JP2015220331A - Photoelectric conversion element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric conversion element having a high photoelectric conversion efficiency.SOLUTION: In a photo electric conversion element having a first electrode, a second electrode and an active layer between the first electrode and the second electrode, the active layer is formed by coating solution of an electron-donative polymer compound and an electron-acceptable polymer compound under inert atmosphere, at least one of the electron-donative polymer compound and the electron-acceptable polymer compound is a polymer compound comprising only one or more kinds of constituent units selected from the group consisting of an arylene group which may have a substituent group and a divalent heterocyclic group which may have a substituent group, the polystyrene-converted weight average molecular weight of the electron-donative polymer compound ranges from not less than 20,000 to not more than 70,000, and the polystyrene-converted weight average molecular weight of the electron-acceptable polymer compound is equal to 70,000 or more.

Description

  The present invention relates to a photoelectric conversion element having an active layer containing a predetermined polymer compound and a method for producing the photoelectric conversion element.

  A photoelectric conversion element is an element provided with a pair of electrodes composed of an anode and a cathode, and an active layer provided between the pair of electrodes. An organic thin-film solar cell having an active layer made of an organic compound, which is an embodiment of a photoelectric conversion element, may be able to significantly reduce manufacturing costs compared to an inorganic solar cell having an active layer made of an inorganic compound such as silicon. It is attracting attention as a cheaper photovoltaic power generation element.

  As a photoelectric conversion element, for example, a layer containing poly (ethylenedioxythiophene) (PEDOT) on a positive electrode made of indium oxide (ITO) to which tin oxide is added, a conjugated polymer compound represented by the following formula: An active layer containing a mixture of a certain poly (3-hexylthiophene) (P3HT) and [6,6] -phenyl C61 butyric acid methyl ester (PCBM) which is a fullerene derivative, a cathode composed of a calcium layer and an aluminum layer in this order. Laminated bulk heterojunction photoelectric conversion elements are widely used because of their high efficiency.

  In addition, a photoelectric conversion element using a mixture (polymer blend) of two types of polymers of electron donating P3HT and electron accepting F8TBT represented by the following formula as a material of an active layer is known (non-patent document). 1).

APPLIED PHYSICS LETTERS 90, 193506 (2007)

  However, the photoelectric conversion element using the polymer blend as a material for the active layer does not have sufficient photoelectric conversion efficiency. Accordingly, an object of the present invention is to provide a photoelectric conversion element having high photoelectric conversion efficiency.

（式（１）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５及びＲ^６は、それぞれ独立に、水素原子又は置換基を表す。Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５及びＲ^６のうちの２個が連結し、連結しているＲ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５及びＲ^６のうちの２個がそれぞれ結合している炭素原子とともに環状構造を形成していてもよい。Ｘ^１、Ｘ^２及びＸ^３は、それぞれ独立に、硫黄原子、酸素原子、セレン原子、−Ｎ（Ｒ^７）−で表される基、又は−ＣＲ^８＝ＣＲ^９−で表される基を表す。Ｒ^７、Ｒ^８及びＲ^９は、それぞれ独立に、水素原子又は置換基を表す。ｎ及びｍは、それぞれ独立に、０〜５の整数を表す。Ｒ^１が複数個ある場合、それらは同一であっても異なっていてもよい。Ｒ^２が複数個ある場合、それらは同一であっても異なっていてもよい。Ｒ^５が複数個ある場合、それらは同一であっても異なっていてもよい。Ｒ^６が複数個ある場合、それらは同一であっても異なっていてもよい。Ｘ^１が複数個ある場合、それらは同一であっても異なっていてもよい。Ｘ^３が複数個ある場合、それらは同一であっても異なっていてもよい。）
［５］前記式（１）で表される構成単位を含む高分子化合物において、前記式（１）で表される構成単位が、該高分子化合物が有する全ての種類の構成単位の中で、前記式（１）で表される構成単位が最も多く含まれる、［４］に記載の光電変換素子。
［６］［１］〜［５］のいずれか１つに記載の光電変換素子を含む太陽電池モジュール。
［７］［１］〜［５］のいずれか１つに記載の光電変換素子、又は［６］に記載の太陽電池モジュールを含むイメージセンサー。
［８］第１の電極と、第２の電極とを有し、該第１の電極と該第２の電極との間に活性層を有する光電変換素子の製造方法であって、
電子供与性高分子化合物及び電子受容性高分子化合物のうちの少なくとも一方が、アリーレン基、及び２価の複素環基からなる群から選ばれる１種以上の構成単位のみからなる高分子化合物であり、ポリスチレン換算の重量平均分子量が２００００以上７００００以下である電子供与性高分子化合物及びポリスチレン換算の重量平均分子量が７００００以上である電子受容性高分子化合物を含む溶液を不活性雰囲気下で塗布して活性層を形成する工程を含む、［１］〜［７］のいずれか１つに記載の光電変換素子の製造方法。
［９］前記活性層を形成する工程が、前記溶液を不活性雰囲気下で塗布した後に、さらに不活性雰囲気下で加熱処理することにより活性層を形成する工程である、［８］に記載の光電変換素子の製造方法。 That is, the present invention provides the following [1] to [9].
[1] A photoelectric conversion element having a first electrode and a second electrode, and having an active layer between the first electrode and the second electrode,
The active layer is formed by applying a solution containing an electron-donating polymer compound and an electron-accepting polymer compound under an inert atmosphere, and the active layer includes the electron-donating polymer compound and the electron-accepting polymer compound. A polymer comprising at least one structural unit selected from the group consisting of an arylene group which may have a substituent and a divalent heterocyclic group which may have a substituent. A photoelectric conversion element, which is a compound, wherein the electron-donating polymer compound has a polystyrene-equivalent weight average molecular weight of 20,000 or more and 70000 or less, and the electron-accepting polymer compound has a polystyrene-equivalent weight average molecular weight of 70000 or more. .
[2] A polymer compound in which both the electron-donating polymer compound and the electron-accepting polymer compound are composed only of one or more structural units selected from the group consisting of an arylene group and a divalent heterocyclic group. The photoelectric conversion element according to [1].
[3] The photoelectric conversion according to [1] or [2], wherein at least one of the electron-donating polymer compound and the electron-accepting polymer compound is a polymer compound containing a structural unit containing a thiophene skeleton. element.
[4] At least one of the electron-donating polymer compound and the electron-accepting polymer compound is a polymer compound containing a structural unit represented by the following formula (1): [1] to [3 ] The photoelectric conversion element as described in any one of.

(In the formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom or a substituent. R ¹ , R ² , R ³ , R ⁴ , 2 is connected one of R ⁵ and ^{R 6,} ring together with the carbon atom to which two of ^{R 1, R 2, R 3} , R 4, R 5 and ^{R 6} which are connected are coupled respectively X ¹ , X ² and X ³ each independently represent a sulfur atom, an oxygen atom, a selenium atom, a group represented by —N (R ⁷ ) —, or —CR ⁸ ═ CR ⁹ - represents a group represented by ^.R 7, ^{R 8} and ^{R 9} each independently, .n and m represents a hydrogen atom or a substituent, each independently, represent an integer of 0 to 5. When there are a plurality of R ^{1 s} , they may be the same or different, and when there are a plurality of R ^{2 s} , they are the same. When there are a plurality of R ^{5 s} , they may be the same or different, and when there are a plurality of R ^{6 s} , they may be the same or different. When there are a plurality of X ^{1 s} , they may be the same or different.When there are a plurality of X ^{3 s} , they may be the same or different.)
[5] In the polymer compound containing the structural unit represented by the formula (1), the structural unit represented by the formula (1) is a structural unit of all kinds of the polymer compound, The photoelectric conversion element according to [4], wherein the constitutional unit represented by the formula (1) is contained most.
[6] A solar cell module including the photoelectric conversion element according to any one of [1] to [5].
[7] An image sensor including the photoelectric conversion element according to any one of [1] to [5] or the solar cell module according to [6].
[8] A method for producing a photoelectric conversion element having a first electrode and a second electrode, and having an active layer between the first electrode and the second electrode,
At least one of the electron donating polymer compound and the electron accepting polymer compound is a polymer compound comprising only one or more structural units selected from the group consisting of an arylene group and a divalent heterocyclic group. And applying a solution containing an electron-donating polymer compound having a polystyrene-equivalent weight average molecular weight of 20000 or more and 70000 or less and an electron-accepting polymer compound having a polystyrene-equivalent weight average molecular weight of 70000 or more in an inert atmosphere. The manufacturing method of the photoelectric conversion element as described in any one of [1]-[7] including the process of forming an active layer.
[9] The method according to [8], wherein the step of forming the active layer is a step of forming the active layer by applying the solution in an inert atmosphere and then performing heat treatment in the inert atmosphere. A method for producing a photoelectric conversion element.

  According to the photoelectric conversion element of the present invention, a photoelectric conversion element having high photoelectric conversion efficiency can be provided.

  Hereinafter, the present invention will be described in detail.

(Basic form of photoelectric conversion element)
The photoelectric conversion element of the present invention is a photoelectric conversion element having a first electrode and a second electrode, and having an active layer between the first electrode and the second electrode, The layer is formed by applying a solution containing an electron-donating polymer compound and an electron-accepting polymer compound under an inert atmosphere, and at least one of the electron-donating polymer compound and the electron-accepting polymer compound is An arylene group which may have a substituent, and a polymer compound composed of only one or more structural units selected from the group consisting of a divalent heterocyclic group which may have a substituent, The electron-donating polymer compound has a polystyrene-equivalent weight average molecular weight of 20,000 to 70,000, and the electron-accepting polymer compound has a polystyrene-equivalent weight average molecular weight of 70,000 or more.

(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 electrode is formed and the organic layer is formed. Examples of the material for the substrate include glass, plastic, polymer film, and silicon. In the case where the photoelectric conversion element is formed on an opaque substrate, it is preferable that the electrode on the side opposite to the substrate (that is, the electrode far from the substrate) is transparent or translucent.

(First electrode and second electrode)
At least one of the first electrode and the second electrode (hereinafter referred to as an electrode) is preferably a transparent or translucent electrode.

  As the transparent or translucent electrode, for example, a conductive metal oxide film and a translucent metal thin film can be used. Transparent or semi-transparent electrode materials include indium oxide, zinc oxide, tin oxide, and composite metal oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and NESA, Examples include metal materials such as gold, platinum, silver, and copper, and ITO, IZO, and tin oxide are preferable.

  Examples of the electrode manufacturing method include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method. In addition, as the transparent or translucent electrode, a transparent conductive film containing an organic material such as polyaniline and a derivative thereof, polythiophene and a derivative thereof may be used. The transparent or translucent electrode may be either the first electrode or the second electrode, and may be an anode or a cathode.

  The photoelectric conversion element of the present invention may have an electrode that is not transparent or translucent. Examples of the material of such an electrode include metals and conductive polymers. Specific examples of electrode materials that are not transparent or translucent include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium A metal such as terbium and ytterbium, an alloy of two or more of the metals, one or more of the metals, and gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, and tin Examples thereof include alloys with one or more metals selected from the group, graphite, graphite intercalation compounds, polyaniline and derivatives thereof, and polythiophene and derivatives thereof. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.

(Middle layer)
The photoelectric conversion element of the present invention may have an additional intermediate layer (such as a charge transport layer) other than the active layer as a means for improving the photoelectric conversion efficiency. Examples of the material that can be used for the intermediate layer include alkali metal halides such as lithium fluoride, alkaline earth metal halides, alkali metal oxides, and alkaline earth metal oxides.

  In addition, fine particles of inorganic semiconductor such as titanium oxide, a mixture of PEDOT (poly (3,4-ethylenedioxythiophene)) and PSS (poly (4-styrenesulfonate)) (PEDOT: PSS), etc. are used for the intermediate layer. May be.

(Active layer)
The photoelectric conversion element of the present invention includes an active layer. The active layer is provided between the first electrode and the second electrode, and includes an electron donating polymer compound and an electron accepting polymer compound. That is, the photoelectric conversion element of the present invention has a bulk heterojunction active layer.

  At least one of the electron donating polymer compound and the electron accepting polymer compound is a polymer compound comprising only one or more structural units selected from the group consisting of an arylene group and a divalent heterocyclic group. . It is preferable that both the electron donating polymer compound and the electron accepting polymer compound are polymer compounds composed of only one or more structural units selected from the group consisting of an arylene group and a divalent heterocyclic group. .

  Whether an electron-donating polymer compound or an electron-accepting polymer compound is determined from the energy level of the highest occupied molecular orbital (HOMO) or the energy level of the lowest unoccupied molecular orbital (LUMO). Relatively determined.

  In the present specification, the arylene group means a group obtained by removing two hydrogen atoms bonded to an aromatic ring from an aromatic hydrocarbon compound, and the number of carbon atoms constituting the aromatic ring is usually about 6 to 60. Preferably, it is 6-20. The arylene group may have a substituent, and the substituent is preferably a halogen atom or a group having 1 to 30 carbon atoms, such as a fluorine atom or an alkyl group having 1 to 30 carbon atoms. , An alkoxy group having 1 to 30 carbon atoms, and an aryl group having 6 to 30 carbon atoms. Examples of the arylene group include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a pyrenediyl group, and a fluorenediyl group.

  The divalent heterocyclic group means a group obtained by removing two hydrogen atoms bonded to the heterocyclic ring from the heterocyclic compound, and the number of carbon atoms constituting the heterocyclic ring is usually about 4 to 60. Preferably, it is 4-20. The divalent heterocyclic group may have a substituent, and the substituent is preferably a halogen atom or a group having 1 to 30 carbon atoms, such as a fluorine atom or 1 to 30 carbon atoms. And an alkyl group having 1 to 30 carbon atoms and an aryl group having 6 to 30 carbon atoms. Examples of the divalent heterocyclic group include a thiophene diyl group, a benzothiadiazole diyl group, a furandyl group, a pyridinediyl group, and a pyrrole diyl group. The divalent heterocyclic group is preferably a divalent aromatic heterocyclic group.

(Electron donating polymer)
The electron-donating polymer compound has a polystyrene-equivalent weight average molecular weight of 20,000 or more and 70,000 or less and is not particularly limited as long as it absorbs light in the wavelength region of sunlight, but the energy level of the highest occupied molecular orbital is −4. A polymer compound having an energy level of 7 eV or less and a lowest unoccupied molecular orbital of −4.0 eV or more is preferable.

  Examples of the electron-donating polymer compound include polythiophene and derivatives thereof, polypyrrole and derivatives thereof, polythiophene and polythiophene derivatives are preferable, and a structure containing 2 to 5 mers of thiophene or 2 to 5 mers of thiophene derivatives A polymer compound having a structure containing is more preferable. Here, the polythiophene derivative is a polymer compound having a thiophenediyl group having a substituent.

  The polythiophene and the polythiophene derivative 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. Specific examples of polythiophene derivatives that are homopolymers include poly (3-hexylthiophene-2,5-diyl) (P3HT), poly (3-octylthiophene-2,5-diyl), poly (3-dodecylthiophene- 2,5-diyl), and poly (3-octadecylthiophene-2,5-diyl). Among the polythiophene derivatives that are homopolymers, polythiophene derivatives composed of thiophene diyl groups substituted with alkyl groups having 6 to 30 carbon atoms are preferred.

(Electron-accepting polymer compound)
The electron-accepting polymer compound has a polystyrene-equivalent weight average molecular weight of 70000 or more. The electron accepting polymer compound is preferably a polymer compound having an energy level of the highest occupied molecular orbital of −5.0 eV or lower and an energy level of the lowest unoccupied molecular orbital of −4.3 eV or higher. Examples of the electron-accepting polymer compound include polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, polyfluorene and derivatives thereof, and polythiophene and derivatives thereof. As the electron-accepting polymer compound, a polymer compound containing a benzothiadiazole structure as a structural unit, a polymer compound containing a quinoxaline structure as a structural unit, or a polymer compound containing a thiophene skeleton as a structural unit is preferable, and a benzothiadiazole as a structural unit A polymer compound containing a structure and a thiophene skeleton is more preferable.

  Examples of the polymer compound containing a benzothiadiazole structure and a thiophene skeleton as structural units include a polymer compound represented by the following formula (3). In formula (3), p represents an integer of 2 or more.

  The weight of the electron-accepting polymer compound relative to the weight of the electron-donating polymer compound in the active layer is preferably 10 to 1000 parts by weight with respect to 100 parts by weight of the electron-donating polymer compound, and 20 parts by weight. More preferably, it is -500 weight part.

  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.

  The weight average molecular weight of the electron donating polymer compound and the electron accepting polymer compound is a value measured by gel permeation chromatography (GPC), and is a weight average molecular weight converted to standard polystyrene.

  What is necessary is just to implement the measurement of the weight average molecular weight converted with polystyrene at the temperature which can dissolve the compound used as a measuring object in a solvent. That is, GPC may be measured under either normal temperature or higher temperature conditions. For example, the GPC measurement of the electron-accepting polymer compound according to the embodiment of the present invention is preferably performed at about 140 ° C. from the viewpoint of solubility in a solvent. An example of GPC measurement conditions in this case is an example in which 2 mg of the polymer to be measured is dissolved in 4 mL of 1,2-dichlorobenzene (ODCB), ODCB is used as a developing solvent, and the flow rate is 1 mL / min. It is done.

  The weight average molecular weight in terms of polystyrene of the electron donating polymer compound is preferably from 20,000 to 70,000, more preferably from 30,000 to 70,000, and more preferably from 40,000 to 70,000 from the viewpoint of photoelectric conversion efficiency. Is more preferable.

  The weight average molecular weight in terms of polystyrene of the electron-accepting polymer compound is preferably 70000 or more from the viewpoint of photoelectric conversion efficiency. Moreover, it is preferable that the polystyrene conversion weight average molecular weight of an electron-accepting high molecular compound is 200000 or less from a synthetic | combination viewpoint.

  In the photoelectric conversion element of the present invention, it is preferable that at least one of the electron donating polymer compound and the electron accepting polymer compound is a polymer compound containing a structural unit containing a thiophene skeleton. It is more preferable that both the molecular compound and the electron-accepting polymer compound are polymer compounds containing a structural unit containing a thiophene skeleton.

  The photoelectric conversion element of the present invention is preferably a polymer compound in which at least one of the electron donating polymer compound and the electron accepting polymer compound includes a structural unit represented by the following formula (1), The electron-accepting polymer compound is more preferably a polymer compound containing a structural unit represented by the following formula (1).

  In formula (1), n and m each independently represent an integer of 0 to 5, an integer of 1 to 3 is preferable, and 1 is more preferable.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a substituent. When there are a plurality of R ^{1 s} , they may be the same or different. When there are a plurality of R ^{2 s} , they may be the same or different. When there are a plurality of R ⁵ , they may be the same or different. When there are a plurality of R ^{6 s} , they may be the same or different.

As the substituent represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , a fluorine atom and a group having 1 to 30 carbon atoms are preferable. Examples of the substituent include an alkyl group such as a fluorine atom, a methyl group, an ethyl group, a butyl group, a hexyl group, an octyl group, and a dodecyl group, a methoxy group, an ethoxy group, a butoxy group, a hexyloxy group, an octyloxy group, and a dodecyl group. Examples thereof include an alkoxy group such as an oxy group, and an aryl group such as a phenyl group and a naphthyl group.

^Further, R ^1, 2 or it is connected one of ^{R 2, R 3, R 4} , R 5 and ^{R 6,} linked to ^{R 1, R 2, R 3} , R 4, of ^{R 5} and ^{R 6} You may form a cyclic structure with the carbon atom which two couple | bonded. R ¹ and R ² are linked, the cyclic structure formed together with the carbon atom to which R ¹ is bonded and the carbon atom to which R ² is bonded, and R ⁵ and R ⁶ are linked, and R ⁵ is bonded. As a specific example of the cyclic structure formed with the carbon atom to which R ⁶ is bonded and the carbon atom to which R ⁶ is bonded, a structure represented by the following formula (4) can be given.

As a specific example of the cyclic structure formed together with the carbon atom to which R ³ and R ⁴ are connected and R ³ is bonded and the carbon atom to which R ⁴ is bonded, a structure represented by the following formula (5) and The structure represented by following formula (6) is mentioned.

In formula (5), R ¹² and R ¹³ each independently represents a hydrogen atom or a substituent.

Specific examples of the substituents represented by R ¹² and R ¹³ are the same as the specific examples of the substituents represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ .

R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are preferably a hydrogen atom and an alkyl group, and more preferably a hydrogen atom.

X ¹ , X ² and X ³ each independently represents a sulfur atom, an oxygen atom, a selenium atom, a group represented by —N (R ⁷ ) —, or a group represented by —CR ⁸ ═CR ⁹ —. Represent. R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent. When there are a plurality of X ¹ , they may be the same or different. When there are a plurality of X ³ , they may be the same or different.

Examples of the substituent represented by R ⁷ , R ⁸ and R ⁹ include alkyl groups such as methyl group, ethyl group, butyl group, hexyl group, octyl group and dodecyl group, and aryl groups such as phenyl group and naphthyl group. Groups.
X ¹ , X ² and X ³ are preferably sulfur atoms.

  As the structural unit represented by the formula (1), a structural unit represented by the following formula (1-1) is preferable.

  When at least one of the electron-donating polymer compound and the electron-accepting polymer compound is a polymer compound containing the structural unit represented by the formula (1), the structural unit represented by the formula (1) However, it is preferable that the polymer compound is contained in the largest amount among all kinds of structural units of the polymer compound.

  From the viewpoint of increasing the photoelectric conversion efficiency of the photoelectric conversion element, the entire structure of the polymer compound having the number of structural units represented by the formula (1) included in the polymer compound including the structural unit represented by the formula (1). The ratio to the total number of units is preferably 50% or more, more preferably 52% or more, and further preferably 55% or more.

  The ratio of the number of structural units represented by the formula (1) to the total number of all structural units in the polymer compound is preferably less than 100%, more preferably 98% or less, More preferably, it is 70% or less.

  At least one of the electron-donating polymer compound and the electron-accepting polymer compound preferably contains another structural unit in addition to the structural unit represented by the formula (1).

  As another structural unit, the structural unit represented by following formula (2) is mentioned, for example. The polymer compound containing the structural unit represented by the formula (1) and the structural unit represented by the following formula (2) is at least one of an electron-donating polymer compound and an electron-accepting polymer compound. It is preferable that it is an electron-accepting polymer compound.

In formula (2), ring A and ring B each independently represent an aromatic ring. R ¹⁰ and R ¹¹ each independently represents a hydrogen atom or a substituent. A ring structure may be formed together with the carbon atom to which R ¹⁰ and R ¹¹ are linked and R ¹⁰ and R ¹¹ are bonded.

Examples of the substituent represented by R ¹⁰ and R ¹¹ include methyl, ethyl, butyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, and the like. Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group and other alkyl groups, and phenyl group, naphthyl group and other aryl groups. The number of carbon atoms of the substituent represented by R ¹⁰ and R ¹¹ is preferably 12 or more. R ¹⁰ and R ¹¹ are preferably an alkyl group and a hydrocarbon group such as an aryl group, and more preferably an alkyl group.

  Examples of the ring A and the ring B include aromatic carbocycles such as a benzene ring and a naphthalene ring, and aromatic heterocycles such as thiophene. Ring A and ring B are preferably 5- to 10-membered rings, and more preferably benzene rings and naphthalene rings.

  As the structural unit represented by the formula (2), a structural unit represented by the following formula (2-1) is preferable.

In formula (2-1), R ¹⁰ and R ¹¹ represent the same meaning as in formula (2).

  When at least one of the electron-donating polymer compound and the electron-accepting polymer compound includes the structural unit represented by the formula (1) and the structural unit represented by the formula (2), the polymer compound It is preferable that the number of structural units represented by the formula (1) is the largest among all types of structural units possessed by and then the number of structural units represented by the formula (2) is large. The high molecular compound containing the structural unit represented by Formula (1) and the structural unit represented by Formula (2) is only the structural unit represented by Formula (1) and the structural unit represented by Formula (2). Preferably it consists of.

  In order to express various functions, the active layer may contain other components in addition to the electron donating polymer compound and the electron accepting polymer compound as necessary. 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 blending amount of the other components is preferably 5 parts by weight or less with respect to 100 parts by weight of the total amount of the electron-donating compound and the electron-accepting compound, and particularly 0.01 to 3 parts by weight. It is effective to mix in an amount.

  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 preferable, and a polymer compound that absorbs less visible light is preferable. Examples of the polymer binder include poly (N-vinylcarbazole), polyaniline and derivatives thereof, polythiophene and derivatives thereof, poly (p-phenylene vinylene) and derivatives thereof, and poly (2,5-thienylene vinylene) and derivatives thereof. , Polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, and polysiloxane.

<Method of synthesizing polymer compound>
The method for synthesizing the electron-donating polymer compound and the electron-accepting polymer compound used in the present invention is not particularly limited, but from the viewpoint of the ease of synthesizing the polymer compound, a Suzuki coupling reaction or Stille is used. A synthetic method using a coupling reaction is preferred.

As a method using the Suzuki coupling reaction, for example, one or more compounds represented by the following formula (100) and one or more compounds represented by the following formula (200) are present in the presence of a palladium catalyst and a base. The manufacturing method which has the process made to react below is mentioned.
Q ₁ -E ₁ -Q ₂ (100)
In formula (100), E ₁ represents an arylene group or a divalent heterocyclic group. Q ₁ and Q ₂ each independently represents a dihydroxyboryl group [—B (OH) ₂ ] or a borate ester residue.
T ₁ -E ₂ -T ₂ (200)
In Formula (200), E ₂ represents a group represented by Formula (1). T ₁ and T ₂ each independently represent a halogen atom or a sulfonic acid residue.

E ₁ is preferably a group represented by the formula (2). E ₂ may be the same group as E ₁ or a different group, but is preferably a different group.

  The boric acid ester residue means a group obtained by removing a hydroxyl group from a boric acid diester, and examples thereof include a dialkyl ester residue, a diaryl ester residue, and a di (arylalkyl) ester residue. Examples of the boric acid ester residue include groups represented by the following formula.

  In the formula, Me represents a methyl group, and Et represents an ethyl group.

In the formula (200), examples of the halogen atom represented by T ₁ and T ₂ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In view of the ease of synthesis of the polymer compound, a bromine atom and an iodine atom are preferable, and a bromine atom is more preferable.

In formula (200), the sulfonic acid residue represented by T ₁ and T ₂ means an atomic group obtained by removing acidic hydrogen from sulfonic acid (—SO ₃ H), and specific examples include an alkyl sulfonate group. (For example, methanesulfonate group, ethanesulfonate group), arylsulfonate group (for example, benzenesulfonate group, p-toluenesulfonate group), arylalkylsulfonate group (for example, benzylsulfonate group) and trifluoromethanesulfonate group.

  Specifically, the method for carrying out the Suzuki coupling reaction includes a method in which a palladium catalyst is used as a catalyst in an arbitrary solvent and the reaction is performed in the presence of a base.

  Examples of the palladium catalyst used in the Suzuki coupling reaction include a Pd (0) catalyst and a Pd (II) catalyst. Specifically, palladium [tetrakis (triphenylphosphine)], palladium acetates, dichlorobis ( Triphenylphosphine) palladium, palladium acetate, tris (dibenzylideneacetone) dipalladium, and bis (dibenzylideneacetone) palladium. From the viewpoint of ease of reaction (polymerization) operation and reaction (polymerization) rate, dichlorobis ( Triphenylphosphine) palladium, palladium acetate, and tris (dibenzylideneacetone) dipalladium are preferred.

  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). , Preferably 0.0003 mol to 0.1 mol.

  When palladium acetate is used as a palladium catalyst used in the Suzuki coupling reaction, for example, a phosphorus compound such as triphenylphosphine, tri (o-tolyl) phosphine, tri (o-methoxyphenyl) phosphine is added as a ligand. can do. In this case, the addition amount of the ligand is usually 0.5 mol to 100 mol, preferably 0.9 mol to 20 mol, more preferably 1 mol to 10 mol, relative to 1 mol of the palladium catalyst. is there.

  Examples of the base used for the Suzuki coupling reaction include inorganic bases, organic bases, inorganic salts and the like. Examples of the inorganic base include potassium carbonate, sodium carbonate, and barium hydroxide. Examples of the organic base include triethylamine and tributylamine. An example of the inorganic salt is cesium fluoride.

  The addition amount of the base is usually 0.5 mol to 100 mol, preferably 0.9 mol to 20 mol, more preferably 1 mol to 10 mol, relative to 1 mol of the compound represented by the formula (100). It is.

The Suzuki coupling reaction is usually performed in a solvent. Examples of the solvent used include N, N-dimethylformamide, toluene, dimethoxyethane, and tetrahydrofuran. From the viewpoint of solubility of the polymer compound used in the present invention, toluene and tetrahydrofuran are preferred. Further, the base may be added as an aqueous solution and reacted in a two-phase system. When an inorganic salt is used as the base, it is usually added as an aqueous solution and reacted from the viewpoint of solubility of the inorganic salt.
In addition, when adding a base as aqueous solution and making it react with a two-phase system, you may add phase transfer catalysts, such as a quaternary ammonium salt, as needed.

  Although the temperature at which the Suzuki coupling reaction is performed depends on the solvent, it is usually about 50 ° C. to 160 ° C., and 60 ° C. to 120 ° C. is preferable from the viewpoint of increasing the molecular weight of the polymer compound. Alternatively, the temperature may be raised to near the boiling point of the solvent and refluxed. The reaction time may be the end when the target degree of polymerization is reached, but is usually about 0.1 to 200 hours. About 1 hour to 30 hours is efficient and preferable.

The reaction is performed in a reaction system in which the Pd (0) catalyst is not deactivated under an inert atmosphere containing argon gas, nitrogen gas, or the like.
Here, the inert atmosphere refers to a place filled with a gas whose oxygen and water contents are below a certain value.

  The concentration of oxygen in the inert atmosphere is preferably 10 ppm or less, and the concentration of water is preferably 0.1 ppm or less.

  Examples of gases that can be used to construct an inert atmosphere include argon gas, nitrogen gas, and the like.

  The reaction is performed in a system sufficiently deaerated with, for example, argon gas or nitrogen gas. Specifically, in the reaction, after the gas in the polymerization vessel (reaction system) is sufficiently substituted with nitrogen gas and degassed, the polymerization vessel is charged with the compound represented by the formula (100), the formula (200). The compound represented by), dichlorobis (triphenylphosphine) palladium (II), and the gas in the polymerization vessel is sufficiently replaced with nitrogen gas and degassed, and then degassed by bubbling with nitrogen gas in advance. After adding a solvent, for example, toluene, to this solution, a base degassed by bubbling with nitrogen gas in advance, for example, an aqueous sodium carbonate solution was added dropwise, and then heated and heated, for example, at a reflux temperature. It can be carried out while maintaining an inert atmosphere for 8 hours.

  The terminal groups of the electron-donating polymer compound and the electron-accepting polymer compound, when the polymerization active group remains as it is, reduces the characteristics and lifetime of the photoelectric conversion element obtained when used for the production of the photoelectric conversion element. May be protected with a stable group. This stable group is preferably a group having a conjugated bond continuous with the conjugated structure of the main chain.

<Method for forming active layer>
The method for producing a photoelectric conversion element according to the present invention is a process for producing a photoelectric conversion element having a first electrode and a second electrode, and having an active layer between the first electrode and the second electrode. In this method, at least one of the electron donating polymer compound and the electron accepting polymer compound comprises only one or more structural units selected from the group consisting of an arylene group and a divalent heterocyclic group. An inert atmosphere comprising a polymer compound, which includes an electron-donating polymer compound having a polystyrene-equivalent weight average molecular weight of 20000 to 70000 and an electron-accepting polymer compound having a polystyrene-equivalent weight average molecular weight of 70000 or more. A step of forming an active layer by applying undercoat.

  In the method for producing a photoelectric conversion element of the present invention, the step of forming the active layer is a step of forming the active layer by further applying heat treatment in an inert atmosphere after applying the solution in an inert atmosphere. It is preferable.

  The step of forming the active layer is performed using a solution containing an electron donating polymer compound and an electron accepting polymer compound.

  From the viewpoint of improving the characteristics of the photoelectric conversion element, the coating step using a solution containing an electron donating polymer compound and an electron accepting polymer compound for forming an active layer is performed in an inert atmosphere. From the viewpoint of reducing the manufacturing cost, it is preferable to use nitrogen gas in order to obtain an inert atmosphere.

  The solvent used in the solution for coating is not particularly limited as long as it dissolves the electron donating polymer compound and the electron accepting polymer compound. Examples of the solvent include hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexyl, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, Examples include halogenated hydrocarbon solvents such as chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, chlorobenzene, dichlorobenzene, and trichlorobenzene, and ether solvents such as tetrahydrofuran and tetrahydropyran. . The electron donating polymer compound and the electron accepting polymer compound can usually be dissolved in the solvent in an amount of 0.1% by weight or more.

  For solution application, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, gravure printing method Application methods such as flexographic printing method, offset printing method, inkjet printing method, dispenser printing method, nozzle coating method, capillary coating method, spin coating method, flexographic printing method, gravure printing method, inkjet printing method, And the dispenser printing method is preferred.

  From the viewpoint of improving the mixing state of the electron-donating polymer compound and the electron-accepting polymer compound in the active layer and improving the crystallinity of the electron-donating polymer compound and the electron-accepting polymer compound, It is preferable to heat-treat the film (coating film) formed after coating in an inert atmosphere under an inert atmosphere. From the viewpoint of improving the mixed state of the electron-donating polymer compound and the electron-accepting polymer compound or improving the crystallinity of the electron-donating polymer compound and the electron-accepting polymer compound, the temperature of the heat treatment is The temperature is preferably 120 ° C. or higher, and more preferably 140 ° C. or higher.

<Application of photoelectric conversion element>
The photoelectric conversion element of the present invention can be operated as an organic thin film solar cell by generating photovoltaic power in an active layer between electrodes by making light such as sunlight enter from a transparent or translucent electrode side. . It can also be used as a solar cell module by accumulating a plurality of organic thin film solar cells.

  In addition, since a photocurrent flows when light is incident from the transparent or translucent electrode side with voltage applied between the electrodes or without application, a plurality of photoelectric conversion elements or photoelectric conversion elements are integrated. The solar cell module can be operated as an organic light sensor. It can also be used as an image sensor by integrating a plurality of organic light sensors.

<Solar cell module>
The organic thin film solar cell 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. Specifically, a module structure called a super straight type, a substrate type, and a potting type, a substrate integrated module structure used in an amorphous silicon solar cell, and the like are known. The organic thin film solar cell using the photoelectric conversion element of the present invention can also be appropriately selected from these solar cell module structures depending on the purpose of use, the place of use and the environment.

  In a typical super straight type or substrate type solar cell module, cells are arranged at regular intervals between support substrates that are transparent on one or both sides and treated with antireflection, and adjacent cells are metal leads or flexible wiring. The current collecting electrodes are arranged on the outer edge portion, and the generated power is taken out to the outside. Various types of plastic materials such as ethylene vinyl acetate (EVA) may be used between the 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. Also, when used in places where there is no need to cover the surface with a hard material, such as where there is little impact from the outside, the surface protective layer is made of a transparent plastic film, or the protective function is achieved by curing the filling resin. It is possible to eliminate the supporting substrate on one side. The periphery of the support substrate is fixed in a sandwich shape with a metal frame in order to ensure the internal sealing and the rigidity of the solar cell module, and the support substrate and the frame are hermetically sealed with a sealing material. In addition, if a flexible material is used for the cell itself, the support substrate, the filling material, and the sealing material, a solar cell module having a curved surface can be configured.

  In the case of a solar cell using a flexible support such as a polymer film, cells are sequentially formed while feeding out a roll-shaped support, cut to a desired size, and then the periphery is sealed with a flexible and moisture-proof material. Thus, the battery body can be produced. Moreover, it can also be set as the solar cell module structure called "SCAF" as described in Solar Energy Materials and Solar Cells, 48, p383-391.

  Hereinafter, examples will be shown to describe the present invention in more detail, but the present invention is not limited to the examples.

(Synthesis Example 1) Synthesis of Polymer Compound A1 Polymer compound A1 was synthesized using the following monomer (1) and the following monomer (2).

  Into a 200 mL flask in which the internal gas was replaced with argon gas, 1.181 g (2.00 mmol) of monomer (1), 0.9164 g (2.00 mmol) of monomer (2), Aliquat 336 (Aldrich) 460 mg, toluene (40 mL), and tris (o-methoxyphenyl) phosphine (26.4 mg) were added to form a suspension. The resulting suspension was bubbled with argon gas for 30 minutes. After bubbling, 5.2 mg of palladium (II) acetate was added, and the flask was immersed in an oil bath at 100 ° C. Thereafter, 10 mL of a 16.7% by weight aqueous sodium carbonate solution was added dropwise over 15 minutes. After the dropwise addition, the mixture was stirred at 100 ° C. for 3.5 hours, and then a solution prepared by dissolving 270 mg of phenyl borate in 1 mL of THF was added and further stirred at 100 ° C. for 9 hours. After stirring, the flask was cooled to 25 ° C., and 25 mL of toluene was added. The resulting solution was washed twice with 50 mL of water, washed twice with 50 mL of a 3 wt% aqueous acetic acid solution, and further washed twice with 50 mL of water. The obtained organic layer was poured into 1000 mL of methanol to precipitate a polymer.

  The precipitated polymer was collected by filtration to obtain 1.43 g of polymer. The polymer obtained was dissolved in 100 mL of chloroform and purified by passing through a column packed with 100 g of alumina. The obtained chloroform solution was poured into methanol for precipitation, filtered and dried to obtain a purified polymer. The obtained purified polymer is referred to as polymer compound A1. The weight average molecular weight measured under high temperature conditions (140 ° C.) was a polystyrene equivalent weight average molecular weight of 78,000, and a polystyrene equivalent number average molecular weight of 28,000.

  A polymer comprising the same structural unit as the polymer compound A1 and having a molecular weight different from that of the polymer compound A1 by the same reaction route as in Synthesis Example 1 using the monomer (1) and the monomer (2). Compound A2 and polymer compound A3 were obtained. The polymer compound A2 measured at 140 ° C. had a polystyrene equivalent weight average molecular weight of 43,300 and a polystyrene equivalent number average molecular weight of 19,400. The polystyrene equivalent weight average molecular weight of the polymer compound A3 measured at 140 ° C. was 26900, and the polystyrene equivalent number average molecular weight was 8,000.

Example 1 Production and Evaluation of Photoelectric Conversion Element A glass substrate with an ITO film having a thickness of 150 nm formed by sputtering was ultrasonically cleaned for 15 minutes each using toluene, acetone and ethanol in this order, and then UV- Using an O ₃ cleaning machine (Nippon Laser & Electronics Lab, NL-UV253S), surface treatment was performed by cleaning with ozone generated by irradiation of ultraviolet rays for 30 minutes.

  A poly (3,4-ethylenedioxythiophene): poly (4-styrenesulfonate) (PEDOT: PSS, HC Stark, PH-500) is spin-coated on a surface-treated ITO substrate ( 400 rpm, 10 s, 3000 rpm, 99 s) to obtain a thin film. The obtained thin film was heat-treated at 140 ° C. for 10 minutes in the air.

  Next, poly (3-hexylthiophene) which is an electron donating polymer compound represented by the following formula (polymer compound B, manufactured by Aldrich, Mw = 42300, Mw / Mn = 1.9, RR = 90%) The electron-accepting polymer compound A1 was weighed so that the ratio of the weight of the electron-accepting polymer compound A1 to the weight of the polymer compound B was 1. Chloroform (Nacalai Tesque, spectral characteristic reagent) was added under an inert atmosphere using nitrogen gas in the glove box so that the total concentration of the polymer compound B and the electron-accepting polymer compound A1 was 12 mg / mL. The mixture was stirred at 60 ° C. for 3 hours to prepare a chloroform solution. The obtained chloroform solution was applied by spin coating (3000 rpm, 60 s) on a thin film of PEDOT: PSS in an inert atmosphere using nitrogen gas in a glove box to form a film. The thickness of the formed film was about 66 nm. The structure on which the film was formed was heat-treated at 140 ° C. for 10 minutes in an inert atmosphere in a glove box to form an active layer. Then, the photoelectric conversion element was produced by vapor-depositing Ca layer with a thickness of 10 nm on an active layer with a vacuum evaporation machine, and vapor-depositing Al layer with a thickness of 70 nm then. The planar shape seen from the thickness direction of the obtained photoelectric conversion element was a circle having a diameter of 3.0 mm.

The obtained photoelectric conversion element is irradiated with light equivalent to sunlight (AM1.5G, 100 mWcm ^-2 ) using a solar simulator (Eagle Engineering, Xe500ES-AM1.5G), and the generated current is measured and short-circuited. The current density (J _SC ), open circuit voltage (V _OC ), fill factor (FF), and photoelectric conversion efficiency (η) were determined. J _SC is 5.687mAcm _{^-2, V OC} is 1.282V, FF is .6305, eta was 4.597%.

Comparative Example 1 Production and Evaluation of Photoelectric Conversion Element A photoelectric conversion element was produced and evaluated in the same manner as in Example 1 except that polymer compound A2 (weight average molecular weight 43300) was used instead of polymer compound A1. did. J _SC is 2.64mAcm _{^-2, V OC} is 1.26V, FF is 0.559, eta was 1.86%.

Comparative Example 2 Production and Evaluation of Photoelectric Conversion Element A photoelectric conversion element was produced and evaluated in the same manner as in Example 1 except that polymer compound A3 (weight average molecular weight 26900) was used instead of polymer compound A1. did. J _SC is 3.976mAcm _{^-2, V OC} is 1.286V, FF is 0.588, eta was 3.006%.

  As described above, according to the photoelectric conversion element of the present invention, since the active layer is formed by applying a solution in an inert atmosphere, the electrical characteristics of the active layer are reduced due to, for example, oxygen. It can suppress and can improve photoelectric conversion efficiency. In order to improve the photoelectric conversion efficiency, the microphase separation structure should be a more preferable structure by setting the weight average molecular weight of the electron-donating polymer compound and the electron-accepting polymer compound within the predetermined range described above. Is considered to have contributed.

  The photoelectric conversion element concerning this invention is useful for application to photoelectric devices, such as a solar cell and an optical sensor, and can be used especially suitably as a solar cell.

Claims (9)

A photoelectric conversion element having a first electrode and a second electrode, and having an active layer between the first electrode and the second electrode,
The active layer is formed by applying a solution containing an electron-donating polymer compound and an electron-accepting polymer compound under an inert atmosphere, and the active layer includes the electron-donating polymer compound and the electron-accepting polymer compound. A polymer comprising at least one structural unit selected from the group consisting of an arylene group which may have a substituent and a divalent heterocyclic group which may have a substituent. A photoelectric conversion element, which is a compound, wherein the electron-donating polymer compound has a polystyrene-equivalent weight average molecular weight of 20,000 or more and 70000 or less, and the electron-accepting polymer compound has a polystyrene-equivalent weight average molecular weight of 70000 or more. .   Both the electron-donating polymer compound and the electron-accepting polymer compound are polymer compounds composed of only one or more structural units selected from the group consisting of an arylene group and a divalent heterocyclic group. The photoelectric conversion element according to claim 1.   3. The photoelectric conversion device according to claim 1, wherein at least one of the electron donating polymer compound and the electron accepting polymer compound is a polymer compound containing a structural unit containing a thiophene skeleton. 4. The polymer compound according to claim 1, wherein at least one of the electron-donating polymer compound and the electron-accepting polymer compound is a polymer compound containing a structural unit represented by the following formula (1). The photoelectric conversion element of a term.

(In the formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom or a substituent. R ¹ , R ² , R ³ , R ⁴ , 2 is connected one of R ⁵ and ^{R 6,} ring together with the carbon atom to which two of ^{R 1, R 2, R 3} , R 4, R 5 and ^{R 6} which are connected are coupled respectively X ¹ , X ² and X ³ each independently represent a sulfur atom, an oxygen atom, a selenium atom, a group represented by —N (R ⁷ ) —, or —CR ⁸ ═ CR ⁹ - represents a group represented by ^.R 7, ^{R 8} and ^{R 9} each independently, .n and m represents a hydrogen atom or a substituent, each independently, represent an integer of 0 to 5. When there are a plurality of R ^{1 s} , they may be the same or different, and when there are a plurality of R ^{2 s} , they are the same. When there are a plurality of R ^{5 s} , they may be the same or different, and when there are a plurality of R ^{6 s} , they may be the same or different. When there are a plurality of X ^{1 s} , they may be the same or different.When there are a plurality of X ^{3 s} , they may be the same or different.)   In the polymer compound containing the structural unit represented by the formula (1), the structural unit represented by the formula (1) is the structural unit represented by the formula (1) among all types of structural units of the polymer compound. The photoelectric conversion element according to claim 4, wherein most of the structural unit represented by 1) is contained.   The solar cell module containing the photoelectric conversion element of any one of Claims 1-5.   The image sensor containing the photoelectric conversion element of any one of Claims 1-5, or the solar cell module of Claim 6. A method of manufacturing a photoelectric conversion element having a first electrode and a second electrode, and having an active layer between the first electrode and the second electrode,
At least one of the electron donating polymer compound and the electron accepting polymer compound is a polymer compound comprising only one or more structural units selected from the group consisting of an arylene group and a divalent heterocyclic group. And applying a solution containing an electron-donating polymer compound having a polystyrene-equivalent weight average molecular weight of 20000 or more and 70000 or less and an electron-accepting polymer compound having a polystyrene-equivalent weight average molecular weight of 70000 or more in an inert atmosphere. The manufacturing method of the photoelectric conversion element of any one of Claims 1-7 including the process of forming an active layer.   The photoelectric conversion element according to claim 8, wherein the step of forming the active layer is a step of forming the active layer by applying heat treatment under an inert atmosphere after applying the solution under an inert atmosphere. Manufacturing method.