JP2015034239A - Organic hetero polymer and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic hetero polymer having high carrier mobility and high solubility to organic solvents in spite of having high molecular weight, and useful for forming an organic semiconductor.SOLUTION: The organic hetero polymer for an organic semiconductor has a repeating unit represented by the following formula (1) or (2). (in the formula, M is a hetero atom selected from group 14 to 16 elements in the periodic table and having a valence of 3 to 6, Rrepresents an aryl group, Rrepresents an aryl group or the like, m1 and m2 are 0 or 1 (the sum of m1 and m2 is 1 or 2), Rand Rrepresent a halogen atom or the formula -Z-R, (Z represents group 16 elements in the periodic table and Rrepresents an aryl group or the like), Rand Rrepresent a hydrogen atom, an alkyl group, an alkoxy group or an alkylthio group, Rand Rmay bind each other to form a ring, but M is not a phosphorus atom when Ris a phenyl group, m1 is 1 and m2 is 0 in the formula (1)).

Description

  The present invention relates to an organic heteropolymer (or organometallic polymer) useful for forming an organic semiconductor as a semiconductor element, a photoelectric conversion element, etc., an organic semiconductor formed from this polymer, and a device (semiconductor) using the same Device).

  Many organometallic compounds typified by metal phthalocyanines form a unique electronic state or a very stable molecular structure due to the bond between the organic molecule and the metal. Due to these characteristics, it has been used as an organic pigment for a long time.

  In recent years, responsiveness to external energy such as heat, light, and electric field has led to widespread use in the electronics field, such as photosensitive materials for electrophotographic printers and recording media such as CD-Rs. In particular, recently, its function as an organic semiconductor has attracted attention, and its use for organic transistors and organic thin-film solar cells has been studied. Since an electronic device using an organic semiconductor can be manufactured by printing, it is expected that it can be mass-produced at a lower cost than an inorganic device.

  However, many of the conventional organometallic compounds are insoluble or hardly soluble in a solvent, and the film formation is mainly performed by a vacuum deposition method, so that the manufactured electronic device is expensive.

  In order to improve such problems, Japanese Patent Application Laid-Open No. 2011-162575 (Patent Document 1) describes, for example, 4-substituted amidophthalonitrile (4-acetamidophthalonitrile, 4-pyridylamidophthalonitrile, etc.) and 4- Reacting an alkylphthalonitrile (such as 4-t-butylphthalonitrile) in the presence of a metal salt (metal salt such as Ni, Zn, Cu) to produce a metal trisalkyl-4-substituted amide-phthalocyanine. It is also described that the phthalocyanine compound is hydrolyzed to produce a soluble substituted phthalocyanine having an amino group. Such a phthalocyanine derivative has a functional group having a large steric hindrance such as a t-butyl group introduced into phthalocyanine, can prevent stacking between phthalocyanines, and is soluble in a solvent.

  However, when a functional group that inhibits stacking is introduced, electron transfer between molecules becomes difficult, so that the photoelectric characteristics and the function as an organic semiconductor are lowered.

  A polymer having a porphyrin structure is also known. J. Polym. Sci. Part A, 43 (2005) 2997 (Non-Patent Document 1) includes 5- [4- (2-methacryloyloxyethoxycarbonyl) phenyl] -10,15,20-triphenylporfinato platinum. (II) was copolymerized with isobutyl methacrylate and 2,2,2-trifluoroethyl methacrylate to prepare a polymer having a porphyrin structure introduced in the side chain, and this polymer was embedded in an oxygen permeable polymer. It is described that it is used for a pressure-sensitive element made of a luminescent molecule.

  However, since such a polymer prevents stacking formation between side chain complexes due to a structure in which the distance between side chains is sufficiently separated, the electrical characteristics, photoelectric characteristics, and functions as an organic semiconductor are still insufficient. Requires high electron mobility. For example, it has a wide energy band gap, is inferior in characteristics as an organic semiconductor, and is not suitable for organic transistor or organic solar cell applications.

JP 2011-162575 A (Claims, Examples)

J. Polym. Sci. Part A; Polym. Chem, 43 (2005) 2997 (ABSTRACT)

  Accordingly, an object of the present invention is to provide an organic heteropolymer (or organometallic polymer) that has high conductivity (carrier mobility) despite its high molecular weight and is useful for forming a polymer organic semiconductor. It is providing the composition (or coating composition) containing a molecule | numerator, the organic semiconductor formed with this composition, and the device (semiconductor device) containing this organic semiconductor.

  Another object of the present invention is to provide an organic heteropolymer having high solubility in an organic solvent and high conductivity, a composition (or coating composition) containing the polymer, an organic semiconductor formed from the composition, And providing a device including the organic semiconductor.

  Still another object of the present invention is to provide an organic semiconductor composition (coating composition) that can be formed into a film by a simple method such as coating.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that a polymer (conjugated polymer) having a 5-membered ring unit or diene unit containing a thiophene unit and a heteroelement nucleus (such as a heterometal atom) in the main chain. ) Has been found to be highly conductive and useful for forming semiconductors, and that the solubility can be improved by introducing a thiophene unit having an alkyl group, thereby completing the present invention.

  That is, the organic heteropolymer (organometallic polymer) of the present invention has a repeating unit represented by the following formula (1) or (2).

(In the formula, M is selected from Group 14 (or Group 4B) elements, Group 15 (or Group 5B) elements, and Group 16 (or Group 6B) elements of the periodic table, and has a valence of 3 to 6 Indicates a heteroatom,
R ₁ represents an alkyl group, a cycloalkyl group, an aryl group or a heteroaryl group,
R ₂ is a monovalent or divalent selected from an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or a group 16 (or group 6B) element and a group 11 (or group 1B) element of the periodic table A heteroatom or a metal atom complexed with a ligand,

は単結合又は二重結合を示し、
ｍ１及びｍ２はそれぞれ０又は１を示し、ｍ１とｍ２との合計は１又は２であり、
Ｒ_３及びＲ_４はそれぞれ独立して水素原子、ハロゲン原子、又は式−Ｚ−Ｒ_５
（Ｚは周期表１４族（又は４Ｂ族）元素、１５族（又は５Ｂ族）元素又は１６族（又は６Ｂ族）元素を示し、Ｒ_５はアリール基又はヘテロアリール基を示す）を示し、
Ｒ_６a及びＲ_６ｂは、それぞれ独立して、水素原子、直鎖状又は分岐鎖状アルキル基、直鎖状又は分岐鎖状アルコキシ基、直鎖状又は分岐鎖状アルキルチオ基を示し、Ｒ_６a及びＲ_６ｂは互いに結合して環を形成してもよい。

Represents a single bond or a double bond,
m1 and m2 each represent 0 or 1, and the sum of m1 and m2 is 1 or 2,
R ₃ and R ₄ are each independently a hydrogen atom, a halogen atom, or a formula —Z—R ₅
(Z represents a periodic table group 14 (or group 4B) element, group 15 (or group 5B) element or group 16 (or group 6B) element, R ₅ represents an aryl group or a heteroaryl group),
R _6a and R _6b are each independently a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a linear or branched alkylthio group, R _6a and R _6b may be bonded to each other to form a ring.

However, in Formula (1), when R ₁ is a phenyl group, m1 is 1, and m2 is 0, M is not a phosphorus atom)
The organic heteropolymer is useful for forming an organic semiconductor, and can also be referred to as an organic heteropolymer (organic metal polymer) for an organic semiconductor. The repeating unit of the heteropolymer may be represented by, for example, the following formulas (1a) to (1c) and (2a).

(In the formula, M ₁ represents a periodic table group 15 (or group 5B) element or group 16 (or group 6B) element;
M ₂ represents a periodic table group 14 (or group 4B) element, group 15 (or group 5B) element or group 16 (or group 6B) element;
R _1a , R _1b and R _1c are the same or different and each represents an alkyl group, an aryl group or a heteroaryl group,
R _2a represents a group 16 (or group 6B) element of the periodic table,
R _2b represents a metal atom selected from an alkyl group, aryl group or heteroaryl group, a metal atom selected from Group 11 (or Group 1B) elements of the periodic table, or a metal atom complexed with a ligand;
Ring Ar represents an arene ring or a heteroarene ring,
R ₇ represents a linear or branched alkyl group, a linear or branched alkoxy group, a linear or branched alkylthio group,
Z ₁ and Z ₂ are the same or different and represent a group 16 (or group 6B) element of the periodic table,
q represents 0 or an integer of 1 to 3,
R _6a and R _6b are the same or different and each represents a hydrogen atom, a linear or branched C _1-16 alkyl group, a linear or branched C _1-16 alkoxy group, or a linear or branched chain Jo _{C 1-16} show an alkylthio _group, that at least one of the hydrogen atoms of the _{R 6a} and _{R 6b, R 6a} and _{R 6b} are bonded to each other, selected cycloalkane ring, oxygen atom, sulfur atom and nitrogen atom A heterocycle having at least one heteroatom formed)
R _6a and R _6b are the same or different and are a hydrogen atom, a linear or branched C _4-16 alkyl group, a linear or branched C _4-16 alkoxy group, a linear or branched group. It shows the chain _{C 4-16} alkylthio _group, that at least one of the hydrogen atoms of _{R 6a} and _{R 6b, R 6a} and _{R 6b} are bonded to each other, are selected cycloalkane ring, oxygen atom, and sulfur atom A 5- to 8-membered heterocycle having at least one heteroatom may be formed. Further, at least one of R _6a and R _6b is a linear or branched C _4-14 alkyl group, or R _6a and R _6b may be bonded to each other to form an alkylenedioxy group. .

The number average molecular weight of the organic heteropolymer may be, for example, about 1 × 10 ³ to 1 × 10 ⁵ . Moreover, the organic heteropolymer should just have a semiconductor characteristic.

  The organic heteropolymer is characterized by being soluble in an organic solvent. Therefore, the present invention also includes a composition for forming an organic semiconductor, the composition including the organic heteropolymer and an organic solvent, and the composition is useful for forming an organic semiconductor. is there. This invention also includes the manufacturing method of the organic semiconductor which apply | coats the said composition to at least one surface of a base material, and dries and forms an organic semiconductor.

  Furthermore, the present invention also includes an organic semiconductor formed of the organic heteropolymer; and an electronic device including the organic semiconductor. The electronic device may be a kind selected from, for example, a photoelectric conversion element, a switching element, and a rectifying element.

  In the present specification, “organic heteropolymer” means a polymer containing not only heteroatoms such as sulfur, nitrogen, oxygen, and phosphorus but also heterometal atoms. Therefore, the “organic heteropolymer” is sometimes referred to as an organometallic polymer.

  In the present invention, the organic heteropolymer has a structure in which a thiophene ring and a 5-membered aromatic ring containing a hetero atom or a diene unit are conjugatedly bonded (π-electron conjugated bond), and has semiconductor characteristics. In spite of being large, the conductivity (carrier mobility) is high, which is useful for forming a polymer organic semiconductor. In addition, when a long alkyl chain is introduced into the side chain, it has high solubility in an organic solvent and high conductivity. Therefore, an organic semiconductor can be formed by a simple method such as coating using an organic heteropolymer as a coating composition.

[Organic heteropolymer]
In the repeating unit represented by the formula (1) or (2), M is a periodic table group 14 (or group 4B) element (for example, Si, Ge, Sn, Pb), group 15 (or group 5B) element. (For example, N, P, As, Sb, Bi), an element (heteroatom) selected from a group 16 (or group 6B) element (for example, S, Se, Te) is shown. Among these elements M, the group 14 element of the periodic table is preferably, for example, Si, Ge, Sn, etc., particularly Sn, the group 15 element is preferably, for example, P, As, Sb, Bi, etc. For example, S, Se, Te, etc., Se and Te are particularly preferable. In particular, Group 14 elements (Ge, Sn) and Group 16 elements (Se, Te) are preferable. The valences of these elements (heteroatoms) are usually 3-6 valences, preferably 3-5 valences, depending on the type of the element (heteroatom). The periodic table group 14 element (eg, Sn) is often tetravalent, the group 15 element (eg, P) is often 3 to 5 valent, and the periodic table group 16 element (eg, S, Se, Te) is often 3-5.

Examples of the alkyl group represented by R ₁ and R ₂ include linear or branched groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, and t-butyl group. Examples thereof include a chain C _1-6 alkyl group. A preferable alkyl group is a linear or branched C _1-4 alkyl group (for example, a C _1-2 alkyl group).

Examples of the cycloalkyl group represented by R ₁ and R ₂ include C _3-10 cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. . Preferred cycloalkyl groups are C _5-8 cycloalkyl groups.

Examples of the aryl group represented by R ₁ and R ₂ include a C _6-12 aryl group which may be substituted with a C _1-4 alkyl group such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. It can be illustrated. Preferred aryl groups are C _6-10 aryl groups such as phenyl groups.

Examples of the heteroaryl group represented by R ₁ and R ₂ include a 5-membered heterocyclic group containing at least one hetero atom selected from a sulfur atom, a nitrogen atom and an oxygen atom (thienyl group, pyrrolyl group, imidazolyl group). And a 6-membered heterocyclic group (pyridyl group, pyrazyl group, etc.) containing at least one hetero atom selected from a sulfur atom, a nitrogen atom and an oxygen atom.

R ₂ represents a monovalent or divalent heteroatom (heterometallic atom), for example, a periodic table group 16 (or group 6B) element (for example, O, S, Se, Te), a periodic table group 11 (or group 1B). ) May be a heteroatom (heterometallic atom) selected from elements (eg, Cu, Ag, Au). Among the heteroatoms (heterometallic atoms) represented by R ₂ , periodic table group 16 elements (eg, S, Se, Te, etc., particularly S, Se), periodic table group 11 elements (eg, Ag, Au, etc.) In particular, Au) is preferred. Among these heteroatoms (heterometallic atoms), the Group 16 element of the periodic table is bonded to the element (heteroatom) M by forming a double bond, and the Group 11 element of the periodic table is the element (heteroatom) M. They are bonded by forming a single bond. In addition, heteroatoms (heterometallic atoms) (for example, Group 11 elements of the periodic table) are complexes (oxygen atoms, halogen atoms such as chlorine and bromine, OH (hydroxo), H ₂ O (aquo), CO, CN, methoxy groups. An alkoxy group such as an acetyl group, a methoxycarbonyl (acetato) group, an acetylacetonato group, a cyclopentadienyl group, a complex with a ligand such as pyridine or phosphine), and a halide (chlorine, A halide such as bromine).

R ₁ is a linear or branched _{C 1-4} alkyl group such as methyl group _{(e.g., C 1-2} alkyl group), often a _{C 6-10} aryl group such as a phenyl group, _{R 2} Is a linear or branched C _1-4 alkyl group such as a methyl group (eg, C _1-2 alkyl group), a C _6-10 aryl group such as a phenyl group, a monovalent hetero atom (hetero metal atom) ) Or a complex thereof (for example, -AuX (X represents a halogen atom)) or a divalent hetero atom (heterometallic atom) (for example, = S, = Se, = Te, etc.).

  m1 and m2 each represents 0 or 1. However, the sum of m1 and m2 is 1 or 2. That is, depending on the valence of the element (heteroatom) M, m1 = 1 and m2 = 0, m1 = 0 and m2 = 1, m1 = 1 and m2 = 1 may be sufficient.

In the formula (2), R ₃ and R ₄ may each independently be a hydrogen atom, a halogen atom (fluorine, chlorine, bromine or iodine atom) or a group —Z—R ₅ . Preferred R ₃ and R ₄ are the group —Z—R ₅ .

Z is the group 14 (or group 4B) of the above-mentioned periodic table (for example, Si, Ge, Sn, Pb, especially Ge, Sn, etc.), the group 15 (or group 5B) (for example, N, P , As, Sb, Bi, in particular P, As, Sb, Bi, etc.) and heteroatoms (heterometallic atoms) selected from group 16 (or group 6B) elements (eg, O, S, Se, Te) There may be. The heteroatom (heterometallic atom) is often a group 16 (or group 6B) element of the periodic table, for example, S, Se, Te (for example, S, Se). Examples of the aryl group and heteroaryl group represented by R ₅ include the same aryl groups and heteroaryl groups as those described above for R ₁ and R ₂ . R ₅ is often an aryl group (for example, a C _6-10 aryl group such as a phenyl group).

R _6a and R _6b each independently represent a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, or a linear or branched alkylthio group. Alkyl groups, alkoxy groups and alkylthio groups are useful for imparting solvent solubility. Examples of the alkyl group represented by R ₆ and R _6b include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, neopentyl group, Examples thereof include linear or branched alkyl groups such as hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decanyl group, undecanyl group and dodecanyl group (C _1-16 alkyl group and the like). The alkyl group is usually a linear or branched C _4-16 alkyl group, preferably a linear or branched C _6-14 alkyl group, more preferably a linear or branched C _6-12. It is an alkyl group.

The alkoxy group represented by R _6a and R _6b is a linear or branched alkoxy group (such as a C _1-16 alkoxy group) corresponding to the alkyl group, such as a hexyloxy group, an octyloxy group, 2- Linear or branched C _4-16 alkoxy group such as ethylhexyloxy group, preferably linear or branched C _6-14 alkoxy group, more preferably linear or branched C _6-12 alkoxy It is a group.

The alkylthio group represented by R _6a and R _6b is a linear or branched alkylthio group (C _1-16 alkylthio group or the like) corresponding to the alkyl group, such as a hexylthio group, an octylthio group, or 2-ethylhexylthio. A linear or branched C _4-16 alkylthio group such as a group, preferably a linear or branched C _6-14 alkylthio group, more preferably a linear or branched C _6-12 alkylthio group is there.

R _6a and R _6b are often alkyl groups or alkoxy groups.

The substitution positions of R _6a and R _{6b with} respect to the thiophene ring may be, for example, the 3-position, the 4-position, or the 3,4-position.

When two R _6a and R _6b are substituted on the thiophene ring, R _6a and R _6b are linear or branched C _1-16 alkyl groups (for example, C _2-14 alkyl groups, Preferably a C _3-12 alkyl group, more preferably a C _4-10 alkyl group), a linear or branched C _1-16 alkoxy group (eg, a C _2-14 alkoxy group, preferably a C _3-12 alkoxy group). Group, more preferably a C _4-10 alkoxy group), a linear or branched C _1-16 alkylthio group (for example, a C _2-14 alkylthio group, preferably a C _3-12 alkylthio group, more preferably a C ₄ group). _-10 alkylthio group).

R _6a and R _6b may combine with each other to form a ring. The ring formed by R _6a and R _6b is a cycloalkane ring (C _3-10 cycloalkane ring such as cyclopentane ring or cyclohexane ring), cycloalkene ring (C _4-10 cycloalkene ring such as cyclohexene ring), At least one selected from a cycloalkadiene ring (C _4-10 cycloalkadiene ring such as cyclohexadiene ring), an arene ring (C _6-12 arene ring such as benzene ring), an oxygen atom, a sulfur atom and a nitrogen atom It may be a heterocycle having a heteroatom (5- to 8-membered aromatic or non-aromatic heterocycle). The ring is often a cycloalkane ring or a heterocycle, and the heterocycle may be an aliphatic (non-aromatic) heterocycle. The hetero atom of the hetero ring is often an oxygen atom or a sulfur atom, and the hetero ring is a hetero ring having a plurality of hetero atoms, for example, an alkylenedioxy group (for example, C _1-6 such as an ethylenedioxy group). An alkylenedioxy group, preferably a _C1-4 alkylenedioxy group, particularly a _C2-3 alkylenedioxy group). An alkylenedioxy group can be represented by, for example, the formula —O (CH ₂ ) _n O— (n is an integer of 1 to 6).

Preferred R _6a and R _6b are not at least one hydrogen atom (that is, have at least a substituent selected from an alkyl group, an alkoxy group and an alkylthio group), or R _6a and R _6b are bonded to each other Thus, a 5- to 8-membered heterocycle having at least one heteroatom selected from a cycloalkane ring, an oxygen atom, and a sulfur atom is formed. In particular, at least one of R _6a and R _6b is a linear or branched C _4-14 alkyl group, or R _6a and R _6b may be bonded to each other to form an alkylenedioxy group. .

In the formula (1), when R ₁ is a phenyl group, m1 is 1, and m2 is 0, M is not a phosphorus atom. Further, in the formula (1), when R ₁ is an aryl group or a heteroaryl group, m1 is 1, and m2 is 0, M is not a group 15 element of the periodic table but a group 14 element or group 16 of the periodic table Often it is an element.

  Typical examples of the organic heteropolymer having such a repeating unit can be represented by the following formulas (1a) to (1c) and (2a), for example.

(In the formula, M ₁ represents a group 15 element or group 16 element in the periodic table, M ₂ represents a group 14 element, group 15 element or group 16 element in the periodic table, and R _1a , R _1b and R _1c may be the same or different. Represents an alkyl group, an aryl group or a heteroaryl group, R _2a is a group 16 element of the periodic table, R _2b is a metal atom or coordination selected from an alkyl group, an aryl group or a heteroaryl group, and a group 11 element of the periodic table And a ring Ar is the same or different and represents an arene ring or a heteroarene ring, R ₇ represents a chain or branched alkyl group, a linear or branched alkoxy group, a straight chain A linear or branched alkylthio group, Z ₁ and Z ₂ are the same or different and each represents a group 16 element of the periodic table, q represents an integer of 0 or 1 to 3, and R _6a and R _6b are the same or different. , Hydrogen atom, linear Represents a branched _{C 1-16} alkyl group, a linear or branched _{C 1-16} alkoxy group, or a linear or branched _{C 1-16} alkylthio _group, at least one of _{R 6a} and _{R 6b} R _6a and R _6b may be bonded to each other to form a heterocycle having at least one heteroatom selected from a cycloalkane ring, an oxygen atom, a sulfur atom and a nitrogen atom.

In the repeating unit represented by the formulas (1a) and (1b), M ₁ is a group 15 (or group 5B) element or a group 16 (or group 6B) element of the periodic table. Examples of the Group 15 (or Group 5B) element M ₁ of the periodic table include N, P, As, Sb, and Bi. Examples of the Group 16 (or Group 6B) element M ₁ of the periodic table include S, Examples thereof include Se and Te. Preferred elements _{M 1} is P, As, Sb, Bi (e.g., P).

In the repeating unit represented by the formula (1c), M ₂ is a periodic table group 14 (or group 4B) element, group 15 (or group 5B) element or group 16 (or group 6B) element. The periodic table group 14 (or 4B group) elements, for example, Si, Ge, Sn, can be exemplified and Pb, the preferred element _{M 2} is Si, Ge, Sn (e.g., Sn). Examples of Group 15 (or Group 5B) elements of the periodic table include N, P, As, Sb, and Bi. Preferred elements M ₂ are P, As, Sb, and Bi (for example, P). Examples of the periodic table group 16 (or group 6B) element include S, Se, and Te. M ₂ is usually a periodic table group 14 (or group 4B) element or group 15 (or group 5B) element.

In the formula (1a) to the formula (1c), as the alkyl group, aryl group and heteroaryl group represented by R _1a , R _1b and R _1c , the same alkyl group (straight or branched chain) as the above R ₁ A C _1-4 alkyl group, etc.), an aryl group (such as a C _6-12 aryl group) and a heteroaryl group (including 5 or 6 members containing at least one hetero atom selected from a sulfur atom, a nitrogen atom and an oxygen atom) A heterocyclic group). R _1a is often an aryl group (such as a C _6-12 aryl group), and R _1b is an aryl group (such as a C _6-12 aryl group) or an alkyl group (straight or branched C _1-4 alkyl). Group).

In the formula (1b), the group 16 (or group 6B) of the periodic table represented by R _2a can be exemplified by O, S, Se, Te and the like, for example, O, S, Se are preferable.

In the formula (1c), as the alkyl group, aryl group and heteroaryl group represented by R _2b , the same alkyl group as the above R ₂ (such as a linear or branched C _1-4 alkyl group), aryl Examples thereof include a group (such as a C _6-12 aryl group) and a heteroaryl group (such as a 5-membered or 6-membered heterocyclic group containing at least one heteroatom selected from a sulfur atom, a nitrogen atom and an oxygen atom). Examples of the periodic table group 11 (or group 1B) element represented by R _2b include Cu, Ag, and Au, and Au is preferable. This group 11 (or group 1B) element (metal atom) of the periodic table may form a complex as described above. R _2b is a linear or branched C _1-4 alkyl group (for example, a C _1-2 alkyl group), a cycloalkyl group (such as a cyclohexyl group), an aryl group (such as a phenyl group), or a monovalent heterometal. In many cases, it is an atom or a complex thereof (for example, -AuX (X represents a halogen atom)).

In the formula (1a) to the formula (1c), R _6a and R _6b are the same as described above.

In the formula (2a), Z ₁ and Z ₂ are the same or different and represent Group 16 (or Group 6B) elements such as O, S, Se, Te, and the like. Preferred elements Z ₁ and Z ₂ are S, Se, Te (eg, S, Se).

Ring Ar represents an arene ring or a heteroarene ring (a 5-membered or 6-membered heterocycle containing at least one heteroatom selected from a sulfur atom, a nitrogen atom and an oxygen atom). Examples of the ring Ar include aromatic rings corresponding to the same aryl groups and heteroaryl groups as described above, bisarene rings such as fluorene rings, biphenyl rings and binaphthyl rings, and bisheteroarene rings such as bipyridine rings. A representative aromatic ring Ar is a C _6-12 arene ring such as a benzene ring or a naphthalene ring (particularly a C _6-10 arene ring), a 5-membered or 6-membered heteroarene ring such as a thiophene ring or a pyridine ring, Bisarene rings such as a fluorene ring, a biphenyl ring, and a binaphthyl ring. The aromatic ring Ar is often a benzene ring. Preferred ring Ar is an arene ring (eg, a C _6-10 arene ring).

In addition, as the alkyl group, alkoxy group, and alkylthio group represented by R ₇ , the same linear or branched alkyl group (C _1-12 alkyl group etc.), linear or branched chain as those of R ₆ Examples thereof include an alkoxy group (such as a C _1-12 alkoxy group) and a linear or branched alkylthio group (such as a C _1-12 alkylthio group). q represents 0 or an integer of 1 to 3, and may be 0 or 1.

  A preferred organic heteropolymer has a repeating unit represented by the formula (1c) among the formulas (1a) to (1c) and (2a).

The organic heteropolymer of the present invention is characterized by a relatively large molecular weight. The molecular weight of the organic heteropolymer is not particularly limited. For example, when measured by gel permeation chromatography (GPC), the number average molecular weight is 1 × 10 ³ to 1 × 10 ⁵ , preferably 2.5 × in terms of polystyrene. It may be about 10 ^{3 to} 5 × 10 ⁴ , more preferably about 3 × 10 ³ to 1 × 10 ⁴ (for example, 3 × 10 ^{3 to} 7 × 10 ³ ).

  In addition, although organic heteropolymers are often linear, they may have a branched structure if necessary.

  The organic heteropolymer of the present invention contains a 5-membered ring structure or diene structure containing a hetero element nucleus (element nucleus such as a typical metal or transition metal element) and a thiophene ring in the main chain, and is a conjugated system (π-conjugated). Polymer). In addition, since a five-membered ring structure including a heteroatom (heterometal atom) is formed in the main chain skeleton, self-aggregation is weakened, and a peculiarity due to an organic-heteroatom (heterometal atom) bond is formed in the entire main chain. It has excellent semiconductor characteristics because the electronic state is maintained. In addition, since a thiophene ring having a side chain such as an alkyl group can be introduced, the solubility can be increased and the solvent is soluble. Therefore, a film can be easily formed by application (coating).

  In addition, a structure film in which electron transfer between molecules is easy is obtained because of stacking between main chains after film formation. Further, even if there is an alkyl chain in the polymer, stacking is not hindered because the alkyl chain is arranged in parallel with the stacking direction (vertical direction). For this reason, the obtained film functions effectively as an organic semiconductor.

[Method for producing organic heteropolymer]
Such organic heteropolymers can be synthesized according to the method described in Synthetic Metals, 159 (2009), 949-951 or the Journal of Organic Synthetic Chemistry Vol 66 No5 2008. That is, the organic heteropolymer can be prepared by the following reaction process formula.

Wherein R ₈ represents an alkyl group, X represents a halogen atom, L represents a leaving group, M ₁ , M ₂ , R _1a , R _1b , R _2b , R _2a , R _6a and R _6b , a ring Ar, R ₇ , Z ₁ and Z ₂ , q are the same as above)
Examples of the alkyl group represented by R ₈ include linear or branched C _{1 1} -methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group and the like. _{A 6} alkyl group can be exemplified. The alkyl group R ₈ is often a branched alkyl group such as an isopropyl group. Examples of the halogen atom represented by X include a chlorine atom and a bromine atom.

A polymer having a titanacyclopentadiene skeleton represented by the formula (7) can be produced by reacting the diethynylthiophene compound represented by the formula (5) with the low-valent titanium complex (6). The low-valent titanium complex (6) is obtained by reacting tetraalkoxy titanium (such as tetraisopropoxy titanium (Ti (OPr ⁱ ) ₄ )) and alkylmagnesium halide (such as isopropyl magnesium chloride ( ⁱ PrMgCl)). Can be generated. Therefore, the polymer (7) may be produced by reacting the diethynylthiophene compound represented by the formula (5), tetraalkoxytitanium, and alkylmagnesium halide. In addition, the usage-amount of an alkyl magnesium halide is about 1.5-2.5 equivalent with respect to tetraalkoxy titanium. The reaction is usually carried out in an inert solvent (diethyl ether, tetrahydrofuran, etc.) under an inert atmosphere (such as an argon stream) at a temperature of about −100 ° C. to −20 ° C. (eg, −80 ° C. to −40 ° C.). be able to.

  As typical diethynylthiophene compounds (5), for example, 2,5-diethynyl-3,4-dihexylthiophene, 2,5-diethynyl-3,4-dioctylthiophene, 2,5-diethynyl-3 , 4-di (2-ethylhexyl) thiophene, etc., diethynyldialkylthiophene; 2,5-diethynyl-3-octylthiophene, 2,5-diethynyl-3-decanylthiophene, 2,5-diethynyl-3-dodecanyl Examples include diethynylalkylthiophenes such as thiophene; diethynylalkylenedioxythiophenes such as 2,5-diethynyl-3,4-ethylenedioxythiophene, and the like.

The polymer (7) and a dihalide represented by the formula (8) or (9) (X represents a halogen atom. M ₁ , R _1a, M ₂ , R _1b and R _2b are the same as above). By the reaction, a polymer having a repeating unit represented by the formula (1a) or (1c-1) can be obtained. Examples of the dihalide represented by the formula (8) include dihalogen compounds having M ₁ and R _1a , for example, dichlorohetero compounds such as alkyldichlorophosphine and aryldichlorophosphine, and dialkylmetal dichlorides such as alkyldichlorotellurium and alkyldichloroselenium. And diaryl metal dichloride, and the dihalide represented by the formula (9) can be exemplified by dihalogen compounds having M ₂ , R _1b and R _2b , such as dialkyl metal dichloride and diaryl metal dichloride. As dihalide represented by the formula (8), alkyl dichlorophosphine of octyl dichlorophosphine (e.g., linear or branched C _4-12 alkyl dichlorophosphine) Using, in the formula (1b) , R _1a is an alkyl group, and R _2c is an oxygen atom.

A polymer having a repeating unit represented by the formula (2a) can be obtained by reacting the polymer (7) with the halide represented by the formula (10). When halogen (fluorine, chlorine, bromine, iodine) or protonic acid (inorganic acid such as hydrochloric acid or carboxylic acid such as acetic acid) is used instead of the halide represented by the formula (10), the above formula ( In 2), a polymer in which R ₃ and R ₄ are each a halogen atom or a hydrogen atom can be obtained.

  In these reactions, the amount of the halide represented by the formulas (8) to (10) is 1 to 2 equivalents (for example, 1.1 to 1.5) with respect to the titanium atom Ti of the polymer (7). Equivalent). The reaction can usually be performed in an inert solvent (diethyl ether, tetrahydrofuran, etc.) under an inert atmosphere (such as an argon stream) at a temperature of about −80 ° C. to 30 ° C. (eg, −60 ° C. to room temperature). .

Furthermore, a polymer having a repeating unit represented by the formula (1c-2) is obtained by reacting the polymer having a repeating unit represented by the formula (1a) with a compound represented by the formula (11). And a polymer having a repeating unit represented by the formula (1b) can be obtained by reaction with the compound represented by the formula (12). Examples of the compound represented by the formula (11) include a metal compound that forms a complex with a ligand such as a gold chloride complex. In the compound represented by the formula (11), the leaving group L is It may be a ligand coordinated to a metal (for example, tetrahydrothiophene). Examples of the compound represented by the formula (12) include elemental elements corresponding to R _2c (simple elements such as selenium and sulfur).

  The reaction between the polymer having the repeating unit represented by the formula (1a) and the compound represented by the formula (11) or (12) is performed by reacting the polymer represented by the above (7) with the formula (8) to It can be carried out in the same manner as the halide represented by (10).

  After completion of the reaction, a predetermined organic heteropolymer can be obtained by a conventional separation and purification method such as concentration, decantation, reprecipitation, chromatography and the like.

  In addition, the diethynyl thiophene compound represented by said (5) can be prepared by a well-known method, for example, the method of By Baier Moritz C et al JACS. 131 (40), 14267, (2009). In this method, as shown by the following reaction formula, the corresponding dibromo compound (13) is reacted with trimethylethynylsilane, and the resulting di (trimethylsilylethynyl) thiophene compound (14) and tetrabutylammonium fluoride ( The diethynylthiophene compound (5) can be prepared by reacting with a trihydrate and desilylating it.

(In the formula, Me represents a methyl group, nBu represents an n-butyl group, and R _6a and R _6b are the same as above.)

[Uses of organic heteropolymers]
An organic heteropolymer forms a conjugated system (π-conjugated system) with a thiophene ring and a 5-membered ring or diene unit containing a hetero atom, and has extremely high electron mobility and semiconductor characteristics. . Moreover, an organic heteropolymer having an alkyl chain or the like is characterized by being soluble in an organic solvent and exhibiting high semiconductor properties. Therefore, the present invention also includes a composition containing an organic heteropolymer and an organic solvent, and this composition is useful for forming a thin film of an organic semiconductor by an organic semiconductor, particularly by coating (coating).

  Examples of the organic solvent include hydrocarbons (for example, aliphatic hydrocarbons such as hexane, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene), halogenated hydrocarbons ( Chloroform, dichloromethane, trichloroethane, etc.), ethers (chain ethers such as diethyl ether and diisopropyl ether, cyclic ethers such as dioxane, tetrahydrofuran), ketones (acetone, methyl ethyl ketone, etc.), esters (methyl acetate, ethyl acetate, acetic acid) Butyl), amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.), nitriles (eg, acetonitrile, propionitrile, etc.), sulfoxides (eg, dimethyl sulfoxide, etc.) , Pyrrolidones (e.g., 2-pyrrolidone, 3-pyrrolidone, N- methyl-2-pyrrolidone, etc.), and others. These organic solvents can be used alone or as a mixed solvent.

  The amount of the solvent used can be selected from a range that does not impair the coating property and film forming property. For example, the concentration of the organic heteropolymer is 0.01 to 30% by weight, preferably 0.05 to 20% by weight (for example, 0.1 to 10% by weight).

  The composition of the present invention may be prepared by a conventional method, for example, mixing an organic heteropolymer and an organic solvent to dissolve the organic heteropolymer, and if necessary, filtering.

  The organic semiconductor may be manufactured through a step of applying the composition to a base material or a substrate (glass plate, silicon wafer, heat-resistant plastic film, etc.) and a step of drying the coating film to remove the solvent. In addition, as a coating method, for example, a conventional coating method, such as an air knife coating method, a roll coating method, a gravure coating method, a blade coating method, a dip coating method, a spray method, a spin coating method, a screen printing method, an ink jet printing method, etc. Can be illustrated.

  The thickness of the organic semiconductor is appropriately selected depending on the application, and may be, for example, 1 to 5000 nm, preferably 30 to 1000 nm, and more preferably about 50 to 500 nm.

  The organic semiconductor of the present invention may be an n-type semiconductor, a p-type semiconductor, or an intrinsic semiconductor. The organic semiconductor of the present invention has a photoelectric conversion ability, and can increase the mobility of electrons and holes generated by light absorption, for example, and can improve the photoelectric conversion rate. Therefore, the organic semiconductor of the present invention includes a photoelectric conversion device or a photoelectric conversion element (such as a solar cell element or an organic electroluminescence (EL) element), a rectifier element (diode), a switching element or a transistor [top gate type, bottom gate type ( Suitable for applications such as top contact type, bottom contact type).

  As a typical device, a solar cell has a structure in which a surface electrode is laminated on a pn junction type semiconductor. For example, a solar cell can be formed by laminating an organic semiconductor film on a p-type silicon semiconductor and laminating a transparent electrode (such as an ITO electrode) on the organic semiconductor film. In such a solar cell, a high open circuit voltage and a short circuit current can be obtained.

  Moreover, the organic EL forms a light emitting layer in which an electron transport material and a hole transport material are dispersed in a transparent electrode (ITO electrode or the like) in an organic heteropolymer (light emitting polymer) as necessary. The structure which laminated | stacked the electrode (metal electrode etc.) on the light emitting layer can be illustrated.

  Furthermore, the organic thin film transistor is composed of a gate electrode layer, a gate insulating layer, a source / drain electrode layer, and an organic semiconductor layer. The organic thin film transistor can be classified into a top gate type and a bottom gate type (top contact type and bottom contact type) depending on the laminated structure of these layers. For example, an organic semiconductor film is formed on a gate electrode (such as a p-type silicon wafer on which an oxide film is formed), and a source / drain electrode (gold electrode) is formed on the organic semiconductor film, whereby a top contact type electric field is formed. An effect transistor can be manufactured.

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

In Examples, diethyl ether and tetrahydrofuran (THF) were used after being dried with sodium and distilled under a nitrogen atmosphere or a stream of air. Methylene chloride was used after being dried with niline pentoxide and distilled under a nitrogen atmosphere or a stream of air. Tetraisopropoxytitanium (Ti (OPr ⁱ ) ₄ ) and phenyldichlorophosphine were purified by vacuum distillation.

[Λmax and λonset]
Using a methylene chloride solution (concentration: 1 mg / ml) of the polymer of the example, ultraviolet-visible absorption spectrum measurement was performed, and λmax and λonset were measured. Here, λmax means the maximum absorption wavelength (nm), and λonset means the absorption edge (nm) on the long wavelength side. The band gap (BG, eV) was calculated from λonset of the ultraviolet-visible absorption spectrum using the following equation.

E = hc / eλ
(Where E is electron volt (eV), h is Planck's constant (J · s), c is the speed of light (m / s), e is elementary charge (C), and λ is λonset wavelength (nm) )

  Example 1

The polymer having the repeating unit represented by the above formula (1c-1) was prepared through an organic titanium polymer (precursor) synthesized according to the method described in the Society for Synthetic Organic Chemistry Vol 166 No5 2008. That is, 2,5-diethynyl-3-dodecylthiophene (0.21 g, 0.5 mmol) and tetraisopropoxy titanium (Ti (OiPr) ₄ ) (0.198 g, 0.7 mmol) were added to diethyl ether (0.198 g, 0.7 mmol) in an argon atmosphere. 20 mL), and a solution of isopropylmagnesium chloride (iPrMgCl) in diethyl ether (1.0 N, 1.25 mL, 1.25 mmol) was added while stirring the solution at −78 ° C.

Thereafter, the temperature was raised to −50 ° C., and the mixture was stirred for 12 hours. At this temperature, diphenyltin dichloride (Ph ₂ SnCl ₂ ) (0.206 g, 0.6 mmol) was added, and the temperature was slowly raised to room temperature, followed by further stirring for 3 hours. . After the solvent was distilled off, the residue was dissolved in methylene chloride, an aqueous ethylenediaminetetraacetic acid (EDTA) solution (1.0 N, 50 mL) was added, and the mixture was stirred for 2 hours to remove titanium. Thereafter, the organic phase was recovered, dried over magnesium sulfate, the solvent was distilled off, dissolved in a small amount of methylene chloride, poured into hexane, and reprecipitated to obtain a reddish purple polymer (1c-1) in a yield of 55. %.

  Further, the maximum absorption wavelength λmax of the tetrahydrofuran solution having a predetermined concentration (10 mg / 10 ml) of the polymer (1c-1) was 470 nm, and λonset was 748 nm. The energy level was band gap (BG) = 1.66 (eV).

  Example 2

  In the same manner as in Example 2 except that 2,5-diethynyl-3,4-dihexylthiophene is used instead of 2,5-diethynyl-3-dodecylthiophene in Example 1, the above formula (1c-2) A polymer was obtained.

  The maximum absorption wavelength λmax of the tetrahydrofuran solution having a predetermined concentration (10 mg / 10 ml) of the polymer (1c-2) was 474 nm, and λonset was 828 nm. The energy level was band gap (BG) = 1.5 (eV).

  Example 3

  Instead of 2,5-diethynyl-3-dodecylthiophene of Example 1, the above formula (1c-3) was obtained in the same manner as in Example 2, except that 2,5-diethynyl-3,4-ethylenedioxythiophene was used. ) Was obtained.

  The tetrahydrofuran solution having a predetermined concentration (10 mg / 10 ml) of the polymer (1c-3) had a maximum absorption wavelength λmax of 524 nm and λonset of 868 nm. The energy level was band gap (BG) = 1.43 (eV).

  The organic heteropolymer of the present invention is a π-electron conjugated polymer, and is useful for forming an organic semiconductor (polymer organic semiconductor) having low resistance and high conductivity. Organic semiconductors are various devices such as rectifiers (diodes), switching elements or transistors [junction transistors (bipolar transistors), field effect transistors (unipolar transistors), etc.], photoelectric conversion elements (solar cell elements, organic EL elements). Etc.).

Claims (9)

Following formula (1) or (2)

(In the formula, M represents a hetero atom selected from Group 14 element, Group 15 element, and Group 16 element of the periodic table and having a valence of 3 to 6;
R ₁ represents an alkyl group, a cycloalkyl group, an aryl group or a heteroaryl group,
R ₂ forms a complex with an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or a monovalent or divalent heteroatom or a ligand selected from Group 16 elements of the periodic table and Group 11 elements of the periodic table The metal atom

Represents a single bond or a double bond,
m1 and m2 each represent 0 or 1, and the sum of m1 and m2 is 1 or 2,
R ₃ and R ₄ are each independently a hydrogen atom, a halogen atom, or a formula —Z—R ₅
(Z represents a periodic table group 14 element, group 15 element or group 16 element, and R ₅ represents an aryl group or a heteroaryl group)
R _6a and R _6b are each independently a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a linear or branched alkylthio group, R _6a and R _6b may be bonded to each other to form a ring.
However, in Formula (1), when R ₁ is a phenyl group, m1 is 1, and m2 is 0, M is not a phosphorus atom)
An organic heteropolymer having a repeating unit represented by: The following formulas (1a) to (1c) or (2a)

(In the formula, M ₁ represents a group 15 element or a group 16 element in the periodic table,
M ₂ represents a periodic table group 14 element, group 15 element or group 16 element;
R _1a , R _1b and R _1c are the same or different and each represents an alkyl group, an aryl group or a heteroaryl group,
R _2a represents a group 16 element of the periodic table,
R _2b represents an alkyl group, an aryl group or a heteroaryl group, a metal atom selected from the group 11 elements of the periodic table, or a metal atom complexed with a ligand;
Ring Ar represents an arene ring or a heteroarene ring,
R ₇ represents a linear or branched alkyl group, a linear or branched alkoxy group, a linear or branched alkylthio group,
Z ₁ and Z ₂ are the same or different and represent a group 16 element of the periodic table,
q represents 0 or an integer of 1 to 3,
R _6a and R _6b are the same or different and each represents a hydrogen atom, a linear or branched C _1-16 alkyl group, a linear or branched C _1-16 alkoxy group, or a linear or branched chain Jo _{C 1-16} show an alkylthio _group, that at least one of the hydrogen atoms of _{R 6a} and _{R 6b, R 6a} and _{R 6b} are bonded to each other, selected cycloalkane ring, oxygen atom, sulfur atom and nitrogen atom A heterocycle having at least one heteroatom formed)
The organic heteropolymer of Claim 1 which has a repeating unit represented by these. R _6a and R _6b are the same or different and are a hydrogen atom, a linear or branched C _4-16 alkyl group, a linear or branched C _4-16 alkoxy group, a linear or branched chain C _4-16 show an alkylthio _group, that at least one of the hydrogen atoms of _{R 6a} and _{R 6b,} at least _{R 6a} and _{R 6b} are bonded to each other, are selected cycloalkane ring, oxygen atom, and sulfur atom The organic heteropolymer according to claim 1 or 2, which may form a 5- to 8-membered heterocycle having one heteroatom. 4. At least one of R _6a and R _6b is a linear or branched C _4-14 alkyl group, or R _6a and R _6b are bonded to each other to form an alkylenedioxy group. The organic heteropolymer according to any one of the above.   A composition for forming an organic semiconductor, comprising the organic heteropolymer according to any one of claims 1 to 4 and an organic solvent, wherein the organic semiconductor is formed.   The organic semiconductor formed with the organic heteropolymer in any one of Claims 1-4.   The manufacturing method of the organic semiconductor which apply | coats the composition of Claim 5 to at least one surface of a base material, and dries and forms an organic semiconductor.   The electronic device containing the organic semiconductor formed with the organic heteropolymer in any one of Claims 1-4.   The electronic device according to claim 8, wherein the electronic device is a kind selected from a photoelectric conversion element, a switching element, and a rectifying element.