TW201317268A - Conjugated polymer composition and photoelectric conversion element using same - Google Patents

Abstract

Provided is a conjugated polymer composition whereby a phase-separated structure ideal for a photoelectric conversion element can be formed, and whereby a favorable organic thin film that is highly soluble in solvents can be formed. This conjugated polymer composition has a main chain including a divalent heterocyclic group comprising a fused-ring p-conjugated backbone, has a side chain which is an alkoxy group or alkyl group optionally substituted with a fluorine atom or hydroxyl group, and contains at least two types of conjugated polymers having a number average molecular weight in terms of polystyrene of at least 10,000 g/mol, wherein the difference between the conjugated polymer having the greatest value and the conjugated polymer having the lowest value for a solubility parameter of each of the conjugated polymers is 0.6 to 2.0.

Description

Conjugated polymer composition and photoelectric conversion element using same

The present invention relates to a conjugated polymer composition for forming an organic thin film and a photoelectric conversion element by the organic thin film.

Solar cells are attracting attention as a useful energy source for the environment. At present, as the photoelectric conversion element of the solar cell, an inorganic substance such as a single crystal germanium, a polycrystalline germanium, an amorphous germanium or a compound semiconductor is used. These photoelectric conversion elements have high photoelectric conversion efficiency, but are expensive. The high cost is mainly due to the process factor of manufacturing a semiconductor thin film under high vacuum and high temperature, so that the photoelectric conversion element is expensive. Here, an organic solar cell using an organic semiconductor such as a conjugated polymer or an organic crystal or an organic dye is being reviewed as a semiconductor material having a simplified manufacturing process. Since these organic semiconductor materials can be formed by a coating method or a printing method, the manufacturing process is simple and can be mass-produced, and has attracted attention as an inexpensive organic solar cell.

The organic solar cell is a structure in which an organic photoelectric conversion layer composed of an organic thin film is provided between two different kinds of electrodes. In general, the organic photoelectric conversion layer is formed from a mixture of a conjugated polymer and a bulk heterojunction structure of a fullerene derivative. As a representative example thereof, for example, a composition comprising poly(3-hexylthiophene) as a conjugated polymer and [6,6]-phenyl C ₆₁ butyric acid methyl ester (PCBM) as a fullerene derivative is exemplified.

The subject of organic solar cells is to improve the photoelectric conversion efficiency, and in particular, it has been reported that the correlation between the morphology of the organic photoelectric conversion layer and the photoelectric conversion efficiency is improved. For example, a method of treating heat or a solvent vapor, a method of creating a solvent for dissolving a conjugated polymer or a fullerene derivative, a method of adding a high boiling point compound, and a method of lowering a volatilization rate of a solvent may be mentioned.

Further, as another attempt to improve the photoelectric conversion efficiency, it has been reported that the morphology is controlled by using a conjugated polymer composition in order to improve the photoelectric conversion efficiency. However, among the reporters reported so far, there is no strategy for controlling the phase separation of the conjugated polymer composition, and therefore it is difficult to improve the performance of the photoelectric conversion element by using the conjugated polymer composition.

For example, the organic semiconductor composition of the low molecular compound and the polymer compound disclosed in Patent Document 1 causes macroscopic phase separation due to difficulty in mixing the low molecular compound and the conjugated polymer of the polymer compound, or the low molecular compound may bleed out. Therefore, the stability is low. Non-Patent Document 1 is that the conjugated polymer on one side is not a condensed ring π conjugated skeleton, and has a mismatch of HOMO energy levels, so that stable movement of charges cannot be produced, and as a result, high conversion cannot be obtained. effectiveness. Further, in the photoelectric conversion elements described in Patent Documents 2 to 4 and Non-Patent Documents 2 to 3, the conjugated polymer on one side is not a condensed ring π-conjugated skeleton or a heterocyclic skeleton, and thus cannot be obtained high. Conversion efficiency. Further, since the fullerene derivative is substituted by the conjugated polymer containing the N-type semiconductor, the conversion efficiency is low as compared with the photoelectric conversion element composed of the composition of the conjugated polymer composition and the fullerene derivative. . In addition, the phase separation of these conjugated polymers is in the form of micrometers and large macroscopic phases. It is difficult to claim that the phase separation of the conjugated polymer composition has been the controller.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-267372

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-074127

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2010-010438

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2008-091886

[Non-patent literature]

[Non-Patent Document 1] Advanced Functional Materials, 2010, Vol. 20, No. 2, pp. 338-346

[Non-Patent Document 2] Advanced Materials, 2009, Vol. 21, No. 38-39, 3840-3850

[Non-Patent Document 3] Progress in Photovoltaics: Research and Applications, 2007, Vol. 15, pp. 727-740

The present invention has been made to solve the above problems, and an object of the present invention is to provide a conjugated polymer composition which can form an ideal phase separation structure for a photoelectric conversion element, has high solubility to a solvent, and can be formed into a good form. An organic film; and a photoelectric conversion element using an organic film containing the conjugated polymer composition of the present invention and having excellent photoelectric conversion efficiency.

The conjugated polymer composition of claim 1 which achieves the above-mentioned object, which comprises at least two types of conjugated polymer compositions such as conjugated polymers, wherein the conjugated polymer is included in the main chain a divalent heterocyclic group consisting of a condensed ring π-conjugated skeleton, and having a side chain of an alkyl group or an alkoxy group which may be substituted by a fluorine atom or a hydroxyl group, and having a number average molecular weight of at least 10,000 g/mole in terms of polystyrene The conjugated polymer composition is characterized in that, among the solubility parameters of the respective conjugated polymers, the difference between the conjugated polymer having the maximum value and the conjugated polymer having the smallest value is 0.6 or more and 2.0 or less. .

The conjugated polymer composition according to claim 2, wherein the heterocyclic group is composed of a condensed ring π-conjugated skeleton containing at least one thiophene ring.

The conjugated polymer composition of claim 3, wherein the conjugated polymer contains at least one selected from the group consisting of cyclopentadithiophenediyl, dithienopyrrolediyl, and dithiophene. Didienosilolediyl, dithienogermolediyl, benzodithiophenediyl, naphthodithiophene diyl, thienothiophenediyl, thienopyrrolediyl The monomer unit of the ring group is composed.

The conjugated polymer composition according to any one of claims 1 to 3, wherein the two types of conjugated polymers are: the divalent heterocyclic group is a bond of at least a carbon number of 12 The side chain of an alkyl or alkoxy group The conjugated polymer, which is a conjugated polymer of the same or different kinds of the above-mentioned divalent heterocyclic group, is a side chain which is bonded to an alkyl group having at least 8 carbon atoms or an alkoxy group.

The conjugated polymer composition according to any one of claims 1 to 4, wherein the two types of conjugated polymers are: the divalent heterocyclic group is bonded without fluorine substitution. a conjugated polymer of a side chain of an alkyl group or an alkoxy group, which is conjugated to a side chain of an alkyl group or an alkoxy group in which the aforementioned divalent heterocyclic group of the same or a heterogeneous group is bonded with at least 3 fluorine atoms. polymer.

The conjugated polymer composition according to any one of claims 1 to 5, wherein at least one of the conjugated polymers is a random copolymer, and the random copolymer is It is composed of at least two types of monomer units each having a divalent heterocyclic group consisting of a condensed ring π conjugated skeleton.

The conjugated polymer composition according to any one of claims 1 to 6, wherein the conjugated polymer composition contains a conjugated polymer having a solubility parameter as a maximum value and has solubility. The mass ratio of the conjugated polymer whose parameter is the minimum is the conjugated polymer having the maximum value: the conjugated polymer having the smallest value = 95:5 to 5:95.

The organic semiconductor composition of claim 8, which comprises the conjugated polymer composition according to any one of claims 1 to 7 and a fullerene derivative.

The organic film of claim 9, which is characterized by comprising the conjugated polymer composition according to any one of claims 1 to 7.

The organic thin film device of claim 10, characterized in that the substrate is provided with the organic thin film of claim 9.

The photoelectric conversion element of claim 11 characterized by claim 9 The organic film is held between at least two electrodes.

The conjugated polymer composition of the present invention contains at least two kinds of conjugated polymers, and by adjusting the solubility parameters thereof, a phase separation structure can be formed. By this phase separation structure, an organic film having a controlled high photoelectric conversion efficiency can be formed. The conjugated polymer composition is a photoelectric conversion element capable of forming a phase-separated structure and having an improved photoelectric conversion efficiency by a controllable morphology.

The organic semiconductor composition of the present invention is a fullerene derivative containing a conjugated polymer composition having a high solubility to a solvent and an electron-accepting material, and can form an ideal phase-separated structure.

When the organic thin film of the present invention has a controlled morphology and is used in a photoelectric conversion element, a high-performance photoelectric conversion element that imparts excellent photoelectric conversion efficiency can be produced.

The photoelectric conversion element of the present invention has an organic thin film (which is a conjugated polymer composition having a controlled morphology and improved photoelectric conversion efficiency) as an organic photoelectric conversion layer, and has excellent photoelectric conversion performance and can be applied. Various photoelectric conversion devices utilizing photoelectric conversion functions or optical rectification functions.

[Best Mode for Carrying Out the Invention]

The following is a detailed description of the aspects used to carry out the invention, but the scope of the invention is not limited to such aspects.

The conjugated polymer composition of the present invention is a mixture containing at least two types of conjugated polymers, such as conjugated polymer A and conjugated polymer B. Each of these conjugated polymers is composed of a conjugated divalent monomer and contains a divalent heterocyclic group in the main chain. The so-called conjugated divalent monomer refers to a divalent group in which the bonding electrons in the molecule are non-localized. Further, the term "main chain" means the longest chain among the compounds composed of a divalent heterocyclic group. At least two of these conjugated polymers are those in which the main chain is a divalent heterocyclic group consisting of a condensed ring π conjugated skeleton, and having an alkyl group or alkoxy group which may be substituted by a fluorine atom or a hydroxyl group. Side chain structure. In other words, the conjugated polymer composition of the present invention is an essential component which is contained in a conjugated polymer having a divalent heterocyclic group consisting of a condensed ring π conjugated skeleton in its main chain.

The divalent heterocyclic group which consists of a condensed ring π conjugated skeleton is specifically, for example, dibenzofluorenyldiyl, dibenzofluorenyldiyl, dibenzofurandiyl, carbazolediyl, benzo Thiazolidinediyl, benzotriazolyl, cyclopentadithiophenediyl, dithienopyrrolediyl, dithienofluorenyldiyl, dithienofluorenyldiyl, benzodithiophenediyl, naphthalene And dithiophenediyl, thienothiophene diyl, thienopyrroledione, and the like.

Among these, in terms of the easily controllable form and the high performance of the photoelectric conversion element, it is preferred that a part of the chemical structure is a condensed ring π-conjugated skeleton containing at least one thiophene ring. Particularly preferred are cyclopentadithiophenediyl, dithienopyrrolediyl, dithienofluorenyldiyl, dithienofluorenyldiyl, benzodithiophenediyl, naphthobithiophenediyl, thiophene Thiophenediyl, thienopyrroledione.

In another aspect, the conjugated polymer composition of the present invention comprises a total of When the conjugated polymer is composed of a divalent monomer composed of a heterocyclic group having a monocyclic structure, it is not preferable because the photoelectric conversion efficiency is not high when used in a photoelectric conversion element. For example, when the divalent heterocyclic group is a monocyclic structure of an unsubstituted or substituted thiophenediyl group, it is easy to synthesize, but the wavelength range of the absorbed light is a short wavelength, and is used for a photoelectric conversion element due to photoelectric conversion efficiency. Not high, it is not appropriate.

Among the conjugated polymers contained in the conjugated polymer composition, the conjugated polymer contained as an essential component has a main chain skeleton which is a divalent heterocyclic ring which is composed of the same condensed ring π conjugated skeleton. Base, in terms of charge transport, it is appropriate.

The monomer unit of the conjugated polymer has a structure having a plurality of certain repeating structures in the conjugated polymer, and includes a structure in which a plurality of divalent heterocyclic groups are bonded (for example, a monomer unit -ab-). In the case of one unit, it is regarded as a conjugated divalent monomer unit composed of a condensed ring π conjugated skeleton of the present invention. That is, a completely alternating copolymer of the monomer unit -a- and the monomer unit -b- is regarded as a single polymer of the monomer unit -a-b- as long as the substituent is the same repeating unit. In the conjugated polymer A and the conjugated polymer B contained in the conjugated polymer composition of the present invention, even one monomer unit of one type contained in the monomer unit-ab- The substituent is removed, and the total number of carbon atoms constituting the ring structure is preferably 6 to 30. In the case of such a monomer unit -ab-, an alkyl group or an alkoxy group which may be substituted with a fluorine atom or a hydroxyl group in a side chain is bonded to at least a monomer unit - a- or a monomer unit - b- Any one can do it.

More specifically, for example, if cyclopentadithiophenediyl and benzothiadiazole are When the radical is an alternating bond, the cyclopentadithiophenediyl group and the benzothiadiazolediyl group are regarded as a monomer unit -ab-, and -ab- can be regarded as a condensed ring π which constitutes a conjugated polymer. A conjugated divalent monomer composed of a yoke skeleton.

A divalent group other than the divalent heterocyclic group may be copolymerized in the conjugated polymer. When the divalent group other than the divalent heterocyclic group is copolymerized, the copolymerization ratio is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less based on the conjugated polymer. . If the copolymerization rate is too high, the performance of the photoelectric conversion element is lowered. Specific examples of the divalent group other than the divalent heterocyclic group include an ethynyl group and an extended aryl group.

The number average molecular weight of the conjugated polymer of the essential component contained in the conjugated polymer composition is easily separated by phase separation of the conjugated polymer composition, and from the viewpoint of hole mobility or mechanical and physical properties The number average molecular weight in terms of polystyrene is 10,000 g/mole or more, specifically preferably 10,000 to 500,000 g/mole, more preferably 15,000 to 250,000 g/mole, and most preferably 20,000 to 150,000 g/mole. If the number average molecular weight is less than 10000g / mol of low molecular weight conjugated polymer, it is not easy to phase separation, low molecular weight will be at the interface. When the surface is oozing, the performance is lowered when the photoelectric conversion element is fabricated.

As a method of measuring the number average molecular weight, a known method can be used, and in view of a wide range of a simple and applicable polymer, it is preferably measured by size screening chromatography. When the measurement by size screening is used, the standard polymer can be used as long as it is a known polymer having a molecular weight distribution of a narrow molecular weight. In the present invention, standard polystyrene is used, and the number average in terms of polystyrene is used. Molecular weight.

As a method of synthesizing the above conjugated polymer, a known method can be used. That is, various coupling polymerizations can be used. As the coupling reaction, for example, Suzuki coupling, Kumada coupling, Negishi coupling, Stille coupling, Sonogashira coupling, and the like are mentioned.

The conjugated polymer contained in the essential component in the conjugated polymer composition of the present invention, wherein the conjugated polymer having the solubility parameter is the maximum value and the conjugated polymer having the solubility parameter as the minimum value The ratio is not particularly limited, but is preferably 95:5 to 5:95 by mass, more preferably 90:10 to 10:90 by mass, and still more preferably 85:15 to 15:85 by mass. Among the two or more types of conjugated polymers contained in the conjugated polymer composition, it is preferred to contain a large amount of a conjugated polymer which can impart higher photoelectric conversion efficiency.

The conjugated polymer composition preferably contains at least one type of crystalline conjugated polymer from the viewpoint of hole mobility. Here, the crystalline conjugated polymer is one in which a part of the polymer is a polymer in a crystallized or liquid crystalline state. The discrimination as the crystalline polymer can be analyzed by X-ray diffraction or differential scanning calorimetry (DSC). In the present invention, it is judged to have crystallinity by observing by the X-ray diffraction method that the weak polymer stacked state such as only the aromatic ring π-π stack.

The conjugated polymer composition may contain a conjugated polymer having a structure other than the conjugated polymer of the essential component. The content of the film is preferably 50% by mass or less, and more preferably 30% by mass or less, from the viewpoint of controlling the form to achieve a so-called high conversion efficiency of the obtained photoelectric conversion element. More preferably, it is 20% by mass or less. Conjugation as an essential component The conjugated polymer having a structure other than the polymer is preferably a conjugated polymer having a similar structure to an essential component of the conjugated polymer composition (for example, any one of the conjugated polymer A and the conjugated polymer B) .

Further, the conjugated polymer composition may contain other non-conjugated polymers as long as it is two or more kinds of conjugated polymers containing an essential component. The content of the non-conjugated polymer is not particularly limited as long as the conversion efficiency of the photoelectric conversion element is not lowered, but is preferably 50% by mass or less based on the total mass of the conjugated polymer composition. More preferably, it is 30 mass% or less, and it is more preferably 10 mass% or less. Such a non-conjugated polymer has no relationship with the solubility parameter of the present invention.

The conjugated polymer composition of the present invention is characterized in that the solubility parameter of the conjugated polymer contained as an essential component has a solubility parameter having a maximum value of the conjugated polymer A and a solubility parameter having a minimum value. The difference between the yoke polymers B is 0.6 or more and 2.0 or less. In particular, 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, and most preferably 0.7 or more and 1.6 or less.

When the difference between the maximum value and the minimum value of the solubility parameter is 0.6 or more, the conjugated polymer composition can be phase-separated. On the other hand, when it is less than 0.6, the polarities of the respective conjugated polymers are similar, and it becomes difficult to phase separate. Further, the difference between the maximum value and the minimum value of the solubility parameter is 2.0 or less, which is also important. If the difference between the maximum value and the minimum value of the solubility parameter is larger than 2.0, the solubility of the conjugated polymer to the solvent is remarkably lowered, and it is difficult to obtain a film, or the phase separation size may be excessive when the film is formed. High conversion efficiency cannot be obtained when making photoelectric conversion elements shape.

The ideal phase separation structure means that the components of the two or more conjugated polymers contained in the conjugated polymer composition are bicontinuous structures. This is also important in the field of one conjugated polymer of such phase-separated structures as a fullerene derivative containing more electron-accepting materials than other domains. By forming such a form, the charge can be transported to the electrode without re-bonding or deactivation, so that a photoelectric conversion element having a large short-circuit current density or high performance can be produced.

As a method of controlling the solubility parameter, it can be controlled by the molecular structure of the conjugated polymer. For example, when a conjugated polymer composition composed of two types of conjugated polymers is considered, the solubility parameter can be adjusted by changing the main chain skeleton of the respective conjugated polymers. Further, the solubility parameter can also be adjusted by changing the side chain structure or the side chain density. When the side chain structure is changed to control the solubility parameter, the carbon number of the side chain, the atomic type of the carbon bonded to the side chain, the functional group bonded to the side chain, etc. can be controlled, for the purpose of conjugate The polymer has crystallinity, and the side chain is important for those having an alkyl group or an alkoxy group which may be substituted by a fluorine atom or a hydroxyl group. The term "side chain" as used herein refers to a portion having carbon branched by a conjugated main chain. 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 number of carbon atoms bonded to each side chain of the main chain.

When the conjugated polymer is a side chain having a plurality of different types, at least one of them may be 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, only There is no particular limitation if it can be adjusted to the range of the difference in the solubility parameter. As such other side chains, for example, a mercapto group, an ester group or the like can be mentioned.

It is not preferable to control the solubility parameter by the type of the functional group of the carbon of the alkyl group or the alkoxy group which may be bonded to the side chain 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 stacking of the polymer is hindered, and the degree of crystallization is lowered, and a smooth hole movement cannot be produced. Therefore, it is not appropriate. Further, when a functional group bonded to an alkyl group or an alkoxy group which may be substituted with a fluorine atom or a hydroxyl group is a bulky functional group, the so-called crystallization is inhibited, and a smooth hole movement cannot be produced. Not suitable.

On the other hand, the fluorine atom is different from other halogen atoms in that it does not inhibit crystallization, and conversely, since the fluorine atom promotes crystallization, it is suitable. Since the hydroxyl group can also be crystallized by hydrogen bonding, it is expected to be suitable. However, when there are two or more hydroxyl groups per one side chain, since a strong hydrogen bond is formed with each other, or a hydrogen bond is generated between each side chain of the polymer, It is not suitable for the case of hindering crystallization.

The preferred alkyl group substituted by a hydroxyl group may, for example, be a hydroxymethyl group, a 2-hydroxyethyl group, a 3-hydroxypropyl group, a 3-hydroxyisopropyl group, a 4-hydroxybutyl group or a 3-hydroxybutyl group. 3-hydroxyisobutyl, hydroxy tert-butyl, 5-hydroxypentyl, 4-hydroxyisopentyl, 6-hydroxyhexyl, 6-hydroxy-2-ethylhexyl, 7-hydroxyheptyl, 8-hydroxyl Omega-hydroxyalkane of octyl, 9-hydroxyindenyl, 10-hydroxyindole, 12-hydroxydodecyl, 16-hydroxyhexadecyl, 8-hydroxy-3,7-dimethyloctyl An alkyl group having a hydroxyl group other than the ω-position.

Specific examples of the preferred alkoxy group substituted by a hydroxyl group include a hydroxymethoxy group, a 2-hydroxyethoxy group, a 3-hydroxypropoxy group, a 3-hydroxyisopropoxy group, and a 4-hydroxybutoxy group. 3-hydroxybutoxy, 3-hydroxyisobutoxy, hydroxy tert-butoxy, 5-hydroxypentyloxy, 4-hydroxyisopentyloxy, 6-hydroxyhexyloxy, 6-hydroxy-2- Ethylhexyloxy, 7-hydroxyheptyloxy, 8-hydroxyoctyloxy, 9-hydroxydecyloxy, 10-hydroxyoxy, 12-hydroxydodecyloxy, 16-hydroxyhexadecyloxy An ω-hydroxyalkyl 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 by the carbon number of the side chain, the difference between the desired solubility parameter can be adjusted by combining the conjugated polymer having a different alkyl group or alkoxy group. Preferably, it is mainly a combination of a conjugated polymer having a side chain having 8 or less carbon atoms and a conjugated polymer mainly containing a side chain having 12 or more carbon atoms; more preferably: mainly It is a combination of a conjugated polymer having a side chain having 3 or more and 8 or less carbon atoms and a conjugated polymer mainly containing a side chain having 12 or more carbon atoms or less. In the case of a conjugated polymer having a side chain having a small carbon number, although the value of the solubility parameter can be increased, if the carbon number is too small, the solubility of the conjugated polymer to the solvent is lowered, and the solubility cannot be obtained. Good organic film. In addition, when the conjugated polymer having a side chain having a large carbon number is used, the value of the solubility parameter can be lowered. However, when the number of carbon atoms is more than 20 or more, the conjugated polymer chains are hardly accessible to each other. It is difficult to generate a charge or exciton shift between conjugated polymer chains, or a component that does not contribute to photoelectric conversion increases, and the short-circuit current density decreases. In these side chains, since all of the side chains in the conjugated polymer need not be limited to such a carbon number side chain, they may be combined with other side chains. Also, when the monomer unit of the conjugated polymer has a plurality of side chains When at least one side chain which is different from each other is selected among the side chains included in the respective monomer units, it is preferred that one of the side conjugated polymers has a side having a carbon number of 8 or less. The chain and the conjugated polymer on the other side have side chains having a carbon number of 12 or more and 20 or less.

When the solubility parameter of the conjugated polymer is adjusted by the carbon number of the side chain, examples of preferred alkyl groups include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutylene. Base, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, isohexyl, 2-ethylhexyl, n-heptyl, n- Octyl, n-fluorenyl, n-fluorenyl, n-hexadecyl, 3,7-dimethyloctyl, n-dodecyl and the like.

When the solubility parameter of the conjugated polymer is adjusted by the carbon number of the side chain, preferred examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, and an n- group. Butoxy, n-hexyl, n-octyloxy, n-decyloxy, 2-ethylhexyloxy, n-dodecyloxy, n-hexadecyloxy, 3,7-dimethyl Alkoxy group, n-dodecyloxy group, and the like.

When the solubility parameter of the conjugated polymer is adjusted by the atomic species of carbon bonded to the side chain, the conjugated polymer having a side chain which is bonded to the side chain by a hetero atom can be adjusted to a desired ratio. The difference in solubility parameters. In this case, fluorine is particularly suitable because it has the largest abundance of Pauling. When a fluorine atom is substituted for a hydrogen atom to bond with carbon, the number of fluorine atoms is also dependent on the number of carbon atoms in the side chain. When the number of carbon atoms is six or more, the side chain preferably contains three or more fluorine atoms. More preferably, it contains 5 or more side chains, and more preferably contains 5 or more and 13 or less side chains. When the monomer unit of the conjugated polymer has a plurality of side chains, the side contained in the respective monomer units Among the chains, when at least one side chain which is different from each other is compared, it is preferred that one of the conjugated polymers has a side chain having three or more fluorine atoms.

By combining a conjugated polymer having such a side chain and a conjugated polymer having a side chain containing no fluorine atom, a conjugated polymer composition having a desired difference in solubility parameter can be obtained. In this case, the solubility parameter of the conjugated polymer having a side chain containing a fluorine atom is smaller as the number of fluorine atoms is larger. In the case of a conjugated polymer having a side chain having a small number of fluorine atoms, the solubility parameter can be increased, but if 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, in the case of a conjugated polymer having a side chain having a large number of fluorine atoms, the solubility parameter can be lowered, but if the number of fluorine atoms is too large, the difference between the maximum value and the minimum value of the solubility parameter becomes is too big. Further, when the number of fluorine atoms is too large, the conjugated polymer is less soluble in the solvent. The side chain containing these fluorine atoms may be combined with other side chains because the total number of side chains in the conjugated polymer need not be a side chain containing a fluorine atom.

When designing a side chain in which a fluorine atom is a carbon bonded to a side chain to adjust a solubility parameter of a conjugated polymer, as a preferred fluorinated alkyl group, for example, a trifluoromethyl group, 2, 2, 2-Trifluoroethyl, 2,2,2,1,1-pentafluoroethyl, 4,4,4-trifluorobutyl, 6,6,6-trifluorohexyl, 5,5,6,6 ,6-pentafluorohexyl, 7,7,7-trifluoroheptyl, 4,4,5,5,6,6,7,7,7-nonafluoroheptyl, 8,8,8-trifluorooctyl Omega-trifluoromethylalkyl group of 7,7,8,8,8-pentafluorooctyl, 5,5,6,6,7,7,8,8,8-nonafluorooctyl or the like Perfluoroalkyl.

When designing a side chain in which a fluorine atom is a carbon bonded to a side chain to adjust a solubility parameter of a conjugated polymer, a preferred fluorinated alkoxy group is exemplified. Examples are, for example, 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, An ω-trifluoromethylalkoxy group or a perfluoroalkoxy group such as 7,8,8,8-nonafluorooctyloxy.

The conjugated polymer constituting the essential component of the conjugated polymer composition of the present invention may be a single polymer composed of one type of monomer unit, or may be a random copolymer having two or more types of monomer units. , graft copolymer or block copolymer. Among the conjugated polymers constituting the conjugated polymer composition, the solubility parameter can be controlled even if at least one is set as a single polymer and the other is set as a copolymer. Preferably, at least one of the conjugated polymers is a conjugated polymer composition of a random copolymer, and the random copolymer is composed of at least two types of the following monomer units, the monomer The unit is: a divalent heterocyclic group having a condensed ring π conjugated skeleton.

Although there are several methods for measuring or calculating these solubility parameters, in the present invention, Bicerano is used. As another method, for example, a Hildebrand method, a Small method, a Fedors method, a Van Krevelen method, a Hansen method, a Hoy method, an Ascadskii method, a Chongjin method, and the like are exemplified, but in the case of such a method, it is impossible to calculate a polymer having a hetero ring. The solubility parameter, or not the correct factor, cannot be used. The method of calculating by the Bicerano method is as 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 using the Bicerano method to calculate the solubility parameter, various computer software can be used. As the computer software, for example, Scigress Explorer Professional 7.6.0.52 (Fujitsu Co., Ltd.) or Polymer-Design Tools (DTW Associates, Inc) is exemplified. When the Bicerano method is used to process an element with no data, even the same element of the periodic table will be replaced with an element with a period number of one. For example, if there is no data, the solubility parameter calculated using the structure substituted for carbon will be used.

In the conjugated polymer composition of the present invention, it is necessary to calculate the solubility parameter regarding the respective conjugated polymers contained. For example, when the conjugated polymer contained in the conjugated polymer composition 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 (δ i × i).........(A)

δ i = solubility parameter of a polymer consisting only of i units of the constituents of the random copolymer

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

A conjugated polymer composition containing each conjugated polymer having a solubility parameter adjusted is suitable for use as an organic semiconductor material, and can be formed into a controlled organic film. Further, in the formation of the organic thin film, it is preferable to contain an electron-accepting material in addition to the conjugated polymer composition. In particular, it is preferred to use a fullerene derivative as the electron accepting material. Therefore, at least the conjugated polymer composition of the present invention and the fullerene derivative are mixed to form an organic semiconductor composition which forms an organic thin film.

The organic semiconductor composition of the present invention will have at least a total of The conjugated polymer composition is mixed with a fullerene derivative. This organic semiconductor composition is suitable as a functional layer of a photoelectric conversion element.

The fullerene derivatives of the electron-accepting materials are, for example, C ₆₀ , C ₇₀ , C ₈₄ and derivatives thereof. Specific structural examples of the fullerene derivative are shown by the following chemical formulas (A) to (癸).

In the organic semiconductor composition of the present invention, the ratio of the conjugated polymer composition to the fullerene derivative is preferably 10 to 1000 parts by weight based on 100 parts by weight of the conjugated polymer composition. More preferably, it is 50 to 500 parts by weight. Also, it may contain a conjugated polymer composition and The third component other than the fullerene derivative. The content of the third component is preferably 30% by mass or less, and more preferably 10% by mass based on the total weight of the conjugated polymer composition and the fullerene derivative, from the viewpoint of the performance of the photoelectric conversion element. %the following.

The method of mixing the conjugated polymer composition and the fullerene derivative is not particularly limited, and for example, one or more of a combination of heating, stirring, and ultrasonic irradiation after being added to a solvent at a desired ratio. Kind, to dissolve. A method of mixing in a solvent.

The solvent to be used in the mixing of the conjugated polymer composition and the fullerene derivative is not particularly limited as long as it is a solvent which is mostly soluble. Specific examples thereof include ethers such as tetrahydrofuran; halogen solvents such as dichloromethane and chloroform; and aromatic solvents such as benzene, toluene, o-xylene, chlorobenzene, o-dichlorobenzene, and acridine.

The organic semiconductor composition containing the conjugated polymer composition of the present invention, and a conjugated polymer composition thereof and a fullerene derivative can be formed into an organic thin film by a known printing method or coating method. As the film forming method, a spin coating method, a casting method, a micro gravure coating method, a die coating method, a slit coating method, a bar coating method, a roll coating method, a dip coating method, a spray coating method, a stencil, or the like can be specifically used. Printing method, quick-drying printing method, lithography method, inkjet printing method, nozzle coating method, capillary coating method, and the like.

An organic thin film containing a conjugated polymer composition is suitable as an organic transistor, a photoelectric conversion element, or an organic thin film element. The organic thin film element is, for example, a surface of a substrate to which an organic thin film containing a conjugated polymer composition is attached. The film thickness of the organic film containing the conjugated polymer composition, It cannot be used for the purpose of the purpose, and 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 small, light cannot be sufficiently absorbed. Conversely, when the film thickness is too thick, the carrier does not easily reach the electrode, and high conversion efficiency cannot be obtained.

For example, a photoelectric conversion element which is an organic thin film formed of the conjugated polymer composition of the present invention is used as an organic photoelectric conversion layer user.

As shown in FIG. 1, the photoelectric conversion element of the present invention has at least two dissimilar electrodes on the substrate 5, that is, the positive electrode 2 and the negative electrode 4, and the conjugate of the present invention between the positive electrode 2 and the negative electrode 4. The organic photoelectric conversion layer 3 of the organic film of the polymer composition. The photoelectric conversion element 1 can have the opposite positions of the positive electrode 2 and the negative electrode 4 depending on the type of the electrode.

The electrode of the photoelectric conversion element 1 preferably has light transmittance by any of the positive electrode 2 or the negative electrode 4. The light transmittance of the electrode is not particularly limited as long as the incident light can reach the organic photoelectric conversion layer 3 to generate an electromotive force. The thickness of the electrode may be in the range of light transmittance and conductivity, and although it varies depending on the electrode material, it is preferably 20 nm to 300 nm. When the electrode on one side is light transmissive, the electrode on the other side may have conductivity, and it is not necessarily required to have light permeability. Further, the thickness of the electrode is not particularly limited.

As the electrode material, it is preferable that the electrode on one side is a conductive material having a large work function, and the electrode on the other side is a conductive material having a small work function. An electrode using a conductive material having a large work function is used as the positive electrode 2. As a conductive material having a large work function, in addition to metals such as gold, platinum, chromium, and nickel, it is preferable to use a metal oxide such as indium or tin having transparency, and a composite metal oxide (indium tin oxide). (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), etc.). Here, the conductive material used for the positive electrode 2 is preferably an ohmic bond with the organic photoelectric conversion layer 3. Further, when the hole transport layer described later is used, the conductive material used for the positive electrode 2 is preferably an ohmic bond with the hole transport layer.

The electrode 4 is made of an electrode of a conductive material having a small work function, and the conductive material having a small work function is an alkali metal or an alkaline earth metal, specifically lithium, magnesium, or calcium. Also, tin or silver or aluminum should be used. Further, an alloy composed of the above metal or an electrode composed of a laminate of the above metals is also preferably used. Further, by introducing a metal fluoride such as lithium fluoride or cesium fluoride into the interface between the negative electrode 4 and the electron transport layer, the extraction current can be increased. Here, the conductive material used for the negative electrode 4 is preferably an ohmic bond with the organic photoelectric conversion layer 3. Further, when the electron transport layer is used, the conductive material used for the negative electrode 4 is preferably an ohmic bond with the electron transport layer.

The substrate 5 may be any change as long as the electrode is formed and the organic photoelectric conversion layer 3 is formed. For example, an inorganic material such as alkali-free glass, quartz glass, or the like; a metal film of aluminum or the like; or a polyester, a polycarbonate, a polyolefin, a polyamide, a polyimide, a polyphenylene sulfide, a poly-ply can be used. A film or sheet made of an organic material such as toluene, epoxy resin or fluorine-based resin according to any method. When an opaque substrate is used, the electrode on the opposite side, that is, the electrode on the far side from the substrate, must be transparent or translucent. Substrate 5 The film thickness is not particularly limited and is usually in the range of 1 μm to 10 mm.

Further, in order to improve the wettability of the substrate and the interface adhesion between the organic layer and the substrate, it is preferred to apply the surface by physical means such as ultraviolet ozone treatment, corona discharge treatment, or plasma treatment. Wash or upgrade. Further, a method of applying a chemical modification such as a decane-based coupling agent, a titanate-based coupling agent, or an automatic combination of a single-layer molecular film to the surface of a solid substrate is also effective.

The photoelectric conversion element 1 is provided with a hole transport layer between the positive electrode 2 and the organic photoelectric conversion layer 3 in response to the necessity. As a material for forming the hole transport layer, a conductive polymer such as a polythiophene polymer, a poly-p-phenylene vinyl polymer or a polyfluorene polymer, or an anthraquinone derivative (H2Pc) is preferably used. , CuPc, ZnPc, etc., a purple derivative or the like, a low molecular organic compound exhibiting p-type semiconductor characteristics. Particularly preferred is polyethylene dioxythiophene (PEDOT) or PEDOT using a polythiophene-based polymer to which polystyrene sulfonate (PSS) is added. The hole transport layer is preferably from 5 nm to 600 nm, more preferably from 20 nm to 300 nm.

The photoelectric conversion element 1 is provided with an electron transport layer between the negative electrode 4 and the organic photoelectric conversion layer 3 in response to the necessity. As a material for forming the electron transport layer, a phenanthrene compound such as Bathocuproine (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) or naphthalenetetracarboxylic anhydride can be used. An n-type semiconductor material such as naphthotetracarboxylic acid diimide, anthracene tetracarboxylic anhydride, or ruthenium tetracarboxylic acid diimine, and an n-type inorganic oxide such as titanium oxide, zinc oxide or gallium oxide, and lithium fluoride. An alkali metal compound such as sodium fluoride or cesium fluoride. Further, a layer composed of an n-type semiconductor material monomer used for the entire heterojunction layer Can also be used.

The photoelectric conversion element 1 may further have an inorganic layer. Examples of the material contained in the inorganic layer include titanium oxide, tin oxide, zinc oxide, iron oxide, tungsten oxide, zirconium oxide, hafnium oxide, tantalum oxide, indium oxide, antimony oxide, antimony oxide, antimony oxide, and oxidation. Metal oxides such as vanadium, cerium oxide, cerium oxide, gallium oxide, nickel oxide, barium titanate, barium titanate, potassium citrate, sodium citrate; silver iodide, silver bromide, copper iodide, copper bromide, fluorine Metal halides such as lithium sulfide; zinc sulfide, titanium sulfide, indium sulfide, barium sulfide, cadmium sulfide, zirconium sulfide, barium sulfide, molybdenum sulfide, silver sulfide, copper sulfide, tin sulfide, tungsten sulfide, barium sulfide, etc. Lithium selenide, zirconium selenide, zinc selenide, titanium selenide, indium selenide, tungsten selenide, molybdenum selenide, selenium telluride, lead selenide, etc.; cadmium telluride, tungsten telluride Metal ruthenium such as bismuth molybdenum, zinc telluride, bismuth telluride, etc.; metal phosphide such as zinc phosphide, gallium phosphide, indium phosphide, cadmium phosphide, etc.; gallium arsenide, copper-indium-selenide, Copper-indium-sulfide, antimony, bismuth, etc., and a mixture of two or more kinds thereof may be used. As the mixture, for example, a mixture of zinc oxide and tin oxide, a mixture of tin oxide and titanium oxide, and the like are exemplified.

The photoelectric conversion element 1 of the present invention can be applied to various photoelectric conversion devices using photoelectric conversion functions, photo diodes, and the like. For example, it is suitable as a photovoltaic cell (such as a solar cell), an electronic component (photosensor, optical switch, photoelectric crystal, etc.), an optical recording material (optical memory, etc.), or the like.

[Examples]

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

The synthesis of the conjugated polymer contained in the conjugated polymer composition is as shown in Polymerization Examples 1 to 9, and the conjugated polymer composition of the present invention using the same, as shown in Examples 1 to 3. Further, it is not applicable to the inventors, as shown in Comparative Examples 1 to 8.

(polymerization example 1)

The synthesis of the conjugated polymer A1 was carried out in accordance with the following reaction formula (1). Further, in the following reaction formula, the ethylhexyl group of the substituent is simply referred to 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 nitrogen atmosphere. Thiophene (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, 53.5μmol After aliquat 336 (2 mg, 4.95 μmol), the mixture was stirred at 80 ° C for 2 hours. After that, add phenylboronic acid The ester (273 mg, 1.34 mmol) was stirred at 80 ° C for 18 h. 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 a Soxlet's extractor, and extracted with chloroform (200 mL). The obtained solution was poured into methanol (2 L), and the precipitated solid was obtained by filtration, and then dried under reduced pressure to give a conjugated polymer A1 (1.04 g, 41%) as a dark purple solid.

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

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

¹ H-NMR (270 MHz): 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)

Both the number average molecular weight (Mn) and the weight average molecular weight (Mw) were determined by gel permeation chromatography (GPC) and were obtained in terms of polystyrene. Here, as the GPC device, HLC-8320GPC manufactured by Tosoh Co., Ltd. is used, and TSKgel SuperMultipore HZ-M manufactured by Tosoh Co., Ltd. is used as an in-line linker. Using the values of the average molecular weight (Mn) and the weight average molecular weight (Mw), the degree of dispersion (PDI) was determined by (Mw) / (Mn).

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

The result of this physicochemical analysis is to support the chemical structure shown in the above reaction formula (1).

(polymerization example 2)

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

2,6-Dibromo-4,4'-bis(2-ethylhexyl)-dithieno[3,2-b:2',3'-d was added to a 100 mL three-necked flask under nitrogen atmosphere. ] 锗茂(1.66g, 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, After 53.5 μmol) and aliquat 336 (2 mg, 4.95 μmol), the mixture was stirred at 80 ° C for 2 hours. After that, add phenylboronic acid The ester (273 mg, 1.34 mmol) was stirred at 80 ° C for 18 h. 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 a Soxhlet extractor, and extracted with chloroform (200 mL). The obtained solution was poured into methanol (2 L), and the precipitated solid was obtained by filtration, and then dried under reduced pressure to give a conjugated polymer A2 (1.03 g, 38%) as a dark purple solid.

The physicochemical analysis of the obtained conjugated polymer A2 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR (270 MHz), 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

The result of this physicochemical analysis is to support the chemical structure shown in the above reaction formula (2).

(polymerization example 3)

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

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 nitrogen atmosphere. Thiophene (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), bromobenzene (42mg, 0.26mmol), 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. Thereafter, bromobenzene (210 mg, 1.34 mmol) was added, and the mixture was 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 a Soxhlet extractor, and extracted with chloroform (200 mL). The obtained solution was poured into methanol (2 L), and the precipitated solid was obtained by filtration, and then dried under reduced pressure to give a conjugated polymer A3 (1.06, 42%) as a dark purple solid.

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

¹ H-NMR (270 MHz): 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 = 7000 g / mol, Mw = 16500 g / mol, PDI = 2.36

The result of this physicochemical analysis is to support the chemical structure shown in the above reaction formula (3).

(polymerization example 4)

The synthesis of the conjugated polymer A4 was carried out in accordance with the following reaction formula (4).

2,6-Dibromo-4,4'-di(hexadecyl)cyclopenta[2,1-b:3,4-b']dithiophene was added to a 100 mL three-necked flask under 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), the mixture was stirred at 80 ° C for 2 hours. After that, add phenylboronic acid The ester (273 mg, 1.34 mmol) was stirred at 80 ° C for 18 h. 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 a Soxhlet extractor, and extracted with chloroform (200 mL). The obtained solution was poured into methanol (2 L), and the precipitated solid was obtained by filtration, and then dried under reduced pressure to give a conjugated polymer A4 (1.11 g, 36%) as a dark purple solid.

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

¹ H-NMR (270 MHz): 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

The result of this physicochemical analysis is to support the chemical structure shown in the above reaction formula (4).

(polymerization example 5)

The synthesis of the conjugated polymer A5 was carried out in accordance with the following reaction formula (5).

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 (1.04 g, 2.68 mmol), toluene (50 mL), 2M aqueous potassium carbonate (25 mL, 50 mmol), After hydrazine (triphenylphosphine) palladium (0) (61.9 mg, 53.5 μmol) and aliquat 336 (2 mg, 4.95 μmol), the mixture was stirred at 80 ° C for 2 hours. After that, add phenylboronic acid The ester (273 mg, 1.34 mmol) was stirred at 80 ° C for 18 h. 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 a Soxhlet extractor, and extracted with chloroform (200 mL). The obtained solution was poured into methanol (2 L), and the precipitated solid was obtained by filtration, and then dried under reduced pressure to give a conjugated polymer A5 (1.20 g, 43%) as a dark purple solid.

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

¹ H-NMR (270 MHz): 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

The result of this physicochemical analysis is to support the chemical structure shown in the above reaction formula (5).

(polymerization example 6)

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

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 nitrogen atmosphere. b'] dithiophene (1.64 g, 2.68 mmol), 4,7-bis(3,3,4,4-tetramethyl-2,5,1-dioxaborolan-1-yl)benzene And [c][1,2,5]thiadiazole (1.04g, 2.68mmol), toluene (50mL), 2M aqueous potassium carbonate solution (25mL, 50mmol), hydrazine (triphenylphosphine) palladium (0) (61.9 After mg, 53.5 μmol) and aliquat 336 (2 mg, 4.95 μmol), the mixture was stirred at 80 ° C for 2 hours. After that, add phenylboronic acid The ester (273 mg, 1.34 mmol) was stirred at 80 ° C for 18 h. 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 a Soxhlet extractor, and extracted with chloroform (200 mL). The obtained solution was poured into methanol (2 L), and the precipitated solid was obtained by filtration, and then dried under reduced pressure to give conjugated polymer A6 (1.18 g, 44%) as a dark purple solid.

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

¹ H-NMR (270 MHz): 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

The result of this physicochemical analysis is to support the chemical structure shown in the above reaction formula (6).

(polymerization example 7)

The synthesis of the conjugated polymer A7 was carried out in accordance with the following reaction formula.

In the eggplant flask A which had been sufficiently dried and replaced with argon, 25 mL of THF subjected to dehydration and peroxide removal treatment, and 1.825 g (5 mmol) of 2-bromo-5-iodo-3-hexylthiophene, i-propyl group were added. 2.5 mL of a 2.0 M solution of magnesium chloride 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.

In a dried and argon-substituted eggplant flask B, 25 mL of tetrahydrofuran (THF) subjected to dehydration and peroxide removal treatment, and 27 mg (0.05 mmol) of NiCl ₂ (dppp) were added, and the mixture was heated to 35 ° C, and then organic was added. Magnesium compound solution (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 sodium hydrogen carbonate water and 100 mL of distilled water, and the organic layer was dried over anhydrous sodium sulfate, and concentrated and dried to solidify. The obtained dark purple solid was dissolved in 30 mL of chloroform, and reprecipitated in 300 mL of methanol. The sufficiently dried GPC column was used for purification, and conjugated polymer A7 (690 mg) was obtained by purification.

In addition, the THF of the solvent is distilled and purified by dehydrating tetrahydrofuran (without stabilizer) manufactured by Wako Pure Chemical Industries Co., Ltd. in the presence of sodium metal. Purification was carried out by contacting with molecular sieve 5A manufactured by Wako Pure Chemical Industries Co., Ltd. for one day or more. Further, the purification of the polymer was carried out using a GPC column for separation. The apparatus was a Recycling Preparative HPLC LC-908 manufactured by Japan Analytical Industry Co., Ltd. In addition, the type of the column is a styrene-based polymer column 2H-40 and 2.5H-40 manufactured by Nippon Analytical Industries Co., Ltd., which are used in two in-line couplings. Further, the solvent to be eluted was chloroform.

The physicochemical analysis of the obtained conjugated polymer A7 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

The result of this physicochemical analysis is to support the chemical structure shown in the above reaction formula (7).

(polymerization example 8)

In addition to the addition of 2-bromo-5-iodo-3-(2-ethyl)hexylthiophene 2.005 g (5 mmol) in place of 2-bromo-5-iodo-3-hexylthiophene 1.865 g (5 mmol), and polymerization examples 7 The same operation was carried out to give conjugated polymer A8 (710 mg).

The physicochemical analysis of the obtained conjugated polymer A8 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, 11H), 0.91 (t, J = 6.8 Hz, 6H)

GPC (CHCl ₃ ): Mn = 23,600 g/mol, Mw = 28,000 g/mol, PDI = 1.19

(polymerization example 9)

The same as in Polymerization Example 7, except that 1.725 g (5 mmol) of 2-bromo-5-iodo-3-phenoxymethylthiophene was substituted for 2.865 g (5 mmol) of 2-bromo-5-iodo-3-hexylthiophene. The conjugated polymer A9 (600 mg) was obtained.

The physicochemical analysis of the obtained conjugated polymer A9 was carried out in the same manner as in Polymerization Example 1.

¹ H-NMR: δ = 7.40-6.70 (m, 6H), 5.20-4.80 (m, 2H)

GPC (CHCl ₃ ): Mn = 19,300 g / mol, Mw = 23,200 g / mol, PDI = 1.20

(polymerization example 10)

The synthesis of the conjugated polymer A10 was carried out in accordance with the following reaction formula. Further, in the following reaction formula, the 3-heptyl group of the substituent is abbreviated as 3-Hep or Hep-3. Further, in the following reaction formula, the methyl group of the substituent is simply referred to as Me.

2,6-bis(trimethyltin)-4,8-di(dodecyl)benzo[1, which is a monomer constituting the conjugated polymer A10, was added to a 50 mL eggplant flask under a nitrogen atmosphere. 2-b:4,5-b']dithiophene (0.64 g, 0.75 mmol) and 1-(4,6-dibromothieno[3,4-b)thiophen-2-yl)-2-ethyl Hexane-1-one (0.32 g, 0.75 mmol), with DMF (6.2 mL), toluene (25 mL), hydrazine (triphenylphosphine) palladium (0) (9.2 mg, 7.8 μmol), heated at 115 ° C 30 minutes in an hour. Next, 2,5-dibromothiophene (1.84 g, 7.6 mmol) as a terminal blocking agent was added, and 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 obtained by filtration, 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 extractor, and extracted with chloroform (200 mL). The organic layer was concentrated to dryness and solidified, and the obtained dark purple solid was dissolved in chloroform (30 mL) and re-precipitated in methanol (300 mL).

Purification of the obtained conjugated polymer A10 was carried out using a GPC column for separation. The purification apparatus was a Recycling Preparative HPLC LC-908 manufactured by Japan Analytical Industry Co., Ltd. In addition, the type of the column is a styrene-based polymer column 2H-40 and 2.5H-40 manufactured by Nippon Analytical Industries Co., Ltd., which are used in two in-line couplings. Further, the column and the syringe were set to 145 ° C, and the solvent to be eluted was chloroform.

The average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained conjugated polymer A10 (0.51 g, 86%) were all determined by gel permeation chromatography (GPC), in terms of polystyrene. Find the value. Here, GPC/V2000 manufactured by Waters was used as the GPC device, and Shodex AT-G806MS manufactured by Showa Denko was used as the column. Further, the column and the syringe were set to 145 ° C, and o-dichlorobenzene was used as the elution solvent.

¹ H NMR (270MHz, CDCl ₃ ): 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)

GPC (CHCl ₃ ): Mn = 14600 g / mol, Mw = 33100 g / mol, PDI = 2.27

(polymerization example 11)

The synthesis of the conjugated polymer A11 was carried out in accordance with the following reaction formula.

2,6-bis(trimethyltin)-4,8-bis(2-ethylhexyloxy)benzene which constitutes a monomer of the conjugated polymer A11 was added to a 50 mL eggplant type flask under a nitrogen atmosphere. [1,2-b:4,5-b']dithiophene (0.41 mg, 0.53 mmol), 2,6-bis(trimethyltin)-4,8-dipropylbenzo[1,2- b: 4,5-b']dithiophene (0.14 mg, 0.23 mmol) and 1-(4,6-dibromothieno[3,4-b]thiophen-2-yl)-2-ethylhexane 1-one (0.32 g, 0.75 mmol), DMF (6.2 mL), chlorobenzene (25 mL), hydrazine (triphenylphosphine) palladium (0) (9.2 mg, 7.8 μmol), heated at 135 ° C for 1 hour 30 minute. After completion of the reaction, the reaction solution was concentrated, poured into methanol (500 mL), and the precipitated solid was obtained by filtration, 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 extractor, and extracted with chloroform (200 mL). The organic layer was concentrated to dryness and solidified, and the obtained dark purple solid was dissolved in chloroform (30 mL) and re-precipitated in methanol (300 mL). Purification of the obtained conjugated polymer A11 was carried out using the same method and conditions as in the above Polymerization Example 10.

The physicochemical analysis of the obtained conjugated polymer A11 was carried out in the same manner and under the same conditions as in the above Polymerization Example 10. The following physicochemical analysis results support the chemical structure 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), 3.20-3.00 (br, 3H), 2.00-0.60 (br, 41H)

GPC(CHCl ₃ ): Mn=44000g/mole, Mw=86400g/mole, PDI=2.99

(polymerization example 12)

The synthesis of the conjugated polymer A12 was carried out in accordance with the following reaction formula.

In addition to the monomer constituting the conjugated polymer A12, 2,6-bis(trimethyltin)-4,8-dipropylbenzo[1,2-b:4,5-b']dithiophene was used. (0.45 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) Other than Polymerization Example 11 Using the same method, a conjugated polymer A12 (0.31 g, 77%) was obtained.

The physicochemical analysis of the obtained conjugated polymer A12 (0.31 g, 77%) was carried out using the same method and conditions as in the above Polymerization Example 11. The following physicochemical analysis results support the chemical structure shown in the above reaction formula.

1H 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 / m, Mw = 24,400 g / m, PDI = 2.34

(Example 1)

2.5 mg of conjugated polymer A1 (Mn = 19,600 g/mole), 2.5 mg of conjugated polymer A4 (Mn = 18,900 g/mole), and 1 mL of chlorobenzene as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B1.

(Example 2)

A conjugated polymer composition B2 was produced in the same manner as in Example 1 except that the conjugated polymer A5 (Mn = 19,200 g/mole) was used instead of the conjugated polymer A4.

(Example 3)

2.5 mg of conjugated polymer A2 (Mn = 17500 g/mole), 2.5 mg of conjugated polymer A5, and 1 mL of chlorobenzene as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B3.

(Example 4)

2.5 mg of conjugated polymer A10 (Mn = 14600 g/mole), 2.5 mg of conjugated polymer A11 (Mn = 44,000 g/mole), and 1,8- mixed with a volume fraction of 2.5% as a solvent were added. 1 mL of chlorobenzene of diiodooctane was mixed at 100 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B4.

(Comparative Example 1)

A conjugated polymer composition B5 was produced in the same manner as in Example 1 except that the conjugated polymer A7 (Mn = 21,000 g/mol) was used instead of the conjugated polymer A4.

(Comparative Example 2)

A conjugated polymer composition B6 was produced in the same manner as in Example 1 except that the conjugated polymer A6 (Mn = 20600 g/mol) was used instead of the conjugated polymer A4.

(Comparative Example 3)

Add conjugated polymer A7 2.5mg, conjugated polymer A8 (Mn= 2.5 mg of 23600 g/mole and 1 mL of chlorobenzene as a solvent were mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B7.

(Comparative Example 4)

2.5 mg of conjugated polymer A1, 2.5 mg of polystyrene (Toyo Styrol G32; Mn = 83800), and 1 mL of chlorobenzene as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B8.

(Comparative Example 5)

2.5 mg of conjugated polymer A5, 2.5 mg of conjugated polymer A9 (Mn = 19,300 g/mole), and 1 mL of chlorobenzene as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B9.

(Comparative Example 6)

5.0 mg of the conjugated polymer A1 and 1 mL of chlorobenzene as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B10.

(Comparative Example 7)

5.0 mg of conjugated polymer A7 and 1 mL of chlorobenzene as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. After that, cool to room temperature 20 ° C, The conjugated polymer composition B11 was produced.

(Comparative Example 8)

2.5 mg of conjugated polymer A3 (Mn = 7000 g/mole), 2.5 mg of conjugated polymer A4, and 1 mL of chlorobenzene as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B12.

(Comparative Example 9)

2.5 mg of conjugated polymer A12 (Mn = 10400 g/mole) and 1 mL of chlorobenzene mixed with 1,8-diiodooctane at a volume fraction of 2.5% as a solvent were added, and the mixture was taken at 100 ° C for 6 hours. mixing. Thereafter, the mixture was cooled to room temperature at 20 ° C to prepare a conjugated polymer composition B13.

(Comparative Example 10)

2.5 mg of conjugated polymer A10 and 1 mL of chlorobenzene in which 1,8-diiodooctane was mixed at a volume fraction of 2.5% as a solvent were added, and the mixture was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 100 ° C to prepare a conjugated polymer composition B14.

(Manufacture of a mixed solution of a conjugated polymer composition and an electron accepting material)

A PCBM as an electron accepting material was added to a solution containing 5.0 mg of the conjugated polymer composition prepared in the foregoing Example 1. 20.0 mg (E100H manufactured by Frontier Carbon Co., Ltd.) was mixed at 40 ° C for 6 hours. Thereafter, the mixture was cooled to room temperature at 20 ° C, and filtered through a PTFE filter having a pore size of 0.45 μm to prepare a solution containing the conjugated polymer composition and PCBM.

A solution containing PCBM was also produced by the same method for each of the conjugated polymer compositions obtained in Examples 2 to 3 and Comparative Examples 1, 2, 4 to 6, and 8.

With respect to each of the conjugated polymer compositions obtained in Comparative Examples 3 and 7, except that 16.0 mg of the conjugated polymer composition and 12.8 mg of PCBM (E100H manufactured by Frontier Carbon Co., Ltd.) as an electron-accepting material were used, The same method was used to produce a solution containing a conjugated polymer composition and PCBM.

Each of the conjugated polymer compositions obtained in Example 4 and Comparative Examples 9 and 10 was used in an amount of 5.0 mg of a conjugated polymer composition and PC ₇₁ BM (E110 manufactured by Frontier Carbon Co., Ltd.) as an electron accepting material. A solution containing a conjugated polymer composition and PC ₇₁ BM was produced by the same method except for 7.5 mg.

(production and evaluation of organic solar cells)

The ITO film (resistance value: 10 Ω/□) was adhered to the glass substrate at a thickness of 150 nm by a sputtering method, and the glass substrate was subjected to surface treatment by ozone UV treatment for 15 minutes. A PEDOT:PSS aqueous solution (CLEVIOS PH500 manufactured by HC Starc K Co., Ltd.) serving as a hole transport 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 through a hot plate, a solution containing a conjugated polymer composition and PCBM (which is manufactured according to the above) is applied by spin coating to obtain an organic thin film solar cell. Organic photoelectric conversion layer (film thickness: about 100 nm). After vacuum drying for 3 hours, thermal annealing was applied to Comparative Examples 3 and 7 at 120 ° C for 30 minutes. Thereafter, lithium fluoride having a thickness of 1 nm was deposited by a vacuum vapor deposition machine, and then aluminum was masked with a regular square shape of 5 × 5 mm therebetween, and vapor deposition was performed at a film thickness of 100 nm. The degree of vacuum at the time of vapor deposition was 2 × 10 ^-4 Pa or less. Thus, a 5×5 mm organic thin film solar cell (which is a photoelectric conversion element composed of a conjugated polymer composition) was obtained.

(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 using a 150 W daylight simulator (manufactured by Peccell Technologies, trade name: PEC L11: AM 1.5G filter, illuminance: 100 mW/cm ² ). The measurement was carried out. The measurement results are shown in Tables 1 to 3. Further, the solubility parameter of each conjugated polymer constituting the conjugated polymer composition of each Example was calculated by the Bicerano method using a computer software Scigress Explorer Professional 7.6.0.52 (manufactured by Fujitsu Co., Ltd.). The solubility parameters were also determined by the same method for the polymers and compositions of the respective comparative examples. The results are shown together in Tables 1-3.

In Tables 1 to 3, the conjugated polymer composition and the conjugated polymer used as the film forming material of the organic photoelectric conversion layer, and the structure of the conjugated polymer constituting the conjugated polymer composition and Solubility parameter (SP value), difference in solubility parameters of conjugated polymers A and B, organic Photoelectric conversion efficiency of thin film solar cells.

From the evaluation results, an organic thin film solar cell (Examples 1 to 4) using the conjugated polymer composition of the present invention, which is at least two types of conjugated polymers constituting the conjugated polymer composition, is known. The main chain is a divalent heterocyclic group consisting of a condensed ring π conjugated skeleton, and each conjugated polymer has a number average molecular weight of at least 10,000 g/mole, and a maximum value among the solubility parameters of each conjugated polymer ( When the difference between the conjugated polymer A) and the minimum value (conjugated polymer B) is 0.6 or more and 2.0 or less, the conversion efficiency of the organic thin film solar cell (Examples 1 to 4) is high.

On the other hand, since Comparative Examples 1, 4 to 6, 9, and 10 are only one type of conjugated polymer having a divalent heterocyclic group including a condensed ring π conjugated skeleton, the main chain is not available. High conversion efficiency. Although Comparative Example 2 is a type of conjugated polymer containing a divalent heterocyclic group consisting of a condensed ring π conjugated skeleton in the main chain, it is the highest among the solubility parameters constituting the composition. Since the difference between the yoke polymer A) and the minimum value (conjugated polymer B) is not in the range of 0.6 or more and 2.0 or less, it can be understood that high conversion efficiency cannot be obtained. Since Comparative Examples 3 and 7 are conjugated polymers which are not contained in the main chain and contain a divalent heterocyclic group consisting of a condensed ring π conjugated skeleton, it is found that the conversion efficiency is poor. The number average molecular weight of the conjugated polymer contained in Comparative Example 8 was less than 10,000 g/mole, and since the constituent elements of the present invention were not satisfied, it was found that the conversion efficiency was poor.

[Industry Utilization]

The conjugated polymer composition of the present invention is a photoelectric conversion layer which can be utilized as a photoelectric conversion element. Also, using a conjugated polymer containing the present invention The photoelectric conversion element of the organic thin film of the composition can be widely used as various photosensors including solar cells.

1‧‧‧ photoelectric conversion components

2‧‧‧ positive

3‧‧‧Organic photoelectric conversion layer

4‧‧‧negative

5‧‧‧Substrate

〔figure 1〕

A schematic cross-sectional view of a photoelectric conversion element to which the present invention is applied.

Claims (11)

A conjugated polymer composition comprising at least two types of conjugated polymer compositions such as conjugated polymers, wherein the conjugated polymer comprises a condensed ring π conjugated backbone in the main chain a divalent heterocyclic group having a side chain of an alkyl group or an alkoxy group which may be substituted by a fluorine atom or a hydroxyl group, and having a number average molecular weight of at least 10,000 g/mole in terms of polystyrene; composition of the aforementioned conjugated polymer The substance is characterized in that the difference between the solubility parameter of the conjugated polymer and the conjugated polymer having the smallest value is 0.6 or more and 2.0 or less. The conjugated polymer composition of claim 1, wherein the heterocyclic group is composed of a condensed ring π-conjugated skeleton comprising at least one thiophene ring in one of chemical structures. The conjugated polymer composition of claim 2, wherein the conjugated polymer is composed of at least one selected from the group consisting of cyclopentadithiophenediyl, dithienopyrrolediyl, dithienofluorenyldiyl, A monomer unit of a dithienofluorenyldiyl group, a benzodithiophenediyl group, a naphthodithiophenediyl group, a thienothiophene diyl group, and a divalent heterocyclic group of a thienopyrroledione group. The conjugated polymer composition according to any one of claims 1 to 3, wherein the two types of conjugated polymers are: the divalent heterocyclic group is an alkyl group having at least a carbon number of 12 or an alkoxy group. a conjugated polymer of a side chain of the group, which is bonded to the above-mentioned divalent heterocyclic group of the same or different species to an alkyl group having at most a carbon number of 8 Or a conjugated polymer of a side chain of an alkoxy group. The conjugated polymer composition according to any one of claims 1 to 4, wherein the two types of conjugated polymers are: the above-mentioned divalent heterocyclic group is an alkyl group or alkoxy group which is bonded without fluorine substitution. The conjugated polymer of the side chain, and the above-mentioned divalent heterocyclic group of the same or different kind is a conjugated polymer of a side chain of an alkyl group or an alkoxy group which is bonded with at least three fluorine atoms. The conjugated polymer composition according to any one of claims 1 to 5, wherein at least one of the conjugated polymers is a random copolymer, and the random copolymer is at least 2 types. The monomer unit is a monomer unit having a divalent heterocyclic group consisting of a condensed ring π-conjugated skeleton. The conjugated polymer composition according to any one of claims 1 to 6, wherein the conjugated polymer composition contains a conjugated polymer having a solubility parameter as a maximum value and a total solubility parameter having a minimum value. The mass ratio of the conjugated polymer is a conjugated polymer having a maximum value: a conjugated polymer having a minimum value of 95:5 to 5:95. An organic semiconductor composition characterized by comprising the conjugated polymer composition according to any one of claims 1 to 7 and a fullerene derivative. An organic film characterized by comprising the conjugated polymer composition according to any one of claims 1 to 7. An organic thin film device characterized in that the substrate is provided with the organic thin film of claim 9. A photoelectric conversion element characterized in that the organic thin film of claim 9 is held between at least two electrodes.