WO2013047293A1

WO2013047293A1 - Photoelectric conversion element

Info

Publication number: WO2013047293A1
Application number: PCT/JP2012/073934
Authority: WO
Inventors: 邦仁三宅; 有和梅山; 博今堀
Original assignee: 住友化学株式会社; 国立大学法人京都大学
Priority date: 2011-09-30
Filing date: 2012-09-19
Publication date: 2013-04-04
Also published as: JP2013084919A

Abstract

Provided is a photoelectric conversion element in which a large amount of charge is converted from long-wavelength light. A photoelectric conversion element having a positive electrode, a negative electrode, and an active layer provided between the positive electrode and the negative electrode; the active layer containing an electron donor compound and an electron acceptor compound; and the electron donor compound and/or the electron acceptor compound being a polymeric compound containing repeating units represented by formula (I-1) and repeating units represented by formula (I-2). (X¹ represents a sulfur atom, an oxygen atom, or a divalent group; each of X² and X³ independently represents =C(R¹)- or a nitrogen atom; and R¹ represents a hydrogen atom or a substitution group. If X² and X³ are =C(R¹)-, the atom contained in R¹ in X² and the atom contained in R¹ in X³ may bond and form a cyclic structure.) (Ar¹ represents a divalent fused ring group that may have a substitution group.)

Description

Photoelectric conversion element

The present invention relates to a photoelectric conversion element.

A photoelectric conversion element is an element provided with a pair of electrodes consisting of an anode and a cathode, and an active layer provided between the pair of electrodes. In order to improve various characteristics of the photoelectric conversion element, use of an organic semiconductor material for an active layer of the photoelectric conversion element has been studied. As a photoelectric conversion element using an organic semiconductor material for an active layer, for example, a photoelectric conversion element using a compound 1 represented by the following formula for an active layer has been proposed (Non-patent Document 1).

However, the photoelectric conversion element using the compound 1 as an active layer has a problem that the amount of charges converted from light having a long wavelength is small.

Therefore, an object of the present invention is to provide a photoelectric conversion element having a large amount of charge converted from light having a long wavelength.

The present invention provides the following [1] to [29].
[1] It has an anode, a cathode, and an active layer provided between the anode and the cathode, and the active layer contains an electron donating compound and an electron accepting compound. A photoelectric conversion element, wherein at least one of the compound and the electron-accepting compound is a polymer compound including a repeating unit represented by the formula (I-1) and a repeating unit represented by the formula (I-2).

[Wherein, X ¹ represents a sulfur atom, an oxygen atom or a divalent group. X ² and X ³ each independently represent a group represented by the formula: ═C (R ¹ ) — or a nitrogen atom. R ¹ represents a hydrogen atom or a substituent. X ² and ^{X 3} has the formula: = C ^{(R 1)} - in the case of a group represented, by bonding the atoms contained in ^{R 1} in the atoms and ^{X 3} contained in ^{R 1} in ^{X 2} An annular structure may be formed. ]

[In the formula, Ar ¹ represents a divalent fused ring group which may have a substituent. ]
[2] X ¹ is a sulfur atom, an oxygen atom, a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) ₂ —, a formula: —N (R ²⁾ -, a group represented by the formula: ^-CR 2 = CR ² -, a group represented by the formula: group, or the formula represented by ^-CR 2 = N-: -N = group represented by N- The photoelectric conversion element according to [1], wherein R ² represents a hydrogen atom or a substituent.
[3] The photoelectric conversion element according to [1] or [2], wherein X ¹ is a sulfur atom.
[4] The photoelectric conversion element according to any one of [1] to [3], wherein X ² and X ³ are a group represented by the formula: ═C (R ¹ ) —.
[5] The polymer compound further includes a repeating unit represented by the formula (II), and the repeating unit represented by the formula (II) is bonded to the repeating unit represented by the formula (I-1). The photoelectric conversion element according to any one of [1] to [4].
= C (R ³ )-(II)
[Wherein R ³ represents a hydrogen atom or a substituent. ]
[6] The photoelectric conversion element according to any one of [1] to [5], wherein Ar ¹ is a divalent group containing a nitrogen-containing condensed ring which may have a substituent.
[7] The photoelectric conversion element according to [6], wherein Ar ¹ is a diketopyrrolopyrrole diyl group which may have a substituent.
[8] The photoelectric conversion device according to any one of [1] to [7], wherein the polymer compound further contains a thiophenediyl group which may have a substituent as a repeating unit.
[9] The photoelectric conversion element according to any one of [1] to [8], wherein an absorption wavelength end of the polymer compound is 600 nm or more.
[10] The photoelectric conversion device according to any one of [1] to [9], wherein the energy level of the highest occupied orbit of the polymer compound is −4.5 eV or less.
[11] A solar cell module including the photoelectric conversion element according to any one of [1] to [10].
[12] An image sensor including the photoelectric conversion element according to any one of [1] to [10].
[13] A polymer compound comprising a repeating unit represented by the formula (I-1) and a repeating unit represented by the formula (I-2).

[In the formula, Ar ¹ represents a divalent fused ring group which may have a substituent. ]
[14] X ¹ is a sulfur atom, an oxygen atom, a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) ₂ —, a formula: —N (R ²⁾ -, a group represented by the formula: ^-CR 2 = CR ² -, a group represented by the formula: group, or the formula represented by ^-CR 2 = N-: -N = group represented by N- The polymer compound according to [13], wherein R ² represents a hydrogen atom or a substituent.
[15] The polymer compound according to [13] or [14], wherein X ¹ is a sulfur atom.
[16] The polymer compound according to any one of [13] to [15], wherein X ² and X ³ are a group represented by the formula: ═C (R ¹ ) —.
[17] Further comprising a repeating unit represented by formula (II), wherein the repeating unit represented by formula (II) is bonded to the repeating unit represented by formula (I-1), [13] ] The polymer compound according to any one of [16] to [16].
= C (R ³ )-(II)
[Wherein R ³ represents a hydrogen atom or a substituent. ]
[18] The polymer compound according to any one of [13] to [17], wherein Ar ¹ is a diketopyrrolopyrrole diyl group which may have a substituent.
[19] The polymer compound according to any one of [13] to [18], further including a thiophenediyl group which may have a substituent as a repeating unit.
[20] The polymer compound according to any one of [13] to [19], wherein an absorption wavelength end is 600 nm or more.
[21] The polymer compound according to any one of [13] to [20], wherein the energy level of the highest occupied orbit is −4.5 eV or less.
[22] A compound containing a group represented by the formula (III) and a substituted stannyl group.

[Wherein, X ⁴ represents a sulfur atom, an oxygen atom or a divalent group. X ⁵ and X ⁶ each independently represent a group represented by the formula: ═C (R ¹ ) — or a nitrogen atom. R ¹ represents a hydrogen atom or a substituent. When X ⁵ and X ⁶ are a group represented by the formula: ═C (R ¹ ) —, an atom contained in R ¹ in X ⁵ is bonded to an atom contained in R ¹ in X ⁶ An annular structure may be formed. ]
[23] X ⁴ is a sulfur atom, an oxygen atom, a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) ₂ —, a formula: —N (R ²⁾ -, a group represented by the formula: ^-CR 2 = CR ² -, a group represented by the formula: group, or the formula represented by ^-CR 2 = N-: -N = group represented by N- The compound according to [22], wherein R ² represents a hydrogen atom or a substituent.
[24] The compound according to [22] or [23], wherein X ⁴ is a sulfur atom.
[25] The compound according to any one of [22] to [24], wherein X ⁵ and X ⁶ are a group represented by the formula: ═C (R ¹ ) —.
[26] The method further includes a group represented by formula (IV), and the group represented by formula (IV) is bonded to the group represented by formula (III). [22] to [25] The compound as described in any one of these.
= C (R ⁴ )-(IV)
[Wherein, R ⁴ represents a hydrogen atom or a substituent. ]
[27] The compound according to any one of [22] to [26], which contains two substituted stannyl groups.
[28] The compound according to any one of [22] to [27], wherein the substituted stannyl group is a group represented by the formula (V).

[Wherein R ⁵ represents an alkyl group. Three R ⁵ may be the same or different. ]
[29] The compound according to any one of [22] to [28], further containing a thiophene ring.

Since the photoelectric conversion element of the present invention has a large amount of charge converted from light having a long wavelength, the present invention is extremely useful.

It is a figure which shows the action spectrum of the organic thin film solar cell 1 and the organic thin film solar cell 2 which are one Embodiment of this invention.

The photoelectric conversion element of the present invention has an anode, a cathode, and an active layer provided between the anode and the cathode, and includes an electron donating compound and an electron accepting compound in the active layer. And at least one of the electron-donating compound and the electron-accepting compound is a polymer compound containing a repeating unit represented by the formula (I-1) and a repeating unit represented by the formula (I-2). It is characterized by that.

In formula (I-1), X ¹ represents a sulfur atom, an oxygen atom or a divalent group. Examples of the divalent group include a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) ₂ —, and a formula: —N (R ² ) —. group represented by the formula: ^-CR ² = CR 2 -, a group represented by the formula: ^-CR 2 = group and the formula represented by N-: -N = include groups represented by N-, R ² represents a hydrogen atom or a substituent. Examples of the substituent represented by R ² include an optionally substituted alkyl group, an optionally substituted alkoxy group, and an optionally substituted aryl group. X ¹ has the formula: ^-CR 2 = CR ² - if it is a group represented by the two is ^{R 2} may be different from each be the same.

The alkyl group in the “optionally substituted alkyl group” represented by R ² may be linear or branched, and may be a cycloalkyl group. The alkyl group generally has 1 to 30 carbon atoms, preferably 1 to 20, and more preferably 1 to 12. Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl tomb, pentyl group, isopentyl group, 2-methylbutyl group, 1-methylbutyl. Group, hexyl group, isohexyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, heptyl group, octyl group, isooctyl group, 2-ethylhexyl group, 3,7-dimethyloctyl group, nonyl group And chain alkyl groups such as decyl group, undecyl group, dodecyl group, tetradecyl group, hexadecyl tomb, octadecyl group and eicosyl group, and cycloalkyl groups such as cyclopentyl group, cyclohexyl group and adamantyl group. The hydrogen atom in the alkyl group may be substituted with a substituent, and examples of the substituent include a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the substituted alkyl group include a trifluoromethyl group and a pentafluoroethyl group.

The alkoxy group in the “optionally substituted alkoxy group” represented by R ² may be linear or branched, and may be a cyclic alkyloxy group. The number of carbon atoms in the alkoxy group is usually 1-20, preferably 1-15, and more preferably 1-12. Specific examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group, heptyloxy group, octyloxy group Group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group and dodecyloxy group. The hydrogen atom in the alkoxy group may be substituted with a substituent, and examples of the substituent include a halogen atom and an alkoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The definition and specific examples of the alkoxy group are the same as the definition and specific examples of the alkoxy group described in the substituent represented by R ^2. The same. Examples of the substituted alkoxy group include trifluoromethoxy group, pentafluoroethoxy group, perfluorobutoxy group, perfluorohexyloxy group, perfluorooctyloxy group, methoxymethyloxy group and 2-methoxyethyloxy group. It is done.

The aryl group in the “optionally substituted aryl group” represented by R ² means a group obtained by removing one hydrogen atom on an aromatic ring from an aromatic hydrocarbon. The number of carbon atoms of the aryl group is usually 6 to 60, preferably 6 to 16, and more preferably 6 to 10. Specific examples of the aryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, and a C1 to C12 alkylphenyl group (“C1 to C12” represents 1 to 12 carbon atoms. The same applies hereinafter. .). The hydrogen atom in the aryl group may be substituted with a substituent, and examples of the substituent include a halogen atom and an alkoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The definition and specific examples of the alkoxy group are the same as the definition and specific examples of the alkoxy group described in the substituent represented by R ² . Examples of the substituted aryl group include a pentafluorophenyl group.

R ² is preferably a hydrogen atom or an alkyl group.

X ¹ is preferably a sulfur atom.

In formula (I-1), X ² and X ³ each independently represent a group represented by the formula: ═C (R ¹ ) — or a nitrogen atom. R ¹ represents a hydrogen atom or a substituent. X ² and ^{X 3} has the formula: = C ^{(R 1)} - in the case of a group represented, by bonding the atoms contained in ^{R 1} in the atoms and ^{X 3} contained in ^{R 1} in ^{X 2} An annular structure may be formed.

Specific examples of the substituent represented by R ¹ are the same as the specific examples of the substituent represented by R ² described above. R ¹ is preferably a hydrogen atom or an alkyl group.

X ² and X ³ are preferably ═C (R ¹ ) —.

Examples of the repeating unit represented by the formula (I-1) include the following repeating units.

In formula (I-2), Ar ¹ represents a divalent condensed ring group which may have a substituent. The divalent condensed ring group means a group in which two hydrogen atoms on the ring are removed from the condensed ring. The number of carbon atoms in the divalent fused ring group is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 15. Examples of the condensed ring include naphthalene ring, anthracene ring, pyrene ring, fluorene ring, thienothiophene ring, quinoline ring, isoquinoline ring, carbazole ring, dibenzothiophene ring, dibenzofuran ring, phenoxazine ring, phenothiazine ring and diketopyrrolopyrrole. A ring is mentioned.
Specific examples of the substituent that the divalent condensed ring group may have are the same as the specific examples of the substituent represented by R ² described above.

Examples of the divalent fused ring group include the following groups.

[Wherein, R represents a substituent. ]

The definition and specific examples of the substituent represented by R are the same as the definition and specific examples of the substituent represented by R ² .

Ar ¹ is preferably a divalent group containing a nitrogen-containing condensed ring which may have a substituent, and more preferably a diketopyrrolopyrrole diyl group which may have a substituent.

Examples of the diketopyrrolopyrrole diyl group which may have a substituent include a group represented by the formula (VI).

[Wherein, R ⁷ represents an optionally substituted alkyl group. Two R ⁷ may be the same or different. ]

The definition and specific examples of the optionally substituted alkyl group represented by R ⁷ are the same as the definition and specific examples of the optionally substituted alkyl group represented by R ² described above.

The polymer compound used in the present invention preferably further contains a repeating unit represented by the formula (II). The repeating unit represented by the formula (II) is preferably bonded to the repeating unit represented by the formula (I-1).
= C (R ³ )-(II)

In formula (II), R ³ represents a hydrogen atom or a substituent. The definition and specific examples of the substituent represented by R ³ are the same as the definition and specific examples of the substituent represented by R ² described above. R ³ is preferably an optionally substituted aryl group.

The repeating unit represented by the formula (II) is preferably a repeating unit represented by the formula (II-1).

[Wherein, R ⁶ represents a halogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group or an optionally substituted aryl group. a represents an integer of 0 to 5. When there are a plurality of R ^{6 s} , they may be the same or different. ]

Examples of the halogen atom represented by R ⁶ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Optionally substituted alkyl group, defined and specific examples of the aryl group which is a alkoxy group and substituted also be substituted, an alkyl group which may be substituted represented by the aforementioned R ^2, The definitions and specific examples of the alkoxy group which may be substituted and the aryl group which may be substituted are the same. R ⁶ is preferably an alkyl group. a is preferably an integer of 0 to 3, and more preferably 1.

The polymer compound used in the present invention may further contain a thiophenediyl group which may have a substituent as a repeating unit. Specific examples of the substituent that the thiophenediyl group may have are the same as the specific examples of the substituent represented by R ² described above.
As the thiophenediyl group which may have a substituent, a group represented by the formula (VII) is preferable.

[Wherein, R ⁸ represents a hydrogen atom or an optionally substituted alkyl group. Two R ⁸ may be the same or different. ]

The definition and specific examples of the optionally substituted alkyl group represented by R ⁸ are the same as the definition and specific examples of the optionally substituted alkyl group represented by R ² described above.

The polymer compound used in the present invention includes a repeating unit represented by the formula (I-1), a repeating unit represented by the formula (I-2), a repeating unit represented by the formula (II), and a substituent. Is preferably a thiophenediyl group optionally having a repeating unit represented by formula (I-1), a group represented by formula (VI), a repeating unit represented by formula (II), And more preferably a group represented by formula (VII).

The polymer compound used in the present invention has a polystyrene-equivalent number average molecular weight of preferably 1 × 10 ³ to 1 × 10 ⁸ , more preferably 3 × 10 ³ to 1 × 10 ^7. More preferably, it is from × 10 ³ to 1 × 10 ⁷ .

The polymer compound used in the present invention may form a cyclic structure by bonding two ends of the polymer compound, but preferably does not form a cyclic structure.

The polymer compound used in the present invention preferably has an absorption wavelength end of 600 nm or more. A polymer compound having an absorption wavelength end of 600 nm or more absorbs sunlight in a wide wavelength range, and a photoelectric conversion element including the polymer compound in an active layer has high photoelectric conversion efficiency.

The absorption wavelength end of the polymer compound can be determined by the following method.
For the measurement, a spectrophotometer (for example, JASCO-V670, UV-visible near infrared spectrophotometer manufactured by JASCO Corporation) operating in the wavelength region of ultraviolet, visible and near infrared is used. When JASCO-V670 is used, the measurable wavelength range is 200 to 1500 nm. Therefore, measurement is performed in this wavelength range. First, the absorption spectrum of the substrate used for measurement is measured. As the substrate, a quartz substrate, a glass substrate, or the like is used. Next, a thin film containing a polymer compound is formed on the substrate from a solution containing the polymer compound or a melt containing the polymer compound. In film formation from a solution, drying is performed after film formation. Thereafter, an absorption spectrum of the laminate of the thin film and the substrate is obtained. The difference between the absorption spectrum of the laminate of the thin film and the substrate and the absorption spectrum of the substrate is obtained as the absorption spectrum of the thin film.
In the absorption spectrum of the thin film, the vertical axis represents the absorbance of the polymer compound, and the horizontal axis represents the wavelength. It is desirable to adjust the thickness of the thin film so that the absorbance at the largest absorption peak is about 0.5 to 2. The absorbance of the absorption peak with the longest wavelength among the absorption peaks is defined as 100%, and the intersection of the absorption peak and a straight line parallel to the horizontal axis (wavelength axis) including the absorbance of 50% of the absorption peak. The intersection point that is longer than the peak wavelength is taken as the first point. The intersection point between the absorption peak and a straight line parallel to the wavelength axis containing 25% of the absorbance and the absorption peak, which is longer than the peak wavelength of the absorption peak, is defined as a second point. The intersection of the straight line connecting the first point and the second point and the reference line is defined as the absorption wavelength end. Here, the reference line is the intersection of the absorption peak and the straight line parallel to the wavelength axis including the absorbance of 10% at the absorption peak of the longest wavelength, where the absorbance of the absorption peak is 100%. The third point on the absorption spectrum which is 100 nm longer than the reference wavelength and the third wavelength on the absorption spectrum which is 150 nm longer than the reference wavelength, with the wavelength of the intersection point being longer than the peak wavelength of the absorption peak as the reference wavelength. A straight line connecting 4 points.

The energy level of the highest occupied orbit of the polymer compound used in the present invention is preferably −4.5 eV or less, more preferably −5.0 eV or less. When the energy level of the highest occupied orbit of the polymer compound is −4.5 eV or less, the open-circuit voltage of the photoelectric conversion element containing the polymer compound in the active layer is increased, and the photoelectric conversion efficiency is increased.

(Photoelectric conversion element)
The anode, the active layer, the electron-donating compound and the electron-accepting compound constituting the active layer, the cathode, and other components formed as necessary in the photoelectric conversion element of the present invention are described in detail below. explain.

(Basic form of photoelectric conversion element)
The photoelectric conversion element of the present invention has a pair of electrodes (anode and cathode), at least one of which is transparent or translucent, and an active layer provided between the pair of electrodes. As the active layer, a bulk hetero active layer formed from an organic composition of an electron-donating compound (p-type organic semiconductor, etc.) and an electron-accepting compound (n-type organic semiconductor, etc.), and electron donation And a p / n stacked active layer in which a first active layer formed of a conductive compound and a second active layer formed of an electron accepting compound are stacked.

In the photoelectric conversion element of the present invention, the polymer compound containing the repeating unit represented by the formula (I-1) and the repeating unit represented by the formula (I-2) contained in the active layer thereof has a long wavelength region. In order to absorb light of a large wavelength, it is possible to photoelectrically convert light of a wide range of wavelengths including light of a long wavelength, so that the photoelectric conversion efficiency is increased.

(substrate)
The photoelectric conversion element of the present invention is usually formed on a substrate. The substrate may be any substrate that does not chemically change when the electrodes are formed and the organic layer is formed. Examples of the material for the substrate include glass, plastic, polymer film, and silicon. In the case of an opaque substrate, the opposite electrode (that is, the electrode far from the substrate) is preferably transparent or translucent.

(electrode)
Examples of the material for the transparent or translucent electrode include a conductive metal oxide film and a translucent metal thin film. Specifically, using conductive materials such as indium oxide, zinc oxide, tin oxide, and composites thereof (for example, indium tin oxide (ITO), indium zinc oxide (IZO), NESA)). A produced film or a film produced using a metal such as gold, platinum, silver or copper is used, and a film produced using ITO, IZO or tin oxide is preferable. Examples of the method for producing the electrode include a vacuum deposition method, a sputtering method, an ion plating method, a plating method, and the like. Moreover, you may use organic transparent conductive films, such as polyaniline and its derivative (s), polythiophene, and its derivative (s) as an electrode material. The transparent or translucent electrode may be an anode or a cathode.

The other electrode may not be transparent. As a material for the electrode, a metal, a conductive polymer, or the like can be used. Specific examples of the electrode material include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like. An alloy of two or more of these metals; from one or more of these metals and the group consisting of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten and tin Alloys with one or more selected metals; graphite; graphite intercalation compounds; polyaniline and its derivatives; polythiophene and its derivatives. Examples of the alloy include a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy.

(Buffer layer)
As a means for improving the photoelectric conversion efficiency, an additional intermediate layer (such as a charge transport layer) other than the active layer may be used. Examples of the material of the intermediate layer include alkali metal halides, alkali metal oxides, alkaline earth metal halides, and alkaline earth metal oxides. Specifically, lithium fluoride is used. It is done.
In addition, fine particles of inorganic semiconductor such as titanium oxide, PEDOT (poly (3,4-ethylenedioxythiophene)) and PSS (poly (4-styrenesulfonate)) mixture (PEDOT: PSS), etc. It may be used as

(Active layer)
The active layer included in the photoelectric conversion device of the present invention includes an electron donating compound and an electron accepting compound, and at least one of the electron donating compound and the electron accepting compound is represented by the formula (I-1). And a repeating compound represented by formula (I-2). The electron-donating compound and the electron-accepting compound are relatively determined from the HOMO or LUMO energy levels of these compounds.

(Electron donating compound)
When a polymer compound containing a repeating unit represented by the formula (I-1) and a repeating unit represented by the formula (I-2) is used as an electron accepting compound, the electron donating compound may be a low molecular compound. Although a high molecular compound may be sufficient, a high molecular compound is preferable. Examples of the electron donating compound include pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, oligothiophene and derivatives thereof, polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, and aromatic amines in side chains or main chains. Polysiloxane derivatives having polyaniline and derivatives thereof, polythiophene and derivatives thereof, polymer compounds having thiophene as a partial skeleton, polypyrrole and derivatives thereof, polyphenylene vinylene and derivatives thereof, polythienylene vinylene and derivatives thereof, High molecular compounds are preferred.
Examples of the electron-donating compound include polythiophene (polythiophene and derivatives thereof) which may have a substituent, a structure containing a dithiopentameric thiophene or a structure containing a dithiopentameric thiophene derivative. Molecular compounds and polymer compounds having thiophene as a partial skeleton are preferred, and polythiophene and derivatives thereof are more preferred. Here, the polythiophene derivative is a polymer compound containing a thiophenediyl group having a substituent.
Polythiophene and its derivatives are preferably homopolymers. A homopolymer is a polymer formed by bonding only a plurality of groups selected from the group consisting of a thiophenediyl group and a substituted thiophenediyl group. The thiophene diyl group is preferably a thiophene-2,5-diyl group, and the thiophene diyl group having a substituent is preferably an alkylthiophene-2, 5-diyl group. Among the polythiophenes and derivatives thereof which are homopolymers, polythiophene homopolymers comprising thiophene diyl groups having an alkyl group having 6 to 30 carbon atoms as substituents are preferred. Specific examples include poly (3-hexylthiophene-2 , 5-diyl) (P3HT), poly (3-octylthiophene-2,5-diyl), poly (3-dodecylthiophene-2,5-diyl), poly (3-octadecylthiophene-2,5-diyl) Is mentioned.

Examples of the polymer compound having thiophene as a partial skeleton include a polymer compound represented by the formula (2).

[Wherein, R ⁷¹ and R ⁷² each independently represents a hydrogen atom or a substituent. Two R ⁷¹ may be the same or different. Six R ^<72> may be the same or may be different from each other. n represents the number of repetitions and is a number from 2 to 1000. ]

The definition and specific examples of the substituent represented by R ⁷¹ and R ⁷² are the same as the definition and specific example of the substituent represented by R ² described above. As the substituent, an alkoxy group having 1 to 20 carbon atoms or an alkyl group having 1 to 20 carbon atoms is preferable.

As the polymer compound represented by the formula (2), a polymer compound in which R ⁷¹ is an alkyl group and R ⁷² is a hydrogen atom is preferable. Specific examples of the polymer compound represented by the formula (2) include a polymer compound represented by the formula (2-1).

[Wherein n represents the same meaning as in formula (2). ]

(Electron-accepting compound)
When a polymer compound containing a repeating unit represented by the formula (I-1) and a repeating unit represented by the formula (I-2) is used as an electron-donating compound, examples of the electron-accepting compound include oxalates. Diazole derivatives, benzothiadiazole derivatives, quinoxaline derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyanoanthraquinodimethane and its derivatives, fluorenone derivatives, diphenyldicyanoethylene And derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, polybenzothiadiazole and derivatives thereof, polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, polyfluorene and derivatives thereof, Polymer compound containing a benzothiadiazole structure unit returns a polymer compound containing a quinoxaline structure repeating units, fullerene and derivatives thereof such as C _60, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline ( Phenanthroline derivatives such as bathocuproin), metal oxides such as titanium oxide, and carbon nanotubes. The electron-accepting compound includes a compound having a benzothiadiazole structure, a polymer compound having a benzothiadiazole structure in a repeating unit, a compound having a quinoxaline structure in a repeating unit, a polymer compound having a quinoxaline structure in a repeating unit, titanium oxide, carbon nanotube, fullerene, And a fullerene derivative, a compound having a benzothiadiazole structure, a polymer compound having a benzothiadiazole structure in a repeating unit, a compound having a quinoxaline structure, a polymer compound having a quinoxaline structure in a repeating unit, fullerene, and a fullerene derivative are more preferable. , A compound containing a benzothiadiazole structure, a polymer compound containing a benzothiadiazole structure in a repeating unit, a compound containing a quinoxaline structure, a polymer containing a quinoxaline structure in a repeating unit Compound, and more preferably a fullerene derivative, polymer compounds containing benzothiadiazole structure in the repeating unit, the polymer compound including a quinoxaline structure repeating units, and fullerene derivatives are particularly preferred.

Examples of the polymer compound having a benzothiadiazole structure in the repeating unit include a polymer compound represented by the formula (2) exemplified as the electron donating compound, and represented by the formula (2-1). High molecular compounds are preferred. That is, depending on the combination with the compound applied as the electron donating compound, the polymer compound represented by the formula (2) can be applied as the electron accepting compound.

The fullerene, for _{example, C 60} _{fullerene, C 70} _{fullerene, C 76} _{fullerene, C 78} fullerene _{include C 84} fullerene.
The fullerene derivative, for _{example, C 60} fullerene _{derivatives, C 70} fullerene _{derivatives, C 76} fullerene _{derivatives, C 78} fullerene _{derivatives, C 84} fullerene derivatives. The fullerene derivative represents a compound in which at least a part of fullerene is modified.

Specific examples of the C ₆₀ fullerene derivative include the following compounds.

Specific examples of C ₇₀ fullerene derivatives, there are the following.

Suitable fullerene derivatives include, for example, [6,6] phenyl-C61 butyric acid methyl ester (C60PCBM, [6,6] -Phenyl C61 butyric acid methyl ester), [6,6] phenyl-C71 butyric acid methyl ester (C70PCBM) , [6,6] -Phenyl C71 butyric acid methyl ester), [6,6] Phenyl-C85 butyric acid methyl ester (C84PCBM, [6,6] -Phenyl C85 butyric acid methyl ester), [6,6] thienyl- And C61 butyric acid methyl ester ([6,6] -Thienyl C61 butyric acid methyl ester).

In the active layer, the use ratio of the electron accepting compound to the electron donating compound is preferably 10 to 1000 parts by weight, more preferably 20 to 500 parts by weight with respect to 100 parts by weight of the electron donating compound. preferable.

The thickness of the active layer is preferably 1 nm to 100 μm, more preferably 2 nm to 1000 nm, still more preferably 5 nm to 500 nm, and particularly preferably 20 nm to 200 nm.

(Other ingredients)
The active layer may contain other components as necessary in order to express various functions. Examples of other components include an ultraviolet absorber, an antioxidant, a sensitizer for sensitizing the function of generating charges by absorbed light, and a light stabilizer for increasing the stability to ultraviolet rays. It is done.

The components other than the electron donating compound and the electron accepting compound constituting the active layer are each preferably 5 parts by weight or less, more preferably 0 with respect to 100 parts by weight of the total amount of the electron donating compound and the electron accepting compound. .01 to 3 parts by weight is blended.
The active layer may contain a polymer compound other than an electron donating compound and an electron accepting compound as a polymer binder in order to improve mechanical properties. As the polymer binder, a polymer compound that does not inhibit the electron transport property or hole transport property is preferably used. As the polymer binder, a polymer compound that does not strongly absorb visible light is preferably used. Examples of the polymer binder include poly (N-vinylcarbazole), polyaniline and derivatives thereof, polythiophene and derivatives thereof, poly (p-phenylene vinylene) and derivatives thereof, poly (2,5-chenylene vinylene) and derivatives thereof. Derivatives, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, polysiloxane and the like can be mentioned.

(Method for producing active layer)
In the case of the bulk hetero type, the active layer of the photoelectric conversion element of the present invention is formed by film formation from a solution containing the electron-donating compound, the electron-accepting compound, and other components blended as necessary. Can be formed. For example, the active layer can be formed by applying the solution on an anode or a cathode. Then, another electrode can be formed on an active layer and a photoelectric conversion element can be manufactured.

The solvent used for film formation from a solution is not particularly limited as long as it dissolves the above-described electron-donating compound and electron-accepting compound. Examples of such solvents include hydrocarbon solvents (for example, toluene, xylene, mesitylene, tetralin, decalin, bicyclohexyl, butylbenzene, sec-butylbenzene, tert-butylbenzene), halogenated hydrocarbon solvents (for example, four Carbon chloride, chloroform, dichloromethane, dichloroethane, dichloropropane, chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, chlorobenzene, dichlorobenzene, trichlorobenzene, etc.), and ether solvents (e.g., Tetrahydrofuran, tetrahydropyran, etc.). A solvent may be used individually by 1 type and may be used in combination of 2 or more type. The organic material constituting the active layer can be usually dissolved in the solvent in an amount of 0.1% by weight or more.

Examples of film formation methods include spin coating, casting, micro gravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, Examples include gravure printing, flexographic printing method, offset printing method, inkjet printing method, dispenser printing method, nozzle coating method, capillary coating method and the like, spin coating method, flexographic printing method, gravure printing method, inkjet printing method, Dispenser printing is preferred.

(Application of the element)
The photoelectric conversion element of the present invention can be operated as an organic thin film solar cell by irradiating light such as sunlight from a transparent or translucent electrode to generate a photovoltaic force between the electrodes. It can also be used as an organic thin film solar cell module by integrating a plurality of organic thin film solar cells.

Also, by applying light from a transparent or translucent electrode in a state where a voltage is applied between the electrodes or in a state where no voltage is applied, a photocurrent flows and it can be operated as an organic photosensor. It can also be used as an organic image sensor by integrating a plurality of organic photosensors.

(Solar cell module)
When a solar cell module is configured using a photoelectric conversion element as an organic thin film solar cell, the solar cell module can basically have the same module structure as a conventional solar cell module. The solar cell module generally has a structure in which cells are formed on a support substrate such as metal or ceramic, and the cell is covered with a filling resin or protective glass, and light is taken in from the opposite side of the support substrate. It is also possible to use a transparent material such as tempered glass for the support substrate, configure a cell thereon, and take in light from the transparent support substrate side. Examples of the known module structure of the solar cell module include a module structure such as a super straight type, a substrate type, and a potting type, and a substrate integrated module structure used in an amorphous silicon solar cell. Even in the organic thin-film solar cell to which the organic photoelectric conversion element of the present invention is applied, these module structures can be appropriately selected depending on the purpose of use, the place of use and the environment.

In a super straight type or substrate type solar cell module having a typical module structure, cells are arranged at regular intervals between a pair of support substrates which are transparent on one side or both sides and subjected to antireflection treatment. Adjacent cells are connected by wiring such as metal leads or flexible wiring. Current collecting electrodes are arranged on the outer edge of the module, and the generated power is taken out to the outside. Various types of plastic materials such as ethylene vinyl acetate (EVA) may be provided between the support substrate and the cell in the form of a film or a filling resin depending on the purpose in order to protect the cell and improve the current collection efficiency. In addition, when using a solar cell module in a place where the surface does not need to be covered with a hard material, such as a place where there is little impact from the outside, the surface protective layer is made of a transparent plastic film, or the filling resin is cured. Thus, a protective function may be imparted and the support substrate on one side may be omitted. The periphery of the support substrate is usually fixed in a sandwich shape with a metal frame in order to ensure internal sealing and module rigidity, and the support substrate and the frame are hermetically sealed with a sealing material. Further, if a flexible material is used for the cell itself, the support substrate, the filling material, and the sealing material, the solar cell module can be formed on the curved surface.

In the case of a solar cell module using a flexible support such as a polymer film, cells are sequentially formed while feeding out a roll-shaped flexible support, cut into a desired size, and then the periphery is made of a flexible and moisture-proof material. A solar cell module main body can be produced by sealing. Moreover, it can also have a module structure called “SCAF” described in Solar Energy Materials and Solar Cells, 48, p383-391. Furthermore, the solar cell module using the flexible support can be used by being bonded and fixed to curved glass or the like.

The second aspect of the present invention is a polymer compound comprising a repeating unit represented by the formula (I-1) and a repeating unit represented by the formula (I-2).

[In the formula, Ar ¹ represents a divalent fused ring group which may have a substituent. ]

Specific examples and preferred examples of X ¹ , X ² , X ³ and R ¹ in formula (I-1) are the same as described above. Specific examples and preferred examples of Ar ¹ in formula (I-2) are the same as described above.

The polymer compound of the present invention preferably further contains a repeating unit represented by the formula (II). The repeating unit represented by the formula (II) is preferably bonded to the repeating unit represented by the formula (I-1).
= C (R ³ )-(II)
[Wherein R ³ represents a hydrogen atom or a substituent. ]

Specific examples and preferred examples of R ³ in formula (II) are the same as described above.

As the repeating unit represented by the formula (II), the repeating unit represented by the formula (II-1) is preferable.

The polymer compound of the present invention preferably further contains a thiophenediyl group which may have a substituent as a repeating unit. Specific examples of the substituent that the thiophenediyl group may have are the same as the specific examples of the substituent represented by R ² described above. The thiophenediyl group which may have a substituent is preferably a group represented by the formula (VII).

The polymer compound of the present invention has a repeating unit represented by the formula (I-1), a repeating unit represented by the formula (I-2), a repeating unit represented by the formula (II), and a substituent. It is preferable that the thiophene diyl group may be optionally substituted. As described above, the repeating unit represented by the formula (I-1), the group represented by the formula (VI), and the repeating unit represented by the formula (II) More preferably, it consists of a unit and a group represented by the formula (VII).

The polymer compound of the present invention preferably has a polystyrene-equivalent number average molecular weight of 1 × 10 ³ to 1 × 10 ⁸ , more preferably 3 × 10 ³ to 1 × 10 ⁷ , and more preferably 5 × 10. More preferably, it is ³ to 1 × 10 ⁷ .

In the polymer compound of the present invention, two ends of the polymer compound may be bonded to form a cyclic structure, but it is preferable that no cyclic structure is formed.

(Method for producing polymer compound)
A method for producing the polymer compound of the present invention is not particularly limited. For example, a method using a reductive coupling reaction using a Ni catalyst, a method using a Stille coupling reaction, and a Suzuki coupling reaction are used. A method is mentioned.

For example, as a method for producing a polymer compound containing a diketopyrrolopyrrole diyl group as a repeating unit represented by the formula (I-2) using a Stille coupling reaction, the formula (100):
Q ¹ -E ¹ -Q ² (100)
[Wherein E ¹ represents a group containing a diketopyrrolopyrrole diyl group. Q ¹ and Q ² each independently represent a halogen atom or a sulfonic acid residue. ]
One or more compounds represented by formula (200):
T ¹ -E ² -T ² (200)
[Wherein E ² represents a group containing a repeating unit represented by the formula (I-1). T ¹ and T ² each independently represents a substituted stannyl group. ]
The manufacturing method which has a process with which 1 or more types of compounds represented by these are made to react in presence of a palladium catalyst is mentioned.

In Formula (200), E ² preferably includes a repeating unit represented by Formula (II). The repeating unit represented by the formula (II) is preferably bonded to the repeating unit represented by the formula (I-1).

Examples of the substituted stannyl group represented by T ¹ and T ² in the formula (200) include a group represented by the formula: —SnR ²⁰⁰ ₃ . Here, R ²⁰⁰ represents a monovalent organic group. Examples of the monovalent organic group include an optionally substituted alkyl group and an optionally substituted aryl group. Represented by R ^200, definitions and specific examples of the aryl group which is a substituted alkyl group and substituted also be substituted, also be an alkyl group and substituted substituted represented by the aforementioned R ² The definition and specific examples of the aryl group that may be included are the same.
As the substituted stannyl group, —SnMe ₃ , —SnEt ₃ , —SnBu ₃ , and —SnPh ₃ are preferable, and —SnMe ₃ , —SnEt ₃ , and —SnBu ₃ are more preferable. In the above preferred examples, Me represents a methyl group, Et represents an ethyl group, Bu represents a butyl group, and Ph represents a phenyl group.

The total number of moles of one or more compounds represented by formula (200) used for the reaction is preferably excessive with respect to the total number of moles of one or more compounds represented by formula (100). When the total number of moles of one or more compounds represented by formula (200) used in the reaction is 1 mole, the total number of moles of one or more compounds represented by formula (100) is 0.6-0. .99 mol is preferable, and 0.7 to 0.95 mol is more preferable.

Examples of the halogen atom represented by Q ¹ and Q ² in Formula (100) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. From the viewpoint of ease of synthesis of the polymer compound, the halogen atom is preferably a bromine atom or an iodine atom, and more preferably an iodine atom.

The sulfonic acid residue represented by Q ¹ and Q ² in the formula (100) means an atomic group obtained by removing acidic hydrogen from sulfonic acid. Specific examples of the sulfonic acid residue include alkyl sulfonate groups (for example, methane sulfonate group, ethane sulfonate group), aryl sulfonate groups (for example, benzene sulfonate group, p-toluene sulfonate group), aryl alkyl sulfonate groups (for example, benzyl group) Sulfonate groups) and trifluoromethanesulfonate groups.

In the case of producing a polymer compound containing a thiophenediyl group which may have a substituent, the thiophenediyl group which may have a substituent is contained in the compound represented by the formula (100). It may be contained in the compound represented by the formula (200), or may be contained in both compounds.
When the optionally substituted thiophenediyl group is contained in the compound represented by the formula (100), the optionally substituted thiophenediyl group can be contained in E ^1. .
When the optionally substituted thiophenediyl group is contained in the compound represented by the formula (200), the optionally substituted thiophenediyl group can be contained in E ^2. .

Examples of the palladium catalyst used in the Stille coupling reaction include a Pd (0) catalyst and a Pd (II) catalyst. Specific examples of the palladium catalyst include palladium [tetrakis (triphenylphosphine)], palladium acetates, and dichlorobis (triphenylphosphine) palladium (II). From the viewpoints of ease of reaction (polymerization) operation and reaction (polymerization) rate, the palladium catalyst is preferably dichlorobis (triphenylphosphine) palladium (II) and palladium acetates.

The addition amount of the palladium catalyst is not particularly limited as long as it is an effective amount as a catalyst, but is usually 0.0001 mol to 0.5 mol with respect to 1 mol of the compound represented by the formula (100). Yes, preferably 0.0003 mol to 0.1 mol.

When using palladium acetate as the palladium catalyst, a phosphorus compound may be added as a ligand. Examples of the phosphorus compound include triphenylphosphine, tri (o-tolyl) phosphine, and tri (o-methoxyphenyl) phosphine. When a phosphorus compound is added, the amount added is usually 0.5 mol to 100 mol, preferably 0.9 mol to 20 mol, more preferably 1 mol to 1 mol with respect to 1 mol of the palladium catalyst. 10 moles.

In the Stille coupling reaction, the reaction is usually performed in a solvent. Examples of the solvent include N, N-dimethylformamide, toluene, xylene, chlorobenzene, dimethoxyethane, and tetrahydrofuran. From the viewpoint of the solubility of the polymer compound, the solvent is preferably toluene, xylene or tetrahydrofuran.

The temperature of the Stille coupling reaction is usually 50 to 200 ° C., although it depends on the solvent. From the viewpoint of increasing the molecular weight of the polymer compound, the reaction temperature is preferably 60 to 120 ° C. Alternatively, the temperature may be raised to near the boiling point of the solvent and refluxed.

The time for performing the Stille coupling reaction (reaction time) may be the end point when the target degree of polymerization is reached, but is usually 0.1 to 200 hours, preferably 1 to 30 hours.

The Stille coupling reaction is performed in a reaction system in which the palladium catalyst is not deactivated under an inert atmosphere such as argon gas or nitrogen gas. For example, it is performed in a system sufficiently deaerated with argon gas or nitrogen gas. Specifically, after the inside of the reaction vessel (reaction system) is sufficiently substituted with nitrogen gas and degassed, the compound represented by the formula (100), the compound represented by the formula (200), Palladium acetates and ligands were charged, the reaction vessel was sufficiently replaced with nitrogen gas, degassed, and a solvent degassed by bubbling with nitrogen gas in advance, for example, degassed toluene was added. Thereafter, the mixture is heated and heated to polymerize, for example, at the reflux temperature for 8 hours while maintaining an inert atmosphere.

The third aspect of the present invention is a compound containing a group represented by the formula (III) and a substituted stannyl group.

In formula (III), X ⁴ represents a sulfur atom, an oxygen atom or a divalent group. Examples of the divalent group include a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) ₂ —, and a formula: —N (R ² ) —. group represented by the formula: ^-CR ² = CR 2 -, a group represented by the formula: ^-CR 2 = N-, a group represented by and the formula: -N = a group represented by the N-. Here, the definition and specific examples of R ² are the same as described above. X ⁴ is preferably a sulfur atom.

In formula (III), X ⁵ and X ⁶ each independently represent a group represented by the formula: ═C (R ¹ ) — or a nitrogen atom. Here, the definition and specific examples of R ¹ are the same as described above. When X ⁵ and X ⁶ are a group represented by the formula: ═C (R ¹ ) —, an atom contained in R ¹ in X ⁵ is bonded to an atom contained in R ¹ in X ⁶ An annular structure may be formed. X ⁵ and X ⁶ are preferably a group represented by the formula: ═C (R ¹ ) —.

The compound of the present invention preferably further contains a group represented by the formula (IV). The group represented by the formula (IV) is preferably bonded to the group represented by the formula (III).
= C (R ⁴ )-(IV)

In formula (IV), R ⁴ represents a hydrogen atom or a substituent. The definition and specific examples of the substituent represented by R ⁴ are the same as the definition and specific examples of the substituent represented by R ² described above.

The definition and specific examples of the substituted stannyl group contained in the compound of the present invention are the same as the definition and specific examples of the substituted stannyl group represented by the above formula: —SnR ²⁰⁰ ₃ . The compound of the present invention preferably has two substituted stannyl groups.

As the substituted stannyl group, a group represented by the formula (V) is preferable.

In formula (V), R ⁵ represents an alkyl group. Three R ⁵ may be the same or different. The definition and specific examples of the alkyl group represented by R ⁵ are the same as the definition and specific examples of the alkyl group described for the substituent represented by R ² described above.

The compound of the present invention preferably further contains a thiophene ring. For example, it is preferable to contain a thiophenediyl group which may have the aforementioned substituent. Specific examples of the substituent that the thiophenediyl group may have are the same as the specific examples of the substituent represented by R ² described above. The thiophenediyl group which may have a substituent is preferably a group represented by the formula (VII).

As the compound of the present invention, a compound represented by the formula (VIII) is preferable.

[Wherein, X ⁴ , X ⁵ , X ⁶ , R ⁴ and R ⁵ represent the same meaning as described above. R ⁹ represents a hydrogen atom or an optionally substituted alkyl group. Four R ⁹ may be the same or different. ]

The definition and specific examples of the optionally substituted alkyl group represented by R ⁹ are the same as the definition and specific examples of the optionally substituted alkyl group represented by R ² described above.

As the compound represented by the formula (VIII), a compound represented by the formula (IX) is preferable.

[Wherein R ⁵ and R ⁹ represent the same meaning as described above. R ¹⁰ represents a halogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group or an optionally substituted aryl group. b represents an integer of 0 to 5. Two b's may be the same or different. When there are a plurality of R ¹⁰ , they may be the same or different. ]

Examples of the halogen atom represented by R ¹⁰ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Definitions and specific examples of the optionally substituted alkyl group, the optionally substituted alkoxy group, and the optionally substituted aryl group represented by R ¹⁰ are the substituted and substituted groups represented by R ² described above. The definition and specific examples of the alkyl group which may be substituted, the alkoxy group which may be substituted and the aryl group which may be substituted are the same. R ¹⁰ is preferably an alkyl group. b is preferably an integer of 0 to 3, and more preferably 1.

Hereinafter, examples of the present invention will be described. The following examples are preferred examples for explaining the present invention, and do not limit the present invention.

The NMR spectrum of the compound was measured with a nuclear magnetic resonance apparatus (device name: JNM-EX400, manufactured by JEOL). The IR spectrum was measured with an infrared spectrophotometer (device name: FT / IR-470 Plus, manufactured by JASCO Corporation). The high resolution mass spectrometry spectrum was measured with a high resolution mass spectrometer (device name: JMS-T100CS, manufactured by JEOL). The number average molecular weight in terms of polystyrene and the weight average molecular weight in terms of polystyrene of the polymer compound are as follows: gel permeation chromatography device (device name: Prominence, manufactured by Shimadzu Corporation) and GPC column (JAIGEL-3HAF, manufactured by Nihon Analytical Industries, Ltd.) Measurement was performed using chloroform as an eluent.

Synthesis example 1
(Synthesis of Compound 2a)

In an argon atmosphere, 7 mL of anhydrous hexane was added to a 50 mL 2-neck round bottom flask. Thereafter, 2.66 mL (n) of a hexane solution of tetramethylethylenediamine (TMEDA) 0.66 mL, thiophene 0.14 mL (1.8 mmol), and 1.65 mol / L n-butyllithium (n-BuLi) was placed in the flask. -BuLi content: 4.4 mmol) was added at room temperature with stirring. The reaction was refluxed for 1 hour and then cooled to -40 ° C. Thereafter, 7 mL of a solution of 4- (2-ethylhexyl) phenyl thienyl ketone dissolved in distilled diethyl ether was added dropwise to the reaction solution. The solution contained 1.29 g (4.4 mmol) of 4- (2-ethylhexyl) phenyl thienyl ketone. Thereafter, the reaction solution was warmed to room temperature and stirred overnight. The reaction was stopped by adding 20 mL of a 1 mol / L ammonium chloride aqueous solution, and the organic layer of the reaction was extracted with dichloromethane and ethyl acetate. The obtained organic layer was dried over magnesium sulfate, and the solvent was distilled off. The resulting solid was dried under vacuum to give compound 1a. Unpurified compound 1a was dissolved in 30 mL of toluene, and 30 mL of an aqueous solution containing 4.6 g of sodium dithionite and 4.4 mL of 57% hydroiodic acid was added. The reaction solution separated into two layers was stirred at room temperature for 24 hours. The orange reaction mixture was neutralized with sodium bicarbonate, and the organic layer of the reaction solution was extracted several times with chloroform. Thereafter, the organic layer was dried over sodium sulfate, and the solvent was distilled off. The product was purified by silica gel chromatography (developing solvent: dichloromethane / hexane = 1/5 (volume ratio)) to obtain Compound 2a as an orange liquid. The yield of compound 2a was 25%.

Synthesis example 2
(Synthesis of Compound 3a)

In an argon atmosphere, a solution prepared by dissolving 0.32 g (0.5 mmol) of Compound 2a and 0.16 mL of tetramethylethylenediamine (TMEDA) in 5 mL of distilled tetrahydrofuran was added to a 30 mL 2-neck round bottom flask. After the reaction solution was cooled to −78 ° C., 0.64 mL of a 1.65 mol / L n-butyllithium (n-BuLi) hexane solution (n-BuLi content: 1.1 mmol) was stirred in the reaction solution. Added to. The reaction was refluxed for 1 hour and then cooled to -78 ° C. Thereafter, 5 mL of a solution prepared by dissolving trimethyltin chloride in distilled tetrahydrofuran was added dropwise to the reaction solution. After 3 hours, the reaction was warmed to room temperature and stirred overnight. 10 mL of 1 mol / L ammonium chloride aqueous solution was added to the reaction liquid, reaction was stopped, the organic layer of the reaction liquid was extracted with chloroform, the organic layer was washed with brine, and then dried over sodium sulfate. After distilling off the solvent, Compound 3a, an orange liquid, was obtained. The yield of compound 3a was 74%.

Example 1
(Synthesis of polymer compound 1)

In a test tube, compound 3a 49 mg (0.050 mmol), compound 4 34 mg (0.050 mmol), tris (dibenzylideneacetone) dipalladium (Pd ₂ dba ₃ ) 2.3 mg (0.0025 mmol), tri ( 8.8 mg (0.029 mmol) of o-tolyl) phosphine and 1 mL of anhydrous chlorobenzene were added, and argon bubbling was performed for 10 minutes. The reaction was stirred at 170 ° C. for 18 hours under microwave irradiation. Thereafter, the cooled reaction solution was poured into methanol, and the black precipitate was collected with a membrane filter. The product was washed with methanol and hexane. Thereafter, the obtained dark blue solid was extracted with chloroform, and the chloroform solution was poured into methanol to reprecipitate the solid, thereby obtaining polymer compound 1 which was a dark blue solid. The yield of polymer compound 1 was 84%. The number average molecular weight in terms of polystyrene of the polymer compound 1 was 7,800, and the polydispersity was 2.2.

Synthesis example 3
(Synthesis of Compound 2b)

The product was purified by silica gel chromatography (developing solvent: chloroform / hexane = 1/3 (volume ratio)) using 4- (tert-butyl) phenyl thienyl ketone instead of 4- (2-ethylhexyl) phenyl thienyl ketone. Then, synthesis was carried out in the same manner as in Synthesis Example 1 except that recrystallization was performed with ethanol to obtain Compound 2b as an orange solid. The yield of compound 2b was 35%.

Synthesis example 4
(Synthesis of Compound 3b)

Compound 2b was used instead of Compound 2a, and after the reaction was stopped, the organic layer of the reaction solution was extracted with chloroform, and synthesized similarly to Synthesis Example 2 except that the chloroform solution was poured into methanol to reprecipitate the solid, Compound 3b, an orange solid, was obtained. The yield of compound 3b was 70%.

Example 2
(Synthesis of polymer compound 2)

In an argon atmosphere, 43 mg (0.050 mmol) of compound 3; 34 mg (0.050 mmol) of compound 4; 2.3 mg of tris (dibenzylideneacetone) dipalladium (Pd ₂ dba ₃ ) .0025 mmol), 8.8 mg (0.029 mmol) of tri (o-tolyl) phosphine, 0.25 mL of anhydrous dimethylformamide, and 0.75 mL of toluene were added. Thereafter, the reaction solution was stirred at 110 ° C. for 48 hours. Thereafter, the cooled reaction solution was poured into methanol, and the black precipitate was collected with a membrane filter. The product was washed with methanol and hexane. Thereafter, the obtained dark blue solid was extracted with chloroform, and the chloroform solution was poured into methanol to reprecipitate the solid, thereby obtaining a polymer compound 2 which was a dark blue solid. The yield of polymer compound 2 was 58%. The number average molecular weight in terms of polystyrene of the polymer compound 2 was 4,700, and the polydispersity was 1.5.

Example 3
(Production and Evaluation of Organic Thin Film Solar Cell 1)
An organic thin film solar cell 1 having the following element configuration was prepared and evaluated for characteristics.
Anode (ITO) / hole transport layer (PEDOT: PSS) / active layer (composition of polymer compound 1 and PC71BM) / hole block layer (TiO _x ) / cathode (Al)

The hole transport layer is prepared by spin-coating a liquid (trade name: Clevios P VP AI 4083) containing poly (3,4-ethylenedioxythiophene) (PEDOT), polystyrene sulfonic acid (PSS) and water on ITO. did. The active layer contains a chloroform solution containing polymer compound 1 and phenyl C71-butyric acid methyl ester (PC71BM, manufactured by American Dice Source) in an equal amount, and the concentration of the mixture of polymer compound 1 and PC71BM is 15 mg / mL. It was prepared by spin coating on the transport layer. The hole blocking layer is made of titanium oxide (TiO _x ) obtained by spin-coating an ethanol solution of titanium (IV) isopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) at 2000 rpm and then left standing at room temperature for 30 minutes. A film was formed on top. The cathode was prepared by evaporating aluminum on the hole block layer.
The produced organic thin film solar cell 1 was irradiated with light having an irradiance of 100 mW / cm ² using a solar simulator (trade name: PEC-L11, manufactured by Pexel Technology), and the generated current and voltage were measured. The organic thin film solar cell 1 has an open circuit voltage (VOC) of 0.48 V, a short circuit current density (Jsc) of 4.11 mA / cm ² , a fill factor (FF) of 0.54, and a conversion efficiency of 0. 71%.

Example 4
(Production and Evaluation of Organic Thin Film Solar Cell 2)
An organic thin-film solar cell 2 was prepared in the same manner as in Example 3 except that the polymer compound 2 was used in place of the polymer compound 1 and chlorobenzene was used as the dissolving solvent, and the characteristics were evaluated.
The open circuit voltage (VOC) of the organic thin film solar cell 2 is 0.55 V, the short circuit current density (Jsc) is 1.70 mA / cm ² , the fill factor (FF) is 0.32, and the conversion efficiency is 0. 30%.

The action spectrum of the organic thin film solar cell 1 and the organic thin film solar cell 2 is shown in FIG. The vertical axis represents the ratio (IPCE) of the number of electrons flowing through the organic thin film solar cell to the number of photons incident on the active layer of the organic thin film solar cell at a certain wavelength. The horizontal axis indicates the wavelength of the irradiated light.
It was found that both the organic thin film solar cell 1 and the organic thin film solar cell 2 photoelectrically convert not only visible light but also infrared light up to 1000 nm. The IPCE in the light of 800 nm wavelength of the organic thin film solar cell 1 was about 8%, and the IPCE in the light of 800 nm wavelength of the organic thin film solar cell 2 was about 3%.
The energy levels of the highest occupied orbitals of the polymer compound 1 and the polymer compound 2 were measured under the following conditions. Cyclic voltammetry of polymer compound 1 thin film or polymer compound 2 thin film on ITO in acetonitrile solution containing decamethylferrocene as internal standard and 0.1 mol / L n-Bu ₄ N + PF ₆ as supporting electrolyte did. The reduction potential of the polymer compound 1 was −1.06 V (vs. Ag / AgNO ₃ ), and the oxidation potential was 0.62 V (vs. Ag / AgNO ₃ ). From this measurement result, the energy level of the highest occupied orbit and the energy level of the lowest unoccupied orbit calculated by converting the energy level under vacuum of the FeCp2 + / 0 reference electrode to −4.6 eV are −5.4 eV and −3, respectively. It was found to be 7 eV. Similarly, it was found that the energy level of the highest occupied orbit and the energy level of the lowest unoccupied orbit of the polymer compound 2 were −5.2 eV and −3.8 eV, respectively.

(Measurement of absorption wavelength end)
A chlorobenzene solution of polymer compound 1 was applied to a glass substrate by spin coating to obtain a thin film of polymer compound 1. When the absorption spectrum of the thin film was measured with an absorption spectrum measuring apparatus, the absorption wavelength end of the thin film was 1000 nm or more.

(Measurement of absorption wavelength end)
A chlorobenzene solution of the polymer compound 2 was applied to a glass substrate by spin coating to obtain a polymer compound 2 thin film. When the absorption spectrum of the thin film was measured with an absorption spectrum measuring apparatus, the absorption wavelength end of the thin film was 1000 nm or more.

Example 5
(Production and Evaluation of Organic Thin Film Solar Cell 3)
An organic thin film solar cell 3 was prepared in the same manner as in Example 3 except that the amount of the polymer compound 1 and phenyl C71-butyric acid methyl ester (PC71BM) used was 1: 2 (wt: wt) in weight ratio. Evaluated.
The open-circuit voltage (VOC) of the organic thin-film solar cell 3 is 0.53 V, the short-circuit current density (Jsc) is 6.58 mA / cm ² , the fill factor (FF) is 0.42, and the conversion efficiency is 1 .44%.

Synthesis example 5
(Synthesis of Compound 2c)

The product was purified by silica gel chromatography (developing solvent: chloroform / hexane = 1/3 (volume ratio)) using 4-octyloxyphenyl thienyl ketone instead of 4- (2-ethylhexyl) phenyl thienyl ketone, The compound 2c, which was an orange solid, was synthesized in the same manner as in Synthesis Example 1 except that it was recrystallized from ethanol. The yield of compound 2c was 40%.

Synthesis Example 6
(Synthesis of Compound 3c)

Compound 2c was used in place of compound 2a. After the reaction was stopped, the organic layer of the reaction solution was extracted with chloroform, and the solid was reprecipitated by pouring the chloroform solution into methanol. Compound 3c, an orange solid, was obtained. The yield of compound 3c was 96%.

Example 6
(Synthesis of polymer compound 3)

Polymer compound 3 was obtained by synthesis in the same manner as in Example 2 except that 50.4 mg (0.050 mmol) of compound 3c was used instead of compound 3b. The yield of polymer compound 3 was 32%.

Example 7
(Production and Evaluation of Organic Thin Film Solar Cell 4)
Example 3 except that polymer compound 3 was used instead of polymer compound 1 and the amount of polymer compound 3 and phenyl C71-butyric acid methyl ester (PC71BM) used was 1: 2 (wt: wt) by weight. The organic thin film solar cell 4 was prepared in the same manner as in Example 3, and the characteristics were evaluated.
The organic thin-film solar cell 4 has an open circuit voltage (VOC) of 0.45 V, a short circuit current density (Jsc) of 5.58 mA / cm ² , a fill factor (FF) of 0.41, and a conversion efficiency of 0. 96%.

Comparative Example 1
(Production and Evaluation of Organic Thin Film Solar Cell 3)
An organic thin film solar cell 3 was prepared in the same manner as in Example 3 except that the compound 1 represented by the following formula was used in place of the polymer compound 1, and the characteristics were evaluated. When the action spectrum of the organic thin-film solar cell 3 was measured, light having a wavelength longer than 800 nm was not photoelectrically converted.

Claims

An anode, a cathode, and an active layer provided between the anode and the cathode, wherein the active layer includes an electron-donating compound and an electron-accepting compound, the electron-donating compound and the A photoelectric conversion element, wherein at least one of the electron-accepting compounds is a polymer compound including a repeating unit represented by the formula (I-1) and a repeating unit represented by the formula (I-2).

[Wherein, X 1 represents a sulfur atom, an oxygen atom or a divalent group. X 2 and X 3 each independently represent a group represented by the formula: ═C (R 1 ) — or a nitrogen atom. R 1 represents a hydrogen atom or a substituent. X 2 and X 3 has the formula: = C (R 1) - in the case of a group represented, by bonding the atoms contained in R 1 in the atoms and X 3 contained in R 1 in X 2 An annular structure may be formed. ]

[In the formula, Ar 1 represents a divalent fused ring group which may have a substituent. ]
X 1 is a sulfur atom, an oxygen atom, a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) 2 —, a formula: —N (R 2 ) — A group represented by the formula: -CR 2 = CR 2- , a group represented by the formula: -CR 2 = N- or a group represented by the formula: -N = N- The photoelectric conversion element according to claim 1, wherein R 2 represents a hydrogen atom or a substituent.
The photoelectric conversion element according to claim 1, wherein X 1 is a sulfur atom.
The photoelectric conversion device according to claim 1, wherein X 2 and X 3 are groups represented by the formula: = C (R 1 )-.
The polymer compound further includes a repeating unit represented by the formula (II), and the repeating unit represented by the formula (II) is bonded to the repeating unit represented by the formula (I-1). The photoelectric conversion element according to claim 1.
= C (R 3 )-(II)
[Wherein R 3 represents a hydrogen atom or a substituent. ]
The photoelectric conversion element according to claim 1, wherein Ar 1 is a divalent group containing a nitrogen-containing condensed ring which may have a substituent.
The photoelectric conversion element according to claim 6, wherein Ar 1 is a diketopyrrolopyrrole diyl group which may have a substituent.
The photoelectric conversion element according to claim 1, wherein the polymer compound further contains a thiophenediyl group which may have a substituent as a repeating unit.
The photoelectric conversion element according to claim 1, wherein an absorption wavelength end of the polymer compound is 600 nm or more.
The photoelectric conversion element according to claim 1, wherein the energy level of the highest occupied orbit of the polymer compound is -4.5 eV or less.
A solar cell module including the photoelectric conversion element according to claim 1.
An image sensor including the photoelectric conversion element according to claim 1.
A polymer compound comprising a repeating unit represented by formula (I-1) and a repeating unit represented by formula (I-2).

[Wherein, X 1 represents a sulfur atom, an oxygen atom or a divalent group. X 2 and X 3 each independently represent a group represented by the formula: ═C (R 1 ) — or a nitrogen atom. R 1 represents a hydrogen atom or a substituent. X 2 and X 3 has the formula: = C (R 1) - in the case of a group represented, by bonding the atoms contained in R 1 in the atoms and X 3 contained in R 1 in X 2 An annular structure may be formed. ]

[In the formula, Ar 1 represents a divalent fused ring group which may have a substituent. ]
X 1 is a sulfur atom, an oxygen atom, a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) 2 —, a formula: —N (R 2 ) — A group represented by the formula: -CR 2 = CR 2- , a group represented by the formula: -CR 2 = N- or a group represented by the formula: -N = N- The polymer compound according to claim 13, wherein R 2 represents a hydrogen atom or a substituent.
The polymer compound according to claim 13, wherein X 1 is a sulfur atom.
The polymer compound according to claim 13, wherein X 2 and X 3 are a group represented by the formula: = C (R 1 )-.
14. The repeating unit represented by formula (II), wherein the repeating unit represented by formula (II) is bonded to the repeating unit represented by formula (I-1). High molecular compound.
= C (R 3 )-(II)
[Wherein R 3 represents a hydrogen atom or a substituent. ]
The polymer compound according to claim 13, wherein Ar 1 is a diketopyrrolopyrrole diyl group which may have a substituent.
Furthermore, the high molecular compound of Claim 13 which contains the thiophenediyl group which may have a substituent as a repeating unit.
The polymer compound according to claim 13, wherein the absorption wavelength end is 600 nm or more.
The polymer compound according to claim 13, wherein the energy level of the highest occupied orbit is -4.5 eV or less.
A compound containing a group represented by the formula (III) and a substituted stannyl group.

[Wherein, X 4 represents a sulfur atom, an oxygen atom or a divalent group. X 5 and X 6 each independently represent a group represented by the formula: ═C (R 1 ) — or a nitrogen atom. R 1 represents a hydrogen atom or a substituent. When X 5 and X 6 are a group represented by the formula: ═C (R 1 ) —, an atom contained in R 1 in X 5 is bonded to an atom contained in R 1 in X 6 An annular structure may be formed. ]
X 4 is a sulfur atom, an oxygen atom, a group represented by the formula: —S (═O) —, a group represented by the formula: —S (═O) 2 —, a formula: —N (R 2 ) — A group represented by the formula: -CR 2 = CR 2- , a group represented by the formula: -CR 2 = N- or a group represented by the formula: -N = N- The compound according to claim 22, wherein R 2 represents a hydrogen atom or a substituent.
The compound according to claim 22, wherein X 4 is a sulfur atom.
The compound according to any one of claims 22 to 24, wherein X 5 and X 6 are a group represented by the formula: = C (R 1 )-.
The compound according to claim 22, further comprising a group represented by the formula (IV), wherein the group represented by the formula (IV) is bonded to the group represented by the formula (III).
= C (R 4 )-(IV)
[Wherein, R 4 represents a hydrogen atom or a substituent. ]
23. A compound according to claim 22 containing two substituted stannyl groups.
The compound according to claim 22, wherein the substituted stannyl group is a group represented by formula (V).

[Wherein R 5 represents an alkyl group. Three R 5 may be the same or different. ]
The compound according to claim 22, further comprising a thiophene ring.