TW201305237A - Conjugated block copolymer and photoelectric conversion device using same - Google Patents

Abstract

Provided is a conjugated block copolymer which has excellent solubility in solvents and which is capable of forming an organic thin film in which morphology is controlled by a microphase separation. The conjugated block copolymer comprises a bivalent heterocyclic group in a main chain and at least two types of conjugated polymer blocks containing a side chain which is an alykyl group or an alkoxy group which may be substituted with a fluorine atom or a hydroxyl group, and the difference in solubility parameter between the conjugated polymer blocks the solubility parameter of which has a maximum value and a conjugated polymer block the solubility parameter of which has a minimum value is 0.6-2.0.

Description

Conjugated block copolymer and photoelectric conversion element using same

The present invention relates to a conjugated block copolymer which forms an organic thin film as an organic photoelectric conversion layer in a photoelectric conversion element, and a photoelectric conversion element produced using the same.

Solar cells are attracting attention as a powerful source of energy for the environment. At present, a photoelectric conversion element of a solar cell uses an inorganic material such as a single crystal germanium, a polycrystalline germanium, or an amorphous germanium, or an inorganic material such as a compound semiconductor material of GaAs, CIGS, and CdTe. Although these photoelectric conversion elements have high photoelectric conversion efficiency, they are relatively expensive compared with other power supply costs. The main reason for the high cost is the process of manufacturing a semiconductor thin film under high vacuum and high temperature. Therefore, organic semiconductors or organic dyes such as conjugated polymers or organic crystals have been reviewed as organic solar cells which are expected to be manufactured as semiconductor materials with simplified processes. Since these organic semiconductor materials can be formed by a coating method or a printing method, the manufacturing process is simplified, and mass production and availability of an inexpensive organic solar cell can be obtained.

An organic solar cell has a configuration in which an organic photoelectric conversion layer is provided between two different electrodes. Generally, the organic photoelectric conversion layer is formed of a mixture of a conjugated polymer and a fullerene derivative. Representative examples are as follows: poly(3-hexylthiophene) as a conjugated polymer and [6,6]-phenyl C ₆₁ butyric acid methyl ester (PC ₆₁ BM) as a fullerene derivative.

The topic of organic solar cells is to improve the efficiency of photoelectric conversion, especially The photoelectric conversion efficiency is improved by changing the type of the organic photoelectric conversion layer. As a method of changing the form of the organic photoelectric conversion layer, for example, a method of dissolving a conjugated polymer or a fullerene derivative in a solvent by a method of treatment by heat or solvent vapor, and a method of adding a high boiling point compound, A method of reducing the rate of solvent evaporation, and the like.

As another compound, the conjugated block copolymer has been used to control the type of the organic photoelectric conversion layer, and the purpose is to improve the photoelectric conversion efficiency. Block copolymers are known to generally produce microphase separation if they have sufficient molecular weight. It has been reported that even in the conjugated block copolymer, the conversion efficiency can be improved by controlling the structure of the active layer of the organic photoelectric conversion layer by microphase separation (Patent Documents 1 to 8, Non-Patent Documents 1 to 7).

Non-Patent Document 1 proposes a conjugated block copolymer in which a polar machine is introduced into one block of a block copolymer to improve microphase separation performance. However, since the affinity with the fullerene derivative of the N-type organic semiconductor having a very high polarity is small, the fullerene derivative is liable to aggregate, and not sufficient conversion efficiency can be obtained. As for the reason, it is considered that a good form cannot be formed due to aggregation of fullerene derivatives.

Similarly, in the case of a block copolymer of a conjugated polymer and a non-conjugated polymer, since the non-conjugated polymer does not contribute to power generation, high performance cannot be expected. Even if it is a block copolymer of a conjugated polymer and a conjugated polymer, phase separation of the crystal portion and the amorphous portion is observed when the block copolymer contains a conjugated polymer represented by polythiophene. Most of the time, it is not the microphase separation of the block copolymer. As for the reason, for example, since the conjugated block copolymers are difficult to synthesize, two monomers having similar side chains are often used, so The resulting conjugated block copolymer also has a similar framework, and the co-crystals are compatible in the amorphous portion. Further, when co-crystals were formed, microphase separation peculiar to the block copolymer was not formed, and only crystal-amorphous phase separation was observed. In this case, the type control by microphase separation using the advantage of the conjugated block copolymer cannot be achieved, for example, the acceptor material such as a fullerene derivative cannot be biased toward the polymerization present in one of the block copolymers. In the object area, therefore, the improvement of conversion efficiency cannot be expected at all.

For this reason, it is desirable to obtain a sufficient photoelectric conversion efficiency by the microphase separation control type.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] International Publication No. 2009/056496

[Patent Document 2] US Patent No. 7452958

[Patent Document 3] US Patent Application Publication No. 2008/0315751

[Patent Document 4] JP-A-2007-211237

[Patent Document 5] JP-A-2008-223015

[Patent Document 6] JP-A-2010-074127

[Patent Document 7] JP-A-2010-43217

[Patent Document 8] Japanese Patent No. 4126019

[Non-patent literature]

[Non-Patent Document 1] High Performance Polymers, 2007, Vol. 19, pp. 684-699

[Non-Patent Document 2] Macromolecules, 2007, Vol. 40, 4733-4735 pages

[Non-Patent Document 3] Macromolecules, 2008, Vol. 41, pp. 5289-5294

[Non-Patent Document 4] Macromolecules, 2009, Vol. 42, pp. 7008-7015

[Non-Patent Document 5] Macromolecules, 2010, Vol. 43, pp. 3306-3313

[Non-Patent Document 6] Advanced Materials, 2010, Vol. 22, pp. 763-768

[Non-Patent Document 7] Macromolecules, 2011, Vol. 44, pp. 530-539

The present invention has been made to solve the above problems, and an object thereof is to provide a conjugated block copolymer which is excellent in solubility in a solvent and which can form an organic film whose morphology is controlled by microphase separation. And a photoelectric conversion element having an organic thin film containing the same and having excellent photoelectric conversion efficiency.

In order to achieve the above object, the conjugated diene copolymer of claim 1 is characterized in that it contains at least two alkyl groups having a divalent heterocyclic group in the main chain and having a fluorine atom or a hydroxyl group. Conjugation of alkoxy side chains a conjugated block copolymer of a polymer block, and the difference between the solubility parameter of the conjugated polymer block having the maximum solubility parameter value and the conjugated polymer block having the minimum solubility parameter value is 0.6 or more and 2.0 or less .

The conjugated block copolymer of claim 2, wherein the conjugated polymer block is contained in the main chain and has at least one thiophene ring in one of the chemical structures. a condensed ring π conjugated skeleton, a carbazole skeleton, a dibenzosilole skeleton, and a divalent heterocyclic skeleton selected from at least one heterocyclic skeleton of a dibenzogermole skeleton Ring base.

The conjugated block copolymer of claim 3 is the first item of the patent application scope, wherein the conjugated polymer block contains a cyclopentadithiophenediyl group and a dithienopyrrole as a main chain. , dithienofluorene heterocyclopentadienyl, dithienofluorenyl dienyl, benzodithiophenediyl, naphthodithiophene diyl, thienothiophene diyl, thienopyrrole At least one divalent heterocyclic group selected from the group consisting of a ketone diyl group and a diketopyrrolopyrrole group.

The conjugated block copolymer of claim 4 is in the range of items 1 to 3 of the patent application, wherein two of the conjugated polymer blocks are bonded to the side chain of the aforementioned divalent heterocyclic group. a conjugated polymer block having an alkyl group or alkoxy group having a minimum carbon number of 8 and a total of 6 or more alkyl groups or alkoxy groups bonded to the side chain of the same or different kinds of the above-mentioned divalent heterocyclic group Yoke polymer block.

The conjugated block copolymer of claim 5 is the sum of the carbon numbers of the side chains of a conjugated polymer block as in the third aspect of the patent application. The difference between the sum of the carbon numbers of the side chains of the other conjugated polymer block is 6 or more and 16 or less.

The conjugated block copolymer of claim 6 is in the range of items 1 to 3 of the patent application, wherein two of the conjugated polymer blocks are bonded to the side chain of the aforementioned divalent heterocyclic group. a conjugated polymer block of a non-fluorinated alkyl or alkoxy group, and an alkyl or alkoxy group substituted with a minimum of 3 fluorine atoms bonded to the side chain of the same or a heterologous heterocyclic heterocyclic group Conjugated polymer block.

The composition of claim 7 is characterized in that it comprises a conjugated block copolymer and a fullerene derivative according to any one of claims 1 to 6.

The organic film of claim 8 is characterized in that it contains the conjugated block copolymer according to any one of claims 1 to 6.

An organic thin film device according to claim 9 which is characterized in that the organic film of the eighth aspect of the patent application is provided on the substrate.

The photoelectric conversion element of claim 10, characterized in that the organic film of claim 6 is sandwiched between at least two electrodes.

The conjugated block copolymer of the present invention contains at least two types of conjugated polymer blocks, and microphase separation can be formed by adjusting its solubility parameter. By the microphase separation, an organic film having a high controlled photoelectric conversion efficiency can be formed.

The composition of the present invention is an organic semiconductor material, which can be included by The conjugated block copolymer having a good affinity for the acceptor material forms an organic film whose shape is controlled by microphase separation.

The organic film of the present invention can provide a photoelectric conversion element having excellent photoelectric conversion efficiency.

The photoelectric conversion element of the present invention has excellent photoelectric conversion performance and can be used for applications of various photoelectric conversion devices using photoelectric conversion functions or optical rectification functions.

Hereinafter, preferred embodiments of the present invention will be described in detail, but the scope of the present invention is not limited to the embodiments.

The conjugated block copolymer of the present invention is a conjugated polymer block in which at least two types are bonded, for example, a block copolymer obtained by copolymerizing a conjugated polymer block A and a conjugated polymer block B. . The conjugated polymer block constituting each block is a polymer composed of a conjugated divalent monomer, which has a divalent heterocyclic group in its main chain and contains an alkyl group which may be substituted by a fluorine atom or a hydroxyl group or may be Alkoxy side chain substituted by a fluorine atom or a hydroxyl group. Here, the main chain means the longest chain of the compound formed of a divalent heterocyclic group. The conjugated divalent monomer constituting the conjugated polymer block is a compound in which a bond in the molecule is a delocalized divalent group and is a compound formed of a divalent heterocyclic group.

The divalent heterocyclic group is specifically exemplified as dibenzofluorenyl dienyl, dibenzofluorenyl diyl, dibenzofuran diyl, carbazole diyl, thiophenediyl, Furan diyl, pyrrole diyl, benzothiadiazole diyl, thiophene ethylene diyl, benzotriazole diyl and the like. As for the thiophenediyl group, it is listed as a single ring The thiophene diyl group and the thiophene diyl group of the condensed ring structure are more preferably a thiophene diyl group having a condensed ring structure. The thiophene diyl group of the condensed ring structure is exemplified by cyclopentadithiophenediyl, dithienopyrrolediyl, dithienofluorenyldiyl, dithienofluorenyldiyl, benzo Dithiophenediyl, naphthodithiophenediyl, thienothiophenediyl, thienopyrrolediyl, diketopyrrolopyrrodiyl, and the like. Moreover, the thiophenediyl group of the condensed ring structure may also be a polycyclic structure in which an aromatic ring or a heterocyclic ring of a single ring or a condensed ring is further directly bonded. The monocyclic or condensed aromatic ring or heterocyclic ring is exemplified by, for example, thiophene, furan, benzene, naphthalene, pyrrole, pyridine, etc., preferably thiophene. The divalent heterocyclic group constituting the main chain is conjugated to π electrons directly in the aromatic ring or heterocyclic ring of the thiophene diyl group of the condensed ring structure, and is a part of the main chain structure.

Among the divalent heterocyclic groups, the type control is easy, and from the viewpoint of high performance of the photoelectric conversion element, it is preferred to have a condensed ring π conjugate having at least one thiophene ring in one part of the chemical structure. The skeleton, the carbazole skeleton, the dibenzofluorene heterocyclopentene skeleton, or the dibenzofluorene heterocyclic pentadiene skeleton is more preferably a condensed ring π-conjugated skeleton containing at least one thiophene ring in one part of the chemical structure. On the other hand, in the case of a thiophene diyl group having a monocyclic structure, although the synthesis is easy, the wavelength range of the absorbed light is a short wavelength, and when used in a photoelectric conversion element, the photoelectric conversion efficiency may not be high.

The structure of the connection of two or more kinds of conjugated polymer blocks contained in the conjugated block copolymer of the present invention is not particularly limited. When two types of conjugated polymer blocks are contained, for example, an A-B type diblock copolymer, an A-B-A type triblock copolymer, an A-B-A-B type tetrablock copolymer, an A-B-A-B-A type pentablock copolymer, or the like is exemplified. When there are three types of conjugated polymer blocks, It is an A-B-C type triblock copolymer, an A-B-A-C type tetrablock copolymer, or the like.

Further, the bonding pattern of the conjugated block copolymer is not particularly limited as long as it is microphase separation for forming a conjugated block copolymer. The bonding pattern may be a linear conjugated block copolymer in which the ends of the conjugated polymer block are bonded to each other, or the terminal of the conjugated polymer block is bonded to the end of the conjugated polymer block. A T-shaped conjugated block copolymer. Further, the bonding sites may be conjugated by π or may be bonded by a non-conjugated structure.

The monomer unit of the conjugated polymer block is not limited to, for example, a structure in which only the monomer unit -a- is repeated, and may be a link as long as it has a plurality of certain repeating units in the conjugated polymer block. A structure in which a plurality of divalent heterocyclic groups are formed, for example, a monomer unit -ab- as a unit. That is, the completely interactive copolymer block of the monomer unit -a- and the monomer unit -b- is regarded as the homopolymer block of the monomer unit -a-b- as long as it is the same repeating unit of the substituent. In the conjugated polymer block A and the conjugated polymer block B, the total number of carbon atoms only of the constituent ring structures excluding the substituents in one monomer unit of the monomer unit -ab- Good for 6~30. When the monomer unit is -ab-, the alkyl group or alkoxy group of the side chain which may be substituted by a fluorine atom or a hydroxyl group may be bonded to at least one of the monomer unit - a- or the monomer unit - b-. .

More specifically, for example, when cyclopentadithiophenediyl (a) is bonded to benzothiadiazole diyl (b), the adjacent cyclopentadithiophenediyl (a) and benzothiadipine The oxadiazole group (b) as a monomer unit -ab- is regarded as a monomer unit of the present invention.

The conjugated block copolymer of the present invention is a conjugated polymer constituting each block Among the solubility parameters of the block, the difference between the conjugated polymer block A having the solubility parameter of the maximum value and the conjugated polymer block B having the solubility parameter of the minimum value is 0.6 or more and 2.0 or less. The difference between the maximum value and the minimum value of the solubility parameter is preferably 0.6 or more and 1.8 or less, more preferably 0.6 or more and 1.6 or less.

The conjugated block copolymer can be microphase-separated by making the difference between the maximum value and the minimum value of the solubility parameter 0.6 or more. When it is less than 0.6, the polarities of the conjugated polymer blocks of the respective blocks are close to each other, and phase separation becomes difficult. Further, it is also important that the difference between the maximum value and the minimum value of the solubility parameter is 2.0 or less. When the difference between the maximum value and the minimum value of the solubility parameter is more than 2.0, the solubility in the solvent is remarkably lowered, and it is difficult to obtain a film. When the conjugated block copolymer is dissolved in a solvent in a microcellular structure to form a film, the microcellular structure cannot be formed. On the other hand, an ideal microphase-separated structure is formed, and when a photoelectric conversion element is used, high conversion efficiency cannot be obtained.

The ideal microphase separation structure means that two or more kinds of block components contained in the conjugated block copolymer are co-continuous structures. Aspects of fullerene derivatives which contain more electron-accepting materials than other regions in one region of the phase-separated structure are important. By forming this type, the charge which is recombined or not deactivated can be operated to the electrode, so that the short-circuit current density is increased, and a high-performance photoelectric conversion element can be produced.

The solubility parameter of the conjugated polymer block can be controlled by its molecular structure. The method of controlling the solubility parameter, for example, considering the case of the diblock copolymer, can adjust the solubility parameter by changing the main chain skeleton of each copolymer block. However, the main chain skeleton of a general conjugated polymer is similar, so it is preferable to use a side chain. The configuration or side chain density adjusts the solubility parameter. When the side chain structure is changed to control the solubility parameter, the carbon number of the side chain, the atomic species bonded to the side chain carbon, and the functional group bonded to the side chain can also be controlled, but the conjugated polymer is embedded. The segment has crystallinity, and it is important that the side chain is an alkyl group or alkoxy group which may be substituted with a fluorine atom or a hydroxyl group. Here, the side chain is a portion having carbon branched by a conjugated main chain. Further, when the side chain structure of the copolymer block having a plurality of side chains in the main chain is changed to control the solubility parameter, the side chain structure different from each other can be changed to control the solubility parameter. Here, the side chains different from each other mean side chains having different structures in the respective copolymer blocks. The number of carbon atoms in the side chain is preferably one or more, more preferably two or more, and still more preferably three or more. Further, the number of carbon atoms in the side chain is preferably 20 or less, more preferably 16 or less. Here, the carbon number of the side chain means the carbon number of each side chain bonded to the main chain.

The conjugated polymer block has a plurality of different kinds of side chains as long as at least one of them is an alkyl group or alkoxy group which may be substituted by a fluorine atom or a hydroxyl group. The content of the side chain other than the alkyl group or the alkoxy group is not particularly limited as long as it is a range in which the difference in the solubility parameter can be adjusted. Other side chains are exemplified by mercapto groups, ester groups and the like.

The solubility parameter is less preferred depending on the type of functional group bonded to the side chain of the alkyl or alkoxy group substituted by a fluorine atom or a hydroxyl group. For example, when a functional group such as an ether group, an epoxy group, an amine group, a guanamine group or an iodine atom is introduced, the packing of the polymer is inhibited, and the degree of crystallization is lowered, so that it is not preferable to smoothly cause the pore to move. Further, when a functional group bonded to an alkyl group or an alkoxy group which may be substituted by a fluorine atom or a hydroxyl group is a bulky functional group, it is less resistant to crystallization and cannot cause pore movement smoothly. good.

On the other hand, the fluorine atom is different from other halogen atoms and does not inhibit crystallization, but it is useful to promote crystallization. Hydroxyl groups are also expected to be crystallized due to hydrogen bonding, and are also useful. However, when two or more hydroxyl groups are present in each side chain, these mutually form strong hydrogen bonds, and the side chains in one polymer are hydrogen-bonded to each other, which hinders crystallization and is therefore poor. .

Preferred alkyl groups substituted by a hydroxy group are exemplified by hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 3-hydroxyisopropyl, 4-hydroxybutyl, 3-hydroxybutyl, 3- Hydroxyisobutyl, hydroxy tert-butyl, 5-hydroxypentyl, 4-hydroxyisopentyl, 6-hydroxyhexyl, 6-hydroxy-2-ethylhexyl, 7-hydroxyheptyl, 8-hydroxyoctyl An ω-hydroxyalkyl group such as 9-hydroxyindenyl, 10-hydroxyindenyl, 12-hydroxydodecyl, 16-hydroxyhexadecyl, 8-hydroxy-3,7-dimethyloctyl or An alkyl group having a hydroxyl group other than the ω-position.

Preferred alkoxy groups substituted by a hydroxy group are specifically hydroxymethoxy, 2-hydroxyethoxy, 3-hydroxypropoxy, 3-hydroxyisopropoxy, 4-hydroxybutoxy, 3- Hydroxybutoxy, 3-hydroxyisobutoxy, hydroxybutoxy, 5-hydroxypentyloxy, 4-hydroxyisopentyloxy, 6-hydroxyhexyloxy, 6-hydroxy-2-ethyl Hexyloxy, 7-hydroxyheptyloxy, 8-hydroxyoctyloxy, 9-hydroxydecyloxy, 10-hydroxydecyloxy, 12-hydroxydodecyloxy, 16-hydroxyhexadecyloxy, An ω-hydroxyalkoxy group such as 8-hydroxy-3,7-dimethyloctyloxy or an alkoxy group having a hydroxyl group other than the ω-position.

When the difference in solubility parameter is adjusted using the carbon number of the side chain, the desired solubility parameter difference can be adjusted by combining a conjugated polymer block having a different number of carbon atoms of an alkyl group or an alkoxy group. Among them, the better combination mainly contains the smallest carbon number 8 The combination of the conjugated polymer block of the side chain and the conjugated polymer block mainly containing the side chain having the largest carbon number of 6 is more preferably a conjugated polymerization mainly containing a side chain having a carbon number of 8 or more and 20 or less. The block is combined with a conjugated polymer block mainly containing a side chain having 3 or more and 6 or less carbon atoms. Further, the sum of the carbon numbers of the side chains of one conjugated polymer block and the total number of carbon atoms of the side chains of the other conjugated polymer block are more than a certain amount, and it is also preferable to adjust the difference in solubility parameter. The difference in the sum of the carbon numbers of the side chains is preferably 6 or more and 16 or less, more preferably 6 or more and 10 or less.

When the conjugated polymer block constituting the conjugated block copolymer has a plurality of side chains, when at least one side chain different from each other in the side chain contained in each monomer unit is compared, the conjugated polymer block has a conjugated polymer block The side chain having the smallest carbon number of 8 and the side chain having the largest carbon number of 6 in the other conjugated polymer block are preferred.

When the conjugated polymer block having a side chain having a small carbon number is used, the value of the solubility parameter can be increased. However, when the carbon number is too small, the solubility of the conjugated block copolymer to the solvent is lowered, and a preferable organic film cannot be obtained. When the conjugated polymer block having a side chain having a large carbon number is used, the value of the solubility parameter can be made small, but when the carbon number is more than 20 or more, the conjugated polymer block chains are hard to be close to each other, and it is difficult to obtain a conjugated polymer block. The movement of charges or excitons between the chain of conjugated polymer blocks causes a decrease in the short-circuit current density due to a component that does not contribute to photoelectric conversion. These side chains are not limited to the side chains of all the carbon atoms in the conjugated polymer block, and may be combined with other side chains.

When the solubility parameter of the conjugated polymer block is adjusted by using the carbon number of the side chain, specific examples of the preferred alkyl group are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and Dibutyl, tert-butyl, n-pentyl, iso Pentyl, neopentyl, third amyl, n-hexyl, isohexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-decyl, n-decyl, n-hexadecyl, 3,7- Dimethyloctyl, n-dodecyl and the like.

Specific examples of preferred alkoxy groups for adjusting the solubility parameter of the conjugated polymer block using the carbon number of the side chain are exemplified by methoxy, ethoxy, n-propoxy, isopropoxy and n-butoxy groups. , n-hexyloxy, n-octyloxy, n-decyloxy, 2-ethylhexyloxy, n-dodecyloxy, n-hexadecyloxy, 3,7-dimethyloctyloxy, n. Dialoxy and the like.

When the solubility parameter difference is adjusted depending on the atomic species bonded to the side chain carbon, the desired solubility parameter difference can be adjusted by combining the conjugated polymer blocks having side chains of different atoms bonded to the side chain carbon. In this case, the fluorine atom is particularly useful because it has the largest electrical negativeness of Pauling. When a fluorine atom is bonded to a carbon atom instead of a hydrogen atom, the number of fluorine atoms is also related to the number of carbon atoms in the side chain. However, when the number of carbon atoms is six or more, it is preferred that the number of fluorine atoms includes three or more side chains, and more preferably It has more than 5 side chains, and more preferably contains 5 or more and 13 or less side chains. When the polymer block has a plurality of side chains, when comparing at least one side chain different from each other in the side chain contained in each monomer unit, the one polymer block preferably has a side chain having three or more fluorine atoms. .

By combining a copolymer block having the side chain and a conjugated polymer block having a side chain having no fluorine atom, a conjugated block copolymer having a desired difference in solubility parameter can be obtained. In this case, the solubility parameter of the conjugated polymer block having a side chain containing a fluorine atom is smaller as the number of fluorine atoms increases. Solubility parameter when conjugated polymer block having side chains with a small number of fluorine atoms When the number of fluorine atoms is too small, the difference between the maximum value and the minimum value of the solubility parameter becomes small.

On the other hand, when a conjugated polymer block having a side chain having a large number of fluorine atoms is used, the solubility parameter can be made small, but when the number of fluorine atoms is too large, the difference between the maximum value and the minimum value of the solubility parameter becomes too large. . Further, when the number of fluorine atoms is too large, the conjugated block copolymer is difficult to dissolve in the solvent. It is not necessary that the side chain containing the fluorine atom is a side chain in which all of the side chains in the conjugated polymer block are fluorine atoms, and may be combined with other side chains.

When the side chain of the fluorine atom is bonded to the side chain carbon to adjust the solubility parameter of the conjugated polymer block, a specific example of the preferred fluorinated alkyl group is trifluoromethyl, 2,2,2-trifluoro. Ethyl, 2,2,2,1,1-pentafluoroethyl, 4,4,4-trifluorobutyl, 6,6,6-trifluorohexyl, 5,5,6,6,6-five Fluoryl, 7,7,7-trifluoroheptyl, 4,4,5,5,6,6,7,7,7-nonafluoroheptyl, 8,8,8-trifluorooctyl, 7, Omega-trifluoromethylalkyl or perfluoroalkyl group of 7,8,8,8-pentafluorooctyl, 5,5,6,6,7,7,8,8,8-nonafluorooctyl .

When the side chain of the fluorine atom is bonded to the side chain carbon to adjust the solubility parameter of the conjugated polymer block, a specific example of the preferred fluorinated alkoxy group is trifluoromethoxy, 2, 2, 2- Trifluoroethoxy, 2,2,2,1,1-pentafluoroethoxy, 4,4,4-trifluorobutoxy, 6,6,6-trifluorohexyloxy, 5,5, 6,6,6-pentafluorohexyloxy, 7,7,7-trifluoroheptyloxy, 4,4,5,5,6,6,7,7,7-nonafluoroheptyloxy, 8, 8,8-trifluorooctyloxy, 7,7,8,8,8-pentafluorooctyloxy, 5,5,6,6,7,7,8,8,8-nonafluorooctyloxy Omega-trifluoromethylalkoxy or perfluoroalkoxy.

There are several methods for measuring or calculating the solubility parameter, but in the present invention, the Bicerano method is used. Other methods are listed, for example, as the Hildebrand method, the Small method, the Fedors method, the Van Krevelen method, the Hansen method, the Hoy method, the Ascadskii method, the Chongjin method, etc., but the solubility parameters of the polymer having a hetero ring cannot be calculated by these methods, It is not correct and cannot be used. The method calculated by the Bicerano method is described in "Prediction of Polymer Properties, 3rd Ed." (2002) and CRC Press by Jozef Bicerano. Further, the unit of the solubility parameter is MPa ^1/2 . When calculating the solubility parameter using the Bicerano method, various computer software can be used. Computer software is listed, for example, as Scigress Explorer Professional 7.6.0.52 (Fujitsu), or Polymer-Design Tools (DTW Associates, Inc). When the element without data is processed by the Bicerano method, it is replaced by the element of the same family element period number of the periodic table. For example, in the case of flawless data, the solubility parameter is calculated using a carbon substitution structure.

The conjugated block copolymer of the present invention must calculate the solubility parameter associated with the conjugated polymer block constituting each block of the conjugated block copolymer. When the conjugated polymer block constituting each block of the conjugated block copolymer is a random copolymer, the solubility parameter of the random copolymer is calculated as shown in the following formula (A).

[Solubility parameter of random copolymer] = Σ (δi × × i).........(A)

Δi=solubility parameter of polymer composed of component i units of random copolymer

i = the weight fraction of the i unit of the random copolymer (Σ i=1)

Two or more kinds of conjugated polymerizations contained in the conjugated block copolymer of the present invention The respective mass ratios of the blocks are not particularly limited, but are preferably 95:5 to 5:95 by mass, more preferably 90:10 to 10:90 by mass, and even more preferably 85:15 to 15: 85. Among the conjugated polymer blocks of two or more kinds contained in the conjugated block copolymer, the content of the conjugated polymer block which achieves higher photoelectric conversion efficiency is more preferable.

The number average molecular weight of the conjugated block copolymer is not particularly limited, but from the viewpoint of hole mobility or mechanical properties, it is preferably from 600 to 1,000,000 g/mole, more preferably from 5,000 to 500,000 g/ The range of Moer is better than 10,000 to 200,000 g/mole. Here, the number average molecular weight means a polystyrene-converted molecular weight measured by gel permeation chromatography.

From the viewpoint of hole mobility, it is preferred that the conjugated block copolymer is at least a single block which is a crystalline polymer. Here, the crystalline polymer is a polymer in which a part of the polymer is crystallized or in a liquid crystal state. The discrimination of the crystalline polymer can be analyzed by X-ray diffraction or DSC. In the present invention, only the π-π stack of the aromatic ring is observed by the X-ray diffraction method, and the state of accumulation of the weak polymer is judged to be crystalline.

The conjugated block copolymer of the present invention is capable of polymerizing a divalent group other than the divalent heterocyclic group in the conjugated block copolymer and the conjugated polymer block constituting each of the blocks. When the divalent group other than the divalent heterocyclic group is copolymerized, the copolymerization ratio thereof is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass based on the conjugated block copolymer. the following. When the copolymerization rate is too high, the performance of the photoelectric conversion element may be degraded. Specific examples of the divalent group other than the divalent heterocyclic group are ethynyl group and aryl group.

The conjugated block copolymer of the present invention may also contain an exemplary conjugated polymer A conjugated polymer other than the block. The content is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less from the viewpoint of the type control and the conversion efficiency of the obtained photoelectric conversion element by the control type. The conjugated polymer other than the conjugated block copolymer of the present invention is preferably a conjugated polymer having the same structure as that of the block of one of the conjugated block copolymers of the present invention.

Further, if the conjugated block copolymer contains two or more kinds of conjugated polymer blocks, it may contain other non-conjugated polymer blocks. The content of the non-conjugated polymer block is not particularly limited as long as it does not lower the conversion efficiency of the photoelectric conversion element, but is preferably 50% by mass or less, more preferably 30%, based on the total mass of the conjugated block copolymer. The mass% or less is preferably 10% by mass or less. The non-conjugated polymer block is independent of the solubility parameter in the present invention.

Each reaction step and production method will be described in detail by taking the production method of the conjugated block copolymer of the present invention as an example.

The first method of producing a conjugated block copolymer is to separately polymerize at least two conjugated polymer blocks constituting each block, such as a conjugated polymer block A and a conjugated polymer block B, and The method of linking (hereinafter sometimes referred to as "linking method"). The second method is a method of sequentially polymerizing the conjugated polymer block A and the conjugated polymer block B by pseudo-active polymerization (hereinafter sometimes referred to as "sequential polymerization method"). The third method is a method of polymerizing the conjugated block B in the presence of the conjugated polymer block A (hereinafter sometimes referred to as "macro initiator method"). The linking method, the sequential polymerization method, and the giant initiator method can be most suitably used according to the synthesized conjugated block copolymer. method.

The linking method can be carried out by coupling a compound AX having a conjugated polymer block A with a compound BM ^p having a conjugated polymer block B in the presence of a catalyst as shown in the following reaction formula (I). And manufacturing.

[Chemical 1] A-X+BM ^p → AB.........(I)

In the formula (I), A and B represent a conjugated polymer block, X represents a halogen atom, and M ^p represents boric acid, boric acid ester, -MgX, -ZnX, -SnR ^a ₃ (however, R ^a is a carbon number of 1) ~4 linear alkyl group, X is the same as above).

The conjugated polymer block A and the conjugated polymer block B may also be substituted with a terminal substituent to have a conjugated polymer block B in the presence of a catalyst as shown in the following reaction formula (II). The compound BX is produced by a coupling reaction with a compound AM ^p having a conjugated polymer block A.

[Chemical 2] B-X+AM ^p → AB.........(II)

In the formula (II), B and A represent a conjugated polymer block, X represents a halogen atom, and M ^p represents boric acid, boric acid ester, -MgX, -ZnX, -SnR ^a ₃ (however, R ^a is a carbon number of 1) ~4 linear alkyl group, X is the same as above).

According to the following reaction formula (III), a conjugated polymer block A or a total of conjugated polymer can be produced by a so-called coupling reaction in which a monomer M ^q1 -YM ^q1 and M ^q2 -ZM ^{q2 are} reacted in the presence of a catalyst. The compound AX or the compound BX of the conjugated polymer block B. Further, Y and M represent a heterocyclic skeleton constituting at least a part of the monomer unit of the conjugated block copolymer of the present invention.

[M3] M ^q1 -YM ^q1 +M ^q2 -ZM ^q2 → AX or BX M ^q1 -YM ^q1 +M ^q2 -ZM ^q2 → AM ^p or BM ^p .........(III)

In the formula (III), M ^q1 and M ^{q2 are} not the same and each independently represents a halogen atom, or a boric acid, a boric acid ester, -MgX, -ZnX, or -SnR ^a ₃ (but R ^a is a carbon number of 1 to 4). Alkyl group, X is the same as above), A and B represent a copolymer of Y and Z, and M ^p represents boric acid, boric acid ester, -MgX, -ZnX, -SnR ^a ₃ . That is, when M ^q1 is a halogen atom, M ^q2 is boric acid, boric acid ester, -MgX, -ZnX, -SnR ^a ₃ , and when M ^q2 is a halogen atom, M ^q1 is boric acid, boric acid ester, -MgX, -ZnX, -SnR ^a ₃ .

The conjugated polymer block A or the conjugated polymer block B can also be produced by coupling a compound M ^q1 -YM ^q1 with a compound M ^q2 -ZM ^q2 and a compound represented by the formula Ar-M ^r . However, Ar represents an aryl group, M ^r M ^p represents or X, and M ^p represents a boronic acid, boronic _{^{ester, -MgX, -ZnX, -SnR a 3}} (R a is alkyl of 1 to 4), X Indicates a halogen atom.

Thereby, the functional group to be linked can be easily introduced onto only one terminal group of the polymer block A and the polymer block B such as the compound AX, the compound BX, the compound AM ^p and the compound BM ^p .

When the main chain skeleton of the compound AX, the conjugated polymer block A of the compound BX or the conjugated polymer block B is a polythiophene, the conjugated polymer can be produced by a pseudo-active polymerization method described by a sequential polymerization method. Segment A or conjugated polymer block B.

Next, the sequential polymerization method will be described in detail. The sequential polymerization process uses, in particular, polythiophene as the conjugated polymer block A and the conjugated polymer block B. The most effective method for the main chain skeleton of the two. The basic polymerization can be produced using the method shown below. Further, the order of producing the conjugated polymer block may be the conjugated polymer block A followed by the conjugated polymer block B, or conversely, the most appropriate order may be selected depending on the target conjugated block copolymer.

By using a monomer represented by the following chemical formula (IV) in an inert solvent, X-W-X (...)

(In the formula (IV), W is a divalent thienyl group which may have a substituent, X is a halogen atom, and two X's may be the same or different), and the following chemical formula (V) with a Grignard reagent Represented organomagnesium halide compound [5] R'-MgX.........(V)

(In the formula (V), R' is a Grignard metathesis reaction of an exchange reaction of an alkyl group having 1 to 10 carbon atoms and X is a halogen atom), and an organomagnesium compound represented by the following chemical formula (VI) is obtained, [Chemical 6] XW-MgX.........(VI)

In the formula (VI), W is a divalent phenyl group which may have a substituent, and X is a halogen atom, and two X's are the same or different.

The obtained organomagnesium compound (VI) is subjected to a so-called coupling reaction in a solvent in the presence of a metal complex catalyst to obtain a conjugated block copolymer. A series of reactions are shown in the mode reaction formula (VII).

In the formula (VII), W of the obtained conjugated block copolymer is a copolymer of a divalent thiophene group which may have a substituent.

Next, the giant initiator method will be described in detail. The macroinitiator method is a method in which the terminal functionalized conjugated polymer block A is polymerized in the initial stage of polymerization of the conjugated polymer block B or in the middle of polymerization to carry out polymerization of the conjugated polymer block B. Further, the order of producing the conjugated polymer block can be carried out by polymerizing the conjugated polymer block B in the presence of the conjugated polymer block A, and conversely, the most suitable one can be selected according to the purpose of the conjugated block copolymer. order.

The monomer M ^q1 -YM ^{q1 is} reacted with M ^q2 -ZM ^{q2 in the} presence of AX and a catalyst of the conjugated polymer block A according to the following reaction formula (VIII), and the conjugate polymerization is carried out by a so-called coupling reaction. The terminal of the block A and the polymerizable monomer of the conjugated polymer block B or the polymer block B are combined in polymerization, and the conjugated block copolymer of the present invention can be obtained by polymerization. Further, the monomer M ^q1 -YM ^q1 and M ^q2 -ZM ^{q2 can be} reacted in the presence of AM ^p of the conjugated polymer block A and the catalyst according to the following reaction formula (IX), and the coupling reaction is used to make a total The terminal of the conjugated polymer block A and the polymerizable monomer of the conjugated polymer block B or the polymer block B are combined in polymerization, and the conjugated block copolymer of the present invention can be obtained by polymerization.

In the formulae (VIII) and (IX), M ^q1 and M ^{q2 are} not the same and each independently represents a halogen atom, or a boric acid, a boric acid ester, -MgX, -ZnX, -SnR ^a ₃ (but R ^a is a carbon number) A straight chain alkyl group of 1 to 4, X is the same as above), A and B represent a copolymer of Y and Z, and M ^P represents a boric acid, a boric acid ester, -MgX, -ZnX, -SnR ^a ₃ . That is, when M ^q1 is a halogen atom, M ^q2 is boric acid, boric acid ester, -MgX, -ZnX, -SnR ^a ₃ , and when M ^q2 is a halogen atom, M ^q1 is boric acid, boric acid ester, -MgX, -ZnX, -SnR ^a ₃ .

The linking method, the sequential polymerization method, and the giant initiator method must use a complex of a transition metal as a catalyst. Generally, it is exemplified as a complex of transition metals of Groups 3 to 10 of the periodic table (Group 18 long-period periodic table), especially belonging to Groups 8-10. Specifically, it is exemplified by a conventional complex of Ni, Pd, Ti, Zr, V, Cr, Co, Fe or the like. In particular, it is more preferably a Ni complex or a Pd complex. Further, the ligand of the complex used preferably contains trimethylphosphine, triethylphosphine, triisopropylphosphine, tri-tert-butylphosphine, tricyclohexylphosphine, triphenylphosphine, and ginseng. Monodentate phosphine ligand such as (2-methylphenyl)phosphine; diphenylphosphinomethane (dppm), 1,2-diphenylphosphinoethane (dppe), 1,3-diphenylphosphine Propane (dppp), 1,4-diphenylphosphinobutane (pddb), 1,3-bis(dicyclohexylphosphino)propane (dcpp), 1,1'-bis(diphenylphosphino) a bidentate phosphine ligand such as ferrocene (dppf) or 2,2-dimethyl-1,3-bis(diphenylphosphino)propane; tetramethylethylenediamine, bipyridine, acetonitrile, etc. Nitrogen-containing ligands and the like.

The amount of the complex compound used in the linking method, the sequential polymerization, and the macroinitiator method varies depending on the type of the conjugated block copolymer to be produced, but is preferably from 0.001 to 0.1 mol per monomer. When the amount of the catalyst is too large, it may cause a decrease in the molecular weight of the obtained polymer, and it is also economically disadvantageous. On the other hand, when the amount is too small, the reaction rate becomes slow, and it is difficult to produce stably.

The solvent which can be used in the production of the conjugated block copolymer is required to be used depending on the type of the conjugated block copolymer to be produced, but the linking method, the sequential polymerization, and the macroinitiator method can all be selected as a commercially available solvent. . Listed as, for example, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, dimethyl ether, ethyl methyl ether, diethyl ether, dipropyl ether, butyl methyl ether, tert-butyl methyl ether An ether solvent such as dibutyl ether, cyclopentyl methyl ether or diphenyl ether; an aliphatic or alicyclic saturated hydrocarbon solvent such as pentane, hexane, heptane or cyclohexane; benzene or toluene An aromatic hydrocarbon solvent such as xylene, a halogenated alkane solvent such as dichloromethane or chloroform, an aromatic halogenated aryl solvent such as chlorobenzene or dichlorobenzene, dimethylformamide or diethylformamide And a guanamine solvent such as N-methylpyrrolidone, water, a mixture of these, and the like.

The amount of the organic solvent to be used is preferably from 1 to 1,000 times by weight based on the monomer of the conjugated block copolymer to be produced, and from the viewpoint of the solubility of the obtained linker or the stirring efficiency of the reaction liquid, it is preferably 10 parts by weight or more is preferably 100 times by weight or less from the viewpoint of the reaction rate.

The polymerization temperature varies depending on the kind of the conjugated block copolymer to be produced. The linking method, the sequential polymerization method, and the macroinitiator method are usually carried out in the range of -80 ° C to 200 ° C. The pressure of the reaction system is not particularly limited, Good for 0.1 to 10 atmospheres. The reaction is usually carried out at about 1 atmosphere. Further, the reaction time varies depending on the polymer block A to be produced and the polymer block B, but it is usually from 20 minutes to 100 hours.

The conjugated block copolymer obtained by the linking method, the sequential reaction, and the macroinitiator method can be removed by, for example, reprecipitation, solvent removal under heating, solvent removal under reduced pressure, removal of solvent by steam (vapor stripping) And the usual operation when the solution is separated from the conjugated block copolymer, and is isolated and obtained from the reaction mixture. The resulting crude product can be purified by washing or extraction using a commercially available solvent using a Soxhlet extractor.

Listed as, for example, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, dimethyl ether, ethyl methyl ether, diethyl ether, dipropyl ether, butyl methyl ether, tert-butyl methyl ether An ether solvent such as dibutyl ether, cyclopentyl methyl ether or diphenyl ether; an aliphatic or alicyclic saturated hydrocarbon solvent such as pentane, hexane, heptane or cyclohexane; benzene or toluene; An aromatic hydrocarbon solvent such as xylene; a ketone solvent such as acetone, ethyl methyl ketone or diethyl ketone; a halogenated alkane solvent such as dichloromethane or chloroform; or an aromatic halogenated aryl group such as chlorobenzene or dichlorobenzene. A solvent, a guanamine solvent such as dimethylformamide, diethylformamide or N-methylpyrrolidone, water, a mixture thereof, and the like.

The conjugated block copolymer of the present invention may further contain a halogen atom as a terminal group, a coupling residue such as a trialkyltin group, a boronic acid group or a boronic acid ester group, or a hydrogen atom from which the atom or group is removed. Further, a terminal structure in which the terminal groups are substituted with an aromatic blocking agent such as brominated benzene or an aromatic blocking compound such as an aromatic boronic acid compound may be used.

The conjugated block copolymer thus obtained can also be obtained by using an electron accepting material The fullerene derivative is mixed and used as a constituent of an organic semiconductor material forming an organic thin film. These conjugated block copolymers may be used alone or in combination of two or more.

The composition of the present invention is obtained by mixing at least a conjugated block copolymer and a fullerene derivative in the presence of a solvent. This composition can be used as, for example, a functional layer of a photoelectric conversion element.

The ratio of the conjugated block copolymer to the fullerene derivative in the composition is preferably from 10 to 1,000 parts by weight, more preferably from 50 to 500, based on 100 parts by weight of the conjugated block copolymer. Parts by weight.

Further, in addition to the conjugated block copolymer and the fullerene derivative which are essential components in the composition, a non-conjugated polymer, a surfactant, a high boiling point solvent such as 1,8-diiodooctane, or the like may be contained. The third component. The content of the third component is preferably 30% by mass or less, more preferably 10% by mass or less based on the total of the conjugated block copolymer and the fullerene derivative, from the viewpoint of the performance of the photoelectric conversion element. .

The fullerene derivatives contained in the composition are specifically exemplified by C ₆₀ , C ₇₀ , C ₈₄ and derivatives thereof. The specific structure of the fullerene derivative is exemplified by the following chemical formulae (1) to (10).

The mixing method of the conjugated block copolymer and the fullerene derivative is not particularly limited. The mixing method of the conjugated block copolymer and the fullerene derivative is exemplified by being added to the solvent at a desired ratio, and then being dissolved by one or a combination of a plurality of methods such as heating, stirring, and ultrasonic irradiation. A method of mixing in a solvent.

The solvent to be used in the case of mixing the conjugated block copolymer and the fullerene derivative is not particularly limited as long as it is a solvent which can be largely dissolved. Specific examples of the solvent include ethers such as tetrahydrofuran, halogen solvents such as dichloromethane and chloroform, benzene, toluene, o-xylene, chlorobenzene, o-dichlorobenzene, and pyridine. Aroma solvents, etc.

The composition containing the conjugated block copolymer and the fullerene derivative can be formed into an organic thin film by a known printing method or coating method. As for the film forming method, specifically, a spin coating method, a cast coating method, a micro gravure coating method, a gravure coating method, a slit die coating method, a bar coating method, or a roll coating method can be employed. A conventional method such as a dip coating method, a spray coating method, a screen printing method, a soft plate printing method, a lithography method, an inkjet printing method, a nozzle coating method, or a capillary coating method.

The obtained organic film can be used as an organic transistor or a photoelectric conversion element. The film thickness of the organic film containing the conjugated block copolymer is difficult to generalize depending on the intended use, but is usually 1 nm to 1 μm, preferably 2 nm to 1000 nm, more preferably 5 nm to 500 nm, and still more preferably 20 nm to 300 nm. . When used as a photoelectric conversion element, when the film thickness is too thin, light cannot be sufficiently absorbed. Conversely, when the film thickness is too thick, it is difficult for the carrier to reach the electrode, and high conversion efficiency cannot be obtained.

A photoelectric conversion element of an organic thin film formed by the composition of the present invention will be described by way of example.

The photoelectric conversion element of the present invention is an organic photoelectric conversion layer having a film formed by using the conjugated block copolymer of the present invention between at least two different electrodes, that is, a positive electrode and a negative electrode.

The electrode of the photoelectric conversion element preferably has light transmittance in either of the positive electrode or the negative electrode. The light transmittance of the electrode is not particularly limited as long as the incident light reaches the organic photoelectric conversion layer and generates an electromotive force. The thickness of the electrode may be in the range of light permeability and conductivity, and varies depending on the electrode material, but is preferably 20 nm to 300 nm. Moreover, one of the electrodes has light transmission In the case of sex, the other electrode is not necessarily required to have conductivity and does not necessarily have to have light permeability. In addition, the thickness of the electrode is not particularly limited.

As the electrode material, it is preferred to use a conductive material having a large work function for one electrode and a conductive material having a small work function for the other electrode. The electrode using a conductive material having a large work function is a positive electrode. In addition to metals such as gold, platinum, chromium, and nickel, the conductive material having a large work function is preferably a metal oxide or a composite metal oxide (indium tin oxide (ITO)) having transparency such as indium or tin. Indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), etc.). Here, the conductive material used in the positive electrode is preferably an ohmic bond to the organic photoelectric conversion layer. Further, when a hole transport layer to be described later is used, it is preferred that the conductive material used for the positive electrode is an ohmic bond with the hole transport layer.

The electrode using a conductive material having a small work function is a negative electrode, and the conductive material having a small work function is an alkali metal or an alkaline earth metal, specifically, lithium, magnesium, or calcium. In addition, tin or silver or aluminum is also preferably used. Further, an alloy made of the above metal or an electrode made of the laminate of the above metals is preferably used.

Further, by introducing a metal fluoride such as lithium fluoride or cesium fluoride into the interface between the negative electrode and an electron transport layer to be described later, the current drawn can be increased. Here, the conductive material used in the negative electrode is preferably an ohmic bond to the organic photoelectric conversion layer. Further, when the electron transport layer is used, the conductive material used in the negative electrode is preferably an ohmic bond to the electron transport layer.

The photoelectric conversion element is usually formed on a substrate. The substrate may be formed as long as it is an electrode and does not change when the organic photoelectric conversion layer is formed. base The material of the plate may be, for example, an inorganic material such as alkali-free glass or quartz glass, a metal film such as aluminum, polyester, polycarbonate, polyolefin, polyamide, polyimide, polyphenylene sulfide, and parylene. An organic material such as an epoxy resin or a fluororesin, which is a film or a sheet produced by any method. When an opaque substrate is used, the opposite electrode, that is, the electrode farther from the substrate, must be transparent or translucent. The film thickness of the substrate is not particularly limited, but is usually in the range of 1 μm to 10 nm.

Further, in order to improve the wettability of the substrate and the interface adhesion between the organic layer having the organic photoelectric conversion layer between the electrodes of the positive electrode or the negative electrode and the substrate, it is preferably treated by ultraviolet ozone treatment or corona discharge. Physical means such as treatment and plasma treatment are applied to the surface for washing or upgrading. Further, a method of chemically modifying a surface of a solid substrate with a decane coupling agent, a titanate coupling agent, or a self-organized monomolecular film is also effective.

The photoelectric conversion element may also be provided with a hole transport layer between the positive electrode and the organic photoelectric conversion layer as needed. As the material for forming the hole transport layer, a conductive polymer such as a polythiophene polymer, a polyparaphenylene stretched vinyl polymer or a polyfluorene polymer, or a phthalocyanine derivative (H ₂ Pc, CuPc, or the like) is preferably used. A low molecular organic compound exhibiting p-type semiconductor characteristics such as ZnPc or the like, a porphyrin derivative or the like. It is especially preferably used in polyethylene oxythiophene (PEDOT) of polythiophene-based polymer or polystyrene sulfonate (PSS) in PEDOT. The hole transport layer is preferably from 5 nm to 600 nm, more preferably from 20 nm to 300 nm.

The photoelectric conversion element may also be provided with an electron transport layer between the negative electrode and the organic photoelectric conversion layer as needed. As the material for forming the electron transport layer, a phenanthroline compound such as Bathocuproine, naphthalene tetracarboxylic anhydride or naphthalene can be used. An n-type semiconductor material such as bismuth quinone diamine, hydrazine tetracarboxylic anhydride or ruthenium tetracarboxylic acid diamine, and an n-type inorganic oxide such as titanium oxide, zinc oxide or gallium oxide, and lithium fluoride or sodium fluoride. An alkali metal compound such as cesium fluoride or the like. Further, a layer formed of a single n-type semiconductor material used in the bulk heterojunction layer may also be used.

The photoelectric conversion element may further have an inorganic layer. The material contained in the inorganic layer is exemplified by, for example, titanium oxide, tin oxide, zinc oxide, iron oxide, tungsten oxide, zirconium oxide, hafnium oxide, tantalum oxide, indium oxide, antimony oxide, antimony oxide, antimony oxide, vanadium oxide. , cerium oxide, cerium oxide, gallium oxide, nickel oxide, barium titanate, barium titanate, gallium ruthenate, sodium citrate and other metal oxides; silver iodide, silver bromide, copper iodide, copper bromide, lithium fluoride Metal halides; metal sulfides such as zinc sulfide, titanium sulfide, indium sulfide, antimony sulfide, cadmium sulfide, zirconium sulfide, antimony sulfide, molybdenum sulfide, silver sulfide, copper sulfide, tin sulfide, tungsten sulfide, antimony sulfide; Cadmium, zirconium selenide, zinc selenide, titanium selenide, indium selenide, tungsten selenide, molybdenum selenide, selenium telluride, lead selenide and other metal selenides; cadmium telluride, tungsten telluride, molybdenum telluride, Metal antimony compounds such as zinc telluride and antimony telluride; metal phosphorus compounds such as zinc phosphide, gallium phosphide, indium phosphide, and cadmium phosphide; gallium arsenide, copper-indium-selenide, copper-indium-sulfide,矽, 锗, etc. Further, it may be a mixture of two or more of these. The mixture is exemplified by, for example, a mixture of zinc oxide and tin oxide, a mixture of tin oxide and titanium oxide, and the like.

The photoelectric conversion element of the present invention is obtained, for example, by the following production steps. A group of a conjugated block copolymer and an electron-accepting material is formed on a substrate on which a positive electrode is formed on a glass by using the above-described film forming method. The formed film was dried and formed to form an organic photoelectric conversion layer. On the organic photoelectric conversion layer, a photoelectric conversion element can be manufactured by forming an electrode which becomes a negative electrode.

The photoelectric conversion element of the present invention can be applied to applications of various photoelectric conversion devices using a photoelectric conversion function, a photo diode, and the like. For example, it can be used for a photovoltaic cell such as a solar cell; an electronic component such as a photo sensor, an optical switcher, or a phototransistor; or an optical recording material such as an optical memory.

[Examples]

The embodiments of the present invention are described in detail below, but the scope of the present invention is not limited by the embodiments.

The synthesis of the conjugated polymer blocks constituting the conjugated block copolymer is shown in Polymerization Examples 1 to 8, and the synthesis of the conjugated block copolymer of the present invention using the same is shown in Examples 1 to 8. Further, the application of the present invention is shown in Comparative Examples 1 to 9.

(polymerization example 1)

The synthesis of the conjugated polymer block A1 is carried out according to the following reaction formula (1). Further, in the following reaction formula, the ethylhexyl group of the substituent is abbreviated as EtHex or HexEt.

2,6-Dibromo-4,4'-bis(2-ethylhexyl)-cyclopenta[2,1-b:3,4-b'] was added to a 100 mL three-necked flask under a nitrogen atmosphere. Dithiophene (1.50 g, 2.68 mmol), 4,7-bis(3,3,4,4-tetramethyl-2,5,1-dioxaborolan-1-yl)benzo[ c] [1,2,5]thiadiazole (1.04g, 2.68mmol), toluene (50mL), 2M aqueous potassium carbonate solution (25mL, 50mmol), hydrazine (triphenylphosphine) palladium (0) (Pd (PPh) ₃ ) ₄ ) (61.9 mg, 53.5 μmol), aliquat 336 (2 mg, 4.95 μmol), and stirred at 80 ° C for 2 hours. Subsequently, pinacol phenylborate (273 mg, 1.34 mmol) was added and stirred at 80 ° C for 18 hours. After completion of the reaction, the reaction solution was poured into methanol (500 mL), and the precipitated solid was filtered, washed with water (100 mL) and methanol (100 mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using EtOAc (EtOAc) The obtained solution was poured into methanol (2 L), and the precipitated solid was filtered, and then dried under reduced pressure to give a yel.

The physicochemical analysis of the obtained conjugated polymer block A1 was carried out.

The molecular structure was identified by ¹ H-NMR (nuclear magnetic resonance).

¹ H-NMR (270MHz): δ = 8.10-7.95 (m, 2H), 7.80-7.61 (m, 2H), 2.35-2.12 (m, 4H), 1.60-1.32 (m, 18H), 1.18-0.82 ( m, 12H).

The number average molecular weight (Mn) and the weight average molecular weight (Mw) were all obtained based on the measurement by gel permeation chromatography (GPC) in terms of polystyrene. Here, the GPC apparatus uses HLC-8320GPC manufactured by TOSOH Co., Ltd., and the column system uses two series of TSKgel SuperMultipore HZ-M manufactured by TOSOH Co., Ltd. Using the values of the average molecular weight (Mn) and the weight average molecular weight (Mw), the degree of dispersion (PDI) was determined from (Mw) / (Mn).

GPC (CHCl ₃ ): Mn = 19,600 g/mol, Mw = 45,500 g/mol, PDI = 2.32.

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (1) is supported.

(polymerization example 2)

The synthesis of the conjugated polymer block A2 was carried out in accordance with the following reaction formula (2).

Add 2,6-dibromo-4,4'-bis(2-ethylhexyl)-dithieno[3,2-b:2',3'- in a 100 mL three-necked flask under a nitrogen atmosphere. d] hydrazine (1.66 g, 2.68 mmol), 4,7-bis(3,3,4,4-tetramethyl-2,5,1-dioxaborolan-1-yl)benzo [c][1,2,5]thiadiazole (1.04g, 2.68mmol), toluene (50mL), 2M aqueous potassium carbonate solution (25mL, 50mmol), hydrazine (triphenylphosphine) palladium (0) (61.9mg After 53.5 μmol) and aliquat 336 (2 mg, 4.95 μmol), the mixture was stirred at 80 ° C for 2 hours. Subsequently, pinacol phenylborate (273 mg, 1.34 mmol) was added and stirred at 80 ° C for 18 hours. After completion of the reaction, the reaction solution was poured into methanol (500 mL), and the precipitated solid was filtered, washed with water (100 mL) and methanol (100 mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using EtOAc (EtOAc) The obtained solution was poured into methanol (2 L), and the precipitated solid was filtered and dried under reduced pressure to give a yellow polymer block A2 (1.03 g, 38%).

The polymerization conjugated polymer block A2 was obtained in the same manner as in Polymerization Example 1. Chemical analysis.

¹ H-NMR (270MHz), δ = 8.20-7.95 (m, 2H), 7.90-7.12 (m, 2H), 2.34-2.10 (m, 4H), 1.59-1.33 (m, 18H), 1.19-0.81 ( m, 12H)

GPC (CHCl ₃ ): Mn = 17500 g / mol, Mw = 42400 g / mol, PDI = 2.42

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (2) is supported.

(polymerization example 3)

The synthesis of the conjugated polymer block A3 was carried out in accordance with the following reaction formula (3).

In a well-dried argon-substituted pear flask A, 25 mL of tetrahydrofuran (THF), 1.25 g of 2-bromo-5-iodo-3-hexylthiophene (5 mmol) and chlorine were added for dehydration and peroxide removal treatment. 2.5 mL of a 2.0 M solution of isopropylmagnesium was stirred at 0 ° C for 30 minutes to synthesize an organomagnesium compound solution represented by the chemical formula (a1) in the above reaction formula.

After dehydration and peroxide in pear-shaped flask was dried and purged with argon B of added 25mL THF was removed and the process of _{NiCl 2 (dppp) 27mg (0.05} mmol), heated to 35 ℃, was added a solution of organomagnesium compound ( A1). After heating and stirring at 35 ° C for 1.5 hours, 50 mL of 5 M hydrochloric acid was added and the mixture was stirred at room temperature for 1 hour. The reaction liquid was extracted with 450 mL of chloroform, and the organic layer was washed successively with 100 mL of aqueous sodium hydrogen carbonate solution and 100 mL of distilled water. The organic layer was dried over anhydrous sodium sulfate and then concentrated to dryness. The obtained dark purple solid was dissolved in 30 mL of chloroform, reprecipitated in 300 mL of methanol, and purified by a GPC column using a fractionation to obtain a conjugated polymer block A3 (690 mg).

Further, the solvent THF was subjected to distillation purification of tetrahydrofuran (without stabilizer) manufactured by Wako Pure Chemical Industries, Ltd. in the presence of sodium metal, and then purified by contact with molecular sieve 5A manufactured by Wako Pure Chemical Industries, Ltd. for one day or more. Further, the purification of the polymer was carried out using a GPC column for fractionation. The apparatus used was a circulating preparative HPLC LC-908 manufactured by Nippon Analytical Industries Co., Ltd. Further, the type of the column is a tandem polymer column 2H-40 and 2.5H-40 which are manufactured by Nippon Analytical Industries Co., Ltd. Further, chloroform was used as the elution solvent.

The physicochemical analysis of the obtained conjugated polymer block A3 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR: δ = 6.97 (s, 1H), 2.80 (t, J = 8.0 Hz, 2H), 1.89-1.27 (m, 10H), 0.91 (t, J = 6.8 Hz, 3H)

GPC (CHCl ₃ ): Mn = 21000 g / mol, Mw = 24,150 g / mol, PDI = 1.15

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (3) is supported.

(Example 1)

The synthesis of the conjugated block copolymer 1 was carried out in accordance with the following reaction formula (4). Further, in the structural formula or reaction formula of the conjugated block copolymer in the following examples, "-b-" means block copolymerization, and "-r-" or "-ran-" means random copolymerization.

A conjugated polymer block A1 (0.80 g) and a conjugated polymer block A3 (0.80 g), toluene (20 mL), 2M aqueous potassium carbonate solution (10 mL, 20 mmol) were placed in a 100 mL three-necked flask under a nitrogen atmosphere. After hydrazine (triphenylphosphine) palladium (0) (20.5 mg, 17.7 μmol) and aliquat 336 (0.8 mg, 1.98 μmol), the mixture was stirred at 80 ° C for 24 hours. After completion of the reaction, the reaction solution was poured into methanol (200 mL), and the precipitated solid was filtered, washed with water (20mL), methanol (20mL), and the obtained solid was dried under reduced pressure to give a crude product. Use a Soxhlet extractor with acetone ( After washing the crude product with 100 mL of hexane (100 mL), EtOAc (100 mL). The obtained solution was poured into methanol (1 L), and the precipitated solid was filtered and dried under reduced pressure to give a yel-yellow solid conjugated block copolymer 1 (0.53 g, 33%).

The physicochemical analysis of the obtained conjugated block copolymer 1 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.12 - 7.94 (m, 2H), 7.80 - 7.61 (m, 2H), 6.97 (s, 1H) 2.35-2.12 (m, 6H), 1.62-1.31 (m, 26H) ), 1.19-0.83 (m, 15H)

GPC (CHCl ₃ ): Mn = 41000 g / mol, Mw = 86100 g / mol, PDI = 2.10

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (4) is supported.

(Example 2)

The synthesis of the conjugated block copolymer 2 was carried out in accordance with the following reaction formula (5).

A conjugated polymer block A2 (0.80 g) and a conjugated polymer block A3 (0.80 g), toluene (20 mL), 2M aqueous potassium carbonate solution (10 mL, 20 mmol) were placed in a 100 mL three-necked flask under a nitrogen atmosphere. After hydrazine (triphenylphosphine) palladium (0) (20.5 mg, 17.7 μmol) and aliquat 336 (0.8 mg, 1.98 μmol), the mixture was stirred at 80 ° C for 24 hours. After completion of the reaction, the reaction solution was poured into methanol (200 mL), and the precipitated solid was filtered, washed with water (20mL), methanol (20mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (100 mL) and hexane (100 mL) using a Soxhlet apparatus, and extracted with chloroform (100 mL). The obtained solution was poured into methanol (1 L), and the precipitated solid was filtered and dried under reduced pressure to give a yel-yellow solid conjugated block copolymer 2 (0.53 g, 33%).

The physicochemical analysis of the obtained conjugated block copolymer 2 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.21 - 7.94 (m, 2H), 7.92 - 7.13 (m, 2H), 6.97 (s, 1H), 2.35-2.11 (m, 6H), 1.61-1.31 (m, 26H), 1.19-0.83 (m, 15H)

GPC (CHCl ₃ ): Mn = 41000 g / mol, Mw = 86100 g / mol, PDI = 2.10

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (5) is supported.

(polymerization example 4)

The synthesis of the conjugated polymer block A4 was carried out in accordance with the following reaction formula (6).

2,6-Dibromo-4,4'-bis(2-ethylhexyl)-cyclopenta[2,1-b:3,4-b'] was added to a 100 mL three-necked flask under a nitrogen atmosphere. Dithiophene (1.50 g, 2.68 mmol), 4,7-bis(3,3,4,4-tetramethyl-2,5,1-dioxaborolan-1-yl)benzo[ c] [1,2,5]thiadiazole (1.04g, 2.68mmol), toluene (50mL), 2M aqueous potassium carbonate solution (25mL, 50mmol), hydrazine (triphenylphosphine) palladium (0) (61.9mg, 53.5 μmol After aliquat 336 (2 mg, 4.95 μmol), it was stirred at 80 ° C for 2 hours. Subsequently, phenyl bromide (210 mg, 1.34 mmol) was added and stirred at 80 ° C for 18 hours. After completion of the reaction, the reaction solution was poured into methanol (500 mL), and the precipitated solid was filtered, washed with water (100 mL) and methanol (100 mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using EtOAc (EtOAc) The obtained solution was poured into methanol (2 L), and the precipitated solid was filtered and dried under reduced pressure to give a yellow polymer block A4 (1.06 g, 42%).

The physicochemical analysis of the obtained conjugated polymer block A4 was carried out in the same manner as in Polymerization Example 1.

^{1 H-NMR (270MHz):} δ = 8.10-7.96 (m, 2H), 7.81-7.61 (m, 2H), 2.35-2.13 (m, 4H), 1.59-1.32 (m, 18H), 1.18-0.81 ( m, 12H)

GPC (CHCl ₃ ): Mn = 20100 g / mol, Mw = 44300 g / mol, PDI = 2.20

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (6) is supported.

(polymerization example 5)

The synthesis of the conjugated polymer block A5 was carried out in accordance with the following reaction formula (7).

2,6-Dibromo-4,4'-di-hexadecylcyclopenta[2,1-b:3,4-b']dithiophene was added to a 100 mL three-necked flask under a nitrogen atmosphere ( 2.05g, 2.68mmol), 4,7-bis(3,3,4,4-tetramethyl-2,5,1-dioxaborolan-1-yl)benzo[c][ 1,2,5]thiadiazole (1.04g, 2.68mmol), toluene (50mL), 2M aqueous potassium carbonate solution (25mL, 50mmol), hydrazine (triphenylphosphine) palladium (0) (61.9mg, 53.5μmol) After aliquat 336 (2 mg, 4.95 μmol), it was stirred at 80 ° C for 2 hours. Subsequently, phenylboronic acid pinacol (273 mg, 1.34 mmol) was added and stirred at 80 ° C for 18 hours. After completion of the reaction, the reaction solution was poured into methanol (500 mL), and the precipitated solid was filtered, washed with water (100 mL) and methanol (100 mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using EtOAc (EtOAc) The obtained solution was poured into methanol (2 L), and the precipitated solid was filtered and dried under reduced pressure to give a yellow polymer block A5 (1.11 g, 36%).

The physicochemical analysis of the obtained conjugated polymer block A5 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.13 - 7.95 (m, 2H), 7.82 - 7.35 (m, 2H), 3.04 - 2.89 (m, 4H), 2.34 - 2.13 (m, 8H), 1.55-1.42 ( m, 12H), 1.35-1.09 (m, 36H), 0.82 (m, 6H)

GPC (CHCl ₃ ): Mn = 18,900 g/mol, Mw = 37,200 g/mol, PDI = 1.97

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (7) is supported.

(polymerization example 6)

The synthesis of the conjugated polymer block A6 was carried out in accordance with the following reaction formula (8).

2,6-Dibromo-4,4'-bis(4,4,5,5,6,6,7,7,7-nonafluoroheptyl) was added to a 100 mL three-necked flask under a nitrogen atmosphere. Cyclopenta[2,1-b:3,4-b']dithiophene (2.29 g, 2.68 mmol), 4,7-bis(3,3,4,4-tetramethyl-2,5,1 -dioxaborolan-1-yl)benzo[c][1,2,5 Thiadiazole (1.04g, 2.68mmol), toluene (50mL), 2M aqueous potassium carbonate solution (25mL, 50mmol), hydrazine (triphenylphosphine) palladium (0) (61.9mg, 53.5μmol), aliquat 336 (2mg After 4.95 μmol), the mixture was stirred at 80 ° C for 2 hours. Subsequently, phenylboronic acid pinacol (273 mg, 1.34 mmol) was added, and stirred at 80 ° C for 18 hours. After completion of the reaction, the reaction solution was poured into methanol (500 mL), and the precipitated solid was filtered, washed with water (100 mL) and methanol (100 mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using EtOAc (EtOAc) The obtained solution was poured into methanol (2 L), and the precipitated solid was filtered and dried under reduced pressure to give a yellow polymer block A6 (1.20 g, 43%).

The physicochemical analysis of the obtained conjugated polymer block A6 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.12 - 7.97 (m, 2H), 7.90-7.32 (m, 2H), 2.75 (t, J = 7.56 Hz, 4H), 2.31-1.92 (m, 8H)

GPC (CHCl ₃ ): Mn = 19200 g / mol, Mw = 42700 g / mol, PDI = 2.22

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (8) is supported.

(polymerization example 7)

Synthesis of conjugated polymer block A7 according to the following reaction formula (9) .

Add 2,6-dibromo-4,4'-bis(6,6,6-trifluorohexyl)-cyclopenta[2,1-b:3,4 in a 100 mL three-necked flask under a nitrogen atmosphere. -b']dithiophene (1.64 g, 2.68 mmol), 4,7-bis(3,3,4,4-tetramethyl-2,5,1-dioxaborolan-1-yl Benzo[c][1,2,5]thiadiazole (1.04g, 2.68mmol), toluene (50mL), 2M aqueous potassium carbonate solution (25mL, 50mmol), hydrazine (triphenylphosphine) palladium (0) (61.9 mg, 53.5 μmol) and aliquat 336 (2 mg, 4.95 μmol) were stirred at 80 ° C for 2 hours. Subsequently, phenylboronic acid pinacol (273 mg, 1.34 mmol) was added and stirred at 80 ° C for 18 hours. After completion of the reaction, the reaction solution was poured into methanol (500 mL), and the precipitated solid was filtered, washed with water (100 mL) and methanol (100 mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using EtOAc (EtOAc) The resulting solution was poured into methanol (2 L), and the precipitated solid was filtered. Drying under reduced pressure gave a yel-polymer block A7 (1.18 g, 44%).

The physicochemical analysis of the obtained conjugated polymer block A7 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.12 - 7.97 (m, 2H), 7.90-7.32 (m, 2H), 2.75 (t, J = 7.56 Hz, 4H), 2.31-1.92 (m, 16H)

GPC (CHCl ₃ ): Mn = 20600 g / mol, Mw = 46000 g / mol, PDI = 2.23

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (9) is supported.

(Example 3)

The synthesis of the conjugated block copolymer 3 was carried out in accordance with the following reaction formula (10).

A conjugated polymer block A4 (0.80 g) and a conjugated polymer block A5 (0.80 g), toluene (20 mL), 2M aqueous potassium carbonate solution (10 mL, 20 mmol) were placed in a 100 mL three-necked flask under a nitrogen atmosphere. After hydrazine (triphenylphosphine) palladium (0) (20.5 mg, 17.7 μmol) and aliquat 336 (0.8 mg, 1.98 μmol), the mixture was stirred at 80 ° C for 24 hours. After completion of the reaction, the reaction solution was poured into methanol (200 mL), and the precipitated solid was filtered, washed with water (20mL), methanol (20mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (100 mL) and hexane (100 mL) using a Soxhlet apparatus, and extracted with chloroform (100 mL). The obtained solution was poured into methanol (1 L), and the precipitated solid was filtered and dried under reduced pressure to give a yel-yellow solid conjugated block copolymer 3 (0.58 g, 36%).

The physicochemical analysis of the obtained conjugated block copolymer 3 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.13 - 7.94 (m, 4H), 7.82 - 7.35 (m, 4H), 3.04 - 2.90 (m, 4H) 2.35 - 2.12 (m, 12H), 1.60-1.30 (m , 30H), 1.35-1.20 (m, 36H), 1.18-0.82 (m, 18H)

GPC (CHCl ₃ ): Mn = 39,600 g/mol, Mw = 83,700 g/mol, PDI = 2.11

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (10) is supported.

(Example 4)

The synthesis of the conjugated block copolymer 4 was carried out in accordance with the following reaction formula (11).

A conjugated polymer block A4 (0.80 g) and a polymer represented by polymer block A6 (0.80 g), toluene (20 mL), and 2 M potassium carbonate aqueous solution (10 mL) were placed in a 100 mL three-necked flask under a nitrogen atmosphere. 20 mmol), hydrazine (triphenylphosphine) palladium (0) (20.5 mg, 17.7 μmol), and aliquat 336 (0.8 mg, 1.98 μmol) were stirred at 80 ° C for 24 hours. After completion of the reaction, the reaction solution was poured into methanol (200 mL), and the precipitated solid was filtered, washed with water (20mL), methanol (20mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (100 mL) and hexane (100 mL) using a Soxhlet apparatus, and extracted with chloroform (100 mL). The obtained solution was poured into methanol (1 L), and the precipitated solid was filtered and dried under reduced pressure to give a yel-yellow solid conjugated block copolymer 4 (0.67 g, 42%).

The chemistry analysis of the obtained conjugated block copolymer 4 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.12 - 7.96 (m, 4H), 7.85-7.32 (m, 4H), 2.74 (t, J = 7.58 Hz, 4H), 2.35-1.31 (m, 30H), 1.19 -0.82 (m, 12H)

GPC (CHCl ₃ ): Mn = 40200 g / mol, Mw = 86100 g / mol, PDI = 2.14

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (11) is supported.

(Example 5)

The synthesis of the conjugated block copolymer 5 was carried out in accordance with the following reaction formula (12).

In a well-dried argon-substituted pear flask A, 20 mL of THF, 1.52 g (4.05 mmol) of 2-bromo-5-iodo-3-hexylthiophene, and chlorination were added for dehydration and peroxide removal treatment. 2 mL of a 2.0 M solution of propylmagnesium was stirred at 0 ° C for 30 minutes to synthesize an organomagnesium compound solution (a1-1). In another fully dried argon-substituted pear flask B, 5 mL of THF and 2,5-dibromo-3-[6-(2-tetrahydropyranyl) were added for dehydration and peroxide removal treatment. 0.95 mL of 0.403 g (0.95 mmol) of oxyhexyl thiophene and a 1.0 M solution of tributylmagnesium chloride were stirred at 60 ° C for 2 hours to synthesize an organomagnesium compound solution (a1-2).

After C in pear-shaped flask was sufficiently dried and purged with argon of added peroxide and dehydration process of 25mL THF was removed and _{NiCl 2 (dppp) 27mg (0.05} mmol), heated to 35 ℃, adding the previously prepared organic 70% of the magnesium compound solution (a1-1), and stirred under heating at 35 ° C for 1.5 hours. Next, the remaining organomagnesium compound solution (a1-1) and the organomagnesium compound solution (a1-2) were added, and reacted at 35 ° C for 2 hours. After completion of the reaction, 2 mL of a 1.0 M THF solution of tributylmagnesium chloride was added thereto, and the mixture was stirred at 35 ° C for 1 hour, and then 30 mL of 5 M hydrochloric acid was added thereto, and the mixture was stirred at room temperature for 1 hour. The reaction liquid was extracted with 450 mL of chloroform, and the organic layer was washed successively with 100 mL of sodium hydrogen carbonate aqueous solution and 100 mL of distilled water, and the organic layer was dried over anhydrous sodium sulfate and concentrated to dryness. The obtained black-purple solid was dissolved in 30 mL of chloroform, reprecipitated in 300 mL of methanol, and purified by a GPC column using a fractionation method as in Polymerization Example 3 to obtain a conjugated block copolymer 5 (650 mg).

The number average molecular weight (Mn), weight average molecular weight (Mw), and dispersity (PDI) of the obtained conjugated block copolymer 5 were determined in the same manner as in Polymerization Example 1.

GPC (CHCl ₃ ): Mn = 20,800, Mw = 23,400, PDI = 1.13

(Example 6)

The synthesis of the conjugated block copolymer 6 was carried out in accordance with the following reaction formula (13).

In a well-dried argon-substituted pear flask A, 21 mL of THF, 1.257 g (4.2 mmol) of 2-bromo-5-iodo-3-hexylthiophene, and chlorination were added for dehydration and peroxide removal treatment. 2.1 mL of a 2.0 M solution of propylmagnesium was stirred at 0 ° C for 30 minutes to synthesize an organomagnesium compound solution (a2-1). In a fully dried argon-substituted pear flask B, 4 mL of THF and 2,5-dibromo-3-(6,6,6-trifluorohexyl)thiophene were added for dehydration and peroxide removal treatment. 0.393 g (0.8 mmol) and 0.8 mL of a 1.0 M solution of butyl magnesium chloride were stirred at 60 ° C for 2 hours to synthesize an organomagnesium compound solution (a2-2).

After C in pear-shaped flask was sufficiently dried and purged with argon of added peroxide and dehydration process of 25mL THF was removed and _{NiCl 2 (dppp) 27mg (0.05} mmol), heated to 35 ℃, adding the previously prepared organic The magnesium compound solution (a2-1) was stirred with heating at 35 ° C for 1.5 hours. Next, the organomagnesium compound solution (a2-2) was added and reacted at 35 ° C for 2 hours. After completion of the reaction, 2 mL of a 1.0 M THF solution of tributylmagnesium chloride was added thereto, and the mixture was stirred at 35 ° C for 1 hour, and then 30 mL of 5 M hydrochloric acid was added thereto, and the mixture was stirred at room temperature for 1 hour. The reaction liquid was extracted with 450 mL of chloroform, and the organic layer was washed successively with 100 mL of sodium hydrogen carbonate aqueous solution and 100 mL of distilled water, and the organic layer was dried over anhydrous sodium sulfate and concentrated to dryness. The obtained dark purple solid was dissolved in 30 mL of chloroform, reprecipitated in 300 mL of methanol, and purified by a GPC column as used in Polymerization Example 3 to obtain a conjugated block copolymer 6 (699 mg).

The number average molecular weight (Mn), weight average molecular weight (Mw), and dispersity (PDI) of the obtained conjugated block copolymer 6 were determined in the same manner as in Polymerization Example 1.

GPC (CHCl ₃ ): Mn = ₂₁ , 100, Mw = 25, 100, PDI = 1.19

(polymerization example 8)

The synthesis of the conjugated polymer block A8 was carried out in accordance with the following reaction formula (14). Further, in the subsequent reaction formula, the 3-heptyl group of the substituent is abbreviated as 3-Hep or Hep-3. Further, in the subsequent reaction formula, the methyl group of the substituent is abbreviated as Me.

Adding a conjugate to a 50 ml pear-shaped flask under a nitrogen atmosphere 2,6-bis(trimethyltin)-4,8-di-dodecylbenzo[1,2-b:4,5-b']dithiophene of monomer of polymer block A8 ( 0.64 g, 0.75 mmol) and 1-(4,6-dibromothieno[3,4-b]thiophen-2-yl)-2-ethylhexan-1-one (0.32 g, 0.75 mmol), And DMF (6.2 mL), toluene (25 mL), hydrazine (triphenylphosphine) palladium (0) (9.2 mg, 7.8 μmol), and heated at 115 ° C for 1 hour and 30 minutes. Next, 2,5-dibromothiophene (1.84 g, 7.6 mmol) as a linking group compound was added, and the mixture was heated at 115 ° C for 16 hours. After completion of the reaction, the reaction solution was concentrated, poured into methanol (500 mL), and the precipitated solid was filtered, and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using EtOAc (EtOAc) The organic layer was dried with EtOAc (EtOAc)EtOAc.

The purification of the obtained conjugated polymer A8 was carried out using a GPC column for fractionation. The apparatus used for the purification was a circulating preparative HPLC LC-908 manufactured by Nippon Analytical Industries Co., Ltd. Further, the type of the column is a tandem polymer column 2H-40 and 2.5H-40 which are manufactured by Nippon Analytical Industries Co., Ltd. Further, the column and the injection port were set at 145 ° C, and the elution solvent was chloroform.

The number average molecular weight (Mn) and the weight average molecular weight (Mw) were both measured by a gel permeation chromatography (GPC) and determined in terms of polystyrene.

Here, any GPC device uses GPC/V2000 manufactured by Waters, and the pipe column uses Shodex AT-made by Showa Denko. G806MS two connected by series. Further, the column and the injection port were set at 145 ° C, and the elution solvent was o-dichlorobenzene.

The obtained conjugated polymer block A8 (0.51 g, 86%) had a weight average molecular weight (Mw) of 33,100, a number average molecular weight (Mn) of 14,600, and a polydispersity of 2.27.

1H NMR (270MHz, CDCl3): δ = 7.60-7.30 (br, 3H), 3.30-3.00 (Br, 5H), 2.00-1.10 (br, 52H), 1.00-0.70 (br, 12H)

(Example 7)

The synthesis of the conjugated block copolymer 7 was carried out in accordance with the following reaction formula (15).

A conjugated polymer block A8 (160.0 mg, 0.12 mol) was added to a 5 mL flask under an argon atmosphere, and 2,6-bis(trimethyltin)-4 as a monomer constituting the polymer block B was added. , 8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b']dithiophene (113.0 mg, 0.16 mmol), 2,6-bis(trimethyltin) -4,8-dipropylbenzo[1,2-b:4,5-b']dithiophene (40.9 mg, 0.07 mmol) and 1-(4,6-dibromothieno[3,4- b] thiophen-2-yl)-2-ethylhexan-1-one (86.0 mg, 0.20 mmol), DMF (0.3 mL), with toluene (1.4 mL), bis(triphenylphosphine) 0) (3.4 mg, 2.98 μmol), the inside of the vessel was blown with argon gas for 20 minutes, and then heated at 110 ° C for 10 hours. After the reaction was completed, the reaction solution was injected. In a methanol (500 mL), the crude product was washed with acetone (200 mL) and hexane (200 mL) using a Soxhlet extractor, and then extracted with chloroform (200 mL). The obtained solution was poured into methanol (300 mL), and the precipitated solid was filtered and dried under reduced pressure to give a yel-yellow solid conjugated block copolymer 7 (221.0 mg, 75.4%). Purification of the obtained conjugated block copolymer 7 was carried out in the same manner and under the same conditions as in the above Polymerization Example 8.

The physicochemical analysis of the obtained conjugated block copolymer 7 was carried out in the same manner and under the same conditions as in the above-mentioned polymerization example 8. The chemical analysis results below support the chemical structures shown in the above reaction formula.

¹ H-NMR (270MHz, CDCl ₃ ): δ = 7.60-7.30 (br, 3H), 4.40-4.00 (br, 4H), 3.30-3.00 (Br, 4H), 2.00-0.60 (br, 51H)

GPC (CHCl ₃ ): Mn = 28800 g / mol, Mw = 86400 g / mol, PDI = 2.99

(Example 8)

The synthesis of the conjugated block copolymer 8 was carried out in accordance with the following reaction formula (16).

In addition to the conjugated polymer block A8 (0.59 g, 0.75 mmol), 2,6-bis(trimethyltin)-4,8-bis (5-(2) as a monomer constituting the polymer block B -ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene (0.68 g, 0.75 mmol) and 1-(4,6-dibromothieno[3] A 4-conjugated block copolymer 8 was obtained in the same manner as in Example 7 except that 4-b]thiophen-2-yl)-2-ethylhexan-1-one (0.32 g, 0.75 mmol). 0.48g, 76%).

The physicochemical analysis of the obtained conjugated block copolymer 8 was carried out in the same manner and under the same conditions as in the above Polymerization Example 8. The chemical analysis results below support the chemical structures shown in the above reaction formula.

1H-NMR (270MHz, CDCl ₃ ): δ = 7.60-7.30 (br, 8H), 6.95-6.85 (br, 2H), 3.30-3.00 (br, 6H), 2.85-2.75 (Br, 4H), 2.00- 0.60 (br, 104H)

GPC (CHCl ₃ ): Mn = 27,500 g/mol, Mw = 67,600 g/mol, PDI = 2.46

(Comparative Example 1)

After sufficiently replacing the argon gas in the glass-shaped pear flask A which was sufficiently dried, 45 parts by mass of THF and 0.054 parts by mass of NiCl ₂ (dppp) of a polymerization catalyst were added. 29 parts by mass of THF, 2.8 parts by mass of 2-bromo-5-iodo-3-hexylthiophene, and 3.5 parts by mass of a 2.0 M solution of isopropylmagnesium bromide were added to another dried pear-shaped flask B, and Stir at 0 degrees for 30 minutes. Subsequently, the reaction liquid was added to a pear-shaped flask A, and polymerization was carried out at 35 ° C for 90 minutes. Subsequently, 16 parts by mass of THF and 1.4 parts by mass of 2-bromo-5-iodo-3-(2-ethyl)hexylthiophene, and 1.7 parts by mass of isopropyl bromide were added to another dried pear-shaped flask C. A 2.0 M solution of magnesium was added, and a solution which was reacted at 0 ° C for 30 minutes was added to the pear-shaped flask A for 7 hours. After the reaction, 4 parts by mass of a 1.0 M THF solution of tributylmagnesium chloride was added, and the mixture was stirred for 1 hour, and then 100 parts by mass of 5 M hydrochloric acid was added thereto, and the mixture was stirred for 1 hour to terminate the polymerization. Subsequently, it was extracted with 900 parts by mass of chloroform, washed with 200 parts by mass of an aqueous solution of sodium hydrogencarbonate, 200 parts by mass of distilled water, and concentrated to dryness. The obtained black-purple solid was dissolved in 56 parts by mass of chloroform, reprecipitated in 600 parts by mass of acetone, and sufficiently dried to obtain a conjugated block copolymer C1 [Polymer name: poly(3-hexylthiophene-embedded) Segment-3-(2-ethylhexyl)thiophene)] (P1).

According to the same GPC measurement as in Polymerization Example 1, the obtained conjugated block copolymer C1 had a weight average molecular weight of 21,600 and a number average molecular weight of 17,900. The content of the poly(3-hexylthiophene) block was 79 mol%.

(Comparative Example 2)

The synthesis of the conjugated block copolymer C2 was carried out in accordance with the following reaction formula (17).

In a well-dried argon-substituted pear flask A, 21 mL of THF, 1.257 g (4.2 mmol) of 2-bromo-5-iodo-3-hexylthiophene, and chlorination were added for dehydration and peroxide removal treatment. 2.1 mL of a 2.0 M solution of propylmagnesium was stirred at 0 ° C for 30 minutes to synthesize an organomagnesium compound solution (a3-1). In another fully dried argon-substituted pear flask B, 4 mL of THF and 2,5-dibromo-3-(4,4,5,5,6,6) were added for dehydration and peroxide removal treatment. , 0.77 g (0.8 mmol) of 7,7,7-nonafluoroheptyl)thiophene and 0.8 mL of a 1.0 M solution of tributylmagnesium chloride, and stirred at 60 ° C for 2 hours to synthesize an organomagnesium compound solution (a3-2) ).

After C in pear-shaped flask was sufficiently dried and purged with argon of added peroxide and dehydration process of 25mL THF was removed and _{NiCl 2 (dppp) 27mg (0.05} mmol), heated to 35 ℃, adding the previously prepared organic The magnesium compound solution (a3-1) was stirred with heating at 35 ° C for 1.5 hours. Next, the organomagnesium compound solution (a3-2) was added, and the reaction was carried out at 35 ° C for 2 hours. After completion of the reaction, 2 mL of a 1.0 M THF solution of tributylmagnesium chloride was added thereto, and the mixture was stirred at 35 ° C for 1 hour, and then 30 mL of 5 M hydrochloric acid was added thereto, and the mixture was stirred at room temperature for 1 hour. The reaction liquid was extracted with 450 mL of chloroform, and the organic layer was washed successively with 100 mL of aqueous sodium hydrogen carbonate solution and 100 mL of distilled water. The organic layer was dried over anhydrous sodium sulfate and then concentrated to dryness. The obtained dark purple solid was dissolved in 30 mL of chloroform, reprecipitated in 300 mL of methanol, and purified by a GPC column using a fractionation method as in Polymerization Example 3 to obtain a conjugated block copolymer C2 (721 mg).

The weight average molecular weight (Mw) of the obtained conjugated block copolymer C2 was 23,400, the number average molecular weight (Mn) was 20,800, and the degree of dispersion (Mw/Mn) was 1.13, as measured by GPC in the same manner as in Polymerization Example 1.

(Comparative Example 3)

A diblock copolymer of 3-hexylthiophene and 3-phenoxymethylthiophene having a molar ratio of 1:1 was synthesized as the conjugated block copolymer C3 of Comparative Example 3. The detailed sequence of synthesis of the conjugated block copolymer C3 is based on Non-Patent Document 3. The obtained conjugated block copolymer C3 had a weight average molecular weight (Mw) of 22,500, a number average molecular weight (Mn) of 19,800, and a degree of dispersion (Mw/Mn) of 1.14.

(Comparative Example 4)

Synthesis of 3-hexylthiophene with 3-[2-(2-methoxyethoxy)ethoxy]methylthiophene as a 1:1 diblock copolymer as a comparison The conjugated block copolymer C4 of Example 4. The detailed sequence of synthesis of the conjugated block copolymer C4 is based on Non-Patent Document 1. The obtained conjugated block copolymer C4 had a weight average molecular weight (Mw) of 25,100, a number average molecular weight (Mn) of 20,200, and a degree of dispersion (Mw/Mn) of 1.24.

(Comparative Example 5)

A diblock copolymer having a molar ratio of 3-hexylthiophene to styrene of 1:1 was synthesized as the non-conjugated block copolymer C5 of Comparative Example 5. The detailed sequence of synthesis of the non-conjugated block copolymer C5 is based on Non-Patent Document 2. The obtained non-conjugated block copolymer C5 had a weight average molecular weight (Mw) of 24,000, a number average molecular weight (Mn) of 16,900, and a degree of dispersion (Mw/Mn) of 1.42.

(Comparative Example 6)

The synthesis of the conjugated block copolymer C6 was carried out in accordance with the following reaction formula (18).

A conjugated polymer block A4 (0.80 g) and a polymer represented by the conjugated polymer block A7 (0.80 g), toluene (20 mL), and 2 M potassium carbonate aqueous solution were placed in a 100 mL three-necked flask under a nitrogen atmosphere. (10 mL, 20 mmol), hydrazine (triphenylphosphine) palladium (0) (20.5 mg, 17.7 μmol), and aliquat 336 (0.8 mg, 1.98 μmol) were stirred at 80 ° C for 24 hours. After completion of the reaction, the reaction solution was poured into methanol (200 mL), and the precipitated solid was filtered, washed with water (20mL), methanol (20mL), and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (100 mL) and hexane (100 mL) using a Soxhlet apparatus, and extracted with chloroform (100 mL). The obtained solution was poured into methanol (1 L), and the precipitated solid was filtered and dried under reduced pressure to obtain a conjugate of a dark purple solid. Block copolymer C6 (0.67 g, 42%).

The physicochemical analysis of the obtained conjugated block copolymer C6 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270MHz): δ = 8.12 - 7.96 (m, 4H), 7.85-7.32 (m, 4H), 2.74 (t, J = 7.58 Hz, 4H), 2.35-1.31 (m, 38H), ( m, 12H)

GPC (CHCl ₃ ): Mn = 36000 g/mol, Mw = 80900 g/mol, PDI = 2.25

As a result of the chemistry analysis, the chemical structure shown in the above reaction formula (14) is supported.

(Comparative Example 7)

The conjugated polymer block A1 was used as the conjugated polymer C7 of Comparative Example 7.

(Comparative Example 8)

The conjugated polymer block A3 was used as the conjugated polymer C8 of Comparative Example 8.

(Comparative Example 9)

The synthesis of the conjugated polymer C9 was carried out in accordance with the following reaction formula (19).

2,6-bis(trimethyltin)-4,8-dipropylbenzo[1,2-b constituting a monomer of conjugated polymer C9 was added to a 50 ml pear-shaped flask under a nitrogen atmosphere. :4,5-b']dithiophene (0.45 g, 0.75 mmol) and 1-(4,6-dibromothieno[3,4-b]thiophen-2-yl)-2-ethylhexane- 1-ketone (0.32 g, 0.75 mmol), and DMF (6.2 mL), chlorobenzene (25 mL), bis(triphenylphosphine)palladium(0) (9.2 mg, 7.8 μmol), and heated at 135 ° C for 1 hour 30 minutes. Next, 2,5-dibromothiophene (1.84 g, 7.6 mmol) as a terminal end group was added, and the mixture was heated at 115 ° C for 16 hours. After completion of the reaction, the reaction solution was concentrated, poured into methanol (500 mL), and the precipitated solid was filtered, and the obtained solid was dried under reduced pressure to give a crude product. The crude product was washed with acetone (200 mL) and hexane (200 mL) using a Soxhlet apparatus, and then extracted with chlorobenzene (200 mL). The organic layer was concentrated to dryness, and the obtained dark purple solid was dissolved in chlorobenzene (30mL) and re-precipitated in methanol (300mL).

The obtained conjugated polymer was carried out in the same manner as in the above Polymerization Example 8. Physicochemical analysis of C9 (0.31 g, 77%). The chemical analysis results below support the chemical structures shown in the above reaction formula.

¹ H NMR (270MHz, CDCl3): δ = 7.60-7.30 (br, 3H), 3.30-3.00 (Br, 5H), 2.00-1.10 (br, 12H), 1.00-0.70 (br, 12H)

GPC (CHCl ₃ ): Mn = 10,400 g/mol, Mw = 24,400 g/mol, PDI = 2.34

(Comparative Example 10)

The conjugated polymer block A8 obtained in Polymerization Example 8 and the conjugated polymer C9 obtained in Comparative Example 9 were mixed at a weight ratio of 50:50 to prepare a polymer blend D1.

(Manufacture of a mixed solution of a conjugated block copolymer and an electron accepting material)

16.0 mg of the conjugated block copolymer 1 obtained in Example 1 and 12.8 mg of PCBM (E100H manufactured by FRONTIER CARBON Co., Ltd.) as electron accepting material and 1 mL of chlorobenzene as a solvent were mixed at 40 ° C for 6 hours. Subsequently, it was cooled to room temperature at 20 ° C, and filtered through a PTFE membrane having a pore size of 0.45 μm to prepare a solution containing a conjugated block copolymer and PC ₆₁ BM.

For each of the polymers obtained in Examples 2, 5, and 6 and Comparative Examples 1 to 5, 8, a solution containing PC ₆₁ BM was produced in the same manner.

Each of the polymers obtained in Examples 3 and 4 and Comparative Examples 6 and 7 was used except that 5.0 mg of the polymer and 20.0 mg of PC ₆₁ BM (E100H manufactured by FRONTIER CARBON Co., Ltd.) as an electron accepting material were used. A solution containing a polymer and PC ₆₁ BM was produced in the same manner as in the conjugated block copolymer 1.

For each of the polymers obtained in Examples 7, 8 and Comparative Example 9, and the polymer blend D1 obtained in Comparative Example 10, 10.0 mg of the polymer and 15.0 mg of PC ₇₁ BM as an electron accepting material were used ( E110) manufactured by FRONTIER CARBON Co., Ltd. was mixed into a powder, and 1 mL of chlorobenzene mixed with 1,8-diiodooctane was added as a solvent at a volume fraction of 2.5%, and mixed at 100 ° C for 6 hours. Subsequently, it was cooled to room temperature at 20 ° C, and filtered through a PTFE filter having a pore size of 1.00 μm to prepare a solution containing a polymer and PC ₇₁ BM.

(production and evaluation of organic solar cells)

The glass substrate to which an ITO film (resistance value: 10 Ω/□) was attached by a sputtering method at a thickness of 150 nm was subjected to ozone UV treatment for 15 minutes to carry out surface treatment. A PEDOT:PSS aqueous solution (manufactured by HC Starck Co., Ltd.: CLEVIOS PH500) serving as a hole transporting layer was formed on the substrate by a spin coating method to a thickness of 40 nm. After heating and drying at 140 ° C for 20 minutes on a hot plate, a solution containing the polymer produced above and PC ₆₁ BM or a solution containing the polymer and PC ₇₁ BM is applied by spin coating to obtain an organic thin film solar cell. Photoelectric conversion layer (film thickness about 100 nm). After vacuum drying for 3 hours, the examples 1, 2, 5, and 6 and Comparative Examples 1 to 5 and 8 were subjected to thermal annealing at 120 ° C for 30 minutes. Subsequently, lithium fluoride having a film thickness of 1 nm was deposited by a vacuum vapor deposition machine, and then aluminum having a film thickness of 100 nm was deposited. The degree of vacuum at the time of vapor deposition was 2 × 10 ^-4 Pa or less. According to this, an organic thin film solar cell of a photoelectric conversion element produced by a conjugated block copolymer. The shape of the organic thin film solar cell is a positive square shape of 5 × 5 mm.

(Measurement of photoelectric conversion efficiency and solubility parameters)

The photoelectric conversion efficiency of the obtained organic thin film solar cells of each of the examples and the comparative examples was measured with a 300 W solar simulator (manufactured by PECCEL TECHNOLOGY, trade name: PEC L11: AM 1.5G filter, illuminance: 100 mW/cm ² ). The measurement results are shown in Table 1, Table 2, and Table 3. Further, the solubility parameters of the respective polymer blocks constituting the conjugated block copolymer of each of the examples were calculated by the Bicerano method using a computer software Scigress Explorer Professional 7.6.0.52 (manufactured by Fujitsu). The solubility parameters were also measured in the same manner for the polymers of the respective comparative examples. The results are shown together in Tables 1-3.

In Table 1 (Examples 1 to 4), Table 2 (Examples 5 to 8), Table 3 (Comparative Examples 1 to 5), and Table 4 (Comparative Examples 6 to 10), constituting a conjugated block copolymer was exemplified. The structure of the conjugated polymer block, the solubility parameter (SP value) of the conjugated polymer block, the difference in SP value, and the photoelectric conversion efficiency of the organic thin film solar cell. Further, in the conjugated polymer block constituting the conjugated block copolymer, the conjugated polymer block having the solubility parameter of the maximum value is represented as a conjugated polymer block A, and the conjugate of the solubility parameter having the smallest value The polymer block is represented as a conjugated polymer block B. Further, the polymer blend D1 obtained in Comparative Example 10 is shown in the table as the difference in SP values of the blended homopolymers.

It can be understood from the evaluation that among the solubility parameters of the conjugated polymer blocks constituting each block, the maximum value (polymer block A) and the minimum value (polymerization) The organic thin film solar cell of the conjugated block copolymer of the present invention having a difference of the block B) of 0.6 or more and 2.0 or less has a high conversion efficiency as compared with the conventional conjugated block copolymer.

According to the comparison of Example 1 with Comparative Examples 7 and 8, and the comparison of Examples 7 and 8 with Comparative Example 9, it is understood that the conjugated block copolymer has a conjugated polymer (conjugated by a single monomer unit). The conversion efficiency of the polymer) is high. In Examples 1 and 2, the solubility parameter was adjusted by changing the divalent heterocyclic group of the main chain, and it was found that a preferred conjugated block copolymer can be synthesized. By changing the length of the side chain (Example 3), or by appropriately selecting the number of fluorine atoms bonded to the side chain (Examples 4 and 6), it can be seen that the polymer blocks can be synthesized to have a better solubility parameter difference. Yoke block copolymer. It is also known that the solubility parameter can be appropriately adjusted by bonding a hydroxyl group to a side chain (Example 5). From Examples 5 and 7, it is also known that the polymer block A or B may be a polymer block formed of a random copolymer.

On the other hand, from Comparative Examples 1, 2, 3 and 6, it is understood that among the solubility parameters of the conjugated polymer blocks constituting each block, the maximum value (conjugated polymer block A) and the minimum value (conjugated) If the difference between the polymer blocks B) is not in the range of 0..6 or more and 2.0 or less, high conversion efficiency cannot be obtained. Further, Comparative Example 4 in which the difference in solubility parameter is within the range specified by the present invention, an alkyl group having a fluorine atom and a functional group substituted with a hydroxyl group in the side chain, and a block copolymer mainly containing a non-conjugated polymer block are known. The conversion efficiency of Comparative Example 5 was low. Further, from Comparative Example 10, even if a polymer blend of a polymer having a difference in solubility parameter of 0.6 or more and 2.0 or less was blended, conversion efficiency superior to that of the conjugated block copolymer of the present invention could not be obtained. .

[Industrial useability]

The conjugated conjugated block copolymer of the present invention is a photoelectric conversion layer which can be utilized as a photoelectric conversion element. Further, a photoelectric conversion element made of a conjugated block copolymer thereof is widely used as various photosensors represented by solar cells.

Claims (10)

A conjugated block copolymer characterized by containing at least two conjugated polymerizations having a divalent heterocyclic group in the main chain and having an alkyl or alkoxy side chain which may be substituted by a fluorine atom or a hydroxyl group The difference between the solubility parameter of the conjugated polymer block having the maximum solubility parameter value and the conjugated polymer block having the minimum solubility parameter value is 0.6 or more and 2.0 or less. The conjugated block copolymer according to claim 1, wherein the conjugated polymer block comprises a condensed ring π-conjugated skeleton having at least one thiophene ring in a part of a chemical structure, 咔a divalent heterocyclic group of at least one heterocyclic skeleton selected from the group consisting of an azole skeleton, a dibenzosilole skeleton, and a dibenzogermole skeleton. The conjugated block copolymer of claim 1, wherein the conjugated polymer block comprises, in the main chain, a cyclopentadithiophenediyl group, a dithienopyrrolediyl group, a dithienofluorene diene group. Pentadiene diyl, dithienofluorenyl dicyclopentadienyl, benzodithiophenediyl, naphthobithiophenediyl, thienothiophene diyl, thienopyrroledione diyl and diketopyrrole And at least one divalent heterocyclic group selected from the pyrrole diyl group. The conjugated block copolymer according to any one of claims 1 to 3, wherein the two conjugated polymer blocks are the minimum carbon number of the above-mentioned divalent heterocyclic group bonded to the side chain. a conjugated polymer block of an alkyl or alkoxy group bonded to the aforementioned side chain of the same or different kinds of the above-mentioned divalent heterocyclic group A conjugated polymer block of a large carbon number 6 alkyl or alkoxy group. The conjugated block copolymer of claim 3, wherein a difference between a total number of carbon atoms of a side chain of one conjugated polymer block and a total of a side chain carbon number of another conjugated polymer block is 6 or more and 16 or less . The conjugated block copolymer according to any one of claims 1 to 3, wherein the two of the conjugated polymer blocks are non-fluorine-bonded to the side chain of the divalent heterocyclic group. Conjugated polymer block of an alkyl or alkoxy group, conjugated with an alkyl or alkoxy group substituted with at least 3 fluorine atoms bonded to the side chain of the same or a heterogeneous heterocyclic heterocyclic group Block. A composition comprising a conjugated block copolymer and a fullerene derivative according to any one of claims 1 to 6. An organic film characterized by containing a conjugated block copolymer according to any one of claims 1 to 6. An organic thin film device characterized in that the substrate is provided with an organic thin film as in claim 8 of the patent application. A photoelectric conversion element characterized in that an organic film as in item 8 of the patent application is sandwiched between at least two electrodes.