Structure

Abstract

To provide a structure that can suppress the occurrence of short circuits with other electrical elements via the connection between a conductive substrate and a porous film.SOLUTION: A structure includes a conductive substrate and a porous membrane containing carbon nanofibers and having voids, and the conductive substrate and the porous membrane are fixed in an electrically connected state by a non-conductive polymer material containing a polymer having a weight average molecular weight of 5,000 or more and 100,000 or less penetrating into the voids.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a structure. [Background technology]

[0002] BACKGROUND ART A structure is known that has a conductive substrate and a porous film containing carbon nanofibers, and forms a connection part that electrically connects the conductive substrate and the porous film (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-121648 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a structure that can suppress the occurrence of short circuits with other electrical elements via the connection between the conductive substrate and the porous film. [Means for solving the problem]

[0005] One aspect of the present invention is as follows.

[0006] [1] a conductive substrate; a porous membrane including a carbon nanofiber body and having voids; A structure in which the conductive substrate and the porous membrane are fixed in an electrically connected state by a non-conductive polymer material containing a polymer having a weight-average molecular weight of 5,000 or more and 100,000 or less penetrating into the voids.

[0007] [2] The structure according to [1], wherein the polymer is a hydrogenated polymer.

[0008] [3] The structure according to [1] or [2], wherein the polymer is a polymer having a hydrogenated aromatic or diene skeleton in the main chain.

[0009] [4] The structure according to any one of [1] to [3], wherein the polymer is at least one selected from the group consisting of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer and a hydrogenated aromatic vinyl compound-conjugated diene block copolymer modified with a silicon atom-containing polar group.

[0010] [5] The structure according to [4], wherein the hydrogenated aromatic vinyl compound-conjugated diene block copolymer has a structure in which both the non-aromatic carbon-carbon unsaturated bond and the aromatic carbon-carbon unsaturated bond are hydrogenated.

[0011] [6] The structure according to any one of [1] to [5], wherein the carbon nanofibrous body has an average diameter (Av) and a standard deviation (σ) of the diameters that satisfy the relationship: 0.20<(3σ / Av)<0.60.

[0012] [7] The structure according to any one of [1] to [6], wherein the carbon nanofiber material exhibits an upwardly convex t-plot obtained from an adsorption isotherm.

[0013] [8] A method for producing the structure according to any one of [1] to [7], a step of preparing a solution in which the polymer material is dissolved in a solvent; laminating the porous film and the conductive substrate in a state in which the solution has permeated into the voids in the porous film; a drying step of removing the solvent while the porous film and the conductive substrate are stuck together.

[0014] [9] A method for producing the structure according to any one of [1] to [7], forming a layer of the polymer material on the conductive substrate; a step of laminating the porous film and the conductive substrate together via a layer made of the polymer material in a state in which a liquid containing a solvent that dissolves the polymer material is permeated into the voids in the porous film; a drying step of removing the solvent while the porous film and the conductive substrate are stuck together.

[0015]

[10] The method for manufacturing a structure according to [8] or [9], wherein the drying step is carried out by applying heat and / or pressure.

[0016]

[11] A photoelectric conversion module comprising the structure according to any one of [1] to [7] and a photoelectric conversion part, wherein the photoelectric conversion part comprises, in a stacking direction, a substrate continuous with the substrate of the conductive substrate of the structure, a conductive film spaced from the conductive film of the conductive substrate of the structure, a power generation layer having a photoelectric conversion function, and a porous film, A photoelectric conversion module in which the porous film of the photoelectric conversion section and the structure are electrically connected.

[0017]

[12] The photoelectric conversion module according to

[11] , wherein the porous film of the photoelectric conversion section and the porous film of the structure are formed from a single porous film.

[0018]

[13] The photovoltaic conversion module according to

[11] or

[12] , wherein the power generation layer contains a perovskite compound.

[0019]

[14] A photoelectric conversion module according to any one of

[11] to

[13] , which has a second photoelectric conversion section, the second photoelectric conversion section having, in the stacking direction, a substrate connected to the substrate of the conductive substrate of the structure, a conductive film connected to the conductive film of the conductive substrate of the structure, a power generation layer having a photoelectric conversion function, and a porous film, in this order.

[0020]

[15] A method for manufacturing a photoelectric conversion module according to any one of

[11] to

[14] , forming the power generation layer on the conductive substrate of the photoelectric conversion unit; and forming the photoelectric conversion section and the structure simultaneously by arranging a porous film including the porous film of the photoelectric conversion section and the porous film of the structure so as to straddle the power generation layer and the conductive substrate of the structure.

[0021]

[16] A photoelectric conversion module manufacturing method for manufacturing the photoelectric conversion module according to

[14] , a step of arranging a porous film including the porous film of the photoelectric conversion unit, the porous film of the second photoelectric conversion unit, and the porous film of the structure so as to straddle the power generation layer of the photoelectric conversion unit, the power generation layer of the second photoelectric conversion unit, and the conductive substrate of the structure; a separation step of separating the porous film of the second photoelectric conversion section from the porous film of the structure. [Effects of the Invention]

[0022] According to the present invention, it is possible to provide a structure that can suppress the occurrence of a short circuit with other electrical elements via the connection between the conductive substrate and the porous film. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view showing a photoelectric conversion module according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the structure shown in FIG. [Figure 3] 2 is a cross-sectional view showing a state when a power generation layer is formed in a photovoltaic conversion module manufacturing method for manufacturing the photovoltaic conversion module shown in FIG. 1. FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a state in which a porous membrane is disposed in the state shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] As shown in Figures 1 and 2, in one embodiment of the present invention, a structure 1 has a conductive substrate 2 and a porous film 3 containing carbon nanofibers and having voids, and the conductive substrate 2 and the porous film 3 are fixed in an electrically connected state by a non-conductive polymer material 4 containing a polymer having a weight-average molecular weight of 5,000 to 100,000 penetrating into the voids.

[0026] According to the above configuration, a connection portion 5 can be formed in which the conductive substrate 2 and the porous membrane 3 are fixed in an electrically connected state by the non-conductive polymer material 4, thereby suppressing the occurrence of a short circuit via the connection portion 5 to another electrical element adjacent to the connection portion 5. Therefore, the occurrence of a short circuit between the conductive substrate 2 and the porous membrane 3 and another electrical element via the connection portion 5 can be suppressed. From the viewpoint of suppressing the occurrence of a short circuit, it is preferable that the connection portion 5 be configured in such a way that the conductive substrate 2 and the porous membrane 3 are fixed in an electrically contact state by the non-conductive polymer material 4. Note that "a state in which the conductive substrate 2 and the porous membrane 3 are in electrical contact" means a state in which the conductive substrate 2 and the porous membrane 3 are electrically connected by direct contact.

[0027] The polymer may be a hydrogenated polymer. According to the above-mentioned configuration, the connection part 5 having excellent structural stability can be formed.

[0028] The polymer may be a polymer having a hydrogenated aromatic or diene skeleton in the main chain. This configuration allows the formation of a connecting part 5 with even greater structural stability.

[0029] The polymer may be one or more selected from the group consisting of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer and a hydrogenated aromatic vinyl compound-conjugated diene block copolymer modified with a silicon atom-containing polar group. This configuration allows the formation of a connecting part 5 with even greater structural stability.

[0030] The hydrogenated aromatic vinyl compound-conjugated diene block copolymer may have a structure in which both the non-aromatic carbon-carbon unsaturated bond and the aromatic carbon-carbon unsaturated bond are hydrogenated, which allows the formation of a connecting part 5 with even greater structural stability.

[0031] The carbon nanofiber body may be configured such that the average diameter (Av) and the standard deviation (σ) of the diameters satisfy the relationship: 0.20<(3σ / Av)<0.60. This configuration allows the formation of connecting part 5 with even greater structural stability.

[0032] The "average diameter (Av)" and "standard deviation of diameter (σ)" of carbon nanofibers can be determined by measuring the diameter (outer diameter) of 100 randomly selected carbon nanofibers using a transmission electron microscope. The average diameter (Av) and standard deviation (σ) of carbon nanofibers can be adjusted by changing the manufacturing method or manufacturing conditions of the carbon nanofibers, or by combining multiple types of carbon nanofibers obtained by different manufacturing methods.

[0033] The carbon nanofiber body may be configured so that the t-plot obtained from the adsorption isotherm exhibits an upwardly convex shape. This configuration makes it possible to form a connection part 5 with even greater structural stability.

[0034] The structure 1 may be manufactured by a method for manufacturing a structure including the steps of preparing a solution in which the polymer material 4 is dissolved in a solvent, laminating the porous film 3 and the conductive substrate 2 in a state in which the solution has permeated into the pores of the porous film 3, and drying the porous film 3 and the conductive substrate 2 in a state in which the porous film 3 and the conductive substrate 2 are laminated together to remove the solvent. According to the above configuration, the structure 1 can be formed efficiently.

[0035] The structure 1 may be manufactured by a structure manufacturing method including the steps of forming a layer made of a polymer material 4 on a conductive substrate 2, laminating the porous film 3 and the conductive substrate 2 together with the layer made of the polymer material 4 in a state in which a liquid containing a solvent that dissolves the polymer material 4 is permeated into the voids in the porous film 3, and drying the porous film 3 and the conductive substrate 2 in a state in which the porous film 3 and the conductive substrate 2 are laminated together to remove the solvent. The above-mentioned configuration also allows the structure 1 to be formed efficiently.

[0036] The drying procedure may be performed by applying heat and / or pressure to the porous film 3. According to the above-described configuration, the structure 1 can be formed more efficiently.

[0037] As in this embodiment, the photoelectric conversion module 6 has a structure 1 and a (first) photoelectric conversion part 7A, and the (first) photoelectric conversion part 7A has, in this order in the stacking direction, a substrate 2aA connected to the substrate 2a of the conductive substrate 2 of the structure 1, a conductive film 2bA separated from the conductive film 2b of the conductive substrate 2 of the structure 1, a power generation layer 8A having photoelectric conversion function, and a porous film 3A, and the porous film 3A of the (first) photoelectric conversion part 7A and the porous film 3 of the structure 1 may be electrically connected.

[0038] The porous film 3A of the (first) photoelectric conversion section 7A and the porous film 3 of the structure 1 may be configured to be formed from one porous film, as in this embodiment.

[0039] The power generation layer 8A of the (first) photoelectric conversion section 7A may be configured to contain a perovskite compound.

[0040] As in this embodiment, the photoelectric conversion module 6 may have a second photoelectric conversion unit 7B, which may include, in the stacking direction, a substrate 2aB connected to the substrate 2a of the conductive substrate 2 of the structure 1, a conductive film 2bB connected to the conductive film 2b of the conductive substrate 2 of the structure 1, a power generation layer 8B having a photoelectric conversion function, and a porous film 3B, in this order. This configuration allows for an increase in power generation voltage by connecting the second photoelectric conversion unit 7B in series. Instead of providing the second photoelectric conversion unit 7B, the conductive film 2bB of the second photoelectric conversion unit 7B may be configured as part of, for example, an extraction electrode 9 for extracting power to the outside.

[0041] In this embodiment, the (first) photoelectric conversion section 7A may be configured to have a charge transport layer at the boundary between the power generation layer 8A and the conductive film 2bA. The (first) photoelectric conversion section 7A may be configured to have a layer of polymer material 4 at the boundary between the power generation layer 8A and the porous film 3A. The second photoelectric conversion section 7B may be configured to have a charge transport layer at the boundary between the power generation layer 8B and the conductive film 2bB. The second photoelectric conversion section 7B may be configured to have a layer of polymer material 4 at the boundary between the power generation layer 8B and the porous film 3B.

[0042] The structure 1 may be configured, as in this embodiment, so that the polymer material 4 is located in a first gap 10A between the conductive film 2b of the structure 1 and the power generation layer 8A and conductive film 2bA of the (first) photoelectric conversion section 7A. The structure 1 may be configured, as in this embodiment, so that the polymer material 4 is located in a second gap 10B between the porous film 3 of the structure 1 and the power generation layer 8B and porous film 3B of the second photoelectric conversion section 7B.

[0043] As in this embodiment, the photoelectric conversion module 6 may be manufactured by a photoelectric conversion module manufacturing method including the steps of forming a power generation layer 8A on the conductive substrate 2A of the (first) photoelectric conversion unit 7A (see FIG. 3 ) and simultaneously forming the (first) photoelectric conversion unit 7A and the structure 1 by arranging a porous film including the porous film 3A of the (first) photoelectric conversion unit 7A and the porous film 3 of the structure 1 so as to straddle the power generation layer 8A and the conductive substrate 2 of the structure 1 (see FIG. 4 ). According to the above manufacturing method, the photoelectric conversion module 6 having the (first) photoelectric conversion unit 7A and the structure 1 can be efficiently formed.

[0044] As in this embodiment, the photoelectric conversion module 6 may be manufactured by a photoelectric conversion module manufacturing method including the steps of: arranging a porous film including the porous film 3A of the (first) photoelectric conversion unit 7A, the porous film 3B of the second photoelectric conversion unit 7B, and the porous film 3 of the structure 1 so as to straddle the power generation layer 8A of the (first) photoelectric conversion unit 7A, the power generation layer 8B of the second photoelectric conversion unit 7B, and the conductive substrate 2 of the structure 1 (see FIG. 4); and separating the porous film 3B of the second photoelectric conversion unit 7B from the porous film 3 of the structure 1 (separation at the dashed line in FIG. 4). According to the above manufacturing method, a photoelectric conversion module 6 having not only the (first) photoelectric conversion unit 7A but also the second photoelectric conversion unit 7B can be efficiently formed.

[0045] The number of photoelectric conversion units provided in the photoelectric conversion module 6 is not particularly limited, and for example, three or more photoelectric conversion units may be connected in series.

[0046] (Configuration example of photoelectric conversion module 6) An example of the more detailed configuration of the photoelectric conversion module 6 of this embodiment will be described below.

[0047] <Substrate> The substrate is translucent and constitutes the base of the photovoltaic conversion module 6. The substrate is not particularly limited, and examples thereof include a substrate made of glass or synthetic resin, and a film made of synthetic resin. Examples of glass constituting the substrate include inorganic glass such as soda glass. Examples of synthetic resins constituting the substrate include polyacrylic resin, polycarbonate resin, polyester resin, polyimide resin, polystyrene resin, polyvinyl chloride resin, polyamide resin, and polycycloolefin resin. Among these, from the viewpoint of obtaining a thin, lightweight, and flexible photovoltaic conversion module 6, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are preferred as synthetic resins. The thickness of the substrate is not particularly limited, as long as it can maintain its shape as a substrate. The thickness of the substrate can be, for example, 0.1 mm or more and 10 mm or less.

[0048] <Conductive film> The conductive film is a transparent conductive film layer made of a light-transmitting metal oxide and formed on the surface of the substrate. By providing the conductive film, electrical conductivity can be imparted to the surface of the substrate.

[0049] Examples of metal oxides that form the conductive film include fluorine-doped tin oxide (FTO), tin oxide (SnO), indium oxide (In2O3), tin-doped indium oxide (ITO), zinc oxide (ZnO), indium oxide / zinc oxide (IZO), and gallium oxide / zinc oxide (GZO). While the photovoltaic conversion module 6 shown in FIGS. 1 and 2 has a single conductive film on the substrate, the substrate may have two or more conductive films. When the photovoltaic conversion module 6 has two or more conductive film layers, the conductive films may be made of the same metal oxide or different metal oxides.

[0050] The thickness of the conductive film is not particularly limited as long as it can impart the desired conductivity to the substrate, and can be, for example, 1 nm to 1 μm. The conductive film may be formed on the entire surface of the substrate, or may be formed on only a part of the surface of the substrate, as shown in Figures 1 and 2.

[0051] <Charge transport layer> The charge transport layer is made of an n-type semiconductor. The charge transport layer may be made of two layers, an underlayer and a porous semiconductor layer, but is not limited to this, and the charge transport layer may be made of a single layer made of an n-type semiconductor.

[0052] <Underlayer> The underlayer is an optional layer. The underlayer prevents the substrate or conductive film from coming into direct contact with the porous semiconductor layer. This prevents loss of electromotive force, thereby improving the photoelectric conversion efficiency of the photoelectric conversion module 6. The underlayer may be a porous film or a dense film, for example, as long as it is made of an n-type semiconductor. However, from the viewpoint of adequately preventing contact between the substrate or conductive film and the porous semiconductor layer, the underlayer is preferably a non-porous dense film. The thickness of the underlayer is not particularly limited and may be, for example, 1 nm or more and 500 nm or less. The underlayer may also optionally contain an insulating material other than an n-type semiconductor in a proportion that does not impair the properties of the underlayer as an n-type semiconductor.

[0053] <Porous semiconductor layer> The porous semiconductor layer is a porous layer. When the charge transport layer includes a porous semiconductor layer, the photoelectric conversion efficiency of the photoelectric conversion module 6 can be further improved. The thickness of the porous semiconductor layer is not particularly limited, but is usually 5 nm or more, preferably 10 nm or more, and usually 500 nm or less, preferably 100 nm or less. The porous semiconductor layer may be formed from a single layer or multiple layers.

[0054] <Power generation layer main body> The power generation layer main body is a layer composed of a material that generates electromotive force by absorbing light, preferably a layer containing a perovskite compound, and more preferably a layer (perovskite layer) composed of a perovskite compound. The perovskite compound constituting the power generation layer main body is not particularly limited, and known perovskite compounds can be used. Specific examples include lead-based perovskite compounds such as CH3NH3PbI3, CH3NH3PbBr3, (CH3(CH2)nCHCH3NH3)2PbI4 [n = 5 to 8], and (C6H5C2H4NH3)2PbBr4, as well as lead-free perovskite compounds. The perovskite compound constituting the power generation layer main body is not limited to lead-based or lead-free perovskite compounds, and may be any compound that forms a perovskite structure and functions as the power generation layer main body. The thickness of the power generation layer body is not particularly limited, but is preferably 100 nm or more, more preferably 200 nm or more, and is preferably 1 μm or less, more preferably 800 nm or less. By making the thickness of the power generation layer body 100 nm or more, the electromotive force of the power generation layer body can be increased.

[0055] <Charge transport layer made of porous film> The charge transport layer formed by the porous film is a layer consisting of a porous layer containing at least carbon nanofibers. The carbon nanofibers contained in the charge transport layer formed by the porous film are not particularly limited, but preferably contain carbon nanotubes (hereinafter, carbon nanotubes are also referred to as "CNTs"). The CNTs contained in the charge transport layer formed by the porous film preferably contain single-walled CNTs. This configuration can improve the photoelectric conversion efficiency of the photoelectric conversion module 6.

[0056] Furthermore, the charge transport layer formed by a porous film is preferably a layer formed by a porous free-standing sheet. Using a porous free-standing sheet, which is a free-standing film, can improve the shape stability of the charge transport layer formed by the porous film. Furthermore, since it is easy to manufacture, it is easy to realize a large-area photovoltaic conversion module 6. Furthermore, using a porous free-standing sheet, which is porous, allows for easy drying of the solvent or solution when wet processing is performed. The porous free-standing sheet must contain at least carbon nanofibers, preferably containing at least single-walled CNTs as the carbon nanofibers, more preferably a sheet formed by carbon nanofibers, more preferably a sheet formed by single-walled CNTs, and even more preferably a sheet formed by buckypaper. Using a porous free-standing sheet containing carbon nanofibers with at least p-type semiconductor properties can impart the charge transport layer formed by the porous film with excellent hole transport layer and current collecting electrode functions.

[0057] In this embodiment, the term "porous free-standing sheet" refers to a sheet having a plurality of pores formed therein, which maintains its shape even without a support. The porous free-standing sheet used in this embodiment maintains its shape without tearing even when the porous free-standing sheet is immersed in a predetermined solvent or solution, pulled out, and then attached to an object to be attached. Furthermore, the porous free-standing sheet used in this embodiment does not tear or deform even when, for example, chlorobenzene, which is a poor solvent for perovskite compounds, is dropped onto the sheet or when it is handled using a jig for attaching the sheet. The porous free-standing sheet used in this embodiment has a thickness of 1 μm to 200 μm, an area of ​​1 mm, and a thickness of 1 μm to 200 μm. 2 ~100cm 2 It is preferable that the sheet maintains its shape without a support at this size.

[0058] The carbon nanofibers contained in the charge transport layer made of a porous film (more preferably a porous freestanding sheet) preferably contain carbon nanofibers (more preferably CNTs, more preferably single-walled CNTs) having the following properties.

[0059] -(3σ / Av)- The carbon nanofibers contained in the charge transport layer of the porous film preferably have a ratio (3σ / Av) of the standard deviation (σ) of the diameters multiplied by 3 (3σ) to the average diameter (Av) of the carbon nanofibers greater than 0.20, more preferably greater than 0.25, even more preferably greater than 0.50, and preferably less than 0.60. When 3σ / Av is greater than 0.20 and less than 0.60, even if the amount of carbon nanofibers contained in the charge transport layer of the porous film is small, the charge transport layer of the porous film can be imparted with sufficient functions as a hole transport layer and a collecting electrode.

[0060] -Average diameter of carbon nanofibers (Av)- The average diameter (Av) of the carbon nanofibers is preferably 0.5 nm or more, more preferably 1 nm or more, and preferably 15 nm or less, more preferably 10 nm or less. When the average diameter (Av) of the carbon nanofibers is 0.5 nm or more, aggregation of the carbon nanofibers can be suppressed, and the dispersibility of the carbon nanofibers in the charge transport layer made of a porous film can be improved. Furthermore, when the average diameter (Av) of the carbon nanofibers is 15 nm or less, the charge transport layer made of a porous film can fully function as a collecting electrode.

[0061] -t-plot- The carbon nanofiber material preferably exhibits an upwardly convex t-plot obtained from the adsorption isotherm. Such carbon nanofiber material is more preferably a single-walled CNT that has not been subjected to an opening treatment. By using a carbon nanofiber material exhibiting an upwardly convex t-plot obtained from the adsorption isotherm, a charge transport layer made of a porous film with excellent strength can be obtained.

[0062] The bending point of the t-plot of the carbon nanofiber material is preferably in the range satisfying 0.2≦t(nm)≦1.5, more preferably in the range of 0.45≦t(nm)≦1.5, and even more preferably in the range of 0.55≦t(nm)≦1.0.

[0063] Measurement of the adsorption isotherm of the carbon nanofiber material, creation of the t-plot, and analysis of the t-plot can be performed using, for example, a commercially available measuring device, "BELSORP (registered trademark)-mini" (manufactured by BEL Japan Co., Ltd.).

[0064] Carbon nanofibers having the properties described above can be efficiently produced, for example, by a method in which raw material compounds and a carrier gas are supplied to a substrate having a catalyst layer for producing carbon nanofibers on its surface to synthesize the carbon nanofibers by chemical vapor deposition (CVD), in which the catalytic activity of the catalyst layer is dramatically improved by the presence of a trace amount of oxidant (catalytic activator) in the system (super growth method; see WO 2006 / 011655), and the catalyst layer is formed on the substrate surface by a wet process.

[0065] Among these, from the viewpoint of easily obtaining a charge transport layer made of a porous film with a large thickness, it is preferable to use carbon nanofibers obtained by the super growth method as the carbon nanofibers.

[0066] Furthermore, the charge transport layer made of a porous film preferably contains the material (e.g., perovskite compound) constituting the power generation layer main body described above inside the charge transport layer made of the porous film. More specifically, the charge transport layer made of a porous film preferably contains the material (e.g., perovskite compound) constituting the power generation layer main body inside the multiple pores of the charge transport layer made of the porous film.

[0067] The proportion of carbon nanofibers contained in the charge transport layer made of a porous film is not particularly limited, but is preferably 50% by mass or more, and more preferably 75% by mass or more.

[0068] Furthermore, materials other than carbon nanofibers that may be optionally contained in the charge transport layer made of a porous film include, for example, organic and inorganic materials as p-type semiconductors.

[0069] Examples of organic materials that can be contained in the porous charge transport layer include 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamino)-9,9'-spirobifluorene (spiro-MeOTAD), poly(3-hexylthiophene) (P3HT), and polytriallylamine (PTAA).

[0070] Furthermore, examples of inorganic materials that can be contained in the charge transport layer made of a porous film include CuI, CuSCN, CuO, and Cu2O.

[0071] The thickness of the porous charge transport layer is preferably 20 μm or more, more preferably 30 μm or more, and is preferably 200 μm or less, and more preferably 80 μm or less. If the thickness of the porous charge transport layer is 20 μm or more and 200 μm or less, the porous charge transport layer can exhibit a more excellent function as a collecting electrode.

[0072] <<Method of manufacturing a charge transport layer using a porous film>> The method for producing a charge transport layer using a porous film is not particularly limited, and can include, for example, a method including a step of removing the solvent from a carbon nanofiber dispersion containing carbon nanofibers, a dispersant, and a solvent to form a charge transport layer using a porous film (film formation step). Furthermore, the method for producing a charge transport layer using a porous film may optionally include, prior to the film formation step, a step of dispersing a crude dispersion containing carbon nanofibers, a dispersant, and a solvent to prepare the carbon nanofiber dispersion (dispersion preparation step).

[0073] -Dispersion liquid preparation process- In the dispersion preparation step, a crude dispersion containing carbon nanofibers, a dispersant, and a solvent is preferably subjected to a dispersion treatment that produces a cavitation effect or a disintegration effect, as described below in detail, but is not particularly limited thereto, to disperse the carbon nanofibers and prepare a carbon nanofiber dispersion. By performing a dispersion treatment that produces a cavitation effect or a disintegration effect in this manner, a carbon nanofiber dispersion in which the carbon nanofibers are well dispersed can be obtained. Furthermore, by producing a charge transport layer based on a porous membrane using a carbon nanofiber dispersion in which the carbon nanofibers are well dispersed, the carbon nanofibers can be uniformly dispersed, resulting in a charge transport layer based on a porous membrane that has excellent properties such as electrical conductivity, thermal conductivity, and mechanical properties. The carbon nanofiber dispersion used to produce a charge transport layer based on a porous membrane may also be prepared by dispersing carbon nanofibers in a solvent using a known dispersion treatment other than those described above.

[0074] The carbon nanofibers used to prepare the carbon nanofiber dispersion preferably contain single-walled CNTs, and may be a mixture of single-walled CNTs and carbon nanofibers other than single-walled CNTs (such as multi-walled CNTs).

[0075] Here, the carbon nanofiber dispersion liquid can have a content ratio of single-walled CNTs to carbon nanofibers other than single-walled CNTs of, for example, a mass ratio (single-walled CNTs / carbon nanofibers other than single-walled CNTs) of 50 / 50 to 75 / 25.

[0076] =Dispersant= The dispersant used in preparing the carbon nanofiber dispersion is not particularly limited as long as it can disperse carbon nanofibers and can be dissolved in the solvent used in preparing the carbon nanofiber dispersion. Examples of such dispersants that can be used include surfactants, synthetic polymers, and natural polymers.

[0077] Examples of surfactants include sodium dodecyl sulfonate, sodium deoxycholate, sodium cholate, and sodium dodecylbenzenesulfonate.

[0078] Examples of synthetic polymers include polyether diols, polyester diols, polycarbonate diols, polyvinyl alcohol, partially saponified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, acetal group-modified polyvinyl alcohol, butyral group-modified polyvinyl alcohol, silanol group-modified polyvinyl alcohol, ethylene-vinyl alcohol copolymer, ethylene-vinyl alcohol-vinyl acetate copolymer resin, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, acrylic resins, epoxy resins, modified epoxy resins, phenoxy resins, modified phenoxy resins, phenoxy ether resins, phenoxy ester resins, fluorine-based resins, melamine resins, alkyd resins, phenolic resins, polyacrylamide, polyacrylic acid, polystyrene sulfonic acid, polyethylene glycol, and polyvinylpyrrolidone.

[0079] Further, examples of natural polymers include polysaccharides such as starch, pullulan, dextran, dextrin, guar gum, xanthan gum, amylose, amylopectin, alginic acid, gum arabic, carrageenan, chondroitin sulfate, hyaluronic acid, curdlan, chitin, chitosan, and cellulose, as well as salts or derivatives thereof, where derivatives refer to conventionally known compounds such as esters and ethers.

[0080] These dispersants can be used alone or in combination of two or more. Among them, surfactants are preferred as dispersants because they have excellent dispersibility for carbon nanofiber materials, and sodium deoxycholate is more preferred.

[0081] =Solvent= The solvent for the carbon nanofiber dispersion is not particularly limited, and examples thereof include alcohols such as water, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, and amyl alcohol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, esters such as ethyl acetate and butyl acetate, ethers such as diethyl ether, dioxane, and tetrahydrofuran, amide-based polar organic solvents such as N,N-dimethylformamide and N-methylpyrrolidone, and aromatic hydrocarbons such as toluene, xylene, chlorobenzene, orthodichlorobenzene, and paradichlorobenzene. These solvents may be used alone or in combination of two or more.

[0082] In the dispersion liquid preparation step, it is preferable to carry out a dispersion treatment that can obtain, for example, the cavitation effect or the disintegration effect described below.

[0083] ~Dispersion processing that produces a cavitation effect~ Dispersion treatment that achieves the cavitation effect is a dispersion method that utilizes shock waves generated by the bursting of vacuum bubbles generated in water when high energy is applied to the liquid. By using this dispersion method, carbon nanofibers can be dispersed well.

[0084] Specific examples of dispersion treatments that can achieve the cavitation effect include dispersion treatment using ultrasonic waves, dispersion treatment using a jet mill, and dispersion treatment using high-shear stirring. These dispersion treatments may be performed alone or in combination. More specifically, for example, ultrasonic homogenizers, jet mills, and high-shear stirring devices are preferably used. These devices may be conventionally known.

[0085] When an ultrasonic homogenizer is used to disperse carbon nanofiber materials, the coarse dispersion liquid is irradiated with ultrasonic waves using the ultrasonic homogenizer. The irradiation time can be appropriately set depending on the amount of carbon nanofiber materials, and is, for example, preferably 3 minutes or more, more preferably 30 minutes or more, and preferably 5 hours or less, more preferably 2 hours or less. Furthermore, for example, the output is preferably 20 W or more and 500 W or less, more preferably 100 W or more and 500 W or less, and the temperature is preferably 15°C or more and 50°C or less.

[0086] When a jet mill is used, the number of times of treatment may be appropriately set depending on the amount of carbon nanofibers, etc., and is, for example, preferably 2 times or more, more preferably 5 times or more, and preferably 100 times or less, more preferably 50 times or less. Furthermore, for example, the pressure is preferably 20 MPa or more and 250 MPa or less, and the temperature is preferably 15°C or more and 50°C or less.

[0087] Furthermore, when high shear mixing is used, the coarse dispersion can be stirred and sheared using a high shear mixing device. The faster the rotation speed, the better. For example, the operating time (the time the machine is rotating) is preferably 3 minutes to 4 hours, the peripheral speed is preferably 5 m / s to 50 m / s, and the temperature is preferably 15°C to 50°C.

[0088] It is more preferable that the dispersion treatment that produces the above-mentioned cavitation effect is carried out at a temperature of 50° C. or less, because this suppresses changes in concentration due to evaporation of the solvent.

[0089] ~Dispersion processing that produces a crushing effect~ Dispersion treatments that produce a disintegration effect are not only able to uniformly disperse carbon nanofiber bodies in a solvent, but are also more advantageous than dispersion treatments that produce the cavitation effect described above in that they can suppress damage to the carbon nanofiber bodies caused by shock waves when the bubbles disappear.

[0090] In the dispersion process that produces this disintegration effect, shear force is applied to the coarse dispersion to disintegrate and disperse the agglomerates of carbon nanofibers, and then back pressure is applied to the coarse dispersion, and if necessary, the coarse dispersion is cooled, thereby suppressing the generation of bubbles and uniformly dispersing the carbon nanofibers in the solvent.

[0091] When a back pressure is applied to the crude dispersion, the back pressure applied to the crude dispersion may be reduced to atmospheric pressure in one go, but it is preferable to reduce the pressure in multiple stages.

[0092] -Film forming process- In the film formation step, the solvent is removed from the carbon nanofiber dispersion liquid to form a porous charge transport layer. Specifically, in the film formation step, the solvent is removed from the carbon nanofiber dispersion liquid by, for example, using either method (A) or (B) below to form a porous free-standing sheet that will serve as the porous charge transport layer. (A) A method in which a carbon nanofiber dispersion liquid is applied to a film-forming substrate, and then the applied carbon nanofiber dispersion liquid is dried. (B) A method in which a carbon nanofiber dispersion is filtered using a porous film-forming substrate, and the resulting filtrate is dried.

[0093] [Film-forming base material] Here, the film-forming substrate is not particularly limited, and any known substrate can be used.

[0094] Specifically, examples of the film-forming substrate onto which the carbon nanofiber dispersion is applied in method (A) include resin substrates and glass substrates. Examples of resin substrates include substrates made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE), polyimide, polyphenylene sulfide, aramid, polypropylene, polyethylene, polylactic acid, polyvinyl chloride, polycarbonate, polymethyl methacrylate, alicyclic acrylic resin, cycloolefin resin, and triacetyl cellulose. Examples of glass substrates include substrates made of ordinary soda glass.

[0095] In the method (B), examples of the film-forming substrate for filtering the carbon nanofiber dispersion include filter paper and porous sheets made of cellulose, nitrocellulose, alumina, and the like.

[0096] [Coating] In the method (A), the carbon nanofiber dispersion can be applied to the film-forming substrate by any known application method, such as dipping, roll coating, gravure coating, knife coating, air knife coating, roll knife coating, die coating, screen printing, spray coating, or gravure offset.

[0097] [Filtration] In the above method (B), the carbon nanofiber dispersion can be filtered using a film-forming substrate by any known filtration method, such as natural filtration, reduced pressure filtration, pressure filtration, or centrifugal filtration.

[0098] [Drying] The carbon nanofiber dispersion applied to the film-forming substrate in method (A) or the filtered product obtained in method (B) can be dried by a known drying method. Examples of the drying method include hot air drying, vacuum drying, hot roll drying, and infrared irradiation. The drying temperature is not particularly limited, but is usually room temperature to 200°C. The drying time is not particularly limited, but is usually 0.1 to 150 minutes.

[0099] Post-processing The porous free-standing sheet formed as described above typically contains the components contained in the carbon nanofiber dispersion, such as carbon nanofibers and dispersants, in the same proportions as in the carbon nanofiber dispersion. Therefore, in the method for producing a charge transport layer using a porous film, the porous free-standing sheet formed in the film formation step may optionally be washed to remove the dispersant from the porous free-standing sheet. Removing the dispersant from the porous free-standing sheet can further improve the properties of the porous free-standing sheet, such as its conductivity.

[0100] The porous free-standing sheet can be washed by contacting it with a solvent capable of dissolving the dispersant and dissolving the dispersant in the porous free-standing sheet into the solvent. The solvent capable of dissolving the dispersant in the porous free-standing sheet is not particularly limited, and the solvents described above that can be used as solvents for carbon nanofiber dispersions, preferably the same solvents as those for carbon nanofiber dispersions, can be used. The contact between the porous free-standing sheet and the solvent can be achieved by immersing the porous free-standing sheet in the solvent or by applying the solvent to the porous free-standing sheet. After washing, the porous free-standing sheet can be dried using a known method.

[0101] In producing the porous free-standing sheet, the porous free-standing sheet formed in the film formation step may be optionally press-processed to further increase the density, etc., to adjust the voids as needed. From the viewpoint of suppressing deterioration of the properties due to damage or destruction of the carbon nanofiber body, the pressing pressure during pressing is preferably less than 3 MPa, and it is more preferable not to perform pressing.

[0102] <Polymer material 4> The polymer material 4 is not particularly limited as long as it is a non-conductive adhesive material composed of a polymer having a weight-average molecular weight of 5,000 to 100,000, and capable of adhering the conductive substrate 2 and the porous membrane in contact with each other and electrically connecting them. In this regard, the polymer serving as the polymer material 4 is preferably a hydrogenated polymer, more preferably a polymer having a hydrogenated aromatic or diene skeleton in its main chain, and more preferably one or more types selected from the group consisting of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer and a hydrogenated aromatic vinyl compound-conjugated diene block copolymer modified with a silicon atom-containing polar group. Furthermore, the hydrogenated aromatic vinyl compound-conjugated diene block copolymer preferably has a structure in which both the non-aromatic carbon-carbon unsaturated bond and the aromatic carbon-carbon unsaturated bond are hydrogenated.

[0103] Examples of polymers as the polymer material 4 include ethylene-α-olefin copolymers such as ethylene-propylene copolymers; ethylene-α-olefin-polyene copolymers; copolymers of ethylene and unsaturated carboxylic acid esters such as ethylene-methyl methacrylate and ethylene-butyl acrylate copolymers; copolymers of ethylene and fatty acid vinyl such as ethylene-vinyl acetate copolymers; polymers of alkyl acrylates such as ethyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate; and diene-based polymers such as polybutadiene, polyisoprene, acrylonitrile-butadiene copolymers, butadiene-isoprene copolymers, butadiene-(meth)acrylic acid alkyl ester copolymers, butadiene-(meth)acrylic acid alkyl ester-acrylonitrile copolymers, and butadiene-(meth)acrylic acid alkyl ester-acrylonitrile-styrene copolymers. Examples of suitable thermoplastic elastomers include copolymers; butylene-isoprene copolymers; aromatic vinyl compound-conjugated diene copolymers such as styrene-butadiene random copolymers, styrene-isoprene random copolymers, styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, and styrene-isoprene-styrene block copolymers; hydrogenated aromatic vinyl compound-conjugated diene copolymers such as hydrogenated styrene-butadiene random copolymers, hydrogenated styrene-isoprene random copolymers, hydrogenated styrene-butadiene block copolymers, hydrogenated styrene-butadiene-styrene block copolymers, hydrogenated styrene-isoprene block copolymers, and hydrogenated styrene-isoprene-styrene block copolymers; low-crystalline polybutadiene; styrene-grafted ethylene-propylene elastomers; thermoplastic polyester elastomers; and ethylene-based ionomers. Thermoplastic elastomers may be used singly or in combination of two or more types in any ratio.

[0104] As the polymer serving as the polymer material 4, a hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferred in order to achieve the desired effects of the present invention. The term "hydrogenated aromatic vinyl compound-conjugated diene block copolymer" refers to a hydrogenated product of an aromatic vinyl compound-conjugated diene block copolymer. That is, the term "hydrogenated aromatic vinyl compound-conjugated diene block copolymer" refers to a polymer having a structure obtained by partially or completely hydrogenating the non-aromatic carbon-carbon unsaturated bonds, the aromatic carbon-carbon unsaturated bonds, or both of these in the aromatic vinyl compound-conjugated diene block copolymer. However, the hydrogenated product is not limited by its production method.

[0105] As the aromatic vinyl compound, styrene and its derivatives; vinylnaphthalene and its derivatives; are preferred. In view of industrial availability, it is particularly preferred to use styrene. On the other hand, as the conjugated diene, a chain conjugated diene (straight-chain conjugated diene, branched-chain conjugated diene) is preferred. Preferable examples of the conjugated diene include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. Among these, 1,3-butadiene and isoprene are particularly preferred in view of industrial availability.

[0106] The mass fraction of all aromatic vinyl monomer units in the entire aromatic vinyl compound-conjugated diene block copolymer is w A The mass fraction of all conjugated diene monomer units in the entire aromatic vinyl compound-conjugated diene block copolymer is w B In this case, w A and w B Ratio to (w A / w B ) is preferably in a specific range. Specifically, A / w B ) is preferably 20 / 80 or more, more preferably 30 / 70 or more, and is preferably 60 / 40 or less, more preferably 55 / 45 or less. A / w BWhen the ratio (w) is equal to or greater than the lower limit of the range, the heat resistance of the polymer material 4 can be improved. When the ratio (w) is equal to or less than the upper limit, the flexibility of the polymer material 4 can be increased. A / w B ) within the above range, the temperature range in which the polymer material 4 has rubber elasticity can be widened, and therefore the temperature range in which the photoelectric conversion module 6 has flexibility can be widened.

[0107] The aromatic vinyl compound-conjugated diene block copolymer is preferably a polymer selected from styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, styrene-isoprene-styrene block copolymers, and mixtures thereof. Specific examples thereof include those described in technical documents such as JP-A-2-133406, JP-A-2-305814, JP-A-3-72512, JP-A-3-74409, and WO 2015 / 099079.

[0108] The hydrogenation rate of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 90% or more, more preferably 97% or more, and particularly preferably 99% or more. The higher the hydrogenation rate, the better the heat resistance and light resistance of the polymer material 4. The hydrogenation rate of the hydrogenated product can be determined by measurement using 1H-NMR.

[0109] The hydrogenation rate of the non-aromatic carbon-carbon unsaturated bonds of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 95% or more, more preferably 99% or more. When the hydrogenation rate of the non-aromatic carbon-carbon unsaturated bonds is high, the light resistance and oxidation resistance of the polymer material 4 can be further improved.

[0110] The hydrogenation rate of the aromatic carbon-carbon unsaturated bonds of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 90% or higher, more preferably 93% or higher, and particularly preferably 95% or higher. When the hydrogenation rate of the aromatic carbon-carbon unsaturated bonds is high, the glass transition temperature of the hydrogenated product increases, effectively improving the heat resistance of the polymer material 4. Furthermore, the photoelastic coefficient of the polymer material 4 can be reduced, thereby reducing the occurrence of retardation.

[0111] The hydrogenated aromatic vinyl compound-conjugated diene block copolymer particularly preferably has a structure in which both the non-aromatic carbon-carbon unsaturated bond and the aromatic carbon-carbon unsaturated bond are hydrogenated.

[0112] Particularly preferred block forms of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer are a triblock copolymer in which a block [A] of a hydrogenated aromatic vinyl polymer is bonded to both ends of a block [B] of a hydrogenated conjugated diene polymer, or a pentablock copolymer in which a polymer block [B] is bonded to both ends of a polymer block [A] and a polymer block [A] is bonded to the other end of each of the polymer blocks [B]. In particular, an [A]-[B]-[A] triblock copolymer is particularly preferred because it is easy to produce and can achieve the desired range of physical properties as a thermoplastic elastomer.

[0113] The hydrogenated aromatic vinyl compound-conjugated diene block copolymer can be produced, for example, by the methods described in WO 2015 / 099079 and JP 2016-204217 A.

[0114] The polymer may also be a polymer having a silicon atom-containing polar group. Examples of such polymers include modified products of the polymers exemplified as polymers that can be used as thermoplastic elastomers with a silicon atom-containing polar group. When a polymer having a silicon atom-containing polar group is used as the thermoplastic elastomer, the adhesion between the organic sealing layer and other components can be improved.

[0115] Hereinafter, the polymer used in the reaction to obtain the modified product may be referred to as the "pre-reaction polymer" as appropriate. The modified product may have a structure obtained by, for example, graft polymerization of the pre-reaction polymer with a compound having a silicon atom-containing polar group as a monomer. However, the modified product is not limited by its production method.

[0116] As silicon atom-containing polar group, preferred is alkoxysilyl group.As the compound having alkoxysilyl group as silicon atom-containing polar group, for example, can enumerate vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane and 2-norbornene-5-yltrimethoxysilane etc. ethylenically unsaturated silane compound.

[0117] By reacting a pre-reacted polymer with a compound having a silicon atom-containing polar group, the silicon atom-containing polar group can be introduced into the pre-reacted polymer, resulting in a modified product having the silicon atom-containing polar group. When an alkoxysilyl group is introduced as the silicon atom-containing polar group, the amount of alkoxysilyl group introduced is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, and even more preferably 0.3 parts by weight or more, per 100 parts by weight of the pre-reacted polymer, and preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 3 parts by weight or less. When the amount of alkoxysilyl group introduced falls within the above range, excessive crosslinking between alkoxysilyl groups decomposed by moisture can be prevented, thereby maintaining high adhesiveness. Examples of alkoxysilyl group-containing substances and modification methods used to introduce alkoxysilyl groups include those described in WO 2015 / 099079.

[0118] The amount of polar group introduced can be measured by 1H-NMR spectroscopy. When the amount of polar group introduced is small, the number of integration times can be increased.

[0119] Among the above-mentioned polymers, from the viewpoint of significantly achieving the desired effects of the present invention, one or more types selected from the group consisting of hydrogenated aromatic vinyl compound-conjugated diene block copolymers and hydrogenated aromatic vinyl compound-conjugated diene block copolymers modified with silicon atom-containing polar groups are preferred, and among these, hydrogenated aromatic vinyl compound-conjugated diene block copolymers modified with silicon atom-containing polar groups are particularly preferred.

[0120] Among the modified products of hydrogenated aromatic vinyl compound-conjugated diene block copolymers with silicon atom-containing polar groups, those modified with an alkoxysilyl group as the silicon atom-containing polar group are preferred. Generally, the introduction of an alkoxysilyl group as a polar group into a pre-reaction polymer such as a hydrogenated aromatic vinyl compound-conjugated diene block copolymer is sometimes referred to as silane modification. In the silane modification, the alkoxysilyl group may be bonded directly to the pre-reaction polymer, or may be bonded via a divalent organic group such as an alkylene group. Hereinafter, the polymer obtained by silane modification of the pre-reaction polymer is also referred to as a "silane-modified product."

[0121] Therefore, as the silicon atom-containing polar group-modified hydrogenated aromatic vinyl compound-conjugated diene block copolymer, a silane-modified hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferred, and particularly preferred is one or more silane-modified products selected from the group consisting of a silane-modified hydrogenated styrene-butadiene block copolymer, a silane-modified hydrogenated styrene-butadiene-styrene block copolymer, a silane-modified hydrogenated styrene-isoprene block copolymer, and a silane-modified hydrogenated styrene-isoprene-styrene block copolymer.

[0122] The weight-average molecular weight (Mw) of the polymer is not particularly limited, but is preferably 20,000 or more, more preferably 30,000 or more, even more preferably 35,000 or more, and preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 70,000 or less. The weight-average molecular weight of the thermoplastic elastomer can be measured in polystyrene equivalent terms by gel permeation chromatography using tetrahydrofuran as a solvent. The molecular weight distribution (Mw / Mn) of the thermoplastic elastomer is preferably 4 or less, more preferably 3 or less, even more preferably 2 or less, and preferably 1 or more. When the weight-average molecular weight Mw and molecular weight distribution Mw / Mn of the thermoplastic elastomer are within the above ranges, the mechanical strength and heat resistance of the polymer material 4 can be improved.

[0123] The glass transition temperature of the thermoplastic elastomer is not particularly limited, but is preferably 40°C or higher, more preferably 70°C or higher, and preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower. When a thermoplastic elastomer containing a block copolymer is used, the weight ratio of each polymer block can be changed to adjust the glass transition temperature, thereby achieving a balance between the adhesiveness and flexibility of the polymer material 4. The glass transition temperature of the resin can be measured using a differential scanning calorimeter (DSC) by increasing the temperature at a rate of 10°C / min.

[0124] <Layer 4 of polymer material> As described above, the (first) photoelectric conversion section 7A may be configured to have a layer of polymer material 4 at the boundary between the power generation layer 8A and the porous membrane 3A. In this case, the power generation layer 8A is composed of a layer of polymer material 4, a power generation layer main body, and a charge transport layer. Here, it is preferable that the layer of polymer material 4 is present in at least partial contact with both the power generation layer main body and the charge transport layer made of the porous membrane. With this configuration, the layer of polymer material 4 can function as a buffer layer, thereby ensuring the performance of the photoelectric conversion module 6 and stabilizing the shape of the joint surface.

[0125] The charge transport layer formed of a porous film may contain the above-described polymer material 4 inside the charge transport layer formed of the porous film. The power generation layer main body may contain the above-described polymer material 4 inside the power generation layer main body.

[0126] According to the photovoltaic conversion module 6, the functions of a hole transport layer and a collecting electrode can be fulfilled by a single charge transport layer made of a porous film. Furthermore, the photovoltaic conversion module 6 has a connection 5 between the porous film 3 made of a polymer material 4 and the conductive substrate 2 (conductive film), thereby realizing excellent power generation performance with suppressed short circuits. Furthermore, when the photovoltaic conversion module 6 has a layer made of a polymer material 4 as a buffer layer between the power generation layer main body and the charge transport layer made of a porous film, it can achieve excellent structural stability and photovoltaic conversion efficiency.

[0127] The photovoltaic conversion module 6 of this embodiment is an integrated laminate in which the order of the above-mentioned components is maintained, and may further include other layers, etc., as long as the effect of the present invention is not impaired.

[0128] (Example of manufacturing method of photoelectric conversion module 6) The method for manufacturing the photoelectric conversion module 6 is not particularly limited, but for example, the photoelectric conversion module 6 can be manufactured by a method including a step (hereinafter also referred to as step O) of placing the polymer material 4 on the power generation layer 8A of the (first) photoelectric conversion section 7A, the conductive film 2b of the structure 1, and the power generation layer 8B of the second photoelectric conversion section 7B, and then laminating the porous free-standing sheet onto the polymer material 4 while at least one of the bonding surfaces between the porous free-standing sheet, which becomes a charge transport layer made of a porous film, and the polymer material 4 retains a solvent (hereinafter also referred to as solvent X). Alternatively, the photovoltaic module 6 may be manufactured by a method including a step (hereinafter also referred to as step P) of laminating a porous free-standing sheet to the power generation layer 8A of the (first) photovoltaic converter 7A, the conductive film 2b of the structure 1, and the power generation layer 8B of the second photovoltaic converter 7B while retaining a solution (hereinafter also referred to as solution Y) containing a polymer as the polymer material 4 on at least one of the bonding surfaces of the porous free-standing sheet, which serves as a charge transport layer made of a porous film, and the power generation layer 8A of the (first) photovoltaic converter 7A, the conductive film 2b of the structure 1, and the power generation layer 8B of the second photovoltaic converter 7B. Either method may further include a step of drying the solvent X or solution Y. The "bonding surface" referred to above refers to the bonding surface between the power generation layer 8A of the (first) photovoltaic converter 7A, the conductive film 2b of the structure 1, and the power generation layer 8B of the second photovoltaic converter 7B and the porous free-standing sheet. An example of a manufacturing method for the photovoltaic module 6 of this embodiment will be described in more detail below.

[0129] <Preparing the substrate> First, a substrate is prepared in the method for manufacturing the photoelectric conversion module 6. As the type of substrate, those listed in the section "Configuration example of photoelectric conversion module 6" can be used.

[0130] <Conductive film formation> Next, a conductive film is formed on the substrate. The method for forming the conductive film is not particularly limited, and known methods such as sputtering and vapor deposition can be used. The formation of the conductive film may be omitted by using a commercially available light-transmitting substrate with a transparent conductive film layer formed on its surface. The electrode patterning may be performed during the formation of the conductive film, or may be performed after the film formation by etching, laser scribing, or the like.

[0131] <Formation of charge transport layer> Furthermore, a charge transport layer is formed on the conductive film by forming an underlayer on the conductive film and then forming a porous semiconductor layer.

[0132] [Formation of Underlayer] The method for forming the underlayer is not particularly limited, and for example, the underlayer can be formed by spraying a solution containing a material for forming an n-type semiconductor onto the conductive film, and heating it as necessary.

[0133] Here, examples of methods for spraying the fine particles include spray pyrolysis, aerosol deposition, electrostatic spray, and cold spray.

[0134] [Formation of Porous Semiconductor Layer] The method for forming the porous semiconductor layer is not particularly limited, and for example, the porous semiconductor layer can be formed by applying a solution containing a precursor of an n-type semiconductor onto the underlayer by spin coating or the like, and then drying.

[0135] Here, examples of precursors of n-type semiconductors include titanium alkoxides such as titanium tetrachloride (TiCl), peroxotitanic acid (PTA), titanium ethoxide, and titanium isopropoxide (TTIP); and metal alkoxides such as zinc alkoxide, alkoxysilane, zirconium alkoxide, and titanium diisopropoxide bis(acetylacetonate).

[0136] The solvent used for the solution containing the precursor of the n-type semiconductor is not particularly limited, and for example, an alcohol solution such as ethanol can be used.

[0137] Furthermore, the temperature and time for drying the solution applied onto the underlayer are not particularly limited, and may be adjusted appropriately depending on the type of n-type precursor and the type of solvent used.

[0138] <Formation of the power generation layer body> Then, a main body of the power generation layer is formed on the charge transport layer. The method for forming the main body of the power generation layer includes, but is not particularly limited to, a vacuum evaporation method, a coating method, etc. For example, it can be formed by applying a precursor-containing solution containing a precursor of a perovskite compound onto the charge transport layer and then firing it. Here, examples of the precursor of the perovskite compound include lead iodide (PbI₂), methylammonium iodide (CH₃NH₃I), etc. Further, the solvent contained in the precursor-containing solution is not particularly limited, and for example, N,N-dimethylformamide, dimethyl sulfoxide, etc. can be used. After applying these solutions, it is also possible to promote the precipitation of the perovskite compound using a poor solvent. In this specification, a poor solvent refers to a solvent in which the perovskite compound does not substantially change during the manufacturing process. In the manufacturing process, if no external change such as turbidity of the film is visually observed in the perovskite compound, it can be said that there is no substantial change.

[0139] Here, the concentration of the precursor of the perovskite compound in the precursor-containing solution may be appropriately set to a suitable concentration depending on the solubility of the materials constituting the perovskite compound, etc. For example, it can be set to about 0.5M to 1.5M.

[0140] Also, the method for applying the precursor-containing solution onto the charge transport layer is not particularly limited, and for example, known coating methods such as a spin coating method, a spray method, a bar coating method, etc. can be adopted.

[0141] <Production Example of Polymer> As an example of the polymer as the polymer material 4 used in the present invention, those synthesized based on the production examples shown below can be used.

[0142] <<Production of Hydrogenated Block Copolymer>> Using styrene as an aromatic vinyl compound and isoprene as a chain-conjugated diene compound, a hydride of a block copolymer (hydrogenated block copolymer) having a triblock structure in which polymer blocks [A] are bonded to both ends of a polymer block [B] was produced by the following procedure.

[0143] A reactor equipped with a stirrer and thoroughly purged with nitrogen was charged with 256 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene, and 0.615 parts of n-dibutyl ether, and 1.35 parts of n-butyllithium (15% cyclohexane solution) was added with stirring at 60°C to initiate polymerization. The reaction was continued for 60 minutes with stirring at 60°C. The polymerization conversion at this point was 99.5% (the polymerization conversion was measured by gas chromatography; the same applies hereinafter).

[0144] Next, 50.0 parts of dehydrated isoprene was added, and stirring was continued at the same temperature for 30 minutes. At this point, the polymerization conversion rate was 99%. 25.0 parts of dehydrated styrene was then added, and stirring was continued at the same temperature for 60 minutes. At this point, the polymerization conversion rate was nearly 100%. 0.5 parts of isopropyl alcohol was then added to the reaction solution to terminate the reaction, yielding solution (i) containing a block copolymer. The weight-average molecular weight (Mw) of the block copolymer in the resulting solution (i) was 44,900, and the molecular weight distribution (Mw / Mn) was 1.03 (measured in polystyrene equivalent values ​​by gel permeation chromatography using tetrahydrofuran as a solvent; the same applies below).

[0145] Next, solution (i) was transferred to a pressure-resistant reactor equipped with a stirrer, and 4.0 parts of a silica-alumina-supported nickel catalyst (E22U, 60% nickel loading; manufactured by JGC Chemical Industries, Ltd.) as a hydrogenation catalyst and 350 parts of dehydrated cyclohexane were added and mixed. The atmosphere inside the reactor was replaced with hydrogen gas, and hydrogen was further supplied while stirring the solution. The hydrogenation reaction was carried out at a temperature of 170°C and a pressure of 4.5 MPa for 6 hours to hydrogenate the block copolymer, yielding solution (iii) containing the hydrogenated block copolymer (ii). The weight-average molecular weight (Mw) of the hydrogenated block copolymer (ii) in solution (iii) was 45,100, and the molecular weight distribution (Mw / Mn) was 1.04.

[0146] After the hydrogenation reaction was completed, solution (iii) was filtered to remove the hydrogenation catalyst. Then, 1.0 part of a xylene solution in which 0.1 part of 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetrakis-t-butyldibenzodioxaphosphepine (Sumitomo Chemical's "Sumilizer (registered trademark) GP", hereinafter referred to as "antioxidant A"), a phosphorus-based antioxidant, was dissolved was added to the filtered solution (iii) and dissolved to obtain solution (iv).

[0147] Next, solution (iv) was filtered through a Zeta Plus (registered trademark) filter 30H (manufactured by Cuno, pore size 0.5 μm to 1 μm), and further sequentially filtered through another metal fiber filter (pore size 0.4 μm, manufactured by Nichida) to remove minute solid components. From the filtered solution (iv), using a cylindrical concentration dryer (product name "Contro", manufactured by Hitachi, Ltd.), at a temperature of 260°C and a pressure of 0.001 MPa or less, the solvents cyclohexane, xylene and other volatile components were removed. Then, from a die directly connected to the above-mentioned concentration dryer, the solid content was extruded in a strand form in a molten state, cooled, and cut with a pelletizer to obtain 85 parts of pellets (v) containing a hydride of a block copolymer and antioxidant A. The weight average molecular weight (Mw) of the hydride of the block copolymer (hydrogenated block copolymer) in the obtained pellets (v) was 45,000, and the molecular weight distribution (Mw / Mn) was 1.08. Also, 1 The hydrogenation rate measured by 1H-NMR was 99.9%.

[0148] <<P2. Production of Silane-Modified Product of Hydrogenated Block Copolymer>> To 100 parts of the pellets (v) obtained in step (P1), 2.0 parts of vinyltrimethoxysilane and 0.2 parts of di-t-butyl peroxide were added to obtain a mixture. This mixture was kneaded using a twin-screw extruder at a barrel temperature of 210°C and a residence time of 80 to 90 seconds. The kneaded mixture was extruded and cut using a pelletizer to obtain pellets (vi) of the silane-modified hydrogenated block copolymer. A film-like test piece was prepared from the pellets (vi), and the glass transition temperature (Tg) was evaluated using the tan δ peak of a dynamic viscoelasticity measuring device, which was 124°C. The peak tan δ value of the pellets (vi) at temperatures between 40°C and 200°C was 1.3. The Young's modulus of the pellets (vi) at 23°C was 0.5 GPa, and the tensile elongation was 550%. The refractive index (n1) of the pellets (vi) measured using an Abbe refractometer was 1.50.

[0149] <Attachment using polymer material 4> <<Process O>> When manufacturing a photovoltaic conversion module 6 by step O, after forming the power generation layer body, polymer material 4 is placed on the power generation layer body of power generation layer 8A of the (first) photovoltaic conversion unit 7A, the conductive film 2b of the structure 1, and the power generation layer body of power generation layer 8B of the second photovoltaic conversion unit 7B. Then, the porous free-standing sheet is laminated on the layer of polymer material 4, with solvent X retained on at least one bonding surface between the porous free-standing sheet, which serves as a charge transport layer made of a porous film, and the layer of polymer material 4. This allows the porous free-standing sheet to be efficiently attached to the power generation layer body of power generation layer 8A of the (first) photovoltaic conversion unit 7A, the conductive film 2b of the structure 1, and the power generation layer body of power generation layer 8B of the second photovoltaic conversion unit 7B.

[0150] [Polymer material 4 placement] The method for disposing the polymer material 4 is not particularly limited, and for example, the polymer material 4 can be formed by applying a solution Y in which a polymer for forming the polymer material 4 is dissolved to the power generation layer body and the conductive film 2b, and drying it as necessary.

[0151] The solvent for dissolving the polymer is not particularly limited, but examples include poor solvents such as chlorobenzene, toluene, and anisole. Polymers such as those listed in the section "Polymer Material 4" can be used. The concentration of the polymer in solution Y can be selected appropriately depending on the application amount and application method, as the amount of liquid carried varies depending on the application amount and application method.

[0152] The method for applying the solution Y onto the power generation layer body is not particularly limited, and known application methods such as spin coating, spraying, and bar coating can be used.

[0153] [Configuration of solvent X] The solvent X is not particularly limited, and examples thereof include poor solvents such as chlorobenzene, toluene, anisole, etc. If these poor solvents are used, for example, when the power generation layer main body is a perovskite layer made of a perovskite compound, the performance of the power generation layer main body can be maintained even if the solvent X penetrates into the power generation layer main body through the layer of polymer material 4.

[0154] The method for retaining solvent X on at least one of the bonding surfaces between the porous free-standing sheet and the layer of polymer material 4 is not particularly limited. For example, solvent X may be applied to the porous free-standing sheet, solvent X may be applied to the layer of polymer material 4, or solvent X may be applied to both the porous free-standing sheet and the layer of polymer material 4.

[0155] In particular, if a porous self-supporting sheet impregnated with the solvent X is used, the solvent X can be well retained on at least one of the bonding surfaces between the porous self-supporting sheet and the layer of polymer material 4 .

[0156] Here, a porous free-standing sheet impregnated with solvent X can be obtained, for example, by immersing a porous free-standing sheet in solvent X and then removing it. The immersion time is not particularly limited and may be set appropriately depending on the type of solvent used, etc. Alternatively, the method may be appropriately selected depending on the actual manufacturing process, such as spraying or dripping solvent X onto a porous free-standing sheet placed in an application jig.

[0157] <<Process P>> When manufacturing the photovoltaic conversion module 6 by process P, the porous free-standing sheet is laminated on the power generation layer main body of the power generation layer 8A of the (first) photovoltaic conversion unit 7A, the conductive film 2b of the structure 1, and the power generation layer main body of the power generation layer 8B of the second photovoltaic conversion unit 7B, with the solution Y containing a polymer dissolved therein as the polymer material 4 held on at least one of the bonding surfaces of the porous free-standing sheet, which serves as a charge transport layer made of a porous film, and the power generation layer main body of the power generation layer 8A of the (first) photovoltaic conversion unit 7A, the conductive film 2b of the structure 1, and the power generation layer main body of the power generation layer 8B of the second photovoltaic conversion unit 7B. This allows the porous free-standing sheet to be efficiently attached to the power generation layer main body of the power generation layer 8A of the (first) photovoltaic conversion unit 7A, the conductive film 2b of the structure 1, and the power generation layer main body of the power generation layer 8B of the second photovoltaic conversion unit 7B.

[0158] The solvent for solution Y is not particularly limited, and examples thereof include poor solvents such as chlorobenzene, toluene, and anisole, as long as it can dissolve a predetermined amount of the polymer as polymer material 4. If such poor solvents are used, for example, when the power generation layer main body is a perovskite layer made of a perovskite compound, the performance of the power generation layer main body can be maintained. As the polymer in solution Y, those listed in the section on "Polymer material 4" can be used. The concentration of the polymer in solution Y can be selected appropriately depending on the method, as the amount of liquid supported varies depending on the application amount and application method.

[0159] The method for retaining solution Y on at least one of the bonding surfaces between the porous free-standing sheet and the power generation layer main body of the power generation layer 8A of the (first) photoelectric conversion section 7A, the conductive film 2b of the structure 1, and the power generation layer main body of the power generation layer 8B of the second photoelectric conversion section 7B is not particularly limited. For example, solution Y may be applied to the porous free-standing sheet, or solution Y may be applied to the power generation layer main body of the power generation layer 8A of the (first) photoelectric conversion section 7A, the conductive film 2b of the structure 1, and the power generation layer main body of the power generation layer 8B of the second photoelectric conversion section 7B, or solution Y may be applied to both the porous free-standing sheet and the power generation layer main body of the power generation layer 8A of the (first) photoelectric conversion section 7A, the conductive film 2b of the structure 1, and the power generation layer main body of the power generation layer 8B of the second photoelectric conversion section 7B.

[0160] The specific method for applying solution Y to the porous self-supporting sheet is not particularly limited, and examples of methods that can be used include dipping, roll coating, gravure coating, knife coating, air knife coating, roll knife coating, die coating, screen printing, spray coating, and gravure offset.

[0161] In particular, by using a porous free-standing sheet impregnated with solution Y, solution Y can be well retained at at least one of the bonding surfaces between the porous free-standing sheet and the power generation layer main body of the power generation layer 8A of the (first) photoelectric conversion section 7A, the conductive film 2b of the structure 1, and the power generation layer main body of the power generation layer 8B of the second photoelectric conversion section 7B.

[0162] Here, a porous free-standing sheet impregnated with solution Y can be obtained, for example, by immersing a porous free-standing sheet in solution Y and then removing it. In this case, the immersion time is not particularly limited and may be set appropriately depending on the type of solvent and polymer used, etc.

[0163] The specific method for applying the solution Y to the power generation layer body of the power generation layer 8A of the (first) photoelectric conversion section 7A, the conductive film 2b of the structure 1, and the power generation layer body of the power generation layer 8B of the second photoelectric conversion section 7B is not particularly limited, and for example, spin coating, spraying, bar coating, or other coating methods can be used.

[0164] <Drying> After the porous free-standing sheet is attached in step O or step P, a drying step of drying the porous free-standing sheet may be provided. Known drying methods can be used to dry the porous free-standing sheet. Examples of drying methods include hot air drying, vacuum drying, heat roll drying, infrared irradiation, and heat pressing. The drying temperature and drying time can be appropriately selected depending on the solvent used for solvent X or solution Y, the amount of liquid applied, and the like. The drying temperature is not particularly limited, but is preferably room temperature or higher, more preferably 80°C or higher, and preferably 200°C or lower, and more preferably 120°C or lower. The drying time is not particularly limited, but is preferably 1 second or longer, more preferably 10 seconds or longer, and preferably 10 minutes or shorter, and more preferably 1 minute or shorter.

[0165] Among the above, the hot pressing method is preferred. The hot pressing method allows for the production of a photovoltaic conversion module 6 with excellent integrity. The pressure used during hot pressing is not particularly limited as long as it does not affect the substrate or the formed film, and can be, for example, 0.01 to 0.5 MPa. The heating temperature and heating time during hot pressing can be appropriately selected depending on the solvent used for solvent X or solution Y, the amount of applied liquid, and other factors. Furthermore, during hot pressing, it is preferable to press in a manner that ensures a solvent evaporation path in order to promote the removal of the solvent component contained in the porous free-standing sheet. Specifically, in order to ensure a solvent evaporation path, it is preferable to perform hot pressing via a porous member such as a thick wipe, porous rubber, porous metal, or porous ceramic.

[0166] According to the above-described manufacturing method, it is possible to easily manufacture a photovoltaic conversion module 6 that can achieve excellent power generation performance with suppressed short circuits, as well as excellent structural stability and photovoltaic conversion efficiency. Note that the manufacturing method of the photovoltaic conversion module 6 is not limited to the above-described method, and may include steps other than those described above, as long as the effects of the present invention are not impaired.

[0167] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be modified in various ways without departing from the gist of the present invention. [Example]

[0168] Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

[0169] <Formation of a connection between a porous film and a conductive substrate> A connection between the porous film and the conductive substrate was formed by the following procedure.

[0170] Example 1 [Preparation of porous membrane] A porous film containing single-walled CNTs was prepared according to the following procedure.

[0171] To 500 mL of a 2% by mass aqueous solution of sodium deoxycholate (DOC) as a dispersant, 1.0 g of single-walled CNTs (ZEON Corporation, product name "ZEONANO SG101," mean diameter: 3.5 nm, G / D ratio: 2.1, t-plot with unopened openings is upwardly convex) was added to obtain a crude dispersion containing DOC as a dispersant. This crude dispersion was loaded into a high-pressure homogenizer (BERYU Co., Ltd., product name "BERYU SYSTEM PRO") equipped with a multistage pressure control device (multistage pressure reducer) that applies back pressure during dispersion, and the crude dispersion was dispersed at a pressure of 100 MPa. Specifically, shear force was applied to the crude dispersion while applying back pressure to disperse the fibrous carbon nanostructures containing single-walled CNTs, resulting in a dispersion of fibrous carbon nanostructures containing single-walled CNTs. The dispersion treatment was carried out for 10 minutes while the dispersion liquid flowing out of the high-pressure homogenizer was returned to the high-pressure homogenizer.

[0172] 50 g of the prepared fibrous carbon nanostructure dispersion containing single-walled CNTs was added to a 200 mL beaker, and 50 g of distilled water was added to dilute it two-fold. This was then filtered under 0.09 MPa using a vacuum filtration system equipped with a membrane filter. After filtration, the carbon film formed on the membrane filter was washed by passing isopropyl alcohol and water through the vacuum filtration system, and then air was passed through for 15 minutes. The prepared carbon film / membrane filter was then immersed in ethanol, and the carbon film was peeled off from the membrane filter to obtain a carbon film.

[0173] The obtained carbon membrane was equivalent in size to the membrane filter, had excellent film-forming properties, and maintained its film state even after being peeled off from the filter, demonstrating excellent self-supporting properties. The film density of the obtained carbon membrane was measured and found to be 0.85 g / cm. 3 These results indicated that the carbon membrane was a porous membrane.

[0174] [Connection formation] A conductive glass substrate (manufactured by Sigma-Aldrich) had a fluorine-doped tin (FTO) film formed as a transparent conductive film on the surface of the transparent glass substrate, and the FTO film was removed by a width of 2 mm.

[0175] The porous membrane was immersed in a polymer solution prepared by dissolving 10 mg of the polymer synthesized based on the above manufacturing example in 1 ml of chlorobenzene for 10 seconds, and then removed. After that, the porous membrane was placed symmetrically so as to bridge the FTO membranes spaced 2 mm apart, and while heated on a hot plate at 80°C, it was pressed through a wipe at a pressure of 0.05 MPa to dry the solvent, forming connections with each of the spaced FTO membranes.

[0176] [Resistance measurement] Indium was applied to a position 2 mm away from the installed porous film to form a measurement terminal, and the resistance value was measured using a tester. The measurement value was the average of the measurement results for three samples prepared in the same way, and the results, including whether or not the connection could be formed (whether or not it could be attached), are shown in Table 1.

[0177] Example 2 A connecting portion was formed in accordance with Example 1, except that polymethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of the polymer used in Example 1.

[0178] Example 3 The polymer solution used in Example 1 was spin-coated onto substrates with FTO films formed thereon, spaced 2 mm apart, and then dried to produce substrates with polymer films formed thereon. A connecting portion was formed in the same manner as in Example 1, except that chlorobenzene was added to the porous film.

[0179] (Comparative Example 1) The connection was formed in the same manner as in Example 1, except that the porous membrane was not immersed in a polymer solution, and the FTO membrane and porous sheet were formed at the connection using epoxy resin (room temperature curing two-component, manufactured by ThreeBond Co., Ltd.).

[0180] (Comparative Example 2) A connection was formed in accordance with Example 1, except that chlorobenzene was used instead of the polymer solution used in Example 1.

[0181] (Comparative Example 3) A connection was formed in the same manner as in Example 1, except that a polymer solution was dropped onto the FTO films spaced 2 mm apart, and copper foil was used for attachment instead of the porous film.

[0182] [Table 1]

[0183] As shown in Table 1, it was confirmed that Examples 1 to 3 having the structure of the present invention were able to achieve good structural and electrical connections compared to Comparative Examples 1 to 3 not having the structure of the present invention.

[0184] <Fabrication of perovskite solar cells> A perovskite solar cell was manufactured as a photoelectric conversion module by the following procedure.

[0185] Example 4 [Preparation of a Conductive Substrate Having a Transparent Conductive Film] The conductive glass substrate (manufactured by Sigma-Aldrich) was used, and a portion of the FTO film was removed by etching, thereby obtaining a conductive substrate having a transparent conductive film.

[0186] [Formation of Charge Transport Layer] A solution of titanium diisopropoxide bis(acetylacetonate) in isopropanol (Sigma-Aldrich) was sprayed onto the surface of the FTO film on a conductive substrate with a transparent conductive film by spray pyrolysis. This resulted in a titanium dioxide underlayer (30 nm thick) on the FTO film. Next, a solution was prepared by diluting titanium oxide paste (Sigma-Aldrich) with ethanol. The resulting solution was spin-coated onto the surface of the underlayer and heat-treated at 450°C for 30 minutes to form a porous semiconductor layer (120 nm thick) made of titanium dioxide (TiO2), resulting in a charge transport layer.

[0187] [Formation of perovskite layer] A N,N-dimethylformamide (DMF) solution containing 1.0 M lead iodide (PbI2) and 1.0 M methylammonium iodide (CH3NH3I) was prepared as a solution containing the precursor of the perovskite compound. The resulting solution was applied to the surface of the charge transport layer by spin coating while adding chlorobenzene dropwise, and then baked at 100°C for 10 minutes to form a perovskite layer (450 nm thick) that would form the power generation layer.

[0188] [Formation of a charge transport layer using a porous film] The porous membrane was immersed in the polymer solution for 10 seconds, and then pulled out. The resulting porous membrane impregnated with the polymer solution was laminated on the substrate on which the power generation layer had been formed, and placed on a hot plate at a temperature of 80°C. The entire porous membrane, including the connection parts, was pressed from the porous membrane side using a wipe at a pressure of 0.05 MPa while drying, to obtain a perovskite solar cell.

[0189] [Evaluation of solar cell characteristics] The obtained perovskite solar cell was irradiated with light adjusted to 500 Lux using an LED light, and the solar cell characteristics were evaluated. The electrode on the porous membrane side was taken out from an indium solder coating formed 2 mm away from the connection between the porous membrane and FTO.

[0190] The fabricated perovskite solar cell was connected to a source meter (6244 type DC voltage / current source, manufactured by ADC) and the following current-voltage characteristics were measured.

[0191] Under light irradiation, the bias voltage was selected within a measurement range depending on the number of series connections, and the output current was measured while changing the voltage. The output current was measured by integrating the value from 0.5 seconds to 0.6 seconds after changing the voltage at each voltage step.

[0192] From the measurement results of the current-voltage characteristics above, the short-circuit current density (mA / cm 2 The open circuit voltage (V), fill factor, and photoelectric conversion efficiency (%) were calculated. The results are shown in Table 2.

[0193] Example 5 A perovskite solar cell was fabricated in the same manner as in Example 1, except that a polymer solution was applied to the portion of the substrate on which the power generation layer had been formed, where a connection portion was to be formed, and the resulting film was dried at 80°C, and then a porous film impregnated with chlorobenzene was used.

[0194] Example 6 A perovskite solar cell was fabricated in the same manner as in Example 1, except that a polymer solution was spin-coated onto the portion of the substrate on which the power generation layer and the connection portion were to be formed, and the resulting film was dried at 80°C, and then a porous film impregnated with chlorobenzene was used.

[0195] Comparative Example 4 A perovskite solar cell was fabricated in accordance with Example 4, except that the epoxy resin used in Comparative Example 1 was applied to the connecting portion and a porous film impregnated with chlorobenzene was used.

[0196] (Comparative Example 5) A perovskite solar cell was fabricated in accordance with Example 4, except that a porous film containing chlorobenzene was used.

[0197] [Table 2]

[0198] As shown in Table 2, it was confirmed that Examples 4 to 6 having the structure of the present invention were superior to Comparative Examples 4 to 5 not having the structure of the present invention in terms of short-circuit current density, open-circuit voltage, form factor, and photoelectric conversion efficiency. [Explanation of symbols]

[0199] 1 structure 2. Conductive substrate of the structure 2A Conductive substrate of the (first) photoelectric conversion unit 2B Conductive substrate of second photoelectric conversion unit 2a Structural substrate 2aA (first) photoelectric conversion unit substrate 2aB Substrate of second photoelectric conversion unit 2b Conductive film of the structure 2bA Conductive film of the (first) photoelectric conversion section 2bB Conductive film of the second photoelectric conversion unit 3. Structural porous membrane 3A Porous film of the (first) photoelectric conversion unit 3B Porous film of second photoelectric conversion unit 4 Polymer materials 5 Connection 6 Photoelectric conversion module 7A (first) photoelectric conversion unit 7B Second photoelectric conversion unit 8A (First) photoelectric conversion unit power generation layer 8B Power generation layer of second photoelectric conversion unit 9 Extraction electrode 10A First spaced portion 10B Second spaced portion

Claims

1. a conductive substrate; a porous membrane including a carbon nanofiber body and having voids; A structure in which the conductive substrate and the porous membrane are fixed in an electrically connected state by a non-conductive polymer material containing a polymer having a weight average molecular weight of 5,000 to 100,000 penetrating into the voids.

2. 10. The structure of claim 1, wherein the polymer is a hydrogenated polymer.

3. The structure according to claim 1 , wherein the polymer is a polymer having a hydrogenated aromatic or diene skeleton in the main chain.

4. 2. The structure according to claim 1, wherein the polymer is at least one selected from the group consisting of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer and a hydrogenated aromatic vinyl compound-conjugated diene block copolymer modified with a silicon atom-containing polar group.

5. The structure according to claim 4, wherein the hydrogenated aromatic vinyl compound-conjugated diene block copolymer has a structure in which both non-aromatic carbon-carbon unsaturated bonds and aromatic carbon-carbon unsaturated bonds are hydrogenated.

6. 2. The structure according to claim 1, wherein the carbon nanofibrous body has an average diameter (Av) and a standard deviation (σ) of the diameters that satisfy the relationship: 0.20<(3σ / Av)<0.

60.

7. 2. The structure according to claim 1, wherein the carbon nanofiber material exhibits an upwardly convex t-plot obtained from an adsorption isotherm.

8. A method for manufacturing the structure according to claim 1, comprising: a step of preparing a solution in which the polymer material is dissolved in a solvent; laminating the porous film and the conductive substrate in a state in which the solution has permeated into the voids in the porous film; a drying step of removing the solvent while the porous film and the conductive substrate are stuck together.

9. A method for manufacturing the structure according to claim 1, comprising: forming a layer of the polymer material on the conductive substrate; a step of laminating the porous film and the conductive substrate together via a layer made of the polymer material in a state in which a liquid containing a solvent that dissolves the polymer material is permeated into the voids in the porous film; a drying step of removing the solvent while the porous film and the conductive substrate are stuck together.

10. The method for manufacturing a structure according to claim 8 , wherein the drying step is carried out by applying heat and / or pressure.

11. A photoelectric conversion module comprising the structure according to claim 1 and a photoelectric conversion unit, wherein the photoelectric conversion unit comprises, in this order in a stacking direction, a substrate continuous with the substrate of the conductive substrate of the structure, a conductive film spaced from the conductive film of the conductive substrate of the structure, a power generation layer having a photoelectric conversion function, and a porous film, A photoelectric conversion module in which the porous film of the photoelectric conversion section and the structure are electrically connected.

12. The photoelectric conversion module according to claim 11 , wherein the porous film of the photoelectric conversion section and the porous film of the structure are formed from a single porous film.

13. The photovoltaic conversion module according to claim 11 , wherein the power generation layer contains a perovskite compound.

14. The photoelectric conversion module according to claim 11, further comprising a second photoelectric conversion unit, the second photoelectric conversion unit having, in the stacking direction, a substrate connected to the substrate of the conductive substrate of the structure, a conductive film connected to the conductive film of the conductive substrate of the structure, a power generation layer having a photoelectric conversion function, and a porous film, in this order.

15. A photoelectric conversion module manufacturing method for manufacturing the photoelectric conversion module according to claim 11, comprising: forming the power generation layer on the conductive substrate of the photoelectric conversion unit; and forming the photoelectric conversion section and the structure simultaneously by arranging a porous film including the porous film of the photoelectric conversion section and the porous film of the structure so as to straddle the power generation layer and the conductive substrate of the structure.

16. A photoelectric conversion module manufacturing method for manufacturing the photoelectric conversion module according to claim 14, comprising the steps of: a step of arranging a porous film including the porous film of the photoelectric conversion unit, the porous film of the second photoelectric conversion unit, and the porous film of the structure so as to straddle the power generation layer of the photoelectric conversion unit, the power generation layer of the second photoelectric conversion unit, and the conductive substrate of the structure; a separation step of separating the porous film of the second photoelectric conversion section from the porous film of the structure.

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