Laminate, photoelectric conversion element, and method for manufacturing photoelectric conversion element

Abstract

Provided is a laminate in which deflection due to vacuum adsorption or the like is suppressed. A laminate according to one aspect of the present invention includes: a resin film substrate; a first resin film; and a photoelectric conversion layer disposed between the resin film substrate and the first resin film. If the laminate does not have a resin film on a side opposite to a side where the photoelectric conversion layer is provided, with the resin film substrate serving as a reference, the tensile elastic modulus E1 (GPa) and the thickness T1 (μm) of the laminate satisfy 1000 ≤ E1 × T1.

Description

LAMINATE, PHOTOELECTRIC CONVERSION ELEMENT, AND METHOD FOR MANUFACTURING PHOTOELECTRIC CONVERSION ELEMENT

[0001] The present invention relates to a laminate, a photoelectric conversion element, and a method for manufacturing a photoelectric conversion element.

[0002] For example, a device is known that has a laminate including an active layer (also referred to as a photoelectric conversion layer), an electron transport layer, and a hole transport layer as functional layers of a photoelectric conversion element (Patent Document 1), and efforts are being made to improve solar cells, such as organic thin-film solar cells, that include such devices.

[0003] JP 2012-114424 A

[0004] In the manufacture of organic thin-film solar cells, functional layers can be formed by coating, making it easy to manufacture them on flexible resin film substrates. Organic thin-film solar cells formed on resin film substrates are characterized by being flexible and lightweight. When manufacturing such organic thin-film solar cells, for example, sealing may be performed by attaching a film with barrier properties to prevent the various layers formed on the resin film substrate from being deteriorated by moisture and oxygen in the air.

[0005] Various layers are formed on a resin film substrate, and the thus sealed laminate is then handled using a vacuum suction cup or vacuum lifter for transportation. The resin film substrates typically used in organic thin-film solar cells are thin, at 300 μm or less, and deflection of the laminate occurs at the suction points, for example, when vacuum-chucked during transportation. In organic thin-film solar cells, the side of the resin film substrate that is vacuum-chucked is the light-receiving surface. Repeated vacuum suction and stress release by a vacuum chuck, for example, can easily cause scratches on the light-receiving surface due to the deflection. Scratches on the light-receiving surface can reduce the light-capturing efficiency of the laminate. Furthermore, large deflections can cause cracks in the functional layers of the laminate, reducing the photoelectric conversion efficiency.

[0006] The present invention has been made in light of the above-mentioned circumstances, and its object is to provide a laminate in which deflection due to vacuum suction or the like is suppressed, a photoelectric conversion element using the laminate, and a method for manufacturing a photoelectric conversion element using the laminate.

[0007] That is, the present invention may include the following aspects. [1] A laminate comprising a resin film substrate, a first resin film, and a photoelectric conversion layer between the resin film substrate and the first resin film, wherein when the laminate does not have a resin film on the side opposite to the side on which the photoelectric conversion layer is provided, relative to the resin film substrate, the tensile modulus E1 (GPa) and thickness T1 (μm) of the laminate satisfy the following formula (A): 1000≦E1×T1(A) , and when the laminate has a second resin film on the side opposite to the side on which the photoelectric conversion layer is provided, relative to the resin film substrate, the tensile modulus E2 (GPa) and thickness T2 (μm) of the laminate satisfy the following formula (B): 1500≦E2×T2(B) . [2] The laminate according to the above item [1], wherein the thickness T1 is 200 μm or more and 600 μm or less, and the thickness T2 is 400 μm or more and 1000 μm or less. [3] The laminate according to [1] or [2] above, wherein the resin film substrate has a tensile modulus of 3.5 GPa or more and 8.0 GPa or less, and a thickness of the resin film substrate is 110 μm or more and 280 μm or less. [4] The laminate according to any one of [1] to [3] above, wherein the first resin film and the second resin film each have a tensile modulus of 3.0 GPa or more and 9.0 GPa or less, and a thickness of the first resin film and the second resin film each have a thickness of 80 μm or more and 300 μm or less. [5] The laminate according to any one of [1] to [4] above, wherein the laminate does not have a resin film on the side opposite to the side on which the photoelectric conversion layer is provided, and wherein the absolute value of the amount of warping when heated at 110°C for 30 minutes is 200 μm or less. [6] A laminate comprising a resin film substrate, a first resin film, and a photoelectric conversion layer between the resin film substrate and the first resin film, wherein the laminate does not have a resin film on the side opposite to the side on which the photoelectric conversion layer is provided relative to the resin film substrate, and the tensile modulus E1 (GPa) and thickness T1 (μm) of the laminate satisfy the following formula (A): 1000≦E1×T1 (A) [7] The laminate according to the above [6], wherein the thickness T1 is 200 μm or more and 600 μm or less.[8] The laminate according to [6] or [7] above, wherein the resin film substrate has a tensile modulus of 3.5 GPa to 8.0 GPa and a thickness of 110 μm to 280 μm. [9] The laminate according to any one of [6] to [8] above, wherein the first resin film has a tensile modulus of 3.0 GPa to 9.0 GPa and a thickness of 80 μm to 300 μm.

[10] The laminate according to any one of [6] to [9] above, wherein the absolute value of the amount of warpage when heated at 110°C for 30 minutes is 200 μm or less.

[11] A laminate comprising a resin film substrate, a first resin film, and a photoelectric conversion layer between the resin film substrate and the first resin film, wherein the laminate has a second resin film on the side opposite to the side on which the photoelectric conversion layer is provided relative to the resin film substrate, and wherein the tensile modulus E2 (GPa) and thickness T2 (μm) of the laminate satisfy the following formula (B): 1500≦E2×T2(B).

[12] The laminate according to

[11] above, wherein the thickness T1 is 200 μm or more and 600 μm or less, and the thickness T2 is 400 μm or more and 1000 μm or less.

[13] The laminate according to

[11] or

[12] above, wherein the tensile modulus of the resin film substrate is 3.5 GPa or more and 8.0 GPa or less, and the thickness of the resin film substrate is 110 μm or more and 280 μm or less.

[14] The laminate according to any one of

[11] to

[13] above, wherein the tensile modulus of each of the first resin film and the second resin film is 3.0 GPa or more and 9.0 GPa or less, and the thickness of each of the first resin film and the second resin film is 80 μm or more and 300 μm or less.

[15] A photoelectric conversion element using the laminate according to any one of [1] to

[14] above.

[16] The photoelectric conversion element according to

[15] above, wherein the photoelectric conversion element is an organic thin-film solar cell.

[17] A method for producing a photoelectric conversion element using the laminate according to any one of [1] to

[14] above.

[0008] In the laminate of the present invention, by satisfying formula (A) or (B), deflection of the light-receiving surface due to vacuum suction of the laminate during handling is suppressed. As a result, it is possible to suppress the occurrence of scratches on the light-receiving surface due to repeated vacuum suction and stress release, etc. Furthermore, it is possible to suppress the occurrence of cracks in the functional layer of the laminate. This suppresses deterioration of photoelectric conversion efficiency. Furthermore, in the laminate of the present invention, by satisfying formula (A) or by sandwiching the resin film substrate between the first resin film and the second resin film, warping during heating is suppressed, and the laminate is less susceptible to damage due to warping.

[0009] It is a diagram showing an example of the configuration of the laminate according to the first embodiment. It is a diagram showing another example of the configuration of the laminate according to the first embodiment. It is a diagram showing a schematic configuration of an apparatus for measuring the amount of warpage of the laminate according to the first embodiment.

[0010] The present invention will be described in more detail below based on the following embodiments. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are within the technical scope of the present invention. In each drawing, hatching and component symbols may be omitted for convenience. In such cases, reference should be made to the specification and other drawings. Furthermore, the dimensions of various components in the drawings may differ from their actual dimensions, as priority is given to helping understand the features of the present invention.

[0011] For ease of reference, examples are shown in the drawings, and descriptions in this specification may use the notation "up" and "down," but the present embodiment is not necessarily limited thereto. For example, products and methods that can be realized by the ideas disclosed in this specification even when the orientation is changed, such as upside down, are considered to be within the scope of the disclosure of this embodiment. In this specification, the expressions "contain" and "comprise" include the concepts of "contain," "comprise," "substantially consist," and "consist only of." In this specification, "A and / or B" means "one of A and B" or "both A and B," and specifically means "A," "B," or "A and B."

[0012] In this specification, the relationship between two components A and B may be described as "component B is provided on component A," "component B is provided on the upper surface of component A," or "component B is in contact with component A." Such descriptions are intended to allow not only cases where components A and B are in direct contact with each other, but also cases where another component is interposed between them to the extent that the effect is not impaired.

[0013] With respect to the numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in one stage can be arbitrarily combined with the upper or lower limit of a numerical range in another stage. With respect to the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in an example or a value that can be unambiguously derived from an example. In this specification, a numerical range connected with "to" means a numerical range that includes the numbers before and after "to" as the lower and upper limits.

[0014] <Laminate> Fig. 1 shows an example of the configuration of a laminate 1 according to the first embodiment. The laminate 1 includes a resin film substrate 11 and a resin film (also referred to as a first resin film) 12, and further includes a photoelectric conversion layer 133 between the resin film substrate 11 and the resin film 12. The resin film 12 is provided, for example, on the resin film substrate 11 so as to cover the photoelectric conversion layer 133. As will be described later, the photoelectric conversion layer 133 is capable of photoelectric conversion, and by providing a configuration for extracting electricity generated by photoelectric conversion, the laminate 1 can be used as a photoelectric conversion element. An example of a photoelectric conversion element is an organic thin-film solar cell.

[0015] In the example of FIG. 1 , the laminate 1 does not have a resin film on the side opposite to the side on which the photoelectric conversion layer 133 is provided, relative to the resin film substrate 11. In this case, it is preferable that no other layer is provided on the surface of the resin film substrate 11 opposite to the side on which the photoelectric conversion layer 133 is provided. That is, it is preferable that in the laminate 1, the surface of the resin film substrate 11 opposite to the side on which the photoelectric conversion layer 133 is provided is exposed. In the example of FIG. 1 , it is preferable that in the laminate 1, the surface of the resin film 12 opposite to the side on which the photoelectric conversion layer 133 is provided is exposed. When the term "exposed" is used in this specification, it is intended to also include the case where other components, such as a barrier layer described below, are provided on the surface to the extent that the effect is not impaired.

[0016] 1 shows an example in which the laminate 1 further includes a first conductive layer 131, a first transport layer 132, a second transport layer 134, and a second conductive layer 135. The first conductive layer 131, the first transport layer 132, the photoelectric conversion layer 133, the second transport layer 134, and the second conductive layer 135 are provided in this order on the resin film substrate 11. In this specification, the first transport layer 132, the photoelectric conversion layer 133, and the second transport layer 134 may be collectively referred to as "functional layers." The first conductive layer 131, the first transport layer 132, the photoelectric conversion layer 133, the second transport layer 134, and the second conductive layer 135 may be covered by the resin film 12 on the resin film substrate 11, but when the laminate 1 includes the first conductive layer 131, a portion of the first conductive layer 131 may be extended outside the resin film 12 to serve as an extraction electrode, as shown in FIG. 1 . It is preferable that the first transport layer 132, the photoelectric conversion layer 133, the second transport layer 134, and the second conductive layer 135 are each covered by the resin film 12 on the resin film substrate 11 so as not to be exposed outside the resin film 12. Note that the layers provided between the resin film substrate 11 and the resin film 12 are sometimes collectively referred to as "intermediate layers." The intermediate layer includes a photoelectric conversion layer 133, and may optionally include one or more of a first conductive layer 131, a first transport layer 132, a second transport layer 134, and a second conductive layer 135.

[0017] Figure 2 shows another example of the configuration of the laminate 1 according to the first embodiment. The following description will mainly focus on differences from the description made with reference to Figure 1. The description made with reference to Figure 1 also applies to the example in Figure 2 to the extent that it does not contradict the following description. Furthermore, although the following description may include a description of the laminate 1 without specifying whether it relates to Figure 1 or Figure 2, the description will apply to both the examples in Figures 1 and 2.

[0018] 2, the laminate 1 has a resin film (also referred to as a second resin film) 14 on the side opposite to the side on which the photoelectric conversion layer 133 is provided, with respect to the resin film substrate 11. In this case, the resin film 14 is preferably provided so as to contact the surface of the resin film substrate 11 opposite to the side on which the photoelectric conversion layer 133 is provided. In the example of FIG. 2, it is preferable that the surface of the resin film 14 opposite to the side on which the resin film substrate 11 is provided is exposed in the laminate 1.

[0019] When the laminate 1 includes the second resin film 14 as in the example of Figure 2, it is preferable that the sizes of the first resin film 12 and the second resin film 14 are each larger than the size of the resin film substrate 11 when viewed in the thickness direction of the resin film substrate 11 (the direction perpendicular to the resin film substrate 11), and that the first resin film 12 and the second resin film 14 cover the resin film substrate 11 so as to sandwich it around the entire periphery. In this case, for example, by providing a through electrode that penetrates the first resin film 12 and reaches the first conductive layer 131, the laminate 1 of the example of Figure 2 can be used as a photoelectric conversion element, as in the example of Figure 1. Alternatively, the size of the first resin film 12 may be such that the first conductive layer 131 is exposed when the resin film substrate 11 is sandwiched and covered by the first resin film 12 and the second resin film 14.

[0020] <Resin Film Substrate> The constituent material of the resin film substrate 11 is not particularly limited and is appropriately selected depending on the application of the photoelectric conversion element. Examples of the constituent material of the resin film substrate 11 include polyester films such as PET film and PEN film; PES (polyethersulfone) film; polyamide films such as nylon film; polycarbonate film; cycloolefin film; etc., and polyester film is preferred, and PET film or PEN film is more preferred.

[0021] The thickness of the resin film substrate 11 is preferably 50 μm or more and 350 μm or less, more preferably 75 μm or more and 300 μm or less, and even more preferably 100 μm or more and 250 μm or less.

[0022] A barrier layer for insulating the photoelectric conversion layer 133 and the like from the outside air may be provided on the surface of the resin film substrate 11 facing the photoelectric conversion layer 133 or on the surface opposite to the photoelectric conversion layer 133. The material for the barrier layer is preferably a material with low oxygen permeability and water vapor permeability, and is preferably a transparent material. The barrier layer is, for example, an inorganic thin film, not a resin film. For example, a method for forming the resin film substrate 11 provided with a barrier layer includes a method for forming a transparent inorganic thin film such as silicon oxide or aluminum oxide as a barrier layer on a polymer film serving as the resin film substrate 11. Examples of methods for forming a transparent inorganic thin film on a film include a sol-gel method, a PVD (Physical Vapor Deposition) method, an electron beam evaporation method, a plasma CVD (Chemical Vapor Deposition) method, and a reactive sputtering method. An example of a method for forming the barrier layer is a method of forming a film of silicon-based compounds such as silicon nitride, silicon oxide, silicon oxynitride, and silicon carbide, aluminum-based compounds such as aluminum oxide and aluminum nitride, aluminum silicate, zirconium oxide, tantalum oxide, titanium oxide, indium tin oxide (ITO), titanium nitride, or the like on the resin film substrate 11 (preferably a PEN film) using a plasma CVD method, a Cat-CVD method, a vacuum deposition method, or the like. The thickness of the barrier layer is preferably about 0.05 to 2 μm. The thickness of the barrier layer is sufficiently thin compared to the thickness of the resin film substrate 11, and has almost no effect on the elastic modulus, etc., of the resin film substrate 11.

[0023] <(Transparent) Conductive Layer> The cathode and anode, which may be the first conductive layer 131 and the second conductive layer 135, are made of a conductive material.

[0024] The cathode is preferably made of a conductive material having a work function smaller than that of the anode. The cathode has the function of extracting electrons generated in the photoelectric conversion layer 133. Examples of materials constituting the cathode include conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium-zirconium oxide (IZO), titanium oxide, indium oxide, and zinc oxide; metals such as gold, platinum, silver, chromium, and cobalt, and alloys thereof. When the cathode is a transparent electrode, it is preferable to use a light-transmitting conductive metal oxide such as ITO, zinc oxide, or tin oxide, and ITO is particularly preferable.

[0025] The anode is preferably made of a conductive material having a work function greater than that of the cathode. The anode has the function of extracting holes generated in the photoelectric conversion layer. Examples of materials constituting the anode include metals such as platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, cesium, calcium, and magnesium, and alloys thereof; inorganic salts such as lithium fluoride and cesium fluoride; and metal oxides such as nickel oxide, aluminum oxide, lithium oxide, and cesium oxide. Furthermore, when a conductive n-type semiconductor compound such as zinc oxide is used as a material for the hole transport layer described below, a material having a small work function such as ITO may be used as the anode material.

[0026] The thickness of each of the cathode and anode is preferably 10 nm or more, more preferably 20 nm or more, and even more preferably 40 nm or more, and is preferably 10 μm or less, more preferably 1 μm or less, and even more preferably 500 nm or less.

[0027] <Photoelectric Conversion Layer> The photoelectric conversion layer 133 is a layer where photoelectric conversion occurs, and contains, for example, a p-type semiconductor compound and an n-type semiconductor compound. When the photoelectric conversion element receives light, the light is absorbed by the photoelectric conversion layer 133, electricity is generated at the interface between the p-type semiconductor compound and the n-type semiconductor compound, and the generated electricity is extracted from the cathode and anode. The cathode and anode correspond to the first conductive layer 131 and the second conductive layer 135.

[0028] Known compounds can be used as the p-type semiconductor compound and the n-type semiconductor compound. The p-type semiconductor compound is preferably a polymer compound, and examples thereof include conjugated copolymer semiconductor compounds such as polythiophene, polyfluorene, polyphenylene vinylene, polythienylene vinylene, polyacetylene, and polyaniline; and copolymer semiconductor compounds such as oligothiophenes substituted with alkyl groups or other substituents, with polythiophenes that may have substituents being preferred. Furthermore, the p-type semiconductor compound may also be a copolymer semiconductor compound obtained by copolymerizing two or more types of monomer units. Specific examples of the p-type semiconductor compound that is a polymer compound include PDPPBDT, PDPPDTT, PFs, KP115, PCDTBT, DPPT-TT, PDPP2FT, F82T, F8TBT, F8BT, P3HT-Br10, PPP-P3HT, P3HT (poly(3-hexylthiophene-2,5-diyl)), PhxSDT-DTZ, PBDTDPP-1, P3DDT, PPDTBT, PPDT2FBT, PBDTDPP-2, PCPDTBT-1, PCPDTBT-2, and PBDBT2F(PM6), with P3HT being preferred.

[0029] Examples of n-type semiconductor compounds include low molecular weight compounds such as fullerene or its derivatives, octaazaporphyrin, and perfluoro compounds in which hydrogen atoms of p-type semiconductor compounds are substituted with fluorine atoms (e.g., perfluoropentacene and perfluorophthalocyanine), with fullerene or its derivatives being preferred. Furthermore, examples of n-type semiconductor compounds that can be used include polymeric compounds containing aromatic carboxylic acid anhydrides or imidized products thereof, such as naphthalene tetracarboxylic anhydride, naphthalene tetracarboxylic diimide, perylene tetracarboxylic anhydride, and perylene tetracarboxylic diimide, as their skeletons. Specific examples of polymeric n-type semiconductor compounds include MEH-CN-PPV, F8TBT, PZ1, DCNBT-IDT, P-BNBP-fBT, PF2-DTSi, PDI-V, and PYT. Ｍ , PJ1-H, N2200, Y6, etc.

[0030] Examples of the layer structure of the photoelectric conversion layer 133 include a thin-film stacked structure in which p-type semiconductor compounds and n-type semiconductor compounds are stacked, and a bulk heterojunction structure having a layer in which p-type semiconductor compounds and n-type semiconductor compounds are mixed. The bulk heterojunction structure has a layer (i-layer) in which p-type semiconductor compounds and n-type semiconductor compounds are mixed. The i-layer has a structure in which p-type semiconductor compounds and n-type semiconductor compounds are phase-separated, and carrier separation occurs at the phase interface, and the generated carriers (holes and electrons) are transported to the electrode. From the viewpoint of improving photoelectric conversion efficiency by obtaining a good phase-separated structure, the mass ratio of the p-type semiconductor compounds to the n-type semiconductor compounds in the i-layer (p-type semiconductor compounds / n-type semiconductor compounds) is preferably 0.5 or more, more preferably 1 or more, and preferably 4 or less, more preferably 3 or less, and even more preferably 2 or less.

[0031] The photoelectric conversion layer 133 may contain an additive in addition to the p-type semiconductor compound and the n-type semiconductor compound. The phase-separated structure between the p-type semiconductor compound and the n-type semiconductor compound in a bulk heterojunction photoelectric conversion layer affects light absorption, exciton generation and diffusion, exciton dissociation (carrier separation), carrier transport, etc., so optimizing the phase-separated structure is expected to achieve good photoelectric conversion efficiency. By including an additive having a high affinity for the p-type semiconductor compound or the n-type semiconductor compound in the photoelectric conversion layer 133, a photoelectric conversion layer having a preferable phase-separated structure can be obtained, and photoelectric conversion efficiency can be improved.

[0032] Examples of additives include aliphatic hydrocarbon compounds having 8 to 20 carbon atoms and aromatic compounds having 8 to 20 carbon atoms. These aliphatic hydrocarbon compounds and aromatic compounds may have a substituent. Examples of the substituent that the aliphatic hydrocarbon compound may have include a halogen atom, a hydroxyl group, a mercapto group, a cyano group, an amino group, a carbamoyl group, a carbonyloxy group, a carboxyl group, a carbonyl group, and an aromatic group. Examples of the substituent that the aromatic compound may have include a halogen atom, a hydroxyl group, a cyano group, an amino group, an amido group, a carbonyloxy group, a carboxyl group, a carbonyl group, an oxycarbonyl group, a silyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, and an aromatic group. Specific examples of preferred additives include benzene which may have a substituent, naphthalene which may have a substituent, and octane which may have a substituent. A halogen atom is particularly preferred as the substituent.

[0033] In order to obtain a photoelectric conversion element such as an organic thin-film solar cell that exhibits high conversion efficiency, the photoelectric conversion layer 133 preferably contains an organic semiconductor compound, more preferably contains a polymeric p-type semiconductor compound and / or an n-type semiconductor compound, and further preferably contains a polymeric p-type semiconductor compound and a low-molecular-weight n-type semiconductor compound.

[0034] The photoelectric conversion layer 133 may contain a polymer compound having a benzobisthiazole structural unit as a p-type semiconductor compound, and specifically, it preferably contains a polymer compound having a benzobisthiazole structural unit represented by the following formula (1) (hereinafter referred to as "polymer compound P").

[0035]

[0036] In the above formula (1), T １ and T ２each independently represents an alkoxy group; a thioalkoxy group; a thiophene ring optionally substituted with a hydrocarbon group or an organosilyl group; a thiazole ring optionally substituted with a hydrocarbon group or an organosilyl group; or a phenyl group optionally substituted with a hydrocarbon group, an alkoxy group, a thioalkoxy group, an organosilyl group, a halogen atom, or a trifluoromethyl group. １ and B ２ each independently represents a thiophene ring optionally substituted with a hydrocarbon group, a thiazole ring optionally substituted with a hydrocarbon group, or an ethynylene group. The organosilyl group refers to a monovalent group in which one or more hydrocarbon groups are substituted on a Si atom, and the number of hydrocarbon groups substituted on the Si atom is preferably 2 to 3, and more preferably 3.

[0037] The polymer compound P has a benzobisthiazole structural unit represented by formula (1), and thus can narrow the band gap while deepening the HOMO level, thereby increasing the photoelectric conversion efficiency.

[0038] In the benzobisthiazole structural unit represented by formula (1), T １ and T ２ may be the same or different from each other, but are preferably the same from the viewpoint of ease of production. １ , B ２ may be the same or different from each other, but are preferably the same from the viewpoint of ease of production.

[0039] In the benzobisthiazole structural unit represented by formula (1), T １ and T ２ are preferably groups represented by the following formulae (t1) to (t5), respectively. １ and T ２As the alkoxy group, a group represented by the following formula (t1) is preferred, as the thioalkoxy group, a group represented by the following formula (t2) is preferred, as the thiophene ring which may be substituted with a hydrocarbon group or an organosilyl group, a group represented by the following formula (t3) is preferred, as the thiazole ring which may be substituted with a hydrocarbon group or an organosilyl group, a group represented by the following formula (t4) is preferred, and as the phenyl group which may be substituted with a hydrocarbon group, an alkoxy group, a thioalkoxy group, an organosilyl group, a halogen atom or a trifluoromethyl group, a group represented by the following formula (t5) is preferred. １ and T ２ is a group represented by the following formulae (t1) to (t5), it is possible to absorb light of a short wavelength, and since it has high planarity, π-π stacking is efficiently formed, thereby improving the photoelectric conversion efficiency. The groups represented by formulae (t1) to (t3) exhibit electron-donating properties, and the groups represented by formulae (t4) and (t5) exhibit electron-withdrawing properties.

[0040]

[0041] In the above formulas (t1) to (t5), R １３ and R １４ R each independently represents a hydrocarbon group having 6 to 30 carbon atoms. １５ and R １６ are each independently a hydrocarbon group having 6 to 30 carbon atoms, or *-Si(R １８ ) ３ R represents a group represented by the formula: １５’ is a hydrogen atom, a hydrocarbon group having 6 to 30 carbon atoms, or *-Si(R １８ ) ３ R represents a group represented by the formula: １７ represents a halogen atom, a hydrocarbon group having 6 to 30 carbon atoms, *—O—R １９ , *-S-R ２０ , *-Si(R １８ ) ３ , or *-CF ３ Represents R １８ each independently represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. １８Among them, there are the same R １８ There may be different R １８ There may be R １９ and R ２０ represents a hydrocarbon group having 6 to 30 carbon atoms. * represents a bond bonded to the thiazole ring of benzobisthiazole.

[0042] In the above formulas (t1) to (t5), R １３ ~R １７ , R １９ , R ２０ , and R １５’ The hydrocarbon group having 6 to 30 carbon atoms is preferably a branched hydrocarbon group, more preferably a branched saturated hydrocarbon group. １３ ~R １７ , R １９ , R ２０ , and R １５’ The hydrocarbon group R has a branched structure, which can increase the solubility in organic solvents. １３ ~R １７ , R １９ , R ２０ , and R １５’ The hydrocarbon group preferably has 8 to 25 carbon atoms, more preferably 8 to 20 carbon atoms, and even more preferably 8 to 16 carbon atoms.

[0043] In the above formulas (t1) to (t5), R １５ ~R １７ , and R １５’ *-Si(R １８ ) ３ In the group represented by １８ The aliphatic hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 8 carbon atoms. １８ The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 8, more preferably 6 to 7, and even more preferably 6. １８ Examples of the aromatic hydrocarbon group include a phenyl group. １８ As the R, an aliphatic hydrocarbon group is preferable, a branched aliphatic hydrocarbon group is more preferable, and an isopropyl group is even more preferable. １８ Among them, there are the same R １８There may be different R １８ There may be multiple R １８ are preferably the same. １５ ~R １７ , and R １５’ *-Si(R １８ ) ３ When the group is represented by *—Si(R １８ ) ３ Among these, the group represented by the formula (I) is preferably an alkylsilyl group, more preferably a trimethylsilyl group or a triisopropylsilyl group.

[0044] In the above formula (t5), R １７ When R is a halogen atom, any of fluorine, chlorine, bromine, and iodine can be used. １７ is a halogen atom or *-CF ３ is preferred.

[0045] R １５’ is preferably a hydrogen atom.

[0046] T １ and T ２ As the group represented by formula (t1), groups represented by formula (t3), and (t5) are more preferred, and a group represented by formula (t3) is even more preferred, in terms of excellent planarity of the structural unit represented by formula (1) as a whole.

[0047] In the benzobisthiazole structural unit represented by formula (1), B １ and B ２ is preferably a group represented by any one of the following formulas (b1) to (b3): １ and B ２ When is a group represented by the following formulae (b1) to (b3), the polymer compound P has good planarity and can have an increased photoelectric conversion efficiency.

[0048]

[0049] In the above formulas (b1) to (b3), R ２１ , R ２２ , and R ２１’represents a hydrogen atom or a hydrocarbon group having 6 to 30 carbon atoms. * represents a bond, and in particular the * on the left represents a bond to the benzene ring of benzobisthiazole.

[0050] R ２１ , R ２２ , and R ２１’ is preferably a hydrocarbon group having 6 to 30 carbon atoms, since this may further increase the photoelectric conversion efficiency. ２１ , R ２２ , and R ２１’ When is a hydrogen atom, the formation of a donor-acceptor type semiconducting polymer is facilitated.

[0051] B １ and B ２ are each more preferably a group represented by formula (b1) or (b2). １ and B ２ are groups represented by either formula (b1) or (b2), an interaction occurs between the S atom and the N atom in the benzobisthiazole structural unit, further improving the planarity, thereby enhancing the planarity of the resulting polymer compound P.

[0052] The polymer compound P is preferably a donor-acceptor type semiconducting polymer, and therefore, it is preferable that the polymer compound P has a benzobisthiazole structural unit represented by formula (1) as well as a specific structural unit that provides a donor unit or an acceptor unit. The donor unit means an electron-donating structural unit, and the acceptor unit means an electron-accepting structural unit. In the donor-acceptor type semiconducting polymer, the donor unit and the acceptor unit are preferably arranged alternately, and therefore, the donor-acceptor type semiconducting polymer is preferably a polymer compound in which the benzobisthiazole structural unit represented by formula (1) and the specific structural unit are arranged alternately. By having such a structure, the polymer compound P can be suitably used as a p-type semiconductor compound.

[0053] The specific structural unit may be a conventionally known structural unit that provides a donor unit or an acceptor unit. Specific examples of the specific structural unit include structural units represented by the following formulae (c1) to (c43). Among these, structural units represented by the formulae (c1), (c3) to (c5), (c7), (c9), (c12), (c21), (c27), (c37), and (c42) are preferred, and structural units represented by the formulae (c1), (c5), (c9), (c21), (c37), and (c42) are more preferred.

[0054]

[0055]

[0056] In the above formulas (c1) to (c43), R ３０ ~R ７６ each independently represents a hydrogen atom or a hydrocarbon group having 4 to 30 carbon atoms. ３０ and A ３１ are each independently T １ and T ２ represents the same group as in the structural unit represented by formula (1), and j represents an integer of 1 to 4. １ or B ２ represents a bond bonded to

[0057] The groups represented by the formulae (c1) to (c30) above are groups that act as acceptor units, and the groups represented by the formulae (c32) to (c43) are groups that act as donor units. ３０ and A ３１ Depending on the type of unit, it may act as an acceptor unit or as a donor unit.

[0058] The repeating ratio of the benzobisthiazole structural unit represented by formula (1) in the polymer compound P is usually 1 mol % or more, preferably 5 mol % or more, more preferably 15 mol % or more, and even more preferably 30 mol % or more, and is usually 99 mol % or less, preferably 95 mol % or less, more preferably 85 mol % or less, and even more preferably 70 mol % or less.

[0059] The repeating ratio of the specific structural unit in the polymer compound P is usually 1 mol% or more, preferably 5 mol% or more, more preferably 15 mol% or more, and even more preferably 30 mol% or more, and is usually 99 mol% or less, preferably 95 mol% or less, more preferably 85 mol% or less, and even more preferably 70 mol% or less.

[0060] In the polymer compound P, the arrangement of the benzobisthiazole structural unit represented by formula (1) and the specific structural unit may be any of alternate, block, and random. That is, the polymer compound P may be any of an alternate copolymer, a block copolymer, and a random copolymer. Preferably, the benzobisthiazole structural unit represented by formula (1) and the specific structural unit are arranged alternately.

[0061] The weight-average molecular weight and number-average molecular weight of the polymer compound P are preferably 2,000 or more and 500,000 or less, and more preferably 3,000 or more and 200,000 or less. The weight-average molecular weight and number-average molecular weight of the polymer compound P can be calculated using gel permeation chromatography based on a calibration curve prepared using polystyrene as a standard sample.

[0062] The thickness of the photoelectric conversion layer 133 is preferably 70 nm or more, more preferably 90 nm or more, and even more preferably 100 nm or more, and is preferably 1000 nm or less, more preferably 750 nm or less, still more preferably 500 nm or less, and particularly preferably 300 nm or less.

[0063] <Transport Layer> One of the first transport layer 132 and the second transport layer 134 is an electron transport layer, and the other is a hole transport layer. In the laminate 1, the electron transport layer, photoelectric conversion layer, and hole transport layer may be stacked in this order from the side closest to the resin film substrate 11, or the hole transport layer, photoelectric conversion layer, and electron transport layer may be stacked in this order. While FIGS. 1 and 2 show an example in which the laminate 1 includes the first transport layer 132 and the second transport layer 134, this embodiment is not limited thereto. The laminate 1 may not include at least one of the first transport layer 132 and the second transport layer 134.

[0064] (Electron Transport Layer) The electron transport layer is a layer that extracts electrons from the photoelectric conversion layer 133 to the cathode. The constituent material of the electron transport layer is preferably an electron transporting material that improves the efficiency of electron extraction, and may be either an organic compound or an inorganic compound, but an inorganic compound is preferred.

[0065] The inorganic compound constituting the electron transport layer is preferably a metal compound, such as a salt of an alkali metal, such as lithium, sodium, potassium, or cesium, or a metal oxide. Of these, the alkali metal salt is preferably a fluoride salt, such as lithium fluoride, sodium fluoride, potassium fluoride, or cesium fluoride, and the metal oxide is preferably a metal oxide having n-type semiconductor properties, such as titanium oxide (TiOx) or zinc oxide (ZnO). The organic compound constituting the electron transport layer is preferably a conductive organic compound, such as polyethyleneimine ethoxylate.

[0066] The thickness of the electron transport layer is preferably 0.1 nm or more, more preferably 0.5 nm or more, and even more preferably 1.0 nm or more, and is preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less.

[0067] (Hole transport layer) The hole transport layer is a layer that extracts holes from the photoelectric conversion layer 133 to the anode. The constituent material of the hole transport layer is not particularly limited as long as it is a hole transport material that can improve the efficiency of hole extraction, and examples of the material include conductive organic compounds and metal compounds.

[0068] Examples of conductive organic compounds constituting the hole transport layer include conductive polymers obtained by doping polymers such as polythiophene, polypyrrole, polyacetylene, triphenylenediamine, and polyaniline with sulfonic acid and / or iodine, polythiophene derivatives having sulfonyl groups as substituents, and arylamines. Metal compounds constituting the hole transport layer include metal oxides with p-type semiconductor properties, such as molybdenum trioxide, vanadium pentoxide, and nickel oxide, as well as metals such as gold, indium, silver, and palladium. The hole transport layer may also be formed from a p-type semiconductor compound. Among these, conductive polymers obtained by doping a polymer with sulfonic acid are preferred, and poly(3,4-ethylenedioxythiophene)poly(styrenesulfonic acid) (PEDOT:PSS), obtained by doping a polythiophene derivative with polystyrenesulfonic acid, are more preferred. Metal oxides such as molybdenum oxide and vanadium oxide may also be used.

[0069] The thickness of the hole transport layer is preferably 0.2 nm or more, more preferably 0.5 nm or more, and even more preferably 1.0 nm or more, and is preferably 500 nm or less, and more preferably 400 nm or less.

[0070] <Resin Film> The resin films 12 and 14 are used, for example, as barrier films capable of isolating and sealing the photoelectric conversion layer 133 and the like from the outside air, but the present embodiment is not limited thereto. A barrier layer may be provided on the resin film 12 or 14, and the resin film 12 or 14 and the barrier layer may be used together as a barrier film capable of isolating and sealing the photoelectric conversion layer 133 and the like from the outside air. Such a barrier film can reduce the penetration of oxygen and moisture into the photoelectric conversion layer 133 and the like, thereby improving the long-term durability of a photoelectric conversion element using the laminate 1. In the laminate 1, the barrier layer is preferably provided on the surface of the resin film 12 facing the resin film substrate 11 and / or the surface of the resin film 14 facing the resin film substrate 11.

[0071] Examples of the resin films 12 and 14 include polyester films such as PET film and PEN film; PES (polyethersulfone) film; polyamide films such as nylon film; polycarbonate film; cycloolefin film, etc., and polyester film is preferred, with PET film or PEN film being more preferred.

[0072] The same explanation as given for the barrier layer that can be provided on the resin film substrate 11 applies to the barrier layer that can be provided on the resin film 12 and / or 14 .

[0073] The thicknesses of the resin films 12 and 14 are not limited, but are preferably 30 μm to 300 μm, more preferably 40 μm to 280 μm, and even more preferably 50 μm to 250 μm. When, for example, the resin film 12 and a barrier layer provided on the resin film 12 are used as the barrier film, an inorganic thin film made of silicon nitride or the like is used as the barrier layer, and the thickness of the inorganic thin film is preferably approximately 0.05 to 2 μm. The thickness of the barrier layer is sufficiently thin compared to the thickness of the resin film 12, and has little effect on the elastic modulus of the resin film 12, etc. Similarly, when a barrier layer provided on the resin film 14 is used, an inorganic thin film made of silicon nitride or the like is used as the barrier layer, and the thickness of the inorganic thin film is preferably approximately 0.05 to 2 μm. The thickness of the barrier layer is sufficiently thin compared to the thickness of the resin film 14, and has little effect on the elastic modulus of the resin film 14, etc.

[0074] When attaching the resin film 12 to the resin film substrate 11 or the like, an adhesive method suitable for each material can be applied. Examples include a method of attaching a barrier film with an adhesive, or a method of attaching a barrier film by thermocompression bonding using a heat press or laminator. Using a barrier film having a hot melt layer or adhesive layer on one side allows the barrier film to be easily attached to the resin film substrate 11. Olefin-based resins, rubber-based resins, silicone-based resins, and acrylic-based resins are preferably used as adhesives. The adhesive itself may have a low water vapor permeability, or if the water vapor permeability is high, the sealing properties of the photoelectric conversion layer 133 or the like can be improved by adding a moisture scavenger or reducing the coating thickness.

[0075] The adhesive may be applied in a frame-like manner to the four sides of the surface to which the barrier film is attached, or may be applied to the entire surface. If the adhesive is applied to the entire surface, it must be within a range that does not affect the photoelectric conversion element due to shrinkage when the adhesive hardens.

[0076] The resin films 12 and 14 used in the laminate 1 in the example of Fig. 2 preferably have the same configuration (composition and thickness) as each other. This is because warping when the laminate 1 is heated is due to differences in thermal shrinkage and coefficient of thermal expansion (CTE) between the resin films 12 and 14, and when the laminate 1 is heated, warping is canceled out across the entire laminate 1 between the resin films 12 and 14, which have the same configuration.

[0077] <Shape and Elastic Modulus of Laminate> The shape of the laminate 1 is not particularly limited, and may be a square or rectangular shape when viewed in the thickness direction of the resin film substrate 11 (direction perpendicular to the resin film substrate 11). When the shape of the laminate 1 is square or rectangular, for example, the shape of the resin film substrate 11 when viewed in the thickness direction of the resin film substrate 11 (direction perpendicular to the resin film substrate 11) is also square or rectangular.

[0078] When the resin film substrate 11 has a square or rectangular shape, the two sides of the square or rectangle will be referred to as the long side and the short side for convenience. In the case of a square, the long side and the short side are assumed to be the same length. The long side and the short side of the resin film substrate 11 are each, for example, 20 mm to 2000 mm, or may be 30 mm to 1500 mm, preferably 45 mm to 1000 mm, more preferably 50 mm to 200 mm, even more preferably 65 mm to 150 mm, even more preferably 80 mm to 120 mm, particularly preferably 85 mm to 110 mm, and most preferably 90 mm to 105 mm.

[0079] When the resin film substrate 11 has the above-mentioned square or rectangular shape, the resin films 12 and 14 are preferably also square or rectangular. For each of the resin films 12 and 14, when the resin film has a square or rectangular shape, the two sides of the square or rectangle will be described using the terms "long side" and "short side" for convenience. The lengths of the two sides of each of the resin films 12 and 14 here are those in a planar state before the formation of the laminate 1. As described above, when the resin film has a square shape, the long side and short side are assumed to be the same length. The long and short sides of each of the resin films 12 and 14 are, for example, 20 mm to 2000 mm, and may be 30 mm to 1500 mm, preferably 45 mm to 1000 mm, more preferably 50 mm to 200 mm, even more preferably 65 mm to 150 mm, even more preferably 80 mm to 120 mm, particularly preferably 85 mm to 110 mm, and most preferably 90 mm to 105 mm. In the example of Figure 1, the long and short sides of the resin film 12 are, for example, smaller than the long and short sides of the resin film substrate 11. In the example of Figure 2, the long and short sides of each of the resin films 12 and 14 are, for example, larger than the long and short sides of the resin film substrate 11.

[0080] In the laminate 1 of the example shown in FIG. 1 , that is, when the laminate 1 does not have a resin film on the side opposite the side where the photoelectric conversion layer 133 is provided relative to the resin film substrate 11, the tensile modulus E1 and thickness T1 of the laminate 1 satisfy formula (A). E1 is expressed in GPa, and T1 is expressed in μm. 1000≦E1×T1 (A) E1×T1 is more preferably 1100 or more, even more preferably 1150 or more, and particularly preferably 1250 or more. While there is no particular upper limit, E1×T1 is preferably 6000 or less, more preferably 4500 or less, even more preferably 3000 or less, and particularly preferably 2200 or less. That is, E1×T1 is preferably 1000 or more and 6000 or less, more preferably 1100 or more and 4500 or less, even more preferably 1150 or more and 3000 or less, and particularly preferably 1250 or more and 2200 or less. When E1×T1 satisfies the above formula (A), deformation (deflection) of the laminate 1, for example, when vacuum-chucked, is suppressed, thereby preventing scratches on the light-receiving surface. Furthermore, cracks in the functional layer of the laminate 1 can also be suppressed. This can prevent deterioration of photoelectric conversion efficiency. Therefore, a laminate 1 satisfying formula (A) is useful when using the laminate 1 to manufacture a photoelectric conversion element through the handling process described above. In addition, if another layer is provided on the side of the resin film 12 opposite to the side on which the photoelectric conversion layer 133 is provided, the tensile modulus of the laminate structure from the resin film substrate 11 to the other layer provided on the opposite side is defined as the tensile modulus E1 in formula (A), and the thickness of the laminate structure is defined as the thickness T1 in formula (A). In other words, in the above case, the portion corresponding to the laminate structure is considered to be the laminate 1.

[0081] The tensile modulus E1 of the laminate 1 is preferably 4.5 GPa or more and 6.0 GPa or less, more preferably 4.8 GPa or more and 5.8 GPa or less, and even more preferably 5.0 GPa or more and 5.5 GPa or less. The thickness T1 of the laminate 1 is preferably 200 μm or more and 600 μm or less, more preferably 230 μm or more and 500 μm or less, and even more preferably 250 μm or more and 400 μm or less. The tensile modulus E1 and thickness T1 of the laminate 1 are measured by the methods described in the examples.

[0082] The tensile modulus E1 of the laminate 1 can be controlled by, for example, the tensile modulus and thickness of the resin film substrate 11 and the tensile modulus and thickness of the resin film 12 that constitute the laminate 1.

[0083] In the example of Figure 1, the following applies to the tensile modulus and thickness of the resin film substrate 11 and the resin film 12. The tensile modulus of the resin film substrate 11 is, for example, 3.0 GPa to 9.0 GPa, preferably 3.5 GPa to 8.0 GPa, and more preferably 3.8 GPa to 6.3 GPa. The thickness of the resin film substrate 11 is, for example, 100 μm to 300 μm, preferably 110 μm to 280 μm, and more preferably 120 μm to 260 μm. The tensile modulus of the resin film 12 is preferably 3.0 GPa to 9.0 GPa, more preferably 3.5 GPa to 8.0 GPa, and even more preferably 3.8 GPa to 6.3 GPa. The thickness of the resin film 12 is preferably 80 μm or more and 300 μm or less, more preferably 85 μm or more and 280 μm or less, and even more preferably 90 μm or more and 260 μm or less.

[0084] The ratio of the thickness of the resin film substrate 11 to the thickness T1 of the laminate 1 (thickness of the resin film substrate 11 / thickness T1) is preferably 0.25 or more and 0.80 or less, more preferably 0.30 or more and 0.75 or less, and even more preferably 0.32 or more and 0.70 or less. This range makes it easier for the tensile modulus E1 of the laminate 1 to be determined by the tensile modulus and thickness of the resin film substrate 11 and the tensile modulus and thickness of the resin film 12. The ratio of the thickness of the resin film 12 to the thickness T1 of the laminate 1 (thickness of the resin film 12 / thickness T1) is preferably 0.20 or more and 0.75 or less, more preferably 0.23 or more and 0.70 or less, and even more preferably 0.27 or more and 0.65 or less. This range makes it easier for the tensile modulus E1 of the laminate 1 to be determined by the tensile modulus and thickness of the resin film substrate 11 and the tensile modulus and thickness of the resin film 12.

[0085] The ratio of the thickness of the resin film 12 to the thickness of the resin film substrate 11 (thickness of the resin film 12 / thickness of the resin film substrate 11) is preferably 0.30 or more and 3.0 or less, more preferably 0.35 or more and 2.7 or less, and even more preferably 0.38 or more and 2.2 or less.

[0086] The thickness of the layer (intermediate layer) provided between the resin film substrate 11 and the resin film 12 included in the laminate 1 of the example shown in FIG. 1 is preferably 20 μm or less, more preferably 10 μm or less, even more preferably 1 μm or less, and particularly preferably 800 nm or less. In particular, when the laminate 1 includes a first conductive layer 131 as shown in FIG. 1 and there is a portion of the first conductive layer 131 that is not covered by the resin film 12, the thickness of the first conductive layer 131 is preferably 10 μm or less, more preferably 1 μm or less, and even more preferably 100 nm or less. The lower limit of the thickness of the intermediate layer is not particularly limited, and is preferably, for example, 70 nm or more, more preferably 90 nm or more. The ratio of the thickness of the intermediate layer to the thickness of the laminate 1 (thickness of the intermediate layer / thickness of the laminate 1) is preferably 0.0001 to 0.1, more preferably 0.0005 to 0.05, even more preferably 0.0007 to 0.01, and particularly preferably 0.001 to 0.005. It should be noted that this refers to the total thickness when the intermediate layer is composed of multiple layers (when a layer other than the photoelectric conversion layer is included between the resin film substrate 11 and the resin film 12). When the thickness T1 and tensile modulus E1 of the laminate 1 are within this range, the layer configuration other than the resin film substrate 11 and the resin film 12 included in the laminate 1 has almost no effect on the tensile modulus E1 and thickness T1 of the laminate 1.

[0087] When the above formula (A) is satisfied, warpage of the laminate 1 is suppressed. For example, if the absolute value of the amount of warpage when the laminate 1 is heated is small, the laminate 1 or a photoelectric conversion element using the laminate 1 is less likely to be damaged by warpage when exposed to sunlight and heated, or when heated in a process of connecting the laminate 1 or a photoelectric conversion element using the laminate 1 to an electronic device. This can suppress deterioration of photoelectric conversion efficiency. The absolute value of the amount of warpage when the laminate 1 satisfying the above formula (A) is heated at 110°C for 30 minutes is, for example, 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 70 μm or less. The method for measuring the amount of warpage of the laminate 1 at 110°C is the method described in the Examples.

[0088] In the laminate 1 of the example shown in FIG. 2 , that is, when the laminate 1 has a resin film 14 on the side opposite to the side on which the photoelectric conversion layer 133 is provided, with respect to the resin film substrate 11, the tensile modulus E2 and thickness T2 of the laminate 1 satisfy formula (B). E2 is expressed in GPa, and T2 is expressed in μm. 1500≦E2×T2 (B) E2×T2 is more preferably 1800 or more, even more preferably 2000 or more, and particularly preferably 2500 or more. While there is no particular upper limit, E2×T2 is preferably 6000 or less, more preferably 5000 or less, even more preferably 4000 or less, and particularly preferably 3500 or less. That is, E2×T2 is preferably 1500 or more and 6000 or less, more preferably 1800 or more and 5000 or less, even more preferably 2000 or more and 4000 or less, and particularly preferably 2500 or more and 3500 or less. When E2 × T2 satisfies the above formula (B), deformation (deflection) of the laminate 1, for example, when vacuum-chucked, is suppressed, thereby preventing scratches on the light-receiving surface. Furthermore, cracks in the functional layer of the laminate 1 can also be suppressed. This can prevent deterioration of photoelectric conversion efficiency. Therefore, a laminate 1 satisfying formula (B) is useful when using the laminate 1 to manufacture a photoelectric conversion element through the handling process described above. Even if a layer other than the second resin film 14 is provided on the surface of the resin film substrate 11 opposite the side on which the photoelectric conversion layer 133 is provided, the tensile modulus of the laminate structure from the layer other than the second resin film 14 provided on the opposite surface to the resin film 12 is defined as the tensile modulus E2 in formula (B), and the thickness of the laminate structure is defined as the thickness T2 in formula (B). In other words, in the above case, the portion corresponding to the laminate structure is considered to be the laminate 1.

[0089] The tensile modulus E2 of the laminate 1 is preferably 3.5 GPa or more and 7.0 GPa or less, more preferably 4.0 GPa or more and 6.5 GPa or less, and even more preferably 5.0 GPa or more and 6.0 GPa or less. The thickness T2 of the laminate 1 is preferably 400 μm or more and 1000 μm or less, more preferably 450 μm or more and 900 μm or less, and even more preferably 500 μm or more and 800 μm or less. The tensile modulus E2 and thickness T2 of the laminate 1 are measured by the methods described in the examples.

[0090] The tensile modulus E2 of the laminate 1 can be controlled by, for example, the tensile modulus and thickness of the resin film substrate 11 that constitutes the laminate 1 and the tensile modulus and thickness of the resin films 12 and 14 .

[0091] In the example of Figure 2, the following applies to the tensile modulus and thickness of the resin film substrate 11 and the tensile modulus and thickness of each of the resin films 12 and 14. The tensile modulus of the resin film substrate 11 is, for example, 3.0 GPa to 9.0 GPa, preferably 3.5 GPa to 8.0 GPa, and more preferably 3.8 GPa to 6.1 GPa. The thickness of the resin film substrate 11 is, for example, 100 μm to 300 μm, preferably 110 μm to 280 μm, and more preferably 120 μm to 260 μm. The tensile modulus of each of the resin films 12 and 14 is preferably 3.0 GPa to 9.0 GPa, more preferably 3.8 GPa to 8.0 GPa, and even more preferably 5.7 GPa to 6.3 GPa. The thickness of each of the resin films 12 and 14 is preferably 80 μm or more and 300 μm or less, more preferably 100 μm or more and 280 μm or less, and even more preferably 120 μm or more and 260 μm or less.

[0092] The ratio of the thickness of the resin film substrate 11 to the thickness T2 of the laminate 1 (thickness of the resin film substrate 11 / thickness T2) is preferably 0.10 or more and 0.65 or less, more preferably 0.15 or more and 0.60 or less, and even more preferably 0.19 or more and 0.50 or less. This range makes it easier for the tensile modulus E2 of the laminate 1 to be determined by the tensile modulus and thickness of the resin film substrate 11 and the tensile modulus and thickness of the resin films 12 and 14. The ratio of the total thickness of the resin films 12 and 14 to the thickness T2 of the laminate 1 (total thickness of the resin films 12 and 14 / thickness T2) is preferably 0.35 or more and 0.90 or less, more preferably 0.43 or more and 0.85 or less, and even more preferably 0.49 or more and 0.79 or less. This range makes it easier for the tensile modulus E2 of the laminate 1 to be determined by the tensile modulus and thickness of the resin film substrate 11 and the tensile modulus and thickness of the resin films 12 and 14.

[0093] The ratio of the total thickness of resin films 12 and 14 to the thickness of resin film substrate 11 (total thickness of resin films 12 and 14 / thickness of resin film substrate 11) is preferably 0.50 or more and 6.0 or less, more preferably 0.70 or more and 5.0 or less, and even more preferably 0.90 or more and 4.2 or less.

[0094] The thickness of the layer (intermediate layer) provided between the resin film substrate 11 and the resin film 12 included in the laminate 1 of the example of FIG. 2 is preferably 20 μm or less, more preferably 10 μm or less, even more preferably 1 μm or less, and particularly preferably 800 nm or less. The lower limit of the thickness of the intermediate layer is not particularly limited, and is preferably, for example, 70 nm or more, more preferably 90 nm or more. The thickness of the intermediate layer relative to the thickness of the laminate 1 (thickness of the intermediate layer / thickness of the laminate 1) is preferably 0.0001 to 0.1, more preferably 0.0005 to 0.05, even more preferably 0.0007 to 0.01, and particularly preferably 0.001 to 0.005. Note that when the intermediate layer is composed of multiple layers (when layers other than the photoelectric conversion layer are included between the resin film substrate 11 and the resin film 12), the thickness refers to the total thickness. When the thickness is within such a range, the tensile modulus E2 and thickness T2 of the laminate 1 are hardly affected by the layer structure other than the resin film substrate 11, resin film 12, and resin film 14 contained in the laminate 1.

[0095] This application claims the benefit of priority based on Japanese Patent Application No. 2024-009707, filed on January 25, 2024. The entire contents of the specification of Japanese Patent Application No. 2024-009707, filed on January 25, 2024, are incorporated herein by reference.

[0096] The present invention will be described in detail below using examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. In the following, for the purpose of ease of reference, the names of the components described with reference to Figures 1 and 2 may be used, but the reference numerals described with reference to Figures 1 and 2 may be omitted in the description.

[0097] <Preparation of Resin Film Substrate> In the examples and comparative examples, the following commercially available films S1 to S5 were used as the resin film substrate. S1: Teonex Q51 (PEN film manufactured by Toyobo Co., Ltd., thickness 125 μm, tensile modulus 5.9 GPa) S2: Teonex Q51 (PEN film manufactured by Toyobo Co., Ltd., thickness 250 μm, tensile modulus 6.1 GPa) S3: A4160 (PET film manufactured by Toyobo Co., Ltd., thickness 125 μm, tensile modulus 4.0 GPa) S4: A4360 (PET film manufactured by Toyobo Co., Ltd., thickness 250 μm, tensile modulus 4.0 GPa) S5: PEN film with ITO (thickness 125 μm, 50 nm ITO film formed on one side of S1 by sputtering, tensile modulus 5.9 GPa)

[0098] <Preparation of Resin Films> In the Examples and Comparative Examples, the following commercially available films B1 to B5 were used as the first resin film and the second resin film. B1: E5100 (PET film manufactured by Toyobo Co., Ltd., thickness 100 μm, tensile modulus 4.0 GPa) B2: Teonex Q51 (PEN film manufactured by Toyobo Co., Ltd., thickness 125 μm, tensile modulus 5.9 GPa) B3: Teonex Q51 (PEN film manufactured by Toyobo Co., Ltd., thickness 250 μm, tensile modulus 6.1 GPa) B4: Torayfan BO (PP film manufactured by Toray Industries, Inc., thickness 40 μm, tensile modulus 0.2 GPa) B5: Toretec R213 (polyolefin film manufactured by Toray Industries, Inc., thickness 60 μm, tensile modulus 0.3 GPa)

[0099] <Measurement of Resin Film Thickness> The thicknesses of the resin film substrate, the first resin film, and the second resin film were measured using a macrometer (Militron 1245D, manufactured by Fine Leaf Co., Ltd.). The results are shown in Table 1.

[0100] <Measurement of Thickness (T1 and T2) of Laminate> The thickness (T1 and T2) of each laminate of the examples and comparative examples was measured using a high-precision Digimatic micrometer (MDH-25M, manufactured by Mitutoyo Corporation). The results are shown in Table 1.

[0101] <Tensile Modulus of Elasticity (E1 and E2) of Laminate> Each laminate of the Examples and Comparative Examples was cut into a 100 mm x 10 mm strip in the machine direction of the film using a cutter to prepare a test specimen. Using a tensile tester (Shimadzu Corporation, Autograph Model AG-5000A), the tensile modulus (E1 or E2) was measured in both the MD and TD directions at a tension speed of 50 mm / min and a chuck distance of 40 mm, and the average value was taken as the tensile modulus of elasticity (E1 or E2) of the laminate. The results are shown in Table 1.

[0102] <Warp Amount When Heated at 110°C> The amount of warp at 110°C for each laminate of Examples 1 to 6 and Comparative Examples 1 and 2 was measured using the apparatus shown in FIG. 3 . For this measurement, a line was drawn with a black marker on the surface of the laminate where the displacement was to be measured (the portion directly below the slit in the slit-equipped insulating cover 33). Glass beads 37 were placed on the heating portion of the hot plate 36, and the laminate was placed with the resin film substrate side in contact with the glass beads 37 and heated to 110°C. The hot plate 36 and the entire laminate were covered with the slit-equipped insulating cover 33. The glass beads were used to suppress the influence of one-sided heating of the laminate by the hot plate. After 30 minutes had elapsed since the start of heating, the amount of warp was measured using a laser displacement meter 31. The distance from the corner of the top surface of the resin film 12 (the surface opposite the resin film substrate 11) to the hot plate 36 was measured, and the thickness of the resin film substrate 11 and the glass beads 37 was subtracted from this measurement to determine the amount of warp. The position of the laser displacement meter 31 was changed using the rail-equipped angle 32, and the amount of warpage was measured at the four corners of the upper surface of the resin film substrate in the laminate, and the average value was taken as the amount of warpage of the laminate when heated to 110° C. The results are shown in Table 1. A Keyence LK-H-055 was used as the laser displacement meter 31.

[0103] <Deformation of Laminate Due to Vacuum Chuck> The laminates of the Examples and Comparative Examples were set on a stage with a 1 mm diameter vacuum suction hole, and vacuum suction was performed. A Keyence LK-G85 laser displacement meter was set directly above the vacuum suction hole, and the deflection was evaluated by calculating the deformation amount from the displacement when the suction was on and off. Measurements were performed at five locations on the same laminate, with n = 5 at each location, and the average value was calculated. During vacuum suction, deviations of approximately ±10 μm occurred even without suction due to device vibration, so cases where the absolute value of the deformation amount was 10 μm or less are marked with an * in Table 1.

[0104] Example 1: A resin film substrate S1 was cut to a size of 100 mm x 100 mm using a cutter. A resin film B1 cut to a size of 95 mm x 95 mm was attached to the center of the cut resin film substrate S1 as a first resin film using Aron Alpha EXTRA 2000 manufactured by Toagosei. An adhesive was applied to the entire surface of the first resin film, and the thickness of the adhesive was controlled to 10 μm by immediately passing it through a laminator using a spacer. This produced a laminate including a resin film substrate and a first resin film.

[0105] Example 2 The same procedure as in Example 1 was carried out, except that the resin film substrate was changed to S2.

[0106] Example 3 The same procedure as in Example 1 was carried out, except that the resin film substrate was S3 and the first resin film was B2.

[0107] Example 4 The same procedure as in Example 3 was carried out, except that the first resin film was changed to B3.

[0108] Example 5 The same procedure as in Example 3 was carried out, except that the resin film substrate was S5 and the first resin film was B1.

[0109] Example 6: A resin film substrate S5 (size: 100 mm x 100 mm) was washed with acetone and then dried with clean dry air. A ZnO nanoparticle dispersion manufactured by Avantama was dripped onto the substrate, and the substrate was coated with a coating gap of 25 μm using a No. 0 bar and heated at 80°C for 10 minutes. As a result, an electron transport layer with a thickness of approximately 50 nm was obtained. After wiping off the coating with acetone, leaving an area of ​​95 mm x 95 mm, a photoelectric conversion layer solution was dripped onto the substrate, and the coating was performed with a coating gap of 50 μm and heated at 100°C for 5 minutes. As a result, a photoelectric conversion layer with a thickness of approximately 250 nm was obtained. The photoelectric conversion layer solution was prepared by dissolving equal masses of poly(3-hexylthiophene-2,5-diyl) and the fullerene derivative Nanom Spectra (E100H manufactured by Frontier Carbon Corporation) in chlorobenzene. After wiping the coating with chlorobenzene, leaving a 95 mm x 95 mm area, HTL solar (PEDOT:PSS manufactured by Heraeus-Epirio) was dripped onto the substrate, coated with a coating gap of 50 μm, and heated at 80°C for 30 minutes. This resulted in a hole transport layer approximately 400 nm thick. The coating was then wiped with pure water, leaving a 95 mm x 95 mm area. Resin film B1, cut to 98 mm x 98 mm, was then attached to the substrate as a first resin film using Aron Alpha EXTRA 2000 manufactured by Toagosei. An adhesive was applied to the entire surface of the first resin film, and the adhesive thickness was controlled to 10 μm by immediately passing it through a laminator using a spacer. This produced a laminate comprising a resin film substrate, a first resin film, and a photoelectric conversion layer.

[0110] Example 7 Two pieces of resin film B1 were prepared by cutting them to a size of 100 mm x 100 mm with a cutter. One of the cut B1 pieces was used as the second resin film, and a resin film substrate S4 cut to 95 mm x 95 mm was placed in the center of it. The other cut B1 piece was used as the first resin film, and Aron Alpha EXTRA 2000 manufactured by Toagosei was applied to the entire surface of the first resin film. The other B1 piece, which served as the second resin film, was then bonded to the resin film substrate S4. The thickness of the adhesive was controlled to 10 μm by immediately passing the pieces through a laminator using a spacer. This produced a laminate in which the resin film substrate was sandwiched between the first and second resin films on both sides.

[0111] Example 8 A laminate was produced in the same manner as in Example 7, except that the first resin film and the second resin film were changed to B2.

[0112] Example 9 A laminate was produced in the same manner as in Example 7, except that the first resin film and the second resin film were changed to B3.

[0113] Example 10 A laminate was produced in the same manner as in Example 9, except that the resin film substrate was changed to S5.

[0114] Example 11 A laminate was produced in the same manner as in Example 8, except that the resin film substrate was changed to S1.

[0115] Comparative Example 1 A laminate was produced in the same manner as in Example 1, except that the first resin film was changed to B4.

[0116] Comparative Example 2 A laminate was produced in the same manner as in Example 1, except that the first resin film was changed to B5.

[0117] Comparative Example 3 A laminate was produced in the same manner as in Example 7, except that the first resin film and the second resin film were changed to B4.

[0118] Comparative Example 4 A laminate was produced in the same manner as in Example 7, except that the resin film substrate was changed to S3, and the first resin film and the second resin film were changed to B5.

[0119]

[0120] <Laminates Not Comprising a Second Resin Film> In the laminates of Examples 1 to 6, the tensile modulus E1 (GPa) and thickness T1 (μm) satisfy the above formula (A). On the other hand, in the laminates of Comparative Examples 1 and 2, the above formula (A) is not satisfied. Therefore, the following relationship exists between the deformation amount during vacuum suction and the warpage amount during heating. In the laminates of Examples 1 to 6, the magnitude of the deformation amount during vacuum suction was significantly smaller than that of the laminates of Comparative Examples 1 and 2. Furthermore, in the laminates of Examples 1 to 6, the absolute value of the warpage amount during heating was also significantly smaller than that of the laminates of Comparative Examples 1 and 2. In a laminate including a photoelectric conversion layer, when the magnitude of the deformation amount during vacuum suction is small, the occurrence of scratches on the light-receiving surface and the occurrence of cracks in the functional layer of the laminate are suppressed, and the deterioration of photoelectric conversion efficiency is suppressed. When the absolute value of the warpage amount during heating is small, the deterioration of photoelectric conversion efficiency due to damage caused by warpage is suppressed.

[0121] The laminate of Example 6 has a configuration similar to that of Example 5, except that multiple layers, including a photoelectric conversion layer, are further provided between the resin film substrate and the first resin film. The total thickness of the multiple layers is thought to be approximately 700 nm, which is minute compared to the thickness T1 of the laminate. The laminate of Example 6 has similar amounts of deformation during vacuum suction and warpage during heating as the laminate of Example 5. Therefore, from the results of Examples 6 and 5, it can be seen that the intermediate layer, such as a photoelectric conversion layer, provided between the resin film substrate and the first resin film is a very thin layer compared to the resin film substrate and the first resin film, and therefore the presence or absence of the intermediate layer has little effect on the amount of deformation during vacuum suction or the amount of warpage during heating.

[0122] As in Example 5, in Examples 1 to 4, the absolute values ​​of the deformation amount during vacuum suction and the warpage amount during heating were smaller than those of the laminates of Comparative Examples 1 and 2. Therefore, in Examples 1 to 4, even when an intermediate layer was additionally provided between the resin film substrate and the first resin film, the absolute values ​​of the deformation amount during vacuum suction and the warpage amount during heating were better than those of the laminates of Comparative Examples 1 and 2, and the absolute values ​​of the deformation amount during vacuum suction and the warpage amount during heating were significantly smaller than those of the laminates of Comparative Examples 1 and 2. From the above, it was found that since the evaluation of a laminate without an intermediate layer was similar to the evaluation of a laminate with an intermediate layer, if the absolute values ​​of the deformation amount during vacuum suction and the warpage amount during heating were small in a laminate without an intermediate layer, the absolute values ​​of the deformation amount during vacuum suction and the warpage amount during heating would also be small even when an intermediate layer was additionally provided.

[0123] <Laminates Including a Second Resin Film> In the laminates of Examples 7 to 11, the tensile modulus E2 (GPa) and thickness T2 (μm) satisfy the above formula (B). On the other hand, in the laminates of Comparative Examples 3 and 4, the above formula (B) is not satisfied. Therefore, the following relationship is established for the deformation amount during vacuum suction. In the laminates of Examples 7 to 11, the magnitude of the deformation amount during vacuum suction was significantly smaller than in the laminates of Comparative Examples 3 and 4. Note that, in the laminates including a second resin film, as in the laminates not including a second resin film, the presence or absence of an intermediate layer has almost no effect on the deformation amount during vacuum suction. Therefore, in the laminates of Examples 7 to 11, when an intermediate layer is additionally provided between the resin film substrate and the first resin film, the deformation amount during vacuum suction is smaller than in the laminates of Comparative Examples 3 and 4. In other words, the evaluation of a laminate that does not include an intermediate layer is similar to the evaluation of a laminate that includes an intermediate layer, and if the amount of deformation during vacuum suction is small in a laminate that does not include an intermediate layer, the amount of deformation during vacuum suction will also be small if an intermediate layer is added.

[0124] REFERENCE SIGNS LIST 1 Laminate 11 Resin film substrate 12 First resin film 131 First conductive layer 132 First transport layer 133 Photoelectric conversion layer 134 Second transport layer 135 Second conductive layer 14 Second resin film 31 Laser displacement meter 32 Angle with rail 33 Slit-equipped heat insulating cover 36 Hot plate 37 Glass beads

Claims

1. A laminate comprising a resin film substrate, a first resin film, and a photoelectric conversion layer between the resin film substrate and the first resin film, wherein when the laminate does not have a resin film on the side opposite to the side where the photoelectric conversion layer is provided with respect to the resin film substrate, the tensile elastic modulus E1 (GPa) and the thickness T1 (μm) of the laminate satisfy the following formula (A): 1000 ≦ E1 × T1 (A); and when the laminate has a second resin film on the side opposite to the side where the photoelectric conversion layer is provided with respect to the resin film substrate, the tensile elastic modulus E2 (GPa) and the thickness T2 (μm) of the laminate satisfy the following formula (B): 1500 ≦ E2 × T2 (B).

2. The laminate according to claim 1, wherein the thickness T1 is 200 μm or more and 600 μm or less, and the thickness T2 is 400 μm or more and 1000 μm or less.

3. The laminate according to claim 1 or 2, wherein the tensile elastic modulus of the resin film substrate is 3.5 GPa or more and 8.0 GPa or less, and the thickness of the resin film substrate is 110 μm or more and 280 μm or less.

4. The laminate according to claim 1 or 2, wherein the tensile elastic modulus of each of the first resin film and the second resin film is 3.0 GPa or more and 9.0 GPa or less, and the thickness of each of the first resin film and the second resin film is 80 μm or more and 300 μm or less.

5. The laminate according to claim 1 or 2, wherein when the laminate does not have a resin film on the side opposite to the side where the photoelectric conversion layer is provided with respect to the resin film substrate, the absolute value of the warpage amount during heating at 110 °C for 30 min is 200 μm or less.

6. A photoelectric conversion element using the laminate according to claim 1 or 2.

7. The photoelectric conversion element according to claim 6, wherein the photoelectric conversion element is an organic thin-film solar cell.

8. A method for manufacturing a photoelectric conversion element using the laminate according to claim 1 or 2.

Images