Synthesis Example 13, 2,6-bis [5- (2-ethylhexyl) thiophen-2-yl] -4,8-dithiophen-2-yl-benzo [1,2-d; 4,5-d '] Bisthiazole (DTH-DBTH-EHTH) (Synthesis Example 14), 2,6-bis [5- (2-butyloctyl) thiophen-2-yl] -4,8-dithiophen-2-yl-benzo [ 1,2-d; 4,5-d '] bisthiazole (DTH-DBTH-BOTH) (Synthesis Example 15), 2,6-bis [5- (2-decyltetradecyl) thiophen-2-yl]- 4,8-Dithiophen-2-yl-benzo [1,2-d; 4,5-d ′] bisthiazole (DTH-DBTH-TDTH) (Synthesis Example 16) was obtained. The yield was 45-99%.

Synthesis Example 17
2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bisthiazol-2-yl-benzo [1,2-d; 4,5-d ′] bisthiazole ( Synthesis of DTHA-DBTH-HDTH)

In a 30 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-diiodobenzo [1,2-d; 4,5-d '] bisthiazole (DI-DBTH- HDTH, 800 mg, 0.76 mmol), 2-tributylstannanylthiazole (708 mg, 1.89 mmol), tris (2-furyl) phosphine (29 mg, 0.12 mmol), tris (dibenzylideneacetone) dipalladium (0)- Chloroform adduct (32 mg, 30 μmol) and N, N-dimethylformamide (5 mL) were added and reacted at 80 ° C. for 17 hours. After completion of the reaction, the mixture was cooled to room temperature, added with water, extracted twice with chloroform, and the organic layer was washed with water and dried over anhydrous magnesium sulfate. Then, the crude product obtained by filtration and concentration was purified by column chromatography (silica gel, chloroform) to give 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-. Bisthiazol-2-yl-benzo [1,2-d; 4,5-d '] bisthiazole (DTHA-DBTH-HDTH) was obtained as a yellow solid (684 mg, yield 94%).
¹ H-NMR measurement confirmed that the target compound was formed.

Synthesis Example 18
As in Synthesis Example 19, 4,8-bis- (thiazol-2-yl) -2,6-bis- (5-triisopropylsilanylthiophen-2-yl) -benzo [1,2-d; 4 , 5-d '] bisthiazole (DBTH-TIPSTH-THA). Yield was 45%.

Synthesis Example 19
2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-tributylstannylthiophen-2-yl) -benzo [1,2-d; 4,5 -D '] bisthiazole (DTH-DBTH-HDTH-DSB)

In a 50 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-dithiophen-2-yl-benzo [1,2-d; 4,5-d '] bis Add thiazole (DTH-DBTH-HDTH, 602 mg, 0.62 mmol) and tetrahydrofuran (18 mL), cool to −40 ° C., add dropwise lithium diisopropylamide (2 M solution, 0.65 mL, 1.30 mmol) and stir for 30 minutes. did. Thereafter, tributyltin chloride (352 μL, 1.30 mmol) was added, and the mixture was heated to room temperature and stirred for 2 hours. After completion of the reaction, water was added and the mixture was extracted twice with toluene. The organic layer was washed with water and dried over anhydrous magnesium sulfate. Then, the crude product obtained by filtration and concentration was purified by GPC-HPLC (JAIGEL-1H, 2H, chloroform) to give 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl]-. 634 mg of 4,8-bis (5-tributylstannylthiophen-2-yl) -benzo [1,2-d; 4,5-d ′] bisthiazole (DTH-DBTH-HDTH-DSB), pale brown oil (66% yield).
¹ H-NMR measurement confirmed that the target compound was formed.

Synthesis Examples 20 to 23
As in Synthesis Example 19, 2,6-bis [5- (2-ethylhexyl) thiophen-2-yl] -4,8-bis (5-trimethylstanne was used in place of tributyltin chloride instead of trimethyltin chloride. Nylthiophen-2-yl) -benzo [1,2-d; 4,5-d ′] bisthiazole (DTH-DBTH-EHTH-DSM) (Synthesis Example 20), 2,6-bis [5- (2 -Butyloctyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d; 4,5-d '] bisthiazole (DTH-DBTH -BOTH-DSM) (Synthesis Example 21), 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl)- Be Zo [1,2-d; 4,5-d '] bisthiazole (DTH-DBTH-HDTH-DSM) (Synthesis Example 22) 2,6-bis [5- (2-decyltetradecyl) thiophene-2- Yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d; 4,5-d ′] bisthiazole (DTH-DBTH-TDTH-DSM) (Synthesis Example 23) was obtained. The yield was 27-67%.

Synthesis Examples 24 and 25
As in Synthesis Example 21, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-tributylstannylthiazol-2-yl) -benzo [1, 2-d; 4,5-d '] bisthiazole (DTHA-DBTH-HDTH-DSB) (Synthesis Example 24), 4,8-bis (5-tributylstannylthiazol-2-yl) -2,6- Bis (5-triisopropylsilanylthiophen-2-yl) -benzo [1,2-d; 4,5-d '] bisthiazole (DBTH-TIPSTH-THA-DSB) (Synthesis Example 25) was obtained. Yield was 49%.

Synthesis Example 26
Synthesis of P-THDT-DBTH-EH-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-tributylstannylthiophen-2-yl) -benzo [1,2-d 4,5-d '] bisthiazole (DTH-DBTH-HDTH-DSB, 150 mg, 0.10 mmol), 1,3-dibromo-5- (2-ethylhexyl) thieno [3,4-c] pyrrolo-4 , 6-dione (EH-IMTH-DB, 41 mg, 0.10 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (4 mg, 3.9 μmol), tris (o-tolyl) phosphine (5 mg) , 15.5 μmol) and chlorobenzene (12 mL) were added and reacted at 120 ° C. for 22 hours. After completion of the reaction, the reaction solution was added to methanol (60 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Then, P-THDT-DBTH-EH-IMTH was obtained as a black solid (109 mg, 91%) by Soxhlet extraction (chloroform).

Synthesis Example 27
Synthesis of P-THDT-DBTH-O-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d 4,4-d '] bisthiazole (DTH-DBTH-HDTH-DSM, 90 mg, 0.07 mmol), 1,3-dibromo-5-octylthieno [3,4-c] pyrrolo-4,6-dione ( O-IMTH-DB, 30 mg, 0.07 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (3 mg, 2.8 μmol), tris (2-methoxyphenyl) phosphine (4 mg, 11.1 μmol) ) And chlorobenzene (7 mL) were added and reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (50 mL), and the precipitated solid was collected by filtration. The obtained solid was subjected to Soxhlet washing (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 74 mg (87%) of P-THDT-DBTH-O-IMTH was obtained as a black solid.

Synthesis Example 28
Synthesis of P-THDT-DBTH-DMO-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d 4,5-d '] bisthiazole (DTH-DBTH-HDTH-DSM, 80 mg, 0.06 mmol), 1,3-dibromo-5- (3.7-dimethyloctyl) thieno [3,4, -c ] Pyrrolo-4,6-dione (DMO-IMTH-DB, 28 mg, 0.06 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (3 mg, 2.4 μmol), tris (2-methoxy (Phenyl) phosphine (4 mg, 9.6 μmol) and chlorobenzene (3.2 mL) were added and reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (30 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 68 mg (87%) of P-THDT-DBTH-DMO-IMTH was obtained as a black solid.

Synthesis Example 29
Synthesis of P-THDT-DBTH-H-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d 4,5-d '] bisthiazole (DTH-DBTH-HDTH-DSM, 100 mg, 0.08 mmol), 1,3-dibromo-5-hexylthieno [3,4, -c] pyrrolo-4,6-dione (H-IMTH-DB, 31 mg, 0.08 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (3 mg, 3.2 μmol), tris (2-methoxyphenyl) phosphine (4 mg, 12. (8 μmol) and chlorobenzene (8 mL) were added and reacted at 120 ° C. for 22 hours. After completion of the reaction, the reaction solution was added to methanol (40 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Next, 40 mg (44%) of P-THDT-DBTH-H-IMTH was obtained as a black solid by Soxhlet extraction (chloroform).

Synthesis Example 30
Synthesis of P-TEHT-DBTH-HD-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d 4,5-d '] bisthiazole (DTH-DBTH-EHTH-DSM, 100 mg, 0.09 mmol), 1,3-dibromo-5- (2-hexyldecyl) thieno [3,4-c] pyrrolo- 4,6-dione (HD-IMTH-DB, 50 mg, 0.09 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (4 mg, 3.7 μmol), tris (2-methoxyphenyl) phosphine (6 mg, 14.9 μmol) and chlorobenzene (7 mL) were added and reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (40 mL), and the precipitated solid was collected by filtration, and the obtained solid was subjected to Soxhlet washing (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 39 mg (37%) of P-TEHT-DBTH-HD-IMTH was obtained as a black solid.

Synthesis Example 31
Synthesis of P-TEHT-DBTH-ODD-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-ethylhexyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d; 4,5-d '] bisthiazole (DTH-DBTH-EHTH-DSM, 100 mg, 0.09 mmol), 1,3-dibromo-5- (2-octyldodecyl) thieno [3,4, -c] pyrrolo- 4,6-dione (ODD-IMTH-DB, 55 mg, 0.09 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (4 mg, 3.7 μmol), tris (2-methoxyphenyl) phosphine (6 mg, 14.9 μmol) and chlorobenzene (7 mL) were added and reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (40 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 91 mg (76%) of P-TEHT-DBTH-ODD-IMTH was obtained as a black solid.

Synthesis Example 32
Synthesis of P-TBOT-DBTH-HD-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-butyloctyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2-d 4,5-d '] bisthiazole (DTH-DBTH-BOTH-DSM, 70 mg, 0.06 mmol), 1,3-dibromo-5- (2-hexyldecyl) thieno [3,4, -c] pyrrolo -4,6-dione (HD-IMTH-DB, 32 mg, 0.06 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (2 mg, 2.4 μmol), tris (2-methoxyphenyl) Phosphine (4 mg, 9.6 μmol) and chlorobenzene (6 mL) were added and reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (30 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 57 mg (78%) of P-TBOT-DBTH-HD-IMTH was obtained as a black solid.

Synthesis Example 33
Synthesis of P-TTDT-DBTH-B-IMTH

  In a 20 mL flask, 2,6-bis [5- (2-decyltetradecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2- d; 4,5-d '] bisthiazole (DTH-DBTH-TDTH-DSM, 70 mg, 0.05 mmol), 1,3-dibromo-5-butylthieno [3,4, -c] pyrrolo-4,6- Dione (B-IMTH-DB, 17 mg, 0.05 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (2 mg, 2.0 μmol), tris (2-methoxyphenyl) phosphine (3 mg, 8 2.0 μmol) and chlorobenzene (3 mL) were added and reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (30 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 33 mg (52%) of P-TTDT-DBTH-B-IMTH was obtained as a black solid.

Synthesis Example 34
Synthesis of P-TTDT-DBTH-FFTDZ

  In a 20 mL flask, 2,6-bis [5- (2-decyltetradecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2- d; 4,5-d '] bisthiazole (DTH-DBTH-TDTH-DSM, 90 mg, 0.06 mmol), 4,7-dibromo-5,6-difluorobenzo [1,2,5] thiadiazole (FFTDZ- DB, 20 mg, 0.06 mmol), tetrakis (triphenylphosphine) palladium (2 mg, 1.8 μmol), toluene (4 mL), and N, N-dimethylformamide (0.3 mL) were added and reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (40 mL), and the precipitated solid was collected by filtration, and the obtained solid was subjected to Soxhlet washing (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 70 mg (87%) of P-TTDT-DBTH-FFTDZ was obtained as a black solid.

Synthesis Example 35
Synthesis of P-TTDT-DBTH-NTDZ

  In a 20 mL flask, 2,6-bis [5- (2-decyltetradecyl) thiophen-2-yl] -4,8-bis (5-trimethylstannylthiophen-2-yl) -benzo [1,2- d; 4,5-d '] bisthiazole (DTH-DBTH-TDTH-DSM, 80 mg, 0.05 mmol), 5,10-dibromonaphtho [1,2-c: 5,6-c'] bis [1 , 2,5] thiadiazole (NTDZ-DB, 21 mg, 0.05 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (2 mg, 2.0 μmol), tris (2-methoxyphenyl) phosphine ( 3 mg, 8.0 μmol) and chlorobenzene (6 mL) were added and reacted at 120 ° C. for 28 hours. After completion of the reaction, the reaction solution was added to methanol (30 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Subsequently, 63 mg (84%) of P-TTDT-DBTH-NTDZ was obtained as a black solid by Soxhlet extraction (chloroform).

Synthesis Example 36
Synthesis of P-THDT-DBTH-DMO-DPP

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-tributylstannylthiophen-2-yl) -benzo [1,2-d 4,5-d '] bisthiazole (DTH-DBTH-HDTH-DSB, 100 mg, 0.06 mmol), 3,6-bis (5-bromothiophen-2-yl) -2,5- (3,7 -Dimethyloctyl) -2,5-dihydropyrrolo [3,4-c] pyrrole-1,4-dione (DMO-DPP-DB, 49 mg, 0.06 mmol), tris (dibenzylideneacetone) dipalladium (0) -Chloroform adduct (3 mg, 2.6 μmol), tris (o-tolyl) phosphine (3 mg, 10.4 μmol) and chlorobenzene (10 mL) were added, and the mixture was added at 120 ° C. for 23 hours. Reacted for hours. After completion of the reaction, the reaction solution was added to methanol (60 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 26 mg (26%) of P-THDT-DBTH-DMO-DPP was obtained as a black solid.

Synthesis Example 37
Synthesis of P-THHDT-DBTH-HTT

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-tributylstannylthiazol-2-yl) -benzo [1,2-d 4,5-d ′] bisthiazole (DTHA-DBTH-HDTH-DSB, 120 mg, 0.08 mmol), 5,5′-dibromo-3-hexyl [2,2 ′] bithiophenyl (HTT-DB, 32 mg, 0.08 mmol), a tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (3 mg, 3.1 μmol), tris (o-tolyl) phosphine (4 mg, 12.3 μmol) and chlorobenzene (10 mL), and the mixture was added to the mixture. Reaction was performed at 24 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (60 mL), and the precipitated solid was collected by filtration. The obtained solid was washed with Soxhlet (methanol, acetone, and hexane). Subsequently, 72 mg (77%) of P-THHDT-DBTH-HTT was obtained as a black solid by Soxhlet extraction (chloroform).

Synthesis Example 38
Synthesis of P-THHDT-DBTH-EH-BDT

  In a 20 mL flask, 2,6-bis [5- (2-hexyldecyl) thiophen-2-yl] -4,8-bis (5-tributylstannylthiazol-2-yl) -benzo [1,2-d 4,5-d '] bisthiazole (DTHA-DBTH-HDTH-DSB, 120 mg, 0.08 mmol), 2,6-dibromo-4,8-bis (2-ethylhexyloxy) -1,5-dithia -S-indene (EH-BDT-DB, 47 mg, 0.08 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (3 mg, 3.1 μmol), tris (o-tolyl) phosphine (4 mg) , 12.3 μmol) and chlorobenzene (10 mL) were added and reacted at 120 ° C. for 25 hours. After completion of the reaction, the reaction solution was added to methanol (50 mL), and the precipitated solid was collected by filtration. The obtained solid was subjected to Soxhlet washing (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 70 mg (64%) of P-THHDT-DBTH-EH-BDT was obtained as a dark red solid.

Synthesis Example 39
Synthesis of P-THTIPSTH-DBTH-O-IMTH

  In a 20 mL flask, 4,8-bis (5-tributylstannylthiazol-2-yl) -2,6-bis (5-triisopropylsilanylthiophen-2-yl) -benzo [1,2-d; 4 , 5-d '] bisthiazole (DBTH-TIPSTH-THA-DSB, 88 mg, 0.06 mmol), 1,3-dibromo-5-octylthieno [3,4-c] pyrrolo-4,6-dione (O- IMTH-DB, 26 mg, 0.06 mmol), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (3 mg, 2.5 μmol), tris (o-tolyl) phosphine (4 mg, 10 μmol) and chlorobenzene (8 mL) ) And reacted at 120 ° C. for 24 hours. After completion of the reaction, the reaction solution was added to methanol (50 mL), and the precipitated solid was collected by filtration. The obtained solid was subjected to Soxhlet washing (methanol, acetone, and hexane). Then, by Soxhlet extraction (chloroform), 34 mg (50%) of P-THTIPSTH-DBTH-O-IMTH was obtained as a black solid.

Evaluation method of photoelectric conversion element A 0.05027 mm square metal mask was attached to the photoelectric conversion element, and a solar simulator (CEP2000, AM1.5G filter, radiation intensity 100 mW / cm ² , manufactured by Spectrometer) was used as an irradiation light source. The current-voltage characteristics between the ITO electrode and the aluminum electrode were measured using Keithley's Model 2400). From this measurement result, open circuit voltage Voc (V), short circuit current density Jsc (mA / cm ² ), fill factor FF, and photoelectric conversion efficiency PCE (%) were calculated.

Here, the open voltage Voc is a voltage value when the current value is 0 (mA / cm ² ), and the short-circuit current density Jsc is a current density when the voltage value is 0 (V). The fill factor FF is a factor representing the internal resistance, and is expressed by the following equation when the maximum output is Pmax.
FF = Pmax / (Voc × Jsc)
The photoelectric conversion efficiency PCE is given by the following equation, where the incident energy is Pin.
PCE = (Pmax / Pin) × 100
= (Voc x Jsc x FF / Pin) x 100

Example 1

Preparation of mixed solution of p-type semiconductor compound and n-type semiconductor compound A polymer compound having a structure of P-THDT-DBTH-EH-IMTH (Synthesis Example 26) was used as the p-type semiconductor compound.
As an n-type semiconductor compound, PCBM (C61) (phenyl C61 butyric acid methyl ester, Frontier Carbon Co., Ltd., NS-E100H) was used, and a p-type semiconductor compound: n-type semiconductor compound at a mass ratio of 1: 1.5 (total concentration of 2. 0% by mass) and 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound.

Fabrication of photoelectric conversion element A glass substrate (manufactured by Geomatic), on which an indium tin oxide (ITO) transparent conductive film (cathode) is patterned, is subjected to ultrasonic cleaning with acetone and ultrasonic cleaning with ethanol, and then dried by nitrogen blowing. Was.

  After performing the UV-ozone treatment, a 0.5M zinc acetate / 0.5M aminoethanol / 2-methoxyethanol solution used as an electron transport layer was applied by a spin coater (3000 rpm for 40 seconds), and then annealed at 175 ° C. for 30 minutes. .

  After being carried into a glove box, a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound was spin-coated under an inert gas atmosphere, and annealed or dried under reduced pressure on a hot plate.

  With a vapor deposition machine, molybdenum oxide which is a hole transport layer was vapor-deposited. Thereafter, silver as an electrode was vapor-deposited to obtain an inverted device. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 2

Preparation of mixed solution of p-type semiconductor compound and n-type semiconductor compound A polymer compound having a structure of P-THDT-DBTH-EH-IMTH (Synthesis Example 26) was used as the p-type semiconductor compound.
PCBM (C71) (Methyl Phenyl C71 Butyrate, Frontier Carbon, NS-E112) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 1.5 (total concentration of 2. 0 wt%) and 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 3

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-O-IMTH (Synthesis Example 27) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. Using the obtained mixed solution, an inverted structure device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 4

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-O-IMTH (Synthesis Example 17) was used.
PCBM (C71) (phenyl C71 butyric acid methyl ester, manufactured by Frontier Carbon, NS-E112) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 1.5, (total concentration of 2. 0 wt%) and 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 5

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-DMO-IMTH (Synthesis Example 28) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 6

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-DMO-IMTH (Synthesis Example 28) was used.
PCBM (C71) (methyl phenyl C71 butyrate, Frontier Carbon, NS-E112) was used as the n-type semiconductor compound, and the p-type semiconductor compound: n-type semiconductor compound was in a weight ratio of 1: 2 (total concentration: 2.4 wt%). , And 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 7

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-H-IMTH (Synthesis Example 29) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 8

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-H-IMTH (Synthesis Example 29) was used.
PCBM (C71) (phenyl C71 butyric acid methyl ester, manufactured by Frontier Carbon, NS-E112) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 1.5, (total concentration of 2. 0 wt%) and 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 9

As the p-type semiconductor compound, a polymer compound having a structure of P-TEHT-DBTH-HD-IMTH (Synthesis Example 30) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 10

As the p-type semiconductor compound, a polymer compound having a structure of P-TEHT-DBTH-HD-IMTH (Synthesis Example 30) was used.
PCBM (C71) (methyl phenyl C71 butyrate, Frontier Carbon, NS-E112) was used as the n-type semiconductor compound, and the p-type semiconductor compound: n-type semiconductor compound was in a weight ratio of 1: 2 (total concentration: 2.4 wt%). , And 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 11

As the p-type semiconductor compound, a polymer compound having a structure of P-TEHT-DBTH-ODD-IMTH (Synthesis Example 31) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 12

As the p-type semiconductor compound, a polymer compound having a structure of P-TBOT-DBTH-HD-IMTH (Synthesis Example 32) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 13

As the p-type semiconductor compound, a polymer compound having a structure of P-TBOT-DBTH-HD-IMTH (Synthesis Example 32) was used.
PCBM (C71) (phenyl C71 butyric acid methyl ester, manufactured by Frontier Carbon, NS-E112) was used as the n-type semiconductor compound, and the p-type semiconductor compound: n-type semiconductor compound was in a mass ratio of 1: 2 (total concentration: 2.4% by mass). ) And 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 14

As the p-type semiconductor compound, a polymer compound having a structure of P-TTDT-DBTH-B-IMTH (Synthesis Example 33) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 15

As the p-type semiconductor compound, a polymer compound having a structure of P-TTDT-DBTH-FFTDZ (Synthesis Example 34) was used.
Using PCBM (C61) as the n-type semiconductor compound, a mass ratio of p-type semiconductor compound: n-type semiconductor compound of 1: 2 (total concentration of 2.4% by mass) and 1,8-diiodooctane (0.03 mL) / ML) was dissolved in chlorobenzene and passed through a 0.45 µm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 16

As the p-type semiconductor compound, a polymer compound having a structure of P-TTDT-DBTH-FFTDZ (Synthesis Example 34) was used.
PCBM (C71) (methyl phenyl C71 butyrate, Frontier Carbon Co., NS-E112) was used as the n-type semiconductor compound, and the p-type semiconductor compound: n-type semiconductor compound was in a mass ratio of 1: 2 (total concentration: 2.4% by mass). ) And 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 17

As the p-type semiconductor compound, a polymer compound having a structure of P-TTDT-DBTH-NTDZ (Synthesis Example 35) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 18

As the p-type semiconductor compound, a polymer compound having a structure of P-TTDT-DBTH-NTDZ (Synthesis Example 35) was used.
PCBM (C71) (phenyl C71 butyric acid methyl ester, manufactured by Frontier Carbon, NS-E112) as an n-type semiconductor compound, and a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) , And 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed on a hot stirrer at a temperature of 100 ° C. for 2 hours or more. The solution after stirring and mixing was filtered through a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 19

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-DMO-DPP (Synthesis Example 36) was used.
Using PCBM (C61) as the n-type semiconductor compound, a mass ratio of p-type semiconductor compound: n-type semiconductor compound of 1: 2 (total concentration of 2.4% by mass) and 1,8-diiodooctane (0.03 mL) / ML) was dissolved in orthodichlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. Using the obtained mixed solution, an inverted-type device was produced in the same manner as in Example 1. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 20

As the p-type semiconductor compound, a polymer compound having a structure of P-THHDT-DBTH-HTT (Synthesis Example 37) was used.
Using PCBM (C61) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 2 (total concentration: 2.4 wt%) and 1,8-diiodooctane (0.03 mL / mL) was dissolved in chlorobenzene and passed through a 0.45 μm filter to obtain a mixed solution. A device was manufactured in the same manner as in Example 1 using the obtained mixed solution. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

Example 21

As the p-type semiconductor compound, a polymer compound having a structure of P-THDT-DBTH-O-IMTH (Synthesis Example 27) was used.
PCBM (C71) (phenyl C71 butyric acid methyl ester, manufactured by Frontier Carbon, NS-E112) as an n-type semiconductor compound, a p-type semiconductor compound: n-type semiconductor compound in a weight ratio of 1: 1.5, (total concentration of 2. 0 wt%) and 1,8-diiodooctane (0.03 mL / mL) were dissolved in chlorobenzene. This solution was stirred and mixed at a temperature of 100 ° C. for 2 hours or more on a hot stirrer. The solution after stirring and mixing was filtered with a 0.45 μm filter to obtain a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound.

Production of photoelectric conversion element A glass substrate (manufactured by Geomatic), on which an indium tin oxide (ITO) transparent conductive film (cathode) is patterned, is subjected to ultrasonic cleaning with acetone and ultrasonic cleaning with ethanol, and then dried by nitrogen blowing. Was.

  After performing the UV-ozone treatment, a 0.05 wt% polyethyleneimine ethoxylate / 2-methoxyethanol solution used as an electron transport layer was applied by a spin coater (3000 rpm for 40 seconds), and then annealed at 100 ° C. for 1 minute.

  After being carried into a glove box, a mixed solution of a p-type semiconductor compound and an n-type semiconductor compound was spin-coated under an inert gas atmosphere, and annealed or dried under reduced pressure on a hot plate.

  Molybdenum oxide, which is a hole transport layer, was deposited by an evaporator. Thereafter, silver as an electrode was vapor-deposited to obtain an inverted configuration device. The obtained device was evaluated for the photoelectric conversion element. Table 1 shows the results.

  As described above, the photoelectric conversion element made of the polymer compound used in the present invention can achieve a high short-circuit current density (Jsc) and a high open-circuit voltage (Voc), so that a high photoelectric conversion efficiency η can be achieved. It is possible. Further, according to the production method of the present invention, it is possible to introduce various substituents as the substituents, and it is possible to control the properties (crystallinity, film forming property, absorption wavelength) of the material.

(VII) Photoelectric conversion element (VI) Anode (V) Hole transport layer
(IV) Active layer (III) Electron transport layer (II) Cathode (I) Substrate

Claims (11)

A photoelectric conversion element having a structure in which a substrate, a cathode, an active layer, and an anode are arranged in this order,
A photoelectric conversion element, wherein the active layer contains a polymer compound having a benzobisthiazole structural unit represented by the formula (1).
[In equation (1),
T ^1, T ² each independently represents an thiophene ring optionally substituted with charcoal hydrocarbon group or an organosilyl group.
B ¹ and B ² represent a thiophene ring optionally substituted with a hydrocarbon group, a thiazole ring optionally substituted with a hydrocarbon group, or an ethynylene group. ] ^{2. The} photoelectric conversion element according to claim ¹ , wherein T ¹ and T ² of the polymer compound are each a group represented by the following formula (t3) . 3.
Wherein (t3), R ¹⁵ is a hydrocarbon group having a carbon number of 6 to 30, or * - represents a group represented by Si (R ¹⁸⁾ _3.
R ^{15 ′} represents a hydrogen atom, a hydrocarbon group having 6 to 30 carbon atoms, or a group represented by * —Si (R ¹⁸ ) ₃ .
R ¹⁸ independently represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and a plurality of R ¹⁸ may be the same or different .
* Represents a bond bonded to the thiazole ring of benzobisthiazole. ] The photoelectric conversion element according to claim ¹ , wherein B ¹ and B ² are groups represented by any of the following formulas (b1) to (b3).
[In the formulas (b1) to (b3), R ²¹ , R ²² and R ^{21 ′} represent a hydrogen atom or a hydrocarbon group having 6 to 30 carbon atoms.
* Represents a bond, and particularly * on the left side represents a bond bonded to the benzene ring of the benzobisthiazole compound. ]   The photoelectric conversion device according to claim 1, wherein the polymer compound is a donor-acceptor type semiconductor polymer.   The photoelectric conversion element according to claim 1, wherein the active layer further contains an n-type organic semiconductor compound.   The photoelectric conversion device according to claim 5, wherein the n-type organic semiconductor compound is fullerene or a derivative thereof.   The photoelectric conversion device according to any one of claims 1 to 6, further comprising a hole transport layer between the anode and the active layer.   The photoelectric conversion device according to claim 1, further comprising an electron transport layer between the cathode and the active layer.   The photoelectric conversion device according to claim 1, wherein the cathode is a transparent electrode.   The photoelectric conversion device according to any one of claims 1 to 9, wherein the anode is a metal electrode.   An organic thin-film solar cell comprising the photoelectric conversion element according to claim 1.