WO2012118128A1 - Polymer and organic thin film and organic thin film element using same - Google Patents

Abstract

Provided is a polymer having structural units represented by formula (1) and structural units represented by formula (2). [In the formulas, X¹ and X² are each independently an oxygen atom, and the like; Y is a carbon atom, silicon atom, and the like; R¹, R², R³, and R⁴ are each independently a halogen atom, a linear, branched, or cyclic C_1-30 alkyl group, and the like; Ar¹ is a C_4-60 tetravalent aromatic heterocyclic group optionally having substitution groups, and the like; and Ar² and Ar³ are each independently C^6-60 trivalent aromatic hydrocarbon groups optionally having substitution groups or C_4-60 trivalent aromatic heterocyclic groups optionally having substitution groups, and the like. When Y is a carbon atom, Ar² and Ar³ are trivalent aromatic heterocyclic groups.]

Description

Polymer, organic thin film and organic thin film element using the polymer

The present invention relates to a polymer, an organic thin film using the polymer, and an organic thin film element including the same.

Thin films containing organic materials having charge (electron or hole) transport properties are expected to be applied to organic thin film elements such as organic thin film transistors, organic thin film solar cells, and optical sensors. Organic p-types that can form such thin films Various semiconductor materials (showing hole transport properties) and organic n-type semiconductor materials (showing electron transport properties) have been studied.

Poly (3-alkylthiophene) is known as an organic p-type semiconductor material (see Patent Document 1).

US Pat. No. 6,107,117

However, it has been difficult to say that the conventional organic p-type semiconductor material has sufficient hole transportability.

Therefore, an object of the present invention is to provide a polymer having excellent hole transportability. Furthermore, an object of this invention is to provide the organic thin film element provided with this organic thin film containing this polymer, and this organic thin film.

［式中、
　Ｘ^１及びＸ^２は、それぞれ独立に、酸素原子、硫黄原子又は＝Ｃ（Ａ）_２で表される基（Ａは、それぞれ独立に、水素原子、ハロゲン原子又は置換基を有していてもよい１価の有機基を示す。２個のＡは、同一であっても異なっていてもよい。）を示し、
　Ｙは、炭素原子、ケイ素原子、ゲルマニウム原子、チタン原子又はスズ原子を示す。
　Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立に、水素原子、ハロゲン原子、直鎖状、分岐状若しくは環状の炭素数１～３０のアルキル基（ただし、該アルキル基における水素原子の一部又は全部がハロゲン原子で置換されていてもよい。）、直鎖状、分岐状若しくは環状の炭素数１～３０のアルキル基及び該アルキル基で置換されたアルキル基以外の基を含む１価の基（ただし、該アルキル基における水素原子の一部又は全部がハロゲン原子で置換されていてもよい。）、置換基を有していてもよい炭素数６～６０のアリール基又は置換基を有していてもよい炭素数４～６０の１価の複素環基を示す。
　Ａｒ^１は、置換基を有していてもよい炭素数６～６０の４価の芳香族炭化水素基又は置換基を有していてもよい炭素数４～６０の４価の芳香族複素環基を示す。
　Ａｒ^２及びＡｒ^３は、それぞれ独立に、置換基を有していてもよい炭素数６～６０の３価の芳香族炭化水素基又は置換基を有していてもよい炭素数４～６０の３価の芳香族複素環基を示す。
　ただし、Ｙが炭素原子である場合には、Ａｒ^２及びＡｒ^３は３価の芳香族複素環基である。］ The present invention provides a polymer having a structural unit represented by formula (1) and a structural unit represented by formula (2).

[Where:
X ¹ and X ² are each independently an oxygen atom, a sulfur atom or a group represented by ═C (A) ₂ (A may independently have a hydrogen atom, a halogen atom or a substituent. A monovalent organic group, and two A's may be the same or different.)
Y represents a carbon atom, a silicon atom, a germanium atom, a titanium atom or a tin atom.
R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms (provided that the hydrogen atom of the alkyl group is A part or all of them may be substituted with a halogen atom.), A linear, branched or cyclic alkyl group having 1 to 30 carbon atoms and a group other than an alkyl group substituted with the alkyl group. A valent group (however, part or all of the hydrogen atoms in the alkyl group may be substituted with a halogen atom), an aryl group or substituent having 6 to 60 carbon atoms which may have a substituent A monovalent heterocyclic group having 4 to 60 carbon atoms which may have
Ar ¹ represents an optionally substituted tetravalent aromatic hydrocarbon group having 6 to 60 carbon atoms or an optionally substituted tetravalent aromatic heterocyclic ring having 4 to 60 carbon atoms. Indicates a group.
Ar ² and Ar ³ are each independently a trivalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent or a carbon number having 4 to 60 which may have a substituent. A trivalent aromatic heterocyclic group is shown.
However, when Y is a carbon atom, Ar ² and Ar ³ are trivalent aromatic heterocyclic groups. ]

Such a polymer has a small ionization potential (a shallow HOMO (highest occupied orbit)) and an excellent hole transport property.

Furthermore, in a preferred embodiment, the polymer of the present invention is excellent in solubility in an organic solvent such as chloroform. The polymer of the present invention having such properties is excellent in handleability because an organic thin film element can be formed on a flexible substrate by a printing method.

The present invention also provides an organic thin film containing the polymer of the present invention. Since the organic thin film of the present invention contains the polymer of the present invention, it exhibits excellent hole transportability, and in a preferred embodiment, it can be easily formed by a printing method.

The present invention further provides an organic thin film element comprising the organic thin film of the present invention. As the organic thin film element, an organic thin film transistor and an organic thin film solar cell are suitable. Such an organic thin film element is provided with the organic thin film of the present invention, and since this organic thin film has excellent hole transport properties, it efficiently transports charges injected from the electrodes and charges generated by light absorption. can do. Further, since this organic thin film has a narrow HOMO-LUMO (lowest empty orbit) gap, it can efficiently absorb light having a long wavelength. Therefore, the organic thin film element of the present invention can exhibit excellent performance, the organic thin film transistor has high hole mobility, and the organic thin film solar cell has high photoelectric conversion efficiency.

According to the present invention, a polymer having excellent hole transportability can be provided. Moreover, in preferable embodiment of this invention, the polymer which is excellent also in the solubility to an organic solvent can be provided. Furthermore, according to the present invention, an organic thin film that includes such a polymer of the present invention and exhibits excellent hole transportability, and an organic thin film element that can exhibit excellent performance by including such an organic thin film, In particular, an organic thin film transistor and an organic thin film solar cell can be provided.

It is a schematic cross section of the organic thin-film transistor which concerns on 1st Embodiment. It is a schematic cross section of the organic thin-film transistor which concerns on 2nd Embodiment. It is a schematic cross section of the organic thin-film transistor which concerns on 3rd Embodiment. It is a schematic cross section of the organic thin-film transistor which concerns on 4th Embodiment. It is a schematic cross section of the organic thin-film transistor which concerns on 5th Embodiment. It is a schematic cross section of the organic thin-film transistor concerning 6th Embodiment. It is a schematic cross section of the organic thin-film transistor which concerns on 7th Embodiment. It is a schematic cross section of the solar cell which concerns on suitable embodiment. It is a schematic cross section of the photosensor concerning a 1st embodiment. It is a schematic cross section of the optical sensor which concerns on 2nd Embodiment. It is a schematic cross section of the photosensor concerning a 3rd embodiment. It is a graph which shows the absorption spectrum of the solution of a polymer G, and a thin film.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

Hereinafter, Me represents a methyl group, and TIPS represents a triisopropylsilyl group.

[Polymer]
First, the polymer of this embodiment is demonstrated. The polymer of this embodiment has a structural unit represented by the above formula (1) and the above formula (2). Here, the “structural unit” of the polymer means a structural unit constituting the main chain of the polymer. The “polymer” means one having at least one such “structural unit”, and includes both those usually classified as oligomers or polymers.

Hereinafter, the suitable structure of the structural unit represented by Formula (1) is demonstrated. First, in formula (1), X ¹ and X ² each independently represent an oxygen atom, a sulfur atom or a group represented by ═C (A) ₂ . A each independently represents a hydrogen atom, a halogen atom or a monovalent organic group which may have a substituent. As the monovalent organic group which may have a substituent, an alkyl group having 1 to 12 carbon atoms and an aryl group having 6 to 20 carbon atoms are preferable.

It polymers, as X ¹ or X ^2, = if having a group represented by C (A) _2, since the LUMO may lower, at least one of which is electron-withdrawing groups of the two A The two A are more preferably electron-withdrawing groups. The electron withdrawing group is preferably a cyano group, a nitro group, a formyl group, an acyl group, an alkoxycarbonyl group, a carboxyl group, a hydroxyl group or a halogen atom, more preferably a cyano group, a nitro group or a halogen atom, and a cyano group. Further preferred.

X ¹ and X ² are preferably an oxygen atom or a group represented by ═C (A) ₂ , and more preferably an oxygen atom because LUMO can be further reduced.

In the formula (1), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic group. A monovalent group consisting of an alkyl group having 1 to 30 carbon atoms and a group other than the alkyl group substituted with the alkyl group, an aryl group or substituent having 6 to 60 carbon atoms which may have a substituent; And a monovalent heterocyclic group having 4 to 60 carbon atoms which may be used.

In R ¹ and R ² , examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In R ¹ and R ² , the linear, branched or cyclic alkyl group having 1 to 30 carbon atoms is preferably a linear, branched or cyclic alkyl group having 3 to 24 carbon atoms. A linear or branched alkyl group of ˜20 is more preferred. In order to improve the arrangement between molecules, a linear alkyl group is preferred. On the other hand, a branched alkyl group is preferable in order to increase the solubility in an organic solvent. These can be selected according to desired characteristics. It is more preferable that R ¹ and R ² are the same group because the production of the polymer becomes easy.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, 3-methylbutyl group, pentyl group, hexyl group, 2-ethylhexyl group, Examples include heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, 3,7-dimethyloctyl group, and 3,7,11-trimethyldodecyl group. Some or all of the hydrogen atoms of these alkyl groups may be substituted with halogen atoms. As the halogen atom for substituting the hydrogen atom of the alkyl group, a fluorine atom is preferable.

In the monovalent group consisting of a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms and a group other than the alkyl group substituted with the alkyl group, the group other than the alkyl group substituted with the alkyl group is , At least one of a heteroatom and an unsaturated bond. Specific examples thereof include an alkoxy group, an alkylthio group, an alkenyl group, an alkynyl group, an alkylphenyl group, an alkoxyphenyl group, an alkylthiophenyl group, an alkoxycarbonyl group, an alkylthiocarbonyl group, an alkylsilyl group, and an alkylamino group. Of these, an alkoxy group and an alkylthio group are preferable, and an alkylthio group is more preferable. The alkyl group contained in the monovalent group consisting of a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms and a group other than the alkyl group substituted with the alkyl group is the same as the above-described alkyl group. Can be illustrated. The monovalent group having an alkyl group and an aryl group or heterocyclic group is “an optionally substituted aryl group having 6 to 60 carbon atoms” or “an optionally substituted carbon number”. It may also correspond to “a monovalent heterocyclic group of 4 to 60”.

Examples of the aryl group having 6 to 60 carbon atoms which may have a substituent in R ¹ and R ² include, for example, a phenyl group, an alkoxyphenyl group having an alkoxy group having 1 to 12 carbon atoms, Examples thereof include an alkylphenyl group having 12 alkyl groups, a 1-naphthyl group, and a 2-naphthyl group. Among these, an aryl group having 6 to 20 carbon atoms is preferable, and an alkoxyphenyl group having an alkoxy group having 1 to 12 carbon atoms and an alkylphenyl group having an alkyl group having 1 to 12 carbon atoms are more preferable.

Examples of the monovalent heterocyclic group having 4 to 60 carbon atoms which may have a substituent in R ¹ and R ² include, for example, a thienyl group, an alkyl thienyl group having an alkyl group having 1 to 12 carbon atoms, Examples thereof include a pyrrolyl group, a furyl group, a pyridyl group, and an alkylpyridyl group having an alkyl group having 1 to 12 carbon atoms. Among these, a monovalent heterocyclic group having 4 to 20 carbon atoms is preferable, and has a thienyl group, an alkylthienyl group having an alkyl group having 1 to 12 carbon atoms, a pyridyl group, and an alkyl group having 1 to 12 carbon atoms. An alkylpyridyl group is more preferred. Note that the monovalent heterocyclic group means a group in which at least one atom constituting the ring is a heteroatom in an organic group having a cyclic structure.

As R ¹ and R ² , the solubility in a solvent is increased, and thus a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, and a linear, branched or cyclic carbon number of 1 Monovalent groups consisting of ˜30 alkyl groups and groups other than alkyl groups substituted with the alkyl groups are preferred. Since LUMO can be further reduced, at least one of R ¹ and R ² is substituted with a halogen atom, a group in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, or an alkyl group and the alkyl group. A monovalent group in which a part or all of the hydrogen atoms of a monovalent group consisting of a group other than an alkyl group is substituted with a halogen atom is preferable. It is more preferable that part or all is a group substituted with a halogen atom. Furthermore, it is more preferable that both R ¹ and R ² are a halogen atom or a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and both R ¹ and R ² are halogen atoms. Is particularly preferred. As the halogen atom for substituting the hydrogen atom of the alkyl group, a fluorine atom is preferable.

In the formula (1), Ar ¹ is a tetravalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent or 4 having 4 to 60 carbon atoms which may have a substituent. A valent aromatic heterocyclic group.

In Ar ¹ , the optionally substituted tetravalent aromatic hydrocarbon group having 6 to 60 carbon atoms refers to an aromatic hydrocarbon compound having 6 to 60 carbon atoms that may have a substituent. The tetravalent group remove | excluding four hydrogen atoms on the aromatic ring in is shown. The aromatic hydrocarbon compound may be a single ring or a condensed ring. Among these, since superior solubility is obtained and production is easy, a condensed ring in which a single ring or 5 or less rings are condensed is preferable, and a condensed ring in which a single ring or two rings are condensed is more preferable. Preferably, a single ring is more preferable.

Examples of the aromatic hydrocarbon compound include benzene, naphthalene, anthracene, fluorene, pyrene, and perylene. Of these, benzene or naphthalene is preferable, and benzene is more preferable.

The tetravalent aromatic heterocyclic group having 4 to 60 carbon atoms which may have a substituent is the aromatic in the aromatic heterocyclic compound having 4 to 60 carbon atoms which may have a substituent. A tetravalent group excluding four hydrogen atoms on the heterocyclic ring. The aromatic heterocyclic compound may be a single ring or a condensed ring. Among these, since excellent solubility is obtained and production is easy, a condensed ring in which a single ring or 5 or less rings are condensed is preferable, and a condensed ring in which a single ring or two rings are condensed is more preferable. A monocycle is more preferable.

Examples of the aromatic heterocyclic compound include pyridine, thiophene, thienothiophene, dithienothiophene, benzothiophene, benzodithiophene, dibenzothiophene, pyrrole, quinoline, and indole. Of these, thiophene, thienothiophene or pyridine is preferable, and thiophene is more preferable.

The substituent that the aromatic hydrocarbon group or aromatic heterocyclic group in Ar ¹ may have is preferably a substituent having 20 or less atoms, and a substituent having 17 or less atoms. More preferred. Specific examples of the substituent include alkyl groups such as methyl group, ethyl group and n-propyl group; alkoxy groups such as methoxy group, ethoxy group and propoxy group; aryl groups such as phenyl group and naphthyl group; fluorine atom and chlorine A halogen atom such as an atom or a bromine atom; a nitro group; a cyano group.

Ar ¹ is preferably a tetravalent group excluding four hydrogen atoms on the aromatic ring in benzene or thiophene.

In the polymer according to this embodiment, the structural unit represented by the formula (1) is preferably a structural unit represented by the formula (5).

In the formula (5), R ¹ , R ² , X ¹ and X ² are as defined above. Z ¹ includes a group represented by the following formula (i), a group represented by the formula (ii), a group represented by the formula (iii), a group represented by the formula (iv), a formula (v ), A group represented by formula (vi), a group represented by formula (vii), a group represented by formula (viii), and a group represented by formula (ix) These groups are preferred, any of the groups represented by formulas (ii) and (vii) is more preferred, and the group represented by formula (ii) is particularly preferred. When Z ¹ is a group represented by the formula (i), (ii) or (ix), the group represented by the formula (5) has a furan ring, thiophene ring or pyrrole ring structure, respectively. Since these rings, particularly thiophene rings, exhibit suitable electrical properties, a polymer having these rings can exhibit various electrical characteristics.

In formulas (vii), (viii) and (ix), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently a monovalent organic group optionally having a hydrogen atom, a halogen atom or a substituent. R ¹¹ and R ¹² may be bonded to each other to form a ring. In addition, the group represented by the formula (viii) may be horizontally reversed.

As the monovalent organic group in R ¹¹ , R ¹² , R ¹³ and R ¹⁴ , for example, a linear or branched chain group (here, the chain group is a group having no cyclic structure). A monovalent cyclic group (wherein the cyclic group represents a group having a cyclic structure, which may be a monocyclic ring or a condensed ring, and may be a hydrocarbon ring or a heterocyclic ring; May be saturated or unsaturated.). The monovalent organic group may be an electron donating group or an electron withdrawing group. As the monovalent organic group in R ¹¹ , R ¹² , R ¹³ and R ¹⁴ , an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 20 carbon atoms are preferable.

As the substituent which the monovalent organic group in R ¹¹ , R ¹² , R ¹³ and R ¹⁴ may have, a substituent having 20 or less atoms is preferable, and a substituent having 17 or less atoms is preferable. Substituents are more preferred. Specific examples thereof include alkyl groups; alkoxy groups such as methoxy groups, ethoxy groups and propoxy groups; alkylamino groups such as methylamino groups; alkoxycarbonyl groups such as methoxycarbonyl groups; aryl groups such as phenyl groups and naphthyl groups; Halogen atoms such as fluorine atom, chlorine atom and bromine atom; nitro group; cyano group. In the present specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group as the substituent is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. In these groups, some or all of the hydrogen atoms may be substituted with halogen atoms. As the halogen atom for substituting a hydrogen atom, a fluorine atom is preferable. The alkyl group in which some or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms is preferably a fluoroalkyl group having 1 to 10 carbon atoms.

Examples of the alkyl group as the substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Examples of the alkyl group in a group containing an alkyl group in its structure (for example, an alkoxy group, an alkylamino group, and an alkoxycarbonyl group) include the same groups as described above.

R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or an aryl group, and are preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a 6 to 20 carbon atoms. The aryl group is more preferably.

Next, a preferred configuration of the structural unit represented by the formula (2) will be described. First, in Formula (2), Y is a carbon atom, a silicon atom, a germanium atom, a titanium atom, or a tin atom. Y is preferably a silicon atom, germanium atom, titanium atom or tin atom, more preferably a silicon atom or germanium atom, and particularly preferably a silicon atom. When Y is a silicon atom, the group represented by formula (1) has a silole ring structure. Since a silole ring exhibits suitable electrical properties, a polymer having a silole ring can exhibit various electrical characteristics.

In the formula (2), R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic group. A monovalent group consisting of an alkyl group having 1 to 30 carbon atoms and a group other than the alkyl group substituted with the alkyl group, an aryl group or substituent having 6 to 60 carbon atoms which may have a substituent; And a monovalent heterocyclic group having 4 to 60 carbon atoms which may be used.

Specific examples of R ³ and R ⁴ include the groups exemplified for the above R ¹ and R ² . As R ³ and R ⁴ , the solubility in a solvent is high, and therefore a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, and a linear, branched or cyclic carbon number of 1 Monovalent groups consisting of ˜30 alkyl groups and groups other than alkyl groups substituted with the alkyl groups are preferred. As the linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic alkyl group having 3 to 24 carbon atoms is preferable, and a linear or branched alkyl group having 6 to 20 carbon atoms or A branched alkyl group is more preferred. In order to improve the arrangement between molecules, a linear alkyl group is preferred. On the other hand, a branched alkyl group is preferable in order to increase the solubility in an organic solvent. These can be selected according to desired characteristics. It is more preferable that R ³ and R ⁴ are the same group because the production of the polymer becomes easy.

In Formula (2), Ar ² and Ar ³ each independently have a trivalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, or have a substituent. And a trivalent aromatic heterocyclic group having 4 to 60 carbon atoms. The trivalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent is an aromatic ring in an aromatic hydrocarbon compound having 6 to 60 carbon atoms which may have a substituent. The trivalent group remove | excluding three hydrogen atoms of is shown. The trivalent aromatic heterocyclic group having 4 to 60 carbon atoms which may have a substituent is the aromatic in the aromatic heterocyclic compound having 4 to 60 carbon atoms which may have a substituent. A trivalent group excluding three hydrogen atoms on a heterocyclic ring. Specific examples of these aromatic hydrocarbon compounds and aromatic heterocyclic compounds include the aromatic hydrocarbon compounds and aromatic heterocyclic compounds exemplified in the above Ar ¹ section. As the substituent that the trivalent aromatic hydrocarbon group or the trivalent aromatic heterocyclic group has, the substituent that the aromatic hydrocarbon group or aromatic heterocyclic group may have in the term Ar ¹ above. And the groups exemplified as above.

In the polymer according to the present embodiment, the structural unit represented by the formula (2) is preferably a structural unit represented by the formula (6).

In formula (6), R ³ , R ⁴ and Y are as defined above. W ² and ^{W 3} are each independently, -C ^(R 5) = groups represented by ^{(R 5} is a hydrogen atom, a halogen atom or a monovalent organic group.) Or represented by -N = Represents a group. It is more preferable that W ² and W ³ are the same because the polymer can be easily produced.

It is preferable that both W ¹ and W ² are groups represented by —C (R ⁵ ) ═. In addition, a polymer in which W ¹ and W ² are groups represented by —N═ has higher electron acceptability than a polymer not containing a nitrogen atom, and as a result, the LUMO of the polymer can be adjusted. it can.

Examples of the monovalent organic group represented by R ⁵ include a hydrogen atom, a halogen atom, an alkyl group having 1 to 30 carbon atoms, and an aryl group having 6 to 60 carbon atoms.

In formula (6), Z ² and Z ³ are each independently a group represented by the following formula (xi), a group represented by formula (xii), a group represented by formula (xiii), a formula A group represented by (xiv), a group represented by formula (xv), a group represented by formula (xvi), a group represented by formula (xvii), a group represented by formula (xviii) or a formula It is a group represented by (xix). Z ² and Z ³ are preferably any of the groups represented by formulas (xii) and (xvii), and particularly preferably a group represented by formula (xii). When Z ² or Z ³ is a group represented by the formula (xi), (xii) or (xix), the group represented by the formula (6) has a furan ring, a thiophene ring or a pyrrole ring structure, respectively. . Since these rings, particularly thiophene rings, exhibit suitable electrical properties, a polymer having these rings can exhibit various electrical characteristics. It is more preferable that Z ² and Z ³ are the same because the production of the polymer becomes easy.

In formulas (xvii), (xviii) and (xix), R ²¹ , R ²² , R ²³ and R ²⁴ are each independently a monovalent organic group optionally having a hydrogen atom, a halogen atom or a substituent. R ²¹ and R ²² may be bonded to each other to form a ring. Further, the group represented by the formula (xviii) may be horizontally reversed.

The monovalent organic group represented by R ²¹ , R ²² , R ²³ and R ²⁴ and the substituent thereof include the monovalent organic group represented by R ¹¹ , R ¹² , R ¹³ and R ¹⁴ and the substitution thereof. The same group as the group is exemplified.

The polymer according to this embodiment preferably further has a structural unit represented by the formula (3). Thereby, the range which can change solubility or a mechanical, thermal, or electronic property becomes wide. The structural unit represented by the formula (3) is different from the structural unit represented by the above formula (1) and the structural unit represented by the above formula (2).

In formula (3), Ar ⁴ represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. The divalent aromatic hydrocarbon group which may have a substituent is a divalent group excluding two hydrogen atoms on the aromatic ring in the aromatic hydrocarbon compound which may have a substituent. Indicates. The divalent aromatic heterocyclic group which may have a substituent refers to 2 excluding two hydrogen atoms on the aromatic heterocyclic ring in the aromatic heterocyclic compound which may have a substituent. Indicates a valent group. Specific examples of the aromatic hydrocarbon compound and the aromatic heterocyclic compound include the aromatic hydrocarbon compound and the aromatic heterocyclic compound exemplified in the section for Ar ¹ above. As the substituent that the divalent aromatic hydrocarbon group or divalent aromatic heterocyclic group has, the substituent that the aromatic hydrocarbon group or aromatic heterocyclic group may have in the term Ar ¹ above. And the groups exemplified as above.

In the polymer according to this embodiment, the structural unit represented by the formula (3) is preferably a structural unit represented by the formula (7).

In Formula (7), R ⁷ and R ⁸ each independently represent a hydrogen atom, a halogen atom or a monovalent organic group, and R ⁷ and R ⁸ may be bonded to each other to form a ring. . Specific examples of R ⁷ and R ⁸ include the groups exemplified for R ¹ and R ² above. R ⁷ and R ⁸ are each a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, A monovalent group consisting of a group other than an alkyl group substituted with an alkyl group is preferred, a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms is more preferred, and a hydrogen atom or carbon number 6 More preferred are -20 linear or branched alkyl groups. In order to improve the arrangement between molecules, a linear alkyl group is preferred. On the other hand, a branched alkyl group is preferable in order to increase the solubility in an organic solvent. These can be selected according to desired characteristics. It is more preferable that R ⁷ and R ⁸ are the same group, because the production of the polymer becomes easy.

In formula (7), Z ⁴ represents a group represented by formula (xxi), a group represented by formula (xxii), a group represented by formula (xxiii), a group represented by formula (xxiv), A group represented by formula (xxv), a group represented by formula (xxvi), a group represented by formula (xxvii), a group represented by formula (xxviii) or a group represented by formula (xxix) Any one of these groups is preferable, and a group represented by the formula (xxii) is more preferable. When Z ⁴ is a group represented by the formula (xxi), (xxii) or (xxix), the group represented by the formula (7) has a furan ring, thiophene ring or pyrrole ring structure. Since these rings, particularly thiophene rings, exhibit suitable electrical properties, a polymer having these rings can exhibit various electrical characteristics.

In formulas (xxvii), (xxviii) and (xxix), R ³¹ , R ³² , R ³³ and R ³⁴ are each independently a monovalent organic which may have a hydrogen atom, a halogen atom or a substituent. R ³¹ and R ³² may be bonded to each other to form a ring. The group represented by the formula (xxviii) may be horizontally reversed.

Examples of the monovalent organic group and substituents thereof in R ³¹ , R ³² , R ³³ and R ³⁴ include the same groups as the monovalent organic groups and substituents thereof in R ¹¹ , R ¹² , R ¹³ and R ¹⁴ . Is done.

Among the polymers according to the present embodiment, those having a structure in which the formula (1) and the formula (2) are alternately arranged are preferable because the hole transport property is improved. As such a structure, the structural unit represented by Formula (4) is preferable.

In formula (4), X ¹ , X ² , Y, R ¹ , R ² , R ³ , R ⁴ , Ar ¹ , Ar ² , Ar ³ and Ar ⁴ have the same meanings as described above. s and t each independently represent an integer of 0 to 6, preferably an integer of 0 to 2. When there are a plurality of Ar ^{4 s} , they may be the same or different. It is more preferable that a plurality of Ar ⁴ is the same because the production of the polymer becomes easy.

In the polymer according to this embodiment, the structural unit represented by the formula (4) is more preferably a structural unit represented by the formula (8).

In the formula (8), X ¹ , X ² , Y, R ¹ , R ² , R ³ , R ⁴ , R ⁷ , R ⁸ , W ² , W ³ , Z ¹ , Z ² , Z ³ , Z ⁴ , s and t are as defined above, and when there are a plurality of R ⁷ , R ⁸ and Z ⁴ , they may be the same or different. It is preferable that the plurality of R ⁷ , R ⁸ and Z ⁴ are the same because the polymer can be easily produced.

In the polymer according to this embodiment, in addition to the structural unit represented by the above formula (4) or the structural unit represented by the above (8), the structural unit represented by the above (3) or the above (7 It may have a structural unit represented by

As the polymer according to the present embodiment, those having structures represented by formulas (9) to (14) are preferable. In addition, each symbol in the formulas (9) to (14) has the same meaning as the same symbol described above. R ⁹ and R ¹⁰ each independently represent a hydrogen atom, a halogen atom or a monovalent organic group. Specific examples of R ⁹ and R ¹⁰ include the groups exemplified for R ⁷ and R ⁸ above. A plurality of R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same or different.

Examples of the terminal group of the polymer include a hydrogen atom, a fluorine atom, an alkyl group, an alkoxy group, an acyl group, an aminoketo group, an aryl group, and a monovalent heterocyclic group (one of hydrogen atoms bonded to these groups). Part or all may be substituted with a fluorine atom), a group having an α-fluoroketone structure, and other electron donating groups and electron withdrawing groups. Among them, an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms), an aryl group (preferably an aryl group having 6 to 60 carbon atoms) and a monovalent group are preferable. And a heterocyclic group (preferably a monovalent heterocyclic group having 4 to 60 carbon atoms) is preferred. The terminal group preferably has a conjugated bond continuous with the conjugated structure of the main chain. Examples of such a terminal group include an aryl group bonded to the main chain via a carbon-carbon bond and a monovalent heterocyclic group. The aryl group as the terminal group may be, for example, a phenyl group, a naphthyl group, or a fluorene group. The monovalent heterocyclic group as the terminal group may be, for example, thiophene, thienothiophene, benzothiophene, benzothiazole, or benzodithiazole.

Furthermore, examples of the terminal group of the polymer include a polymerization active group. When it has a polymerization active group as a terminal group, the polymer can also be used as a precursor for obtaining a higher molecular weight polymer. When used as such a precursor, the polymer preferably has two polymerization active groups in the molecule.

Polymerization active groups include halogen atoms, carboxyl groups, alkoxycarbonyl groups, alkylsulfonyl groups, arylsulfonyl groups, arylalkylsulfonyl groups, alkylstannyl groups, arylstannyl groups, arylalkylstannyl groups, boric acid ester residues And sulfonium methyl group, phosphonium methyl group, phosphonate methyl group, monohalogenated methyl group, boric acid residue (group represented by —B (OH) ₂ ), formyl group and vinyl group. Of these, a halogen atom, an alkylstannyl group, and a borate ester residue are preferable. Here, the borate ester residue is a monovalent group having a structure in which one of the bonds of the boron atom in the borate ester is replaced with a bond, and includes, for example, the following formulas (100) to (103 ) Is represented.

Among the above reactive groups, the alkyl group in the alkylsulfonyl group, arylalkylsulfonyl group, alkylstannyl group and arylalkylstannyl group is preferably an alkyl group having 1 to 12 carbon atoms, and having 1 to 6 carbon atoms. More preferred is an alkyl group. The aryl group in the arylsulfonyl group, arylalkylsulfonyl group, arylstannyl group and arylalkylstannyl group is preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 10 carbon atoms.

When the polymer of the present embodiment is used as an organic thin film, if the polymerization active group remains as a terminal group, the device characteristics and durability when the organic thin film device is formed may be lowered. The group may be substituted with a stable group.

As the polymer of the present embodiment, a polymer having a structure represented by any one of the following general formulas (15) to (23) can achieve both higher charge mobility and excellent solubility in a solvent. Are particularly preferred.

In the above formulas (15) to (23), R ⁰ and R ⁰⁰ each independently represent a terminal group of the above-described polymer. R ⁰ and R ⁰⁰ are preferably an alkyl group, an alkoxy group, an aryl group, and a monovalent heterocyclic group. R ¹ , R ² , R ³ , R ⁴ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are as defined above, and R ¹ , R ² , R ³ , R ⁴ , R ⁷ , R ⁸ , R ^When there are a plurality of ⁹ and R ^{10 s} , they may be the same or different. J and j ′ represent integers of 1 to 6, and p represents an integer of 1 or more. p can be appropriately selected depending on the method of forming the organic thin film using the polymer. That is, if the polymer has sublimability, it can be formed into an organic thin film using a vapor phase growth method such as a vacuum vapor deposition method. In this case, p is preferably 2 to 10, and preferably 2 to 5 is more preferable. On the other hand, when forming an organic thin film by a method of applying a solution in which a polymer is dissolved in an organic solvent, p is preferably 3 to 500, more preferably 6 to 300, and still more preferably 20 to 200.

And since the above-mentioned polymer has good film uniformity when an organic thin film is formed by coating, the number average molecular weight in terms of polystyrene is preferably 1 × 10 ³ to 1 × 10 ^8. More preferably, it is × 10 ³ to 1 × 10 ⁶ , and further preferably 4 × 10 ³ to 1 × 10 ⁵ .

[Method for producing polymer]
Next, the manufacturing method of the polymer of embodiment mentioned above is demonstrated. The polymer may be produced by any method, but is preferably produced by the production method described below.

That is, the polymer according to this embodiment includes a monomer compound represented by the following formula (1-m) or the following formula (5-m), and a formula (2-m) or the following formula (6-m). It is preferable to produce the compound by reacting the monomer compound represented by the following formula (3-m) or the following formula (7-m) with necessity. In this case, V ¹ and V ² in one monomer compound react with V ¹ or V ² in another monomer compound, respectively, to form a bond, and a polymer is formed by continuously generating such a reaction. . The monomer compound represented by the formula (1-m) or the formula (5-m) corresponds to the structural unit represented by the formula (1) or the formula (5), respectively, and the formula (2-m) or The monomer compound represented by the formula (6-m) corresponds to the formula (2) or the formula (6) (W ³ is a group represented by —C (R ⁵ ) =), respectively, The monomer compound represented by 3-m) or formula (7-m) corresponds to the structural unit represented by formula (3) or formula (7), respectively.

The polymer according to the present embodiment can also be produced by obtaining a synthetic intermediate by reacting the monomer compound as a raw material and then further reacting the synthetic intermediate. As the synthetic intermediate, a compound represented by the following formula (4-m) or (8-m) is preferable.

In the formulas (1-m), (2-m), (3-m), (4-m), (5-m), (6-m), (7-m) and (8-m), X ¹ , X ² , Y, R ¹ , R ² , R ³ , R ⁴ , W ² , W ³ , Z ¹ , Z ² , Z ³ , Z ⁴ , Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , s and t are as defined above, and when there are a plurality of R ⁷ , R ⁸ , Ar ⁴ , and Z ⁴ , they may be the same or different. V ¹ and V ² each independently represent a polymerization reactive group. Examples of the polymerization reactive group include a hydrogen atom, a halogen atom, an alkylsulfonyl group, an arylsulfonyl group, an arylalkylsulfonyl group, an alkylstannyl group, an arylstannyl group, an arylalkylstannyl group, a boric acid ester residue, Examples include sulfonium methyl group, phosphonium methyl group, phosphonate methyl group, monohalogenated methyl group, boric acid residue, formyl group, and vinyl group. The number of carbon atoms of the alkyl group in the alkylsulfonyl group and the alkylstannyl group is preferably 1-12. The number of carbon atoms of the aryl group in the arylsulfonyl group, arylalkylsulfonyl group, arylstannyl group and arylalkylstannyl group is preferably 6-20. Examples of this aryl group include a phenyl group.

Since the monomer compound is easily synthesized and easily reacted, V ¹ and V ² are each independently a halogen atom, an alkylsulfonyl group, an arylsulfonyl group, an arylalkylsulfonyl group, an alkylstannyl group, a boron Acid ester residues and boric acid residues are preferred. When the polymerization reactive group is any of these groups, the reaction between the monomer compounds is likely to occur, which is advantageous in terms of synthesis.

Examples of the polymer production method include a method using a Wittig reaction, a method using a Heck reaction, a method using a Horner-Wadsworth-Emmons reaction, a method using a Knoevenagel reaction, a method using a Suzuki coupling reaction, and a Grignard reaction. A method using a Stille reaction, a method using a Ni (0) catalyst, a method using an oxidizing agent such as FeCl _{3, a} method using an electrochemical oxidation reaction, or decomposition of an intermediate compound having an appropriate leaving group The method by is mentioned.

Among these, a method using a Wittig reaction, a method using a Heck reaction, a method using a Horner-Wadsworth-Emmons reaction, a method using a Knoevenagel reaction, a method using a Suzuki coupling reaction, a method using a Grignard reaction, and a Stille reaction are used. A method and a method using a Ni (0) catalyst are preferable because the structure of the polymer can be easily controlled. Furthermore, a method using a Suzuki coupling reaction, a method using a Grignard reaction, a method using a Stille reaction, and a method using a Ni (0) catalyst are more preferable because the raw materials are easily available and the reaction operation is simple.

In the above formulas (1-m), (2-m), (3-m), (4-m), (5-m), (6-m), (7-m) and (8-m) The monomer compound represented can be reacted at a melting point or higher and a boiling point or lower of the organic solvent using an alkali or a suitable catalyst in a state dissolved in an organic solvent as necessary.

The organic solvent used in the reaction varies depending on the monomer compound used and the type of reaction, but it is preferable that a sufficient deoxygenation treatment is performed in order to suppress side reactions. Examples of the organic solvent include saturated hydrocarbons such as pentane, hexane, heptane, octane, and cyclohexane; unsaturated hydrocarbons such as benzene, toluene, ethylbenzene, and xylene; carbon tetrachloride, chloroform, dichloromethane, chlorobutane, bromobutane, and chloropentane. Halogenated saturated hydrocarbons such as bromopentane, chlorohexane, bromohexane, chlorocyclohexane and bromocyclohexane; halogenated unsaturated hydrocarbons such as chlorobenzene, dichlorobenzene and trichlorobenzene; methanol, ethanol, propanol, isopropanol, butanol, tert Alcohols such as butyl alcohol; carboxylic acids such as formic acid, acetic acid and propionic acid; dimethyl ether, diethyl ether, methyl-tert-butyl ether Le, tetrahydrofuran, tetrahydropyran, dioxane and the like can be mentioned. In place of the organic solvent, inorganic acids such as hydrochloric acid, bromic acid, hydrofluoric acid, sulfuric acid, and nitric acid may be used.

When an alkali or an appropriate catalyst is added, these may be selected according to the reaction to be generated. As the alkali or catalyst, those which are sufficiently dissolved in the solvent used for the reaction are preferable.

The reaction is preferably allowed to proceed under an inert atmosphere. Furthermore, similarly, during the reaction, it is preferable to perform a dehydration treatment (however, this is not the case in the case of a two-phase reaction with water such as a Suzuki coupling reaction).

After the reaction, the polymer can be obtained, for example, by performing a usual post-treatment such as extraction with an organic solvent after stopping the reaction with water and then distilling off the solvent. Isolation and purification of the obtained polymer can be performed by a method such as fractionation by chromatography or recrystallization.

When a polymer is used as a material for an organic thin film element, its purity may affect the element characteristics. Therefore, after each monomer compound before reaction is purified by a method such as distillation, sublimation purification, or recrystallization, the reaction is performed. It is preferable to perform (polymerize). After the synthesis of the polymer, it is preferable to carry out a purification treatment such as reprecipitation and fractionation by chromatography. In order to increase the purity and obtain good device characteristics, it is preferable to further purify the polymer obtained by the above-described production method by a method such as distillation, sublimation purification, and recrystallization.

In the above example, the structural unit represented by formula (1) or formula (5), the structural unit represented by formula (2) or formula (6), and any formula (3) or formula (7) The method for producing the polymer having the structural unit represented has been described as an example, but the polymer having the structural unit other than these can also be produced in the same manner as the above reaction by appropriately selecting the monomer compound. Can do.

[Organic thin film]
Next, an organic thin film according to a preferred embodiment will be described. The organic thin film which concerns on this embodiment contains the polymer of suitable embodiment mentioned above.

The thickness of the organic thin film is preferably 1 nm to 100 μm, more preferably 2 nm to 1000 nm, further preferably 5 nm to 500 nm, and particularly preferably 20 nm to 200 nm.

The organic thin film may include one type of the polymer according to this embodiment alone, or may include two or more types in combination. Moreover, in order to improve the electron transport property or hole transport property of an organic thin film, in addition to the polymer according to the present embodiment, a low molecular compound or a polymer compound having electron transport property (hereinafter referred to as “electron transport material”). Further, a low molecular compound or a high molecular compound having a hole transporting property (hereinafter referred to as “hole transporting material”) may be mixed and contained.

As the hole transporting material, known materials can be used. Specific examples thereof include pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triaryldiamine derivatives, oligothiophene and derivatives thereof, polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, polysilanes having aromatic amines in side chains or main chains. Examples thereof include siloxane derivatives, polyaniline and derivatives thereof, polythiophene and derivatives thereof, polypyrrole and derivatives thereof, polyarylene vinylene and derivatives thereof, and polythienylene vinylene and derivatives thereof.

As the electron transporting material, known materials can be used. Specific examples include oxadiazole derivatives, anthraquinodimethane and derivatives thereof, benzoquinone and derivatives thereof, naphthoquinone and derivatives thereof, anthraquinone and derivatives thereof, tetracyanoanthraquinodimethane and derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene. and its derivatives, diphenoquinone derivatives, or 8-hydroxyquinoline and metal complexes of derivatives thereof, polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, polyfluorene and derivatives thereof, fullerenes and derivatives thereof such as C _60.

The organic thin film may contain a charge generation material in order to generate a charge by light absorbed in the organic thin film. As the charge generation material, known materials can be used. Specific examples thereof include azo compounds and derivatives thereof, diazo compounds and derivatives thereof, metal-free phthalocyanine compounds and derivatives thereof, metal phthalocyanine compounds and derivatives thereof, perylene compounds and derivatives thereof, polycyclic quinone compounds and derivatives thereof, squarylium compounds. and its derivatives, azulenium compounds and their derivatives, thiapyrylium compounds and their derivatives, fullerenes and derivatives thereof such as C _60.

The organic thin film may contain other materials necessary for developing various functions. Other materials include, for example, a sensitizer for sensitizing the function of generating charge by absorbed light, a stabilizer for increasing stability, and a UV absorber for absorbing ultraviolet (UV) light. Etc.

Since the organic thin film can enhance mechanical properties, a polymer material other than the polymer according to the present embodiment may be included as a polymer binder. As the polymer binder, those not extremely disturbing the electron transport property or hole transport property are preferable, and those not strongly absorbing visible light are preferably used.

Such polymer binders include poly (N-vinylcarbazole), polyaniline and derivatives thereof, polythiophene and derivatives thereof, poly (p-phenylene vinylene) and derivatives thereof, poly (2,5-thienylene vinylene) and derivatives thereof. Examples include derivatives, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, and polysiloxane.

Examples of the method for producing an organic thin film according to the present embodiment include, in addition to the polymer according to the present embodiment, an electron transport material or a hole transport material, a charge generation material, and a polymer binder that are mixed as necessary. The method of forming into a film using a solution is mentioned. Moreover, when the polymer which concerns on this embodiment has sublimability, a thin film can also be formed by a vacuum evaporation method.

As a solvent used for film formation with a solution, any solvent may be used as long as it dissolves the polymer according to the present embodiment, an electron transporting material or a hole transporting material mixed therewith, a charge generating material, and a polymer binder. For example, unsaturated hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexyl, n-butylbenzene, sec-butylbenzene, tert-butylbenzene; carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, Halogenated saturated hydrocarbon solvents such as bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane and bromocyclohexane; Halogenated unsaturated hydrocarbon solvents such as chlorobenzene, dichlorobenzene and trichlorobenzene; tetrahydrofuran, tetrahydro Examples include ether solvents such as pyran. Although the polymer which concerns on this embodiment is based also on the structure and molecular weight, 0.1 mass% or more can be normally melt | dissolved in these solvents.

Examples of film forming methods using a solution include spin coating, casting, micro gravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, and screen printing. Application methods such as flexographic printing, offset printing, ink jet printing, dispenser printing, nozzle coating, and capillary coating can be used. Of these, spin coating, flexographic printing, ink jet printing, dispenser printing, nozzle coating, and capillary coating are preferred.

The step of manufacturing the organic thin film may include a step of orienting the polymer according to this embodiment. By orienting the polymer by this step, the main chain molecules or the side chain molecules are aligned in one direction, so that the electron mobility or hole mobility by the organic thin film is improved.

As a method for aligning the polymer according to the present embodiment, a method known as a liquid crystal alignment method can be used. Among these, the rubbing method, the photo-alignment method, the sharing method (shear stress application method) and the pulling coating method are simple, useful and easy to use as the alignment method, and the rubbing method and the sharing method are more preferable.

Further, the step of manufacturing the organic thin film may include a step of performing an annealing process after the film formation. By this step, the film quality of the organic thin film is improved, for example, the interaction between the polymers according to this embodiment is promoted, and the electron mobility or hole mobility is further improved. The annealing temperature is preferably a temperature between 50 ° C. and the vicinity of the glass transition temperature (Tg) of the polymer according to this embodiment, and more preferably a temperature between (Tg−30 ° C.) and Tg. The annealing time is preferably 1 minute to 10 hours, and more preferably 10 minutes to 1 hour. The atmosphere for the annealing treatment is preferably in a vacuum or in an inert gas atmosphere such as nitrogen gas.

Since the organic thin film according to the present embodiment has a charge transporting property (particularly excellent hole transporting property), an organic thin film transistor is controlled by transporting a charge injected from an electrode or a charge generated by light absorption. It can be used for various organic thin film elements such as organic thin film solar cells and optical sensors. When using an organic thin film for these organic thin film elements, it is more preferable to use the organic thin film by orienting it because of high charge transportability.

[Organic thin film element]
The organic thin film according to the preferred embodiment described above has excellent charge transportability (particularly, excellent hole transportability) because it includes the polymer according to the present embodiment. Therefore, this organic thin film can efficiently transport charges injected from an electrode or the like or generated by light absorption, and can be applied to various electric elements (organic thin film elements) using the organic thin film. Can do. In addition, since the polymer according to the present embodiment is excellent in environmental stability, an organic thin film element having stable performance in normal air can be obtained by forming a thin film using them. Is possible. Hereinafter, examples of organic thin film elements will be described.

(Organic thin film transistor)
First, an organic thin film transistor according to a preferred embodiment will be described. The organic thin film transistor includes a source electrode and a drain electrode, an active layer (ie, an organic thin film layer) including a polymer according to the present embodiment that is a current path between them, and a gate electrode that controls the amount of current passing through the current path. Any structure can be used. Examples of the organic thin film transistor include a field effect type and an electrostatic induction type.

The field effect organic thin film transistor includes a source electrode and a drain electrode, an active layer that is a current path between them, a polymer according to the present embodiment, a gate electrode that controls the amount of current passing through the current path, and an active layer and a gate. It is preferable to provide an insulating layer disposed between the electrodes. In particular, it is preferable that the source electrode and the drain electrode are provided in contact with the active layer containing the polymer according to this embodiment, and further, the gate electrode is provided with an insulating layer in contact with the active layer interposed therebetween.

The static induction organic thin film transistor has a source electrode and a drain electrode, an active layer that becomes a current path between them, and contains a polymer according to the present embodiment, and a gate electrode that controls an amount of current passing through the current path, The gate electrode is preferably provided in the active layer. In particular, the source electrode, the drain electrode, and the gate electrode provided in the active layer are preferably provided in contact with the active layer containing the polymer according to the present embodiment. As the structure of the gate electrode, any structure may be used as long as a current path flowing from the source electrode to the drain electrode is formed and the amount of current flowing through the current path can be controlled by a voltage applied to the gate electrode. .

FIG. 1 is a schematic cross-sectional view of an organic thin film transistor (field effect organic thin film transistor) according to a first embodiment. An organic thin film transistor 100 shown in FIG. 1 includes a substrate 1, a source electrode 5 and a drain electrode 6 formed on the substrate 1 with a predetermined interval, and a source electrode 5 and a drain electrode 6 so as to cover the substrate 1. Formed on the insulating layer 3 so as to cover the region of the insulating layer 3 between the source electrode 5 and the drain electrode 6, the insulating layer 3 formed on the active layer 2, and the insulating layer 3 formed between the source electrode 5 and the drain electrode 6. And a gate electrode 4.

FIG. 2 is a schematic cross-sectional view of an organic thin film transistor (field effect organic thin film transistor) according to a second embodiment. An organic thin film transistor 110 shown in FIG. 2 includes a substrate 1, a source electrode 5 formed on the substrate 1, an active layer 2 formed on the substrate 1 so as to cover the source electrode 5, a source electrode 5 and a predetermined electrode. Of the drain electrode 6 formed on the active layer 2 with an interval of, the insulating layer 3 formed on the active layer 2 and the drain electrode 6, and the insulating layer 3 between the source electrode 5 and the drain electrode 6. And a gate electrode 4 formed on the insulating layer 3 so as to cover the region.

FIG. 3 is a schematic cross-sectional view of an organic thin film transistor (field effect organic thin film transistor) according to a third embodiment. The organic thin film transistor 120 shown in FIG. 3 includes a substrate 1, an active layer 2 formed on the substrate 1, a source electrode 5 and a drain electrode 6 formed on the active layer 2 with a predetermined interval, and a source electrode. 5 and the drain electrode 6 so as to partially cover the insulating layer 3 formed on the active layer 2, the region of the insulating layer 3 where the source electrode 5 is formed below, and the drain electrode 6 are formed below. And a gate electrode 4 formed on the insulating layer 3 so as to partially cover the region of the insulating layer 3.

FIG. 4 is a schematic cross-sectional view of an organic thin film transistor (field effect organic thin film transistor) according to a fourth embodiment. 4 includes a substrate 1, a gate electrode 4 formed on the substrate 1, an insulating layer 3 formed on the substrate 1 so as to cover the gate electrode 4, and the gate electrode 4 at the bottom. The source electrode 5 and the drain electrode 6 formed on the insulating layer 3 with a predetermined interval so as to partially cover the region of the insulating layer 3 formed on the substrate, and the source electrode 5 and the drain electrode 6 are partially And an active layer 2 formed on the insulating layer 3 so as to cover it.

FIG. 5 is a schematic cross-sectional view of an organic thin film transistor (field effect type organic thin film transistor) according to a fifth embodiment. An organic thin film transistor 140 shown in FIG. 5 includes a substrate 1, a gate electrode 4 formed on the substrate 1, an insulating layer 3 formed on the substrate 1 so as to cover the gate electrode 4, and the gate electrode 4 at the bottom. A source electrode 5 formed on the insulating layer 3 so as to partially cover the region of the insulating layer 3 formed on the active layer 2 and an active layer 2 formed on the insulating layer 3 so as to partially cover the source electrode 5. And a drain electrode 6 formed on the insulating layer 3 at a predetermined interval so as to partially cover the region of the active layer 2 formed below the gate electrode 4 It is.

FIG. 6 is a schematic cross-sectional view of an organic thin film transistor (field effect type organic thin film transistor) according to a sixth embodiment. An organic thin film transistor 150 shown in FIG. 6 includes a substrate 1, a gate electrode 4 formed on the substrate 1, an insulating layer 3 formed on the substrate 1 so as to cover the gate electrode 4, and the gate electrode 4 at the bottom. The active layer 2 is formed on the insulating layer 3 so as to partially cover the region of the active layer 2 formed under the active layer 2 and the gate electrode 4 formed below. The source electrode 5 and the drain electrode 6 formed on the insulating layer 3 with a predetermined distance from the source electrode 5 so as to partially cover the region of the active layer 2 where the gate electrode 4 is formed below. , Are provided.

FIG. 7 is a schematic cross-sectional view of an organic thin film transistor (electrostatic induction type organic thin film transistor) according to a seventh embodiment. The organic thin film transistor 160 shown in FIG. 7 includes a substrate 1, a source electrode 5 formed on the substrate 1, an active layer 2 formed on the source electrode 5, and a plurality on the active layer 2 with a predetermined interval. The formed gate electrode 4 and the active layer 2a formed on the active layer 2 so as to cover the gate electrode 4 (the material constituting the active layer 2a may be the same as or different from that of the active layer 2). And a drain electrode 6 formed on the active layer 2a.

In the organic thin film transistors according to the first to seventh embodiments, the active layer 2 and / or the active layer 2a contains the polymer according to the present embodiment, and the current path between the source electrode 5 and the drain electrode 6 (Channel). The gate electrode 4 controls the amount of current passing through the current path (channel) in the active layer 2 and / or the active layer 2a by applying a voltage.

Such a field effect organic thin film transistor can be produced by a known method, for example, a method described in JP-A-5-110069. The electrostatic induction organic thin film transistor can be produced by a known method, for example, a method described in JP-A-2004-006476.

As the substrate 1, it is sufficient that the characteristics as an organic thin film transistor are not hindered, and a glass substrate, a flexible film substrate, or a plastic substrate can be used.

When forming the active layer 2, it is preferable to use a compound soluble in an organic solvent because it is advantageous in production. In that case, the organic thin film used as the active layer 2 can be formed by applying the organic thin film manufacturing method described above.

As the insulating layer 3 in contact with the active layer 2, any material having high electrical insulation may be used, and a known material can be used. For _{example, SiOx, SiNx, Ta 2 O} 5, polyimide, polyvinyl alcohol, polyvinyl phenol, organic glass and photoresists. Since the voltage can be lowered, a material having a high dielectric constant is preferable.

When the active layer 2 is formed on the insulating layer 3, the surface of the insulating layer 3 is treated with a surface treatment agent such as a silane coupling agent in order to improve the interface characteristics between the insulating layer 3 and the active layer 2. It is also possible to form the active layer 2 after the modification. Examples of the surface treatment agent include silylamine compounds such as long-chain alkylchlorosilanes, long-chain alkylalkoxysilanes, fluorinated alkylchlorosilanes, fluorinated alkylalkoxysilanes, and hexamethyldisilazane. Prior to the treatment with the surface treatment agent, the surface of the insulating layer can be treated with ozone UV or O ₂ plasma.

In addition, it is preferable to form a protective film on the organic thin film transistor after the organic thin film transistor is manufactured in order to protect the element. Thereby, an organic thin-film transistor is interrupted | blocked from air | atmosphere and the fall of the characteristic of an organic thin-film transistor can be suppressed. Moreover, the influence from the outside in the process of forming the display device driven by the organic thin film transistor on the organic thin film transistor can be reduced by the protective film.

Examples of the method for forming the protective film include a method of covering with a UV curable resin, a thermosetting resin, or an inorganic SiONx film. In order to effectively cut off from the atmosphere, it is preferable to perform the steps from the preparation of the organic thin film transistor to the formation of the protective film without exposure to the atmosphere (for example, in a dry nitrogen atmosphere or in a vacuum).

An organic thin film transistor array can be formed by integrating a plurality of organic thin film transistors, and can also be used as a backplane of a flat panel display.

(Organic thin film solar cell)
Next, application of the preferred embodiment to an organic thin film solar cell will be described. FIG. 8 is a schematic cross-sectional view of an organic thin-film solar cell according to a preferred embodiment. An organic thin film solar cell 200 shown in FIG. 8 includes an organic material containing a substrate 1, a first electrode 7a formed on the substrate 1, and a polymer according to the present embodiment formed on the first electrode 7a. An active layer 2 made of a thin film and a second electrode 7b formed on the active layer 2 are provided.

In the organic thin film solar cell according to this embodiment, a transparent or translucent electrode is used for at least one of the first electrode 7a and the second electrode 7b. As an electrode material, a metal such as aluminum, gold, silver, copper, alkali metal, alkaline earth metal, or a translucent film or a transparent conductive film thereof can be used. In order to obtain a high open circuit voltage, each electrode is preferably selected so that the difference in work function is large. In the active layer 2, a charge generating agent, a sensitizer and the like can be added and used in order to increase photosensitivity. As the substrate 1, a silicon substrate, a glass substrate, a plastic substrate, or the like can be used.

The operation mechanism of the organic thin film solar cell will be described. Light energy incident from a transparent or translucent electrode is absorbed by the acceptor compound and / or donor compound, and excitons in which electrons and holes are combined are generated. When the generated excitons move and reach the heterojunction interface where the acceptor compound and the donor compound are adjacent to each other, electrons and holes are separated due to the difference in HOMO and LUMO energy of each compound at the interface. Generates a charge that can move independently. The generated electrons can be taken out as electrical energy (current) by moving to the cathode and the generated holes to the anode.

Considering such an operating mechanism, in order to obtain an organic thin film solar cell with high photoelectric conversion efficiency, an acceptor compound and / or a donor having an absorption region capable of efficiently absorbing a spectrum of desired incident light. It is important that organic thin-film solar cells contain many heterojunction interfaces in order to efficiently separate excitons, and that materials that have charge transportability to quickly transport generated charges to the electrode are important in order to efficiently separate excitons. is there.

In the organic thin film solar cell of this embodiment, an additional layer may be provided between at least one of the first electrode 7a and the second electrode 7b and the active layer 2 in the element. Examples of the additional layer include a charge transport layer that transports holes or electrons, and a buffer layer that separates the electrode from the organic layer.

Specifically, in the organic thin film solar cell 200 shown in FIG. 8, the organic layer having a buffer layer between the active layer 2 containing the acceptor compound and the donor compound and one or both of the pair of electrodes. Thin film solar cells are preferred.

An organic thin film solar cell can be operated as a solar cell by generating a photovoltaic force between the electrodes by irradiating light such as sunlight from a transparent or translucent electrode. It can also be used as an organic thin film solar cell module by integrating a plurality of organic thin film solar cells. The polymer of this embodiment functions as an acceptor compound because it has excellent hole transport properties.

(Optical sensor)
Next, application of the organic thin film according to the present embodiment to an optical sensor will be described. FIG. 9 is a schematic cross-sectional view of the photosensor according to the first embodiment. An optical sensor 300 shown in FIG. 9 includes a substrate 1, a first electrode 7a formed on the substrate 1, and an organic thin film containing the polymer according to the present embodiment formed on the first electrode 7a. An active layer 2, a charge generation layer 8 formed on the active layer 2, and a second electrode 7 b formed on the charge generation layer 8.

FIG. 10 is a schematic cross-sectional view of an optical sensor according to the second embodiment. An optical sensor 310 illustrated in FIG. 10 is formed on the substrate 1, the first electrode 7a formed on the substrate 1, the charge generation layer 8 formed on the first electrode 7a, and the charge generation layer 8. The active layer 2 which consists of an organic thin film containing the polymer which concerns on this embodiment and the 2nd electrode 7b formed on the active layer 2 are provided.

FIG. 11 is a schematic cross-sectional view of an optical sensor according to the third embodiment. An optical sensor 320 shown in FIG. 11 includes a substrate 1, a first electrode 7a formed on the substrate 1, and an organic thin film containing a polymer according to the present embodiment formed on the first electrode 7a. And the second electrode 7 b formed on the active layer 2.

In the optical sensors according to the first to third embodiments, a transparent or translucent electrode is used for at least one of the first electrode 7a and the second electrode 7b. The charge generation layer 8 is a layer that absorbs light and generates charges. As an electrode material, a metal such as aluminum, gold, silver, copper, alkali metal, alkaline earth metal, or a translucent film or a transparent conductive film thereof can be used. In the active layer 2, a carrier generating agent, a sensitizer and the like can be added and used in order to increase the photosensitivity. As the substrate 1, a silicon substrate, a glass substrate, a plastic substrate, or the like can be used.

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

In the following examples, for example, a compound represented by the formula A will be referred to as “compound A”, and the compounds represented by the formulas B to U will be similarly represented.

[Measurement conditions]
First, conditions for each measurement performed in an experiment described later will be described. The nuclear magnetic resonance (NMR) spectrum was measured using a product name JMN-270 (400 MHz at ¹ H measurement) manufactured by JEOL (JEOL Ltd.). Chemical shifts are expressed in parts per million (ppm). Tetramethylsilane (TMS) was used for the internal standard of 0 ppm. The coupling constant (J) is shown in hertz, and the abbreviations s, d, t, q, m, and br are singlet, doublet, triplet, quadruple, respectively. Represents a line, a multiplet, and a broad line. Reaction under microwave irradiation was performed by Initiator ^™ Ver. Manufactured by Biotage AB. 2.5 was used and the output was 400 W and 2.45 GHz.

Mass spectrometry (MS) was measured by an electron ionization (EI) method and a direct sample introduction (DI) method using GCMS-QP5050A (trade name) manufactured by Shimadzu Corporation. As silica gel in the column chromatography, trade name Silicagel 60N (40 to 50 μm) manufactured by Kanto Chemical Co., Ltd. was used. All chemical substances are reagent grade and purchased from Wako Pure Chemical Industries, Ltd., Tokyo Chemical Industry Co., Ltd., Kanto Chemical Co., Ltd., Nacalai Tesque Co., Ltd., Sigma Aldrich Japan Co., Ltd., or Daikin Chemicals Co., Ltd. For purification of the compound by gel permeation chromatography (GPC), GPC system CO-8020 (manufactured by Tosoh Corporation) was used.

The absorption spectrum was measured using a self-recording spectrophotometer (UV-3100PC: manufactured by Shimadzu Corporation) under the condition of a slit width of 1 mm. The absorption spectrum of the solution was measured using a quartz cell having a cell width of 1 cm by preparing a polymer in a 1 × 10 ⁻⁶ mol / L chlorobenzene solution. The absorption spectrum of the thin film was obtained by forming a polymer thin film on a quartz substrate.

Example 1
<Synthesis of Polymer C>
Compound A as a raw material was synthesized by the method described in J. Hou, H. Chen, S. Zhang, G. Li, Y. Yang. J. Am. Chem. Soc. 2008, 130, 16144.

Compound B as a raw material was synthesized by the method described in Y. Ie, Y. Umemoto, M. Okabe, T. Kusunoki, Y. Aso., Org. Lett. 2008, 10, 833.

（式中、ｎは繰り返し単位数を示し、以下、同様である。） In a test tube with a lid, compound A (200 mg, 0.27 mmol), compound B (98 mg, 0.27 mmol), tetrakis (triphenylphosphine) palladium (Pd (PPh ₃ ) ₄ ) (7 mg, 0.0054 mmol), toluene ( 2.7 mL) was added and reacted in an argon atmosphere (110 ° C., 24 hours). The reaction product was separated and purified by Soxhlet extraction in the order of methanol, hexane, and chloroform to obtain polymer C as a black solid.
Yield: 65 mg, Yield: 40%
λ _max = 633 nm (chlorobenzene solution)
¹ H NMR (400 MHz, CDCl ₃ ): δ (ppm) = 7.30 (br, 2H), 1.88 (br, 2H), 1.30-1.17 (m, 20H), 0.82 ( br, 12H).

(In the formula, n represents the number of repeating units, and the same applies hereinafter.)

When cyclic voltammetry (CV) measurement was performed on the polymer C, reversible reduction waves and oxidation waves were observed at −1.67 V and 0.48 V, respectively. The LUMO energy estimated from the reduction wave was 3.13 eV, and it was confirmed that the LUMO was deep. Moreover, the HOMO energy estimated from the oxidation wave was 5.28 eV, and it was confirmed that the HOMO was shallow.
The number average molecular weight in terms of polystyrene of the polymer C was 4300.

Example 2
<Synthesis of Polymer G>
Under a nitrogen atmosphere, in a reaction vessel, Compound B (500 mg, 1.45 mmol), 2-tributylstannyl 4-dodecylthiophene (1.64 g, 3.04 mmol), Pd (PPh ₃ ) ₄ (84 mg, 0.07 mmol), Toluene (14.5 mL) was added and allowed to react under microwave irradiation (180 ° C., 5 minutes). The reaction product was separated and purified by column chromatography (developing solvent hexane) to obtain Compound E as a red solid.
Yield: 800 mg, Yield: 80%
¹ H NMR (400 MHz, CDCl ₃ ): δ (ppm) = 8.02 (s, 2H), 7.13 (s, 2H), 2.65-2.63 (t, 4H), 1.65 1.59 (t, 4H), 1.38-1.26 (m, 36H), 0.94-0.88 (t, 6H).

Under a nitrogen atmosphere, Compound E (100 mg, 0.145 mmol), N-bromosuccinimide (NBS) (55 mg, 0.3 mmol), and dimethylformamide (DMF) (6 mL) were placed in a reaction vessel and stirred overnight at room temperature. The reaction product was separated and purified by column chromatography (developing solvent hexane) to obtain Compound F as a red solid.
Yield: 120 mg, yield: 97%
¹ H NMR (400 MHz, CDCl ₃ ): δ (ppm) = 7.81 (s, 2H), 2.63-2.59 (t, 4H), 1.68-1.60 (t, 4H), 1.35-1.27 (m, 36H), 0.94-0.90 (t, 6H).

A test tube with a lid was charged with compound A (105 mg, 0.142 mmol), compound F (120 mg, 0.142 mmol), Pd (PPh ₃ ) ₄ (3 mg, 0.0028 mmol), toluene (2.8 mL), and an argon atmosphere. (110 ° C., 24 hours). The reaction product was separated and purified by Soxhlet extraction in the order of methanol, hexane, and chloroform to obtain a polymer G that was a black solid.
Yield: 99 mg, yield: 63%
λ _max = 660 nm (chlorobenzene solution)
1H NMR (400 MHz, CDCl ₃ ): δ (ppm) = 8.07 (br, 2H), 7.19 (br, 2H), 2.84 (br, 4H), 1.77 (br, 4H), 1.29 (br, 58H), 0.88 (br, 18H).

When the polymer G was subjected to CV measurement, reversible reduction waves and oxidation waves were observed at -1.77 V and 0.51 V, respectively. The LUMO energy estimated from the reduction wave was 3.03 eV, and it was confirmed that the LUMO was deep. Moreover, the HOMO energy estimated from the oxidation wave was 5.31 eV, and it was confirmed that the HOMO was shallow. The absorption spectrum (a) of the polymer G solution and the absorption spectrum (b) of the thin film are shown in FIG. Compared with the solution, the absorption peak wavelength was shifted to the longer wavelength side in the thin film, and it was confirmed that aggregates were formed between the molecules. The HOMO-LUMO gap estimated from the absorption edge of the absorption spectrum of the thin film was 1.38 eV.
The number average molecular weight in terms of polystyrene of the polymer G was 11,500.

Example 3
<Synthesis of Polymer I>
Compound H as a raw material is synthesized by the method described in Chiu-Hsiang Chen et al., Macromolecules 2010, Vol. 43, p.697-p.708.
Compound H, Compound B, Pd (PPh ₃ ) ₄ , and toluene are placed in a test tube with a lid, and reacted in an argon atmosphere (110 ° C., 24 hours). The reaction product is separated and purified by the Soxhlet extraction method in the order of methanol, hexane, and chloroform to obtain a polymer I.

Example 4
<Synthesis of Polymer J>
Compound H, Compound F, Pd (PPh ₃ ) ₄ , and toluene are placed in a test tube with a lid, and reacted in an argon atmosphere (110 ° C., 24 hours). Separation and purification by methanol, hexane, and chloroform in the order of Soxhlet extraction method gives polymer J.

Example 5
<Synthesis of Polymer R>
Under a nitrogen atmosphere, Compound M (1 g, 2.08 mmol) and tetrahydrofuran (THF) (40 mL) were placed in a reaction vessel, cooled to −40 ° C., lithium diisopropylamide (6 mL, 1 M THF solution), Compound N (0.82 g). , 2.5 mmol) and stirred for 4 hours. The reaction product was separated and purified by column chromatography (developing solvent: ethyl acetate: hexane = 10: 1 (volume ratio)) to obtain Compound O as a colorless liquid.
Yield: 460 mg, Yield: 30%
MALDI TOFMS: m / z = 734
¹ H NMR (400 MHz, CDCl ₃ ): δ (ppm) = 1.43-1.36 (m, 2H), 1.31-1.27 (m, 2H), 1.21-1.00 (m , 38H), 0.84-0.81 (t, 3H), 0.79-0.75 (t, 3H), 0.73-0.70 (t, 3H), 0.63-0.60 (T, 3H).

Compound O, THF, and NBS are placed in a reaction vessel and stirred at 60 ° C. for 4 hours. The reaction product is separated and purified by column chromatography to obtain compound P.

In a nitrogen atmosphere, compound P and THF are placed in a reaction vessel, cooled to −78 ° C., n-butyllithium and trimethyltin chloride are added, and the mixture is stirred for 4 hours. The reaction product is separated and purified by column chromatography to obtain compound Q.

Compound Q, compound F, tris (dibenzylideneacetone) dipalladium (0), tri-o-tolylphosphine, and chlorobenzene are placed in a 5 mL test tube and reacted under microwave irradiation (180 ° C., 5 minutes). The reaction product is separated and purified by the Soxhlet extraction method in the order of methanol, hexane and chloroform to obtain a polymer R.

Example 6
<Preparation of Organic Thin Film Element 1 and Evaluation of Solar Cell Characteristics>
A suspension of poly (3,4) ethylenedioxythiophene / polystyrene sulfonic acid (manufactured by Stark Vitec Co., Ltd., Baytron (registered trademark) PAI4083) was filtered through a 0.2 μm membrane filter. The filtered liquid was applied by spin coating to a 150 nm thick ITO film formed on a glass substrate by sputtering to form a 44 nm thick thin film. This thin film was dried by heating at 200 ° C. for 10 minutes using a hot plate. Next, the polymer G synthesized in Example 2 and the fullerene C60PCBM (phenyl C61-butyric acid methyl ester, manufactured by Frontier Carbon Co.) are polymer G / C60PCBM mass ratio = The mixture was mixed at a ratio of 1/2, and the mixture was dissolved in orthodichlorobenzene to prepare a coating solution in which the total concentration of the polymer G and C60PCBM was 1.0% by weight. At this time, since the polymer G and C60PCBM were completely dissolved in orthodichlorobenzene, it was confirmed that the polymer G was soluble in an organic solvent. The coating solution was applied onto the substrate by spin coating to deposit an organic thin film containing the polymer G (film thickness of about 90 nm). The light absorption terminal wavelength of the formed organic thin film was 890 nm. Then, calcium was vapor-deposited with a thickness of 8 nm on the organic thin film by a vacuum vapor deposition machine, and then Al was vapor-deposited with a thickness of 100 nm to obtain an organic thin film element 1. The shape of the obtained organic thin film element 1 was a regular square of 2 mm × 2 mm. The obtained organic thin film element 1 is irradiated with constant light using a solar simulator (trade name: OTENTO-SUNII: AM1.5G filter, irradiance: 100 mW / cm ² , manufactured by Spectrometer Co., Ltd.) The voltage was measured and the photoelectric conversion efficiency, the short circuit current density, the open circuit voltage, and the fill factor were determined. Jsc (short circuit current density) = 1.29 mA / cm ² , Voc (open end voltage) = 0.87 V, ff (fill factor) = 0.48, photoelectric conversion efficiency (η) = 0.54% It was confirmed that the organic thin film element 1 exhibited good solar cell characteristics.

Example 7
<Preparation of organic thin film element 2 and evaluation of solar cell characteristics>
Using fullerene C70PCBM (phenyl C71-butyric acid methyl ester, manufactured by Frontier Carbon Co.) instead of fullerene C60PCBM, polymer G and fullerene C70PCBM are polymerized in the same manner as in Example 6. The organic thin film element 2 which has the organic thin film (film thickness of about 100 nm) contained in the ratio of mass ratio = 1/2 of G / C70PCBM was obtained. The obtained organic thin film element 2 is irradiated with constant light using a solar simulator in the same manner as in Example 6, and the generated current and voltage are measured, and the photoelectric conversion efficiency, short-circuit current density, open-end voltage, and The fill factor was determined. Jsc (short circuit current density) = 1.89 mA / cm ² , Voc (open circuit voltage) = 0.88 V, ff (fill factor) = 0.46, photoelectric conversion efficiency (η) = 0.77% It was confirmed that the organic thin film element 2 exhibited good solar cell characteristics.

Example 8
<Preparation of Organic Thin Film Element 3 and Evaluation of Transistor Characteristics>
A substrate in which a 300 nm silicon oxide film was formed as an insulating film by thermal oxidation on the surface of a heavily doped p-type silicon substrate as a gate electrode was prepared. On this substrate, a source electrode and a drain electrode having a channel width of 2 mm and a channel length of 20 μm were formed by a lift-off method. The substrate with electrodes was ultrasonically cleaned with acetone for 10 minutes and then with isopropyl alcohol for 10 minutes, and then the surface was cleaned by irradiation with ozone UV for 20 minutes. When the polymer G synthesized in Example 2 was dissolved in chloroform at a concentration of 0.5% by mass, it was confirmed that the polymer G was completely dissolved in chloroform and could be dissolved in an organic solvent. This solution was applied onto the surface-treated substrate by spin coating at a rotation speed of 1500 rpm for 1 minute and dried to deposit an organic thin film of polymer G (film thickness of about 100 nm). Thereafter, annealing treatment was performed at 200 ° C. for 30 minutes in a nitrogen atmosphere to obtain an organic thin film element 3. Using a semiconductor parameter analyzer (trade name “4200-SCS” manufactured by Keithley), while changing the gate voltage Vg and the source-drain voltage Vsd in the range of +20 to −40 V in a vacuum, the organic thin film element 3 When the organic transistor characteristics were measured, it was confirmed that the organic thin film element 3 exhibited good p-type semiconductor drain current (Id) -gate voltage (Vg) characteristics. At this time, the mobility was 4.4 × 10 ⁻³ cm ² / Vs, the threshold voltage was −2 V, the on / off ratio was about 10 ⁶ , and both were good. From this, it was confirmed that the organic thin film element 3 functions effectively as a p-type organic transistor. From this, it was confirmed that the polymer G has an excellent hole transport property and can be used as an excellent organic p-type semiconductor.

Example 9
<Synthesis of Polymer U>
Compound S represented by the following chemical formula was synthesized by the method described in Y. Ie, Y. Umemoto, M. Okabe, T. Kusunoki, Y. Aso., Org. Lett. 2008, 10, 833. Used as raw material.

Under a nitrogen atmosphere, in a reaction vessel, Compound S (0.62 g, 2 mmol), 1-iodohexane (C ₆ H ₁₃ I) (3.81 g, 18 mmol), KF / Celite (1.06 g, 10 mmol), acetonitrile (4 ml) ) And stirred at 80 ° C. overnight. The product was separated and purified by column chromatography (hexane: ethyl acetate = 20: 1) to obtain Compound T as a yellow liquid (yield: 260 mg, yield: 24%).
¹ H NMR (400 MHz, CDCl ₃ ): δ (ppm) = 4.35 (s, 4H), 1.79-1.74 (m, 4H), 1.23-1.15 (m, 12H), 0.83 (t, 6H).

The obtained compound T was converted into compound A synthesized in Example 1, tris (dibenzylideneacetone) dipalladium (0) (Pd ₂ (dba) ₃ ), and tri-o-tolylphosphine (P (o-tol)). ₃ ), and placed in a test tube with a lid together with chlorobenzene. After replacing the atmosphere in the test tube with argon for 30 minutes, the reaction was allowed to proceed under microwave irradiation (200 ° C., 30 minutes). The product was separated and purified by column chromatography, and then further separated and purified by Soxhlet extraction in the order of methanol, hexane, and chloroform to obtain a polymer U.
Yield: 90 mg Yield: 61%
Mn = 16.1 kg / mol PDI = 3.78
λ _max = 610 nm
¹ H NMR (400 MHz, CDCl ₃ ): δ (ppm) = 8.02 (br, 2H), 2.82 (br, 4H), 1.80-0.60 (br, 56H).

Example 10
<Preparation of Organic Thin Film Element 4 and Evaluation of Solar Cell Characteristics>
Using the polymer U synthesized in Example 9 instead of the polymer G, the polymer U and the fullerene C70PCBM were mixed at a ratio of the mass ratio of the polymer U / C70PCBM = 1/2 by the same operation as in Example 7. After mixing, the mixture was dissolved in orthodichlorobenzene to prepare a coating solution in which the total concentration of the polymer U and C70PCBM was 0.75% by weight. At this time, since the polymer U and C70PCBM were completely dissolved in orthodichlorobenzene, it was confirmed that the polymer U could be dissolved in an organic solvent. Using the coating solution, an organic thin film element 4 having an organic thin film (thickness: about 97 nm) containing polymer U and C70PCBM was obtained in the same manner as in Example 7. The obtained organic thin film element 4 is irradiated with constant light using a solar simulator in the same manner as in Example 6, and the generated current and voltage are measured, and the photoelectric conversion efficiency, short-circuit current density, open-end voltage, and The fill factor was determined. Jsc (short circuit current density) = 6.13 mA / cm ² , Voc (open circuit voltage) = 0.91 V, ff (fill factor) = 0.31, photoelectric conversion efficiency (η) = 1.73% It was confirmed that the organic thin film element 4 exhibited good solar cell characteristics.

Example 11
<Preparation of organic thin film element 5 and evaluation of transistor characteristics>
When the polymer U synthesized in Example 9 was dissolved in orthodichlorobenzene at a concentration of 0.5% by mass, the polymer U was completely dissolved in orthodichlorobenzene and dissolved in an organic solvent. It could be confirmed. In the same manner as in Example 8, this solution was applied onto a surface-treated substrate by spin coating to deposit an organic thin film of polymer U. Thereafter, annealing treatment was performed at 170 ° C. for 30 minutes in a nitrogen atmosphere to obtain an organic thin film element 5. Using the semiconductor parameter analyzer, the organic transistor characteristics of the organic thin film element 5 were measured while changing the gate voltage Vg and the source-drain voltage Vsd in the range of +20 to −40 V in vacuum. It was confirmed that the drain current (Id) -gate voltage (Vg) characteristics of the p-type semiconductor were good. At this time, the mobility was 1.0 × 10 ⁻⁴ cm ² / Vs, the threshold voltage was 17 V, and the on / off ratio was about 10 ⁵ , both of which were good. From this, it was confirmed that the organic thin film element 5 functions effectively as a p-type organic transistor. From this, it was confirmed that the polymer U has an excellent hole transport property and can be used as an excellent organic p-type semiconductor.

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Active layer, 2a ... Active layer, 3 ... Insulating layer, 4 ... Gate electrode, 5 ... Source electrode, 6 ... Drain electrode, 7a ... 1st electrode, 7b ... 2nd electrode, 8 ... Charge generation layer, 100 ... organic thin film transistor according to the first embodiment, 110 ... organic thin film transistor according to the second embodiment, 120 ... organic thin film transistor according to the third embodiment, 130 ... organic thin film transistor according to the fourth embodiment, 140 ... Organic thin film transistor according to fifth embodiment, 150... Organic thin film transistor according to sixth embodiment, 160. Organic thin film transistor according to seventh embodiment, 200... Solar cell according to embodiment, 300. , 310... Optical sensor according to the second embodiment, 320... Optical sensor according to the third embodiment.

Claims (13)

A polymer having a structural unit represented by formula (1) and a structural unit represented by formula (2).

[Where:
X ¹ and X ² are each independently an oxygen atom, a sulfur atom, or a group represented by ═C (A) ₂ (A may have a hydrogen atom, a halogen atom, or a substituent 1 And two A's may be the same or different, and Y represents a carbon atom, a silicon atom, a germanium atom, a titanium atom, or a tin atom. R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms (provided that the hydrogen atom of the alkyl group is Part or all may be substituted with a halogen atom.), 1 consisting of a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms and a group other than the alkyl group substituted with the alkyl group A valent group (however, part or all of the hydrogen atoms in the alkyl group may be substituted with a halogen atom), an aryl group having 6 to 60 carbon atoms which may have a substituent, or A monovalent heterocyclic group having 4 to 60 carbon atoms which may have a substituent is shown. Ar ¹ represents an optionally substituted tetravalent aromatic hydrocarbon group having 6 to 60 carbon atoms, or an optionally substituted tetravalent aromatic group having 4 to 60 carbon atoms. A heterocyclic group is shown. Ar ² and Ar ³ each independently represent a trivalent aromatic hydrocarbon group having 6 to 60 carbon atoms which may have a substituent, or 4 to 4 carbon atoms which may have a substituent. 60 represents a trivalent aromatic heterocyclic group.
However, when Y is a carbon atom, Ar ² and Ar ³ are trivalent aromatic heterocyclic groups. ] The polymer of Claim 1 which further has a structural unit represented by Formula (3).

[Where:
Ar ⁴ represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. ] The polymer of Claim 1 or 2 which has a structural unit represented by Formula (4).

[Where:
X ¹ , X ² , Y, R ¹ , R ² , R ³ , R ⁴ , Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are as defined above. s and t each independently represent an integer of 0 to 6. When there are a plurality of Ar ^{4 s} , they may be the same or different. ] The polymer according to any one of claims 1 to 3, wherein the structural unit represented by the formula (1) is a structural unit represented by the formula (5).

[Where:
X ¹ , X ² , R ¹ and R ² are as defined above.
Z ¹ is a group represented by formula (i), a group represented by formula (ii), a group represented by formula (iii), a group represented by formula (iv), or a group represented by formula (v). A group represented by formula (vi), a group represented by formula (vii), a group represented by formula (viii) or a group represented by formula (ix). ]

[Where:
R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent a hydrogen atom, a halogen atom or a monovalent organic group which may have a substituent, and R ¹¹ and R ¹² are bonded to each other. May form a ring. ] The polymer according to any one of claims 1 to 4, wherein the structural unit represented by the formula (2) is a structural unit represented by the formula (6).

[Where:
Y represents a carbon atom, a silicon atom, a germanium atom, a titanium atom or a tin atom.
W ² and ^{W 3} are each independently, -C ^(R 5) = groups represented by ^{(R 5} is a hydrogen atom, a halogen atom or a monovalent organic group.) Or represented by -N = Represents a group.
R ³ and R ⁴ each independently represents a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms (provided that part or all of the hydrogen atoms in the alkyl group are halogen atoms). An optionally substituted atom), a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms and a monovalent group consisting of a group other than the alkyl group substituted with the alkyl group (however, A part or all of the hydrogen atoms in the alkyl group may be substituted with a halogen atom.), An aryl group having 6 to 60 carbon atoms which may have a substituent or a substituent. A good monovalent heterocyclic group having 4 to 60 carbon atoms is shown.
Z ² and Z ³ are each independently a group represented by formula (xi), a group represented by formula (xii), a group represented by formula (xiii), or a group represented by formula (xiv) , A group represented by formula (xv), a group represented by formula (xvi), a group represented by formula (xvii), a group represented by formula (xviii), or a group represented by formula (xix) Indicates. ]

[Where:
R ²¹ , R ²² , R ²³ and R ²⁴ each independently represent a hydrogen atom, a halogen atom or a monovalent organic group which may have a substituent, and R ²¹ and R ²² are bonded to each other. May form a ring. ] The polymer according to any one of claims 2 to 5, wherein the structural unit represented by the formula (3) is a structural unit represented by the formula (7).

[Where:
R ⁷ and R ⁸ each independently represent a hydrogen atom, a halogen atom or a monovalent organic group, and R ⁷ and R ⁸ may be bonded to each other to form a ring.
Z ⁴ is a group represented by the formula (xxi), a group represented by the formula (xxii), a group represented by the formula (xxiii), a group represented by the formula (xxiv), or a formula (xxv). A group represented by formula (xxvi), a group represented by formula (xxvii), a group represented by formula (xxviii), or a group represented by formula (xxix). ]

[Where:
R ³¹ , R ³² , R ³³ and R ³⁴ each independently represent a hydrogen atom, a halogen atom or a monovalent organic group which may have a substituent, and R ³¹ and R ³² are bonded to each other. May form a ring. ] The polymer according to any one of claims 3 to 6, wherein the structural unit represented by the formula (4) is a structural unit represented by the formula (8).

[Where:
X ¹ , X ² , Y, R ¹ , R ² , R ³ , R ⁴ , R ⁷ , R ⁸ , W ² , W ³ , Z ¹ , Z ² , Z ³ , Z ⁴ , s and t are And when there are a plurality of R ⁷ , R ⁸ and Z ⁴ , they may be the same or different. ] The polymer according to any one of claims 4 to 7, wherein Z ¹ is a group represented by the formula (ii). The polymer according to any one of claims 5 to 8, wherein Z ² and Z ³ are a group represented by the formula (xii), and Y is a silicon atom. An organic thin film comprising the polymer according to any one of claims 1 to 9. An organic thin film element comprising the organic thin film according to claim 10. An organic thin film transistor comprising the organic thin film according to claim 10. An organic thin film solar cell comprising the organic thin film according to claim 10.

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