Photoelectric conversion module

Abstract

To provide a photoelectric conversion module with improved durability.SOLUTION: A photoelectric conversion module according to the present disclosure includes a substrate 1, a photoelectric conversion element 2, and a first sealing member 7, wherein the photoelectric conversion element 2 is sealed by the substrate 1 and the first sealing member 7, the first sealing member 7 includes a first sealing portion 71 made of a first sealing material, and the first sealing material includes at least one selected from the group consisting of polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, and a butylene diol-vinyl alcohol copolymer. The photoelectric conversion element 2 may include, for example, a first electrode, a photoelectric conversion layer, and a second electrode in this order.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a photovoltaic conversion module. [Background technology]

[0002] The main functions of photoelectric conversion elements are to convert light into electricity and to convert electricity into light. Elements that optimize the former function include photodetectors, photoreceptors, and solar cells, while elements that optimize the latter function include LED elements (light-emitting diode elements) and EL elements (electroluminescent elements).

[0003] Photoelectric conversion elements are composed of components such as a semiconductor layer that performs photoelectric conversion, an electrode layer that extracts current from this, and a collector electrode layer that reduces resistance. These components undergo chemical changes and alteration due to external influences, causing a decrease in the performance of the photoelectric conversion element. The main external influence is water.

[0004] Non-Patent Document 1 reports that water vapor in the atmosphere reacts with perovskite compounds. This reaction results in the formation of substances that do not contribute to power generation, such as lead iodide, methylammonium iodide, or hydrated compounds, on the surface and grain boundaries of the perovskite compounds.

[0005] As a countermeasure, a sealing layer is provided between the components and the outside world to isolate the photoelectric conversion element from the outside world, i.e., photoelectric conversion modularization is being carried out. However, the performance degradation of photoelectric conversion elements is not only caused by water, but also by the influence of oxygen. Non-Patent Document 1 reports that under light irradiation, cations in perovskite compounds react with oxygen, forming metal oxides or hydroxides on the surface and grain boundaries of the perovskite compound. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Q. Sun, et al., Advanced Energy Materials, July 2017, Vol. 7, p. 1700977. Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, oxygen has a major impact on the performance of photovoltaic conversion elements. However, conventional structures do not adequately block oxygen, and there has been a demand for improved durability of photovoltaic conversion modules.

[0008] An object of the present disclosure is to provide a photovoltaic conversion module with improved durability. [Means for solving the problem]

[0009] The photoelectric conversion module of the present disclosure includes: a first substrate; a second substrate facing the first substrate in a thickness direction of the first substrate; a first sealing portion that is provided between the first substrate and the second substrate so as to be in contact with the first substrate and the second substrate in a cross-sectional view in the thickness direction, and that seals a region formed between the first substrate and the second substrate; a second sealing member provided between the first substrate and the second substrate so as to be in contact with the first substrate and the second substrate, and disposed outside the first sealing portion, in a cross-sectional view in the thickness direction; a photoelectric conversion element, the photoelectric conversion element is disposed in a sealed region sealed by the first substrate, the second substrate, and the first sealing unit; the first sealing portion includes a first sealing material; the second sealing member includes a second sealing material different from the first sealing material; The first sealing portion is provided spaced apart from the photoelectric conversion element in a cross-sectional view in the thickness direction. [Effects of the Invention]

[0010] The present disclosure provides a photovoltaic conversion module with improved durability. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a photoelectric conversion module 100 according to the first embodiment. [Figure 2] FIG. 2 is a partially enlarged cross-sectional view of a photoelectric conversion module according to the present disclosure, schematically showing a first configuration example of a photoelectric conversion element 2 according to the present disclosure. [Figure 3] FIG. 3 is a partially enlarged cross-sectional view of the photoelectric conversion module of the present disclosure, schematically showing a second configuration example of the photoelectric conversion element 2 of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a first configuration example of a photoelectric conversion module according to the second embodiment. [Figure 5] FIG. 5 is a cross-sectional view schematically showing a second configuration example of the photoelectric conversion module according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view schematically showing a third configuration example of the photoelectric conversion module according to the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view schematically showing a fourth configuration example of the photoelectric conversion module according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0013] (First embodiment) The photovoltaic conversion module according to the first embodiment includes a substrate, a photovoltaic conversion element, and a first sealing member. The photovoltaic conversion element is sealed by the substrate and the first sealing member. The first sealing member includes a first sealing portion made of a first sealing material. The first sealing material includes at least one selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylene diol-vinyl alcohol copolymer.

[0014] Polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylene diol-vinyl alcohol copolymer have very low oxygen permeability coefficients and excellent oxygen barrier properties. Therefore, the first sealing member including the first sealing portion made of the first sealing material has the function of reducing oxygen that penetrates into the interior of the photovoltaic conversion module from the outside. This prevents performance degradation of the photovoltaic conversion elements in the photovoltaic conversion module according to the first embodiment, which would otherwise be caused by chemical changes due to oxygen. This improves the durability of the photovoltaic conversion module.

[0015] The oxygen permeability coefficient can be measured by the method described in Japanese Industrial Standards (JIS K-7126).

[0016] The first sealing member may further include a second sealing portion, wherein the second sealing portion is a plate-like body disposed opposite the substrate, and the first sealing portion is a sealing layer that seals the region formed between the substrate and the plate-like body that is the second sealing portion.

[0017] FIG. 1 is a cross-sectional view schematically showing a photoelectric conversion module 100 according to the first embodiment.

[0018] The photoelectric conversion module 100 includes a substrate 1, a photoelectric conversion element 2, and a first sealing member 7. The photoelectric conversion element 2 is sealed by the substrate 1 and the first sealing member 7. The photoelectric conversion module 100 may further include a terminal 3, a terminal 4, a lead 5, and a lead 6. The first sealing member 7 includes a first sealing portion 71 made of a first sealing material. As described above, the first sealing material includes at least one selected from the group consisting of polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, and a butylene diol-vinyl alcohol copolymer.

[0019] The first sealing member 7 may further include a second sealing portion 72. As shown in Fig. 1, the second sealing portion 72 is, for example, a plate-like body arranged opposite the substrate 1. In this case, the first sealing portion 71 may be a sealing layer that seals the region formed between the substrate 1 and the second sealing portion 72.

[0020] The first sealing unit 71 may be provided in a frame shape between the substrate 1 and the second sealing unit 72 so as to surround the photoelectric conversion element 2. The first sealing unit 71 may also be provided in a frame shape so as to surround the periphery of the substrate 1 and the second sealing unit 72.

[0021] The leads 5 and 6 are connected to the photoelectric conversion element 2 via the terminals 3 and 4, respectively.

[0022] The leads 5 and 6 may extend to the outside by penetrating the first sealing member 7. In the photovoltaic conversion module 100 shown in FIG. 1, the leads 5 and 6 penetrate the first sealing portion 71. In this case, it is necessary to maintain the hermeticity of the space sealed by the substrate 1 and the first sealing member 7.

[0023] Hereinafter, terminals 3 and 4 may be collectively referred to simply as terminals. Hereinafter, leads 5 and 6 may be collectively referred to simply as leads.

[0024] The first sealing member 7 has the function of preventing oxygen present outside the photovoltaic conversion module 100 from penetrating into the inside of the module. This prevents performance degradation of the photovoltaic conversion elements 2 in the photovoltaic conversion module 100 according to the first embodiment, which would otherwise be caused by chemical changes due to the influence of oxygen. This improves the durability of the photovoltaic conversion module 100.

[0025] The photovoltaic conversion module in the first embodiment may further include a filler provided in the region sealed by the substrate and the first sealing material. In the photovoltaic conversion module 100 shown in Fig. 1, a first filler 8 is provided in the region sealed by the substrate 1 and the first sealing member 7. As shown in Fig. 1, the region sealed by the substrate 1 and the first sealing member 7 may be filled with the first filler 8.

[0026] Each component of the photoelectric conversion module will be specifically described below.

[0027] (Substrate 1) The substrate 1 is made of, for example, an oxygen-impermeable material. The portion of the substrate 1 that comes into contact with the photoelectric conversion element 2 is made of, for example, a non-conductive material.

[0028] Examples of materials for the substrate 1 include glass, ceramics, metal, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylenediol-vinyl alcohol copolymer.

[0029] The substrate 1 may be a resin sheet (resin film) coated with glass, ceramics, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or butylene diol-vinyl alcohol copolymer. In this case, the coated surface faces the photoelectric conversion element 2.

[0030] The main material of the substrate 1 may be a metal sheet, and the surface of the substrate 1 may be coated with glass, ceramics, insulating resin, or the like.

[0031] The substrate 1 may be made of a material that is impermeable to oxygen and water. Examples of such materials are glass and ceramics. The substrate 1 may be glass.

[0032] (First sealing member 7) The first sealing member 7 includes a first sealing portion 71 made of a first sealing material. The first sealing material includes at least one selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylene diol-vinyl alcohol copolymer. Generally, the first sealing material may include ethylene-vinyl alcohol copolymer.

[0033] The first sealing portion 71 is made of, for example, an oxygen-impermeable material. Here, the oxygen-impermeable material has an oxygen permeability coefficient of 0.1 cm 3 mm / m 2 This term refers to a material having a viscosity of 1000 psi (day) atm or less. The first sealing portion 71 may contain the first sealing material as a main component. That is, the first sealing portion 71 may contain the first sealing material in a mass ratio of 50% or more (50 mass% or more) relative to the entire first sealing portion 71. The first sealing portion 71 may contain the first sealing material in a mass ratio of 70% or more (70 mass% or more) relative to the entire first sealing portion 71. The first sealing portion 71 may contain the first sealing material in a mass ratio of 90% or more (90 mass% or more) relative to the entire first sealing portion 71. The first sealing portion 71 may consist of only the first sealing material.

[0034] The saponification degree of polyvinyl alcohol may be 80 mol% or more, 85 mol% or more, 90 mol% or more, 95 mol% or more, 97 mol% or more, or 98 mol% or more. The saponification degree of polyvinyl alcohol may be 99.5 mol%. The saponification degree of ethylene-vinyl alcohol copolymer may be 90 mol% or more, 95 mol% or more, 97 mol% or more, or 100 mol%. The ethylene content of the ethylene-vinyl alcohol copolymer may be 20 mol% or more, 27 mol% or more, 35 mol% or more, or 44 mol% or more. The saponification degree of butylenediol-vinyl alcohol copolymer may be 90 mol% or more, 95 mol% or more, 97 mol% or more, or 99 mol% or more. The butylene diol content of the butylene diol-vinyl alcohol copolymer may be 20 mol % or more, 27 mol % or more, 35 mol % or more, or 44 mol %.

[0035] The first sealing material may consist of at least one selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylene diol-vinyl alcohol copolymer.

[0036] The first sealing portion 71 can be formed by melt coating of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or butylene diol-vinyl alcohol copolymer, or by coating and drying a solution of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or butylene diol-vinyl alcohol copolymer.

[0037] The first sealing member 7 may further include a second sealing portion. The second sealing portion may include a plate-like body arranged opposite the substrate 1, and the first sealing portion 71 may seal the region formed between the substrate 1 and the second sealing portion. For example, in the photovoltaic conversion module 100 shown in FIG. 1 , the first sealing member 7 further includes a second sealing portion 72 in addition to the first sealing portion 71. The second sealing portion 72 is a plate-like body arranged opposite the substrate 1, and the first sealing portion 71 is a sealing layer that seals the region formed between the substrate 1 and the second sealing portion 72.

[0038] The first sealing portion 71 may have a function similar to that of an adhesive that bonds the substrate 1 and the second sealing portion 72 together.

[0039] The second sealing portion 72 is made of an oxygen-impermeable material.

[0040] Examples of materials for the second sealing portion 72 include glass, ceramics, metal, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylenediol-vinyl alcohol copolymer.

[0041] The second sealing portion 72 may be a resin sheet (resin film) coated with glass, ceramics, metal, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, or butylene diol-vinyl alcohol copolymer. In this case, the coated surface faces the photoelectric conversion element 2.

[0042] The second sealing portion 72 may be made of a material that is impermeable to oxygen and water. Examples of such materials include glass and ceramics. The second sealing portion 72 may be glass.

[0043] When the photoelectric conversion element 2 generates power using incident light from either or both of the substrate 1 and the second sealing unit 72, either the substrate 1 or the second sealing unit 72, which are located in the path of incident light, are made of a light-transmitting material. Examples of such materials include glass, light-transmitting ceramics, or a light-transmitting resin coated with glass, light-transmitting ceramics, polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, or a butylene diol-vinyl alcohol copolymer.

[0044] In FIG. 1, the first sealing member 7 in the photoelectric conversion module 100 includes a second sealing portion 72. In the first embodiment, the second sealing portion 72 in the photoelectric conversion module 100 shown in FIG. 1 may be replaced with the first sealing portion 71. That is, the first sealing member 7 may not include the second sealing portion 72. The first sealing member 7 may consist of only the first sealing portion 71. That is, the photoelectric conversion element 2 may be sealed by the substrate 1 and the first sealing portion 71. The first sealing portion 71 may cover the surface of the photoelectric conversion element 2 supported by the substrate 1.

[0045] (Lead) The leads are electrically connected to the photoelectric conversion element 2 via terminals. The leads are connected to an external circuit as mounting terminals.

[0046] The leads are made of a material that is impervious to oxygen and water and conductive to electricity. Examples of such materials are metals or conductive compounds. Examples of metals are copper, aluminum, nickel, iron, chromium, or titanium. Examples of conductive compounds are indium tin oxide and fluorine-doped tin oxide.

[0047] (Terminal) The terminals are made of a material that conducts electricity. Examples of such materials are metals or conductive compounds. The terminals may be solder. The solder used may have a melting temperature of 150°C or higher and 300°C or lower.

[0048] The terminals may be formed by an ultrasonic soldering process.

[0049] (1st filler 8) First filling material 8 disperses the energy of an impact applied from outside the photovoltaic conversion module, and prevents substrate 1 and first sealing member 7 from being destroyed when an impact is applied.

[0050] Examples of materials for the first filler 8 include EVA-based resin (ie, ethylene-vinyl acetate copolymer) and PO-based resin (ie, polyolefin).

[0051] The first filler 8 may contain at least one selected from the group consisting of an oxygen absorber and a moisture absorber. Examples of the oxygen absorber include metals, semimetals such as Si or C, oxides of metals or semimetals that are not fully oxidized, titanium oxide (TiO2), cerium oxide (CeO2), or iron hydroxide (Fe(OH)2). The oxygen absorber may be iron powder. Examples of the moisture absorber include metals, semimetals such as Si or C, oxides of metals or semimetals that are not fully oxidized, silicon oxide (SiO2) (e.g., silica gel), calcium oxide (CaO) (e.g., quicklime), calcium chloride (CaCl2), or activated alumina (Al2O3). The moisture absorber may be at least one selected from iron powder and calcium oxide. The moisture absorber may be calcium oxide.

[0052] The first filler 8 may contain an oxygen absorbing material.

[0053] (Photoelectric conversion element 2) Each component of the photoelectric conversion element 2 will now be described in detail.

[0054] The photoelectric conversion element 2 includes a first electrode, a photoelectric conversion layer, and a second electrode, in this order. The photoelectric conversion element 2 may further include an electron transport layer between the first electrode and the photoelectric conversion layer, or may further include a hole transport layer between the photoelectric conversion layer and the second electrode. The photoelectric conversion element 2 may further include a first electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and a second electrode, in this order.

[0055] 2 is a partially enlarged cross-sectional view of a photoelectric conversion module according to the present disclosure, schematically illustrating a first configuration example of a photoelectric conversion element 2 according to the present disclosure. In FIG. 2, a photoelectric conversion element 2 having a single cell structure is shown.

[0056] Each element constituting the photoelectric conversion element 2 will be described with reference to FIG.

[0057] 2 shows a photoelectric conversion element 2 disposed on a substrate 1. The photoelectric conversion element 2 includes a first electrode 211, an electron transport layer 212, a photoelectric conversion layer 213, a hole transport layer 214, and a second electrode 215 in this order.

[0058] The photoelectric conversion element 2 may include, in this order, a second electrode 215, a hole transport layer 214, a photoelectric conversion layer 213, an electron transport layer 212, and a first electrode 211. In other words, the second electrode 215 may face the substrate 1.

[0059] The photoelectric conversion element 2 may contain a perovskite compound.

[0060] The perovskite compound may contain Pb.

[0061] The perovskite compound may be represented by the chemical formula APbX3, where A is at least one selected from the group consisting of CH3NH3, NH2CH2NH2, K, Cs, and Rb, and X is at least one selected from the group consisting of Cl, Br, and I.

[0062] (1st electrode 211) The first electrode 211 is conductive and has a function of receiving electrons generated in the photoelectric conversion layer 213 and extracting them to the outside.

[0063] It is desirable that the first electrode 211 has a low electrical resistance.

[0064] Examples of materials that form the first electrode 211 include metals, conductive compounds that exhibit electronic conductivity, and conductive carbon.

[0065] There are no restrictions on the metal, and almost all metals can be used.

[0066] If light transmission is required for the first electrode 211, a light-transmitting conductive compound is desirable. Examples of conductive compounds include indium, zinc, or tin oxide, titanium oxide and nitride, or organic conductors. Fluorine-doped tin oxide (SnO2:F), indium tin oxide (ITO), Al-doped zinc oxide (ZnO:Al), Ga-doped zinc oxide (ZnO:Ga), Nb-doped titanium oxide (TiO2:Nb), or barium tin oxide (BTO) have low volume resistivity and can therefore be used in outdoor solar cells that pass large currents. SnO2:F, ITO, ZnO:Al, ZnO:Ga, TiO2:Nb, and BTO are particularly useful for photoelectric conversion elements because they are light-transmitting.

[0067] Examples of conductive carbon are carbon black, carbon nanotubes (CNTs), graphene, or graphite. Ketjen black and acetylene black are materials classified as carbon black.

[0068] Examples of methods for manufacturing the first electrode 211 include vacuum film formation methods such as sputtering, vapor deposition, or ion plating, screen printing, spraying, or CVD (Chemical Vapor Deposition). CVD is a method for forming a film on a substrate surface by spraying fine droplets of a special material liquid or gas onto a heated substrate. For example, the first electrode 211 may be formed on the substrate 1 by sputtering ITO so that the sheet resistance is approximately 10 Ω / □ or more and 40 Ω / □ or less.

[0069] (Electron transport layer 212) The electron transport layer 212 has a function of accepting electrons in the conduction band of the photoelectric conversion layer 213 and conducting the electrons to the first electrode 211 while insulating holes in the valence band of the photoelectric conversion layer 213 .

[0070] The electron transport layer 212 contains an electron transport material. An electron transport material is a material that transports electrons. The electron transport material may be a semiconductor.

[0071] Examples of electron transporting materials are titanium oxide or tin oxide.

[0072] The electron transport layer 212 may be manufactured, for example, by spin coating or spray coating an alcohol dispersion (e.g., 1% by mass concentration) containing TiO2 nanoparticles, and then removing the alcohol by heating at 100°C or higher. For example, the electron transport layer 212 may be formed on the first electrode 211 by sputtering TiO2 to a thickness of 10 nm or more and 100 nm or less. Furthermore, the electron transport layer 212 may be formed by forming an aggregate of TiO2 nanoparticles to a thickness of approximately 100 nm or more and 500 nm or less.

[0073] (Photoelectric conversion layer 213) The photoelectric conversion layer 213 has a function of receiving incident light, generating electrons and holes, and diffusing the electrons and holes without recombining them.

[0074] The photoelectric conversion layer 213 may contain a perovskite compound.

[0075] The perovskite compound refers to a compound having a perovskite-type crystal structure represented by the composition formula ABX3 or a structure similar thereto, where A is a monovalent cation, B is a divalent cation, and X is a monovalent anion.

[0076] Examples of monovalent cations A are alkali metal cations or organic cations. Examples of alkali metal cations include sodium cations (Na + ), potassium cation (K + ), cesium cation (Cs + ), or rubidium cation (Rb + ) An example of an organic cation is the methylammonium cation (CH3NH3 + ) or formamidinium cation (NH2CHNH2 +)

[0077] Examples of divalent cations B are Pb cations, Sn cations, or Ge cations. Cation B may include Pb cations.

[0078] Examples of monovalent anions X are halogen anions, such as chloride, iodide or bromide.

[0079] Each of the cation A, cation B, and anion X sites may be occupied by multiple types of ions.

[0080] The thickness of the photoelectric conversion layer 213 may be 50 nm or more and 10 μm or less.

[0081] An example of a method for manufacturing the photoelectric conversion layer 213 is to apply a solution in which a predetermined material is dissolved in an organic solvent, remove the organic solvent from the coating film, and then perform a heat treatment. Here, the organic solvent can be removed from the coating film by, for example, evaporating the organic solvent by reducing the pressure, or by adding a solvent that is a poor solvent for the predetermined material dissolved in the organic solvent but is compatible with the organic solvent, thereby removing only the organic solvent from the coating film. Such a method is common. According to such a method, a photoelectric conversion layer 213 with high performance can be easily manufactured. The photoelectric conversion layer 213 can also be manufactured by vacuum deposition.

[0082] (Hole transport layer 214) The hole transport layer 214 has a function of accepting only holes from the photoelectric conversion layer 213 and blocking electrons.

[0083] The hole transport layer 214 includes a hole transport material. The hole transport material is a material that transports holes. The hole transport material preferably has a HOMO (Highest Occupied Molecular Orbital) level close to the HOMO level of the photoelectric conversion layer 213 and a LUMO (Lowest Unoccupied Molecular Orbital) level higher than the LUMO level of the photoelectric conversion layer 213.

[0084] For example, in the case of a photoelectric conversion element containing a perovskite compound, the LUMO level of the photoelectric conversion layer 213 is around -4 eV, and the HOMO level is around -5 eV. Therefore, examples of hole transport materials include poly(bis(4-phenyl)(2,4,6-trimethylphenyl))amine (PTAA), N 2 ,N 2 ,N 2’ ,N 2’ ,N 7 ,N 7 ,N 7’ ,N 7’ -octakis(4-methoxyphenyl)-9,9'-spirobi[9H-fluorene]-2,2',7,7'-tetramine (Spiro-OMeTAD), dithiophenebenzene copolymer (DTB), poly-3-hexylthiophene (P3HT), or poly-3-hexylthiophene-polystyrene block polymer (P3HT-b-PSt).

[0085] The hole transport layer 214 may contain at least one selected from the group consisting of PTAA, Spiro-OMeTAD, DTB, P3HT, and P3HT-b-PSt. Note that these materials alone may not provide sufficient hole density in the hole transport layer 214. For this reason, the hole transport layer 214 may contain not only a hole transport material but also an additive. The additive has the function of removing electrons from the valence band from the hole transport material. In other words, the hole transport layer 214 may contain a p-type dopant.

[0086] (Second electrode 215) The second electrode 215 is conductive and has the function of receiving holes generated in the photoelectric conversion layer 213 and extracting them to the outside.

[0087] The second electrode 215 may be made of any of the materials exemplified as materials for the first electrode 211 .

[0088] The photoelectric conversion element 2 may have a structure in which a plurality of cells are connected. Fig. 3 is a partially enlarged cross-sectional view of a photoelectric conversion module according to the present disclosure, which schematically shows a second configuration example of the photoelectric conversion element 2 according to the present disclosure. Fig. 3 shows a photoelectric conversion element 2 having a three-series cell structure as an example of a structure in which a plurality of cells are connected in series.

[0089] In the photoelectric conversion element 2 shown in Fig. 3, three cells 20 are connected in series. The first electrode 211 is electrically connected to the second electrode 215 of the adjacent cell 20 via the electron transport layer 212. The photoelectric conversion element 2 is also connected to leads 5 and 6 via terminals 3 and 4, respectively. The terminal 3 and lead 5 are electrically connected to the first electrode 211 of the cell 20 located at one end of the three-series cell structure via the electron transport layer 212. The terminal 4 and lead 6 are electrically connected to the second electrode 215 of the cell 20 located at the other end.

[0090] (Second embodiment) The photoelectric conversion module of the second embodiment will be described below. The matters described in the first embodiment may be omitted as appropriate.

[0091] The photovoltaic conversion module according to the second embodiment further includes a second sealing member in addition to the configuration of the photovoltaic conversion module according to the first embodiment. The second sealing member is provided so that the first sealing portion of the first sealing member is not exposed on the surface of the photovoltaic conversion module. The second sealing member includes a second sealing material that is a material different from the first sealing material. This configuration can improve the sealing effect by suppressing the influence of outside air on the first sealing member 7 and improving the durability of the first sealing member 7. Therefore, the durability of the photovoltaic conversion module can be further improved. For example, the photovoltaic conversion module can be durable even when used outdoors.

[0092] The first sealing portion of the first sealing member is not exposed on the surface of the photovoltaic conversion module, which means that the first sealing portion of the first sealing member is not exposed to the outside air.

[0093] The second sealing member may include a region made of the second sealing material. Hereinafter, the region of the second sealing member made of the second sealing material will be referred to as a third sealing portion.

[0094] FIG. 4 is a cross-sectional view schematically showing a first configuration example of a photoelectric conversion module according to the second embodiment.

[0095] The photoelectric conversion module 210 shown in FIG. 4 includes a second sealing member 9. The area sealed by the second sealing member 9 contains the photoelectric conversion element 2, the substrate 1, and the first sealing member 7. The second sealing member 9 includes a third sealing portion 91. The second sealing member 9 further includes a first plate-like body 92 and a second plate-like body 93 that are arranged facing each other with a gap between them. The third sealing portion 91 is a sealing layer that seals the area formed between the first plate-like body 92 and the second plate-like body 93. The photoelectric conversion module 100 according to the first embodiment is disposed between the first plate-like body 92 and the second plate-like body 93. The leads 5 and 6 penetrate the third sealing portion 91.

[0096] The third sealing portion 91 may be provided in a frame shape between the first plate-shaped body 92 and the second plate-shaped body 93 so as to surround the substrate 1 and the first sealing member 7 .

[0097] 4, the second sealing member 9 may contain the photoelectric conversion module 100 of the first embodiment. That is, the substrate 1 and the first sealing member 7 may be sealed by the second sealing member 9. The first sealing portion 71 of the first sealing member 7 may be sealed by the second sealing member 9.

[0098] The photovoltaic conversion module in the second embodiment may further include a filler material provided between the first sealing member 7 and the second sealing member 9. In the photovoltaic conversion module 210 shown in Fig. 4, a second filler material 10 is provided between the first sealing member 7 and the second sealing member 9. As shown in Fig. 4, the space between the first sealing member 7 and the second sealing member 9 may be filled with the second filler material 10.

[0099] FIG. 5 is a cross-sectional view schematically showing a second configuration example of the photoelectric conversion module according to the second embodiment.

[0100] 5, the second sealing member 9 includes a third sealing portion 91 and a first plate-like body 92 arranged to face the substrate 1 with a gap therebetween. The third sealing portion 91 is a sealing layer that seals the region formed between the substrate 1 and the first plate-like body 92.

[0101] 5 , in the photoelectric conversion module according to the second embodiment, the area sealed by the substrate 1 and the second sealing member 9 may contain the photoelectric conversion element 2 and the first sealing member 7. That is, the first sealing member 7 may be sealed by the substrate 1 and the second sealing member 9. The first sealing portion 71 of the first sealing member 7 may be sealed by the substrate 1 and the second sealing member 9.

[0102] FIG. 6 is a cross-sectional view schematically showing a third configuration example of the photoelectric conversion module according to the second embodiment.

[0103] 6, the second sealing member 9 includes a third sealing portion 91 and a second plate-like body 93 arranged to face the second sealing portion 72 of the first sealing member 7 with a gap therebetween. The third sealing portion 91 is a sealing layer that seals the region formed between the second sealing portion 72 and the second plate-like body 93.

[0104] 6 , the area sealed by the second sealing portion 72 of the first sealing member 7 and the second sealing member 9 may include the photoelectric conversion element 2, the substrate 1, and the first sealing portion 71 of the first sealing member 7. In other words, the substrate 1 and the first sealing portion 71 may be sealed by the second sealing portion 72 of the first sealing member 7 and the second sealing member 9.

[0105] FIG. 7 is a cross-sectional view schematically showing a fourth configuration example of the photoelectric conversion module according to the second embodiment.

[0106] 7, the second sealing member 9 is disposed between the substrate 1 and the second sealing portion 72 of the first sealing member 7, and further outward than the first sealing portion 71. The second sealing member 9 is a sealing layer that seals the region formed between the substrate 1 and the second sealing portion 72 of the first sealing member 7. The second sealing member 9 is made of a third sealing portion 91.

[0107] As shown in FIG. 7, the second sealing member 9 may consist only of a third sealing portion 91 made of the second sealing material.

[0108] The first sealing portion 71 may be sealed by the substrate 1, the first sealing member 7, and the second sealing member 9. The first sealing portion 71 may be sealed by the substrate 1, the second sealing portion 72 of the first sealing member 7, and the second sealing member 9.

[0109] (Second sealing member 9) The second sealing member 9 includes a second sealing material that is different from the first sealing material. The material different from the first sealing material is, for example, a material that has better water vapor barrier properties than the first sealing material. The second sealing material may be a material that has a lower water vapor permeability coefficient than the first sealing material. For example, the composition of the second sealing material is different from the composition of the first sealing material. This configuration can suppress the influence of water vapor on the photovoltaic conversion element 2. Furthermore, the influence of water vapor on the first sealing member 7 can also be suppressed, and the durability of the first sealing member 7 can be improved. Therefore, the durability of the photovoltaic conversion module can be improved even when used outdoors.

[0110] The water vapor permeability coefficient can be measured by the method described in Japanese Industrial Standards (JIS K-7126).

[0111] The second sealing member 9 may include a region made of the second sealing material, ie, a third sealing portion 91.

[0112] The third sealing portion 91 is made of, for example, a water-impermeable material. The third sealing portion 91 may contain the second sealing material as a main component. That is, the third sealing portion 91 may contain the second sealing material at a mass ratio of 50% or more (50% by mass or more) relative to the entire third sealing portion 91. The third sealing portion 91 may contain the second sealing material at a mass ratio of 70% or more (70% by mass or more) relative to the entire third sealing portion 91. The third sealing portion 91 may contain the second sealing material at a mass ratio of 90% or more (90% by mass or more) relative to the entire third sealing portion 91. The third sealing portion 91 may be made of only the second sealing material.

[0113] The second sealing material may include at least one selected from the group consisting of polyisobutylene and isobutylene-isoprene copolymer.

[0114] An example of a material that constitutes the third sealing portion 91 is butyl rubber (that is, sulfur-crosslinked rubber of isobutylene-isoprene copolymer).

[0115] The third sealing portion 91 can be formed by melt coating of butyl rubber, or by attaching a butyl rubber sheet and heat treating it.

[0116] 4 , the second sealing member 9 may further include a first plate-shaped body 92 and a second plate-shaped body 93 in addition to the third sealing portion 91. The first plate-shaped body 92 and the second plate-shaped body 93 may be disposed opposite each other. The third sealing portion 91 may be a sealing layer that seals the region formed between the substrate 1 and the second sealing portion 72.

[0117] The third sealing portion 91 may have a function similar to that of an adhesive that bonds the first plate-shaped body 92 and the second plate-shaped body 93 together.

[0118] 5 , the second sealing member 9 may further include a first plate-like body 92 in addition to the third sealing portion 91. The first plate-like body 92 may be disposed opposite the substrate 1. The third sealing portion 91 may be a sealing layer that seals the region formed between the substrate 1 and the first plate-like body 92.

[0119] The third sealing portion 91 may have a function similar to that of an adhesive for bonding the substrate 1 and the first plate-shaped body 92 together.

[0120] 6 , the second sealing member 9 may further include a second plate-shaped body 93 in addition to the third sealing portion 91. The second plate-shaped body 93 may be disposed opposite the second sealing portion 72 of the first sealing member 7. The third sealing portion 91 may be a sealing layer that seals the region formed between the second sealing portion 72 and the second plate-shaped body 93.

[0121] The third sealing portion 91 may have a function similar to that of an adhesive for bonding the second sealing portion 72 and the second plate-shaped body 93 together.

[0122] The first plate-shaped body 92 and the second plate-shaped body 93 are made of, for example, a water-impermeable material.

[0123] Examples of materials for the first plate-shaped body 92 and the second plate-shaped body 93 include glass, ceramics, and metal. The first plate-shaped body 92 and the second plate-shaped body 93 may be glass.

[0124] The first plate-shaped body 92 and the second plate-shaped body 93 may be made of a material that is impermeable to oxygen and water, examples of which include glass and ceramics.

[0125] When the photoelectric conversion element 2 generates power using incident light from one or both of the substrates of the first plate 92 and the second plate 93, one or both of the plates in the light incident path must be optically transparent. Examples of such materials include glass and translucent ceramics. Resins coated with a thin film of glass or translucent ceramics can also be used. When translucency is not required, metals can also be used for the first plate 92 and the second plate 93.

[0126] 4 to 6, the second sealing member 9 includes at least one selected from the group consisting of a first plate-like body 92 and a second plate-like body 93. As a modification of the configuration shown in FIGS. 4 to 6, at least one selected from the group consisting of the first plate-like body 92 and the second plate-like body 93 in the photovoltaic conversion modules shown in FIGS. 4 to 6 may be replaced with a third sealing section 91, which is a region made of the second sealing material. In other words, the second sealing member 9 does not have to include the first plate-like body 92 and the second plate-like body 93. The second sealing member 9 may consist only of the third sealing section 91, which is a region made of the second sealing material.

[0127] At least a portion of the surface of the photovoltaic conversion module according to the first embodiment may be covered by the third sealing portion 91. The first sealing member 7 may be covered by the third sealing portion 91. The first sealing portion 71 of the first sealing member 7 may be covered by the third sealing portion 91. The entire surface of the photovoltaic conversion module according to the first embodiment may be covered by the third sealing portion 91.

[0128] (Second filler 10) The second filling material 10 disperses the energy of an impact applied from outside the photovoltaic conversion module by transmitting the impact to, for example, the substrate 1, the second sealing portion 72, and the first sealing member 7, thereby preventing the second sealing member 9 from being destroyed when the impact is applied.

[0129] Examples of materials for the second filler 10 include EVA-based resin (ie, ethylene-vinyl acetate copolymer) and PO-based resin (ie, polyolefin).

[0130] The second filler 10 may contain at least one selected from the group consisting of an oxygen absorber and a moisture absorber. Examples of the oxygen absorber include metals, semimetals such as Si or C, oxides of metals or semimetals that are not fully oxidized, titanium oxide (TiO2), cerium oxide (CeO2), or iron hydroxide (Fe(OH)2). The oxygen absorber may be iron powder. Examples of the moisture absorber include metals, semimetals such as Si or C, oxides of metals or semimetals that are not fully oxidized, silicon oxide (SiO2) (e.g., silica gel), calcium oxide (CaO) (e.g., quicklime), calcium chloride (CaCl2), or activated alumina (Al2O3). The moisture absorber may be at least one selected from iron powder and calcium oxide. The moisture absorber may be calcium oxide.

[0131] The second filler material 10 may contain a moisture absorbent material.

[0132] [Other embodiments] (Addendum) The above description of the embodiments discloses the following techniques.

[0133] (Technology 1) A substrate; a photoelectric conversion element; A first sealing member; Equipped with the photoelectric conversion element is sealed by the substrate and the first sealing member; the first sealing member includes a first sealing portion made of a first sealing material; the first sealing material includes at least one selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylene diol-vinyl alcohol copolymer; Photoelectric conversion module.

[0134] This configuration can improve the durability of the photovoltaic conversion module.

[0135] (Technology 2) The photoelectric conversion module according to Technology 1, wherein the first sealing member further includes a second sealing portion, the second sealing portion including a plate-like body arranged opposite the substrate, and the first sealing portion seals a region formed between the substrate and the second sealing portion.

[0136] This structure can improve the durability of the photovoltaic conversion module.

[0137] (Technology 3) Further comprising a second sealing member; The photovoltaic conversion module according to Technology 1 or 2, wherein the second sealing member is provided so that the first sealing portion is not exposed on the surface of the photovoltaic conversion module, and includes a second sealing material that is a material different from the first sealing material.

[0138] This configuration can further improve the durability of the photovoltaic conversion module. Furthermore, this structure allows the photovoltaic conversion module to be durable even when used outdoors.

[0139] (Technology 4) The photovoltaic conversion module according to technique 3, wherein the second sealing material includes at least one selected from the group consisting of polyisobutylene and an isobutylene-isoprene copolymer.

[0140] This configuration can further improve the durability of the photovoltaic conversion module. Furthermore, this structure allows the photovoltaic conversion module to be durable even when used outdoors.

[0141] (Technology 5) The photovoltaic conversion module according to technique 3 or 4, further comprising a filler provided between the first sealing member and the second sealing member.

[0142] This configuration can further improve the durability of the photovoltaic conversion module.

[0143] (Technology 6) 6. The photovoltaic conversion module according to claim 5, wherein the filler includes at least one selected from the group consisting of an oxygen absorbent and a moisture absorbent.

[0144] This configuration can further improve the durability of the photovoltaic conversion module.

[0145] (Technology 7) 7. The photoelectric conversion module according to any one of claims 1 to 6, wherein the photoelectric conversion element contains a perovskite compound.

[0146] This configuration can improve the photoelectric conversion efficiency of the photoelectric conversion module.

[0147] (Technology 8) 8. The photoelectric conversion module according to claim 7, wherein the perovskite compound contains Pb.

[0148] This configuration can improve the photoelectric conversion efficiency of the photoelectric conversion module.

[0149] (Technology 9) The photoelectric conversion module according to Technology 7 or 8, wherein the perovskite compound is represented by the chemical formula APbX3, where A is at least one selected from the group consisting of CH3NH3, NH2CH2NH2, K, Cs, and Rb, and X is at least one selected from the group consisting of Cl, Br, and I.

[0150] This configuration can improve the photoelectric conversion efficiency of the photoelectric conversion module. [Example]

[0151] Hereinafter, the present disclosure will be described in more detail with reference to examples.

[0152] For Samples 1 to 11, the effectiveness of the first sealing member and the photovoltaic conversion module of the present disclosure was evaluated by a high-temperature durability test in a dry environment at 85°C using specimens having the structure shown in Figure 1, i.e., photovoltaic conversion modules.

[0153] For samples 12 to 26, the effectiveness of the first sealing member, the second sealing member, and the photovoltaic conversion module of the present disclosure was evaluated by a high-temperature, high-humidity durability test in an environment of 85°C and 85% RH using specimens having the structure shown in Figure 7, i.e., photovoltaic conversion modules.

[0154] (Sample 1) (Fabrication of photoelectric conversion element) A 30 mm square, 0.7 mm thick glass substrate was prepared. Indium tin oxide (ITO) was sputtered onto one side of the glass to give a sheet resistance of 10 Ω / □. In this way, a first electrode was formed on the substrate.

[0155] Titanium oxide (TiO2) was formed on the first electrode by sputtering to a thickness of 30 nm.

[0156] Furthermore, an aggregate of TiO2 nanoparticles was formed to a thickness of 250 nm, thus forming an electron transport layer on the first electrode.

[0157] Using a laser scriber (wavelength 1.06 μm, 3 W), unnecessary portions of the first electrode and electron transport layer were removed.

[0158] Next, a raw material solution for the photoelectric conversion layer was prepared by dissolving 2.91 g of formamidinium hydroiodide ((NH2)2CH2I), 0.57 g of methylammonium hydroiodide (CH3NH3I), and 10 g of lead iodide (PbI2) in a mixed solvent of 23.3 mL of N,N-dimethylformamide (DMF) and 5.8 mL of dimethyl sulfoxide (DMSO).

[0159] The raw material solution (80 μL) was dropped onto the electron transport layer, and the substrate including the electron transport layer was rotated at 6000 rpm for 70 seconds using a spin coater. 30 to 60 seconds after the start of rotation, 1 mL of toluene was dropped onto the rotating electron transport layer onto which the raw material solution had been dropped using a pipette. The substrate was then heated on a hot plate at 115°C for 30 minutes. In this way, a photoelectric conversion layer was formed on the electron transport layer.

[0160] Next, a hole transport material solution was prepared by adding 4.8 μL of a solution in which 500 mg of LiTFSI was dissolved in 1 mL of acetonitrile to a solution in which 10 mg of PTAA and 6 μL of tert-butylpyridine were added to 1 mL of toluene.

[0161] The hole transport layer was formed by dropping 100 μL of the hole transport material solution onto the photoelectric conversion layer and rotating it at 4000 rpm for 30 seconds with a spin coater.

[0162] On the hole transport layer, ITO was formed as a second electrode by sputtering so that the sheet resistance value was 10 Ω / □.

[0163] In order to expose the first electrode to which the terminal was attached, the electron transport layer, photoelectric conversion layer, hole transport layer, and second electrode present in that area were laser scribed (wavelength 355 nm, output 3 W) to remove the electron transport layer, photoelectric conversion layer, and hole transport layer.

[0164] Terminals were attached to the first and second electrodes using a Cu wire (thickness 160 μm, width 2 mm) and solder material (melting point 219° C.) with an ultrasonic soldering iron.

[0165] Similarly, the leads were attached to the respective terminals with a soldering iron.

[0166] (Attachment of first filling material and preparation of first sealing member) Four polyolefin sheets (10 mm square, 0.6 mm thick, melting point 70°C) large enough to sufficiently cover the photoelectric conversion element were placed on top of each other on a substrate (30 mm square, 0.7 mm thick) on which a photoelectric conversion element had been formed. A second sealing part of a first sealing member made of a glass plate of the same size as the substrate (i.e., 30 mm square, 0.7 mm thick) was then placed on top of the polyolefin sheets so that they faced each other, creating a laminated glass structure.

[0167] The laminated glass was placed in a vacuum heat treatment furnace, evacuated to 10 Pa, and heated to 80°C to melt the polyolefin sheet. The pressure was then restored to 100 Pa, cooled to room temperature, and then restored to 1 atmosphere before being removed. In this way, the first filling material and the second sealing portion of the first sealing member were attached.

[0168] A 190°C melt of polyvinyl alcohol (JMR-3H, manufactured by Nippon Vinyl Acetate & Poval Co., Ltd., degree of polymerization 110, degree of saponification 80 mol%) was poured into the approximately 2 mm gap between the substrate and the second sealing portion as the first sealing material that constituted the first sealing portion of the first sealing member, sealing the entire periphery of the side of the first filler placed on the photoelectric conversion element, i.e., the first filler attached so as to cover the photoelectric conversion element. At this time, the leads were maintained in a state where they penetrated the first sealing member and were led out to the outside.

[0169] In this manner, a photoelectric conversion module using Sample 1 was fabricated.

[0170] (Sample 2) A photovoltaic conversion module using Sample 2 was fabricated in the same manner as Sample 1, except that a 205°C melt of polyvinyl alcohol (JF-05 manufactured by Japan Vinyl Acetate & Poval Co., Ltd., saponification degree 98 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0171] (Sample 3) A photovoltaic conversion module using Sample 3 was fabricated in the same manner as Sample 1, except that a 220°C melt of polyvinyl alcohol (VC-10 manufactured by Nippon Vinyl Acetate & Poval Co., Ltd., polymerization degree 1000, saponification degree 99.5 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0172] (Sample 4) A photovoltaic conversion module using Sample 4 was fabricated in the same manner as Sample 1, except that a 240°C melt of ethylene-vinyl alcohol (L171B manufactured by Kuraray Co., Ltd., ethylene 27 mol%, saponification degree 100 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0173] (Sample 5) A photovoltaic conversion module using Sample 5 was fabricated in the same manner as Sample 1, except that a 200°C melt of ethylene-vinyl alcohol (E105B manufactured by Kuraray Co., Ltd., ethylene 44 mol%, saponification degree 100 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0174] (Sample 6) A photovoltaic conversion module using Sample 6 was fabricated in the same manner as Sample 1, except that a 195°C melt of butylenediol-vinyl alcohol (BVE8049Q manufactured by Nippon Synthetic Chemical Industry Co., Ltd., saponification degree 99 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0175] (Sample 7) A photovoltaic conversion module using Sample 7 was fabricated in the same manner as Sample 1, except that a 220°C melt of rice-grain-sized solid raw materials, polyvinyl alcohol (VC-10 manufactured by Japan Vinyl Acetate & Poval Co., Ltd., degree of polymerization 1000, degree of saponification 99.5 mol%) and ethylene-vinyl alcohol (L171B manufactured by Kuraray Co., Ltd., ethylene 27 mol%, degree of saponification 100 mol%), mixed at a mass ratio of 1:1, was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0176] (Sample 8) A photovoltaic conversion module using Sample 8 was fabricated in the same manner as Sample 1, except that a 240°C melt of rice-grain-sized solid raw materials, polyvinyl alcohol (VC-10 manufactured by Nippon Vinyl Acetate & Poval Co., Ltd., degree of polymerization 1000, degree of saponification 99.5 mol%) and butylenediol-vinyl alcohol (BVE8049Q manufactured by Nippon Synthetic Chemical Industry Co., Ltd., degree of saponification 99 mol%), mixed at a mass ratio of 1:1, was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0177] (Sample 9) (Fabrication of photoelectric conversion element) A photoelectric conversion element was fabricated on a substrate in the same manner as in Sample 1, and terminals and leads were attached to the first electrode and second electrode, respectively.

[0178] (Attachment of first filling material and preparation of first sealing member) The first filler and the second sealing portion of the first sealing member were attached in the same manner as Sample 1, except that iron powder (JIP 303A-60 manufactured by JFE Steel Corporation) was added as an oxygen absorber between the four polyolefin sheets in a mass ratio of polyolefin sheet:iron powder = 9:1.

[0179] Similar to Sample 4, a first sealing member was produced in the same manner as Sample 1, except that a 240°C melt of ethylene-vinyl alcohol (L171B manufactured by Kuraray Co., Ltd., ethylene 27 mol %, saponification degree 100 mol %) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0180] In this manner, a photoelectric conversion module using Sample 9 was fabricated.

[0181] (Sample 10) A photovoltaic conversion module of Sample 10 was fabricated in the same manner as Sample 1, except that the first sealing portion of the first sealing member was not fabricated.

[0182] (Sample 11) A photovoltaic conversion module using Sample 11 was fabricated in the same manner as Sample 1, except that a 220°C melt of polyvinylidene chloride (223-0255 manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0183] (Evaluation of photoelectric conversion modules) The photoelectric conversion modules of Samples 1 to 11 were stored in the following environment, and the storage time and the output of the photoelectric conversion module after the storage time had elapsed were recorded.

[0184] The storage environment was a dry environment with a temperature of 85°C and a dew point of -40°C. The output of the photoelectric conversion module was determined as the maximum output value calculated from the results of measuring the current value when irradiated with light from a low-illuminance light source (fluorescent lamp, illuminance 200lx) and changing the voltage from -0.2V to 1.0V in 0.02V steps using a curve tracer (ADCDC Source Meter 2242).

[0185] The change over time in the maximum output of the photovoltaic conversion modules of Samples 1 to 11 was measured. The composition of each sample is shown in Table 1, and the evaluation results are shown in Table 2. The output maintenance rate shown in Table 2 is the percentage of the maximum output after the storage time has elapsed, with the maximum output before exposure to the storage environment being taken as 100%.

[0186] [Table 1]

[0187] [Table 2]

[0188] (Consideration) Samples 1 to 9 maintained an output maintenance rate of 90% or more even after 40 days, but Sample 10, which did not have a first sealing portion made of the first sealing material, had an output maintenance rate below 90% after 26 hours. Sample 11, which used polyvinylidene chloride as the first sealing material, had an output maintenance rate below 90% after 20 days. This indicates that the sealing function provided by the first sealing member containing the first sealing material, which contains at least one selected from the group consisting of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and butylene diol-vinyl alcohol copolymer, is effective.

[0189] In Sample 7, in which the first sealing material is polyvinyl alcohol VC-10 and ethylene-vinyl alcohol copolymer L171B (mixing mass ratio 1:1), and in Sample 8, in which the first sealing material is polyvinyl alcohol VC-10 and butylenediol-vinyl alcohol copolymer BVE8049Q (mixing mass ratio 1:1), there are no problems with the sealing performance of the first sealing member, and it can be said that these vinyl alcohol-based polymer materials can be used in combination.

[0190] (Sample 12) (Fabrication of photoelectric conversion element) A photoelectric conversion element was fabricated on a substrate in the same manner as in Sample 1, and terminals and leads were attached to the first electrode and second electrode, respectively.

[0191] (Attachment of first filling material and preparation of first sealing member) In the same manner as in Sample 1, a first filling material was attached and a first sealing member was fabricated.

[0192] (Preparation of second filling material) The second filler was prepared by pouring a melt of ethylene-vinyl acetate copolymer (EVA) into the gap of about 2 mm between the substrate and the second sealing portion of the first sealing member.

[0193] (Fabrication of second sealing member) A second sealing member with a sealing width of 4 mm was formed using 200°C molten butyl rubber (HX-760BB manufactured by Aica Kogyo) for a gap of approximately 2 mm between the substrate and the second sealing portion of the first sealing member. That is, the second sealing member was formed between the substrate and the periphery of the second sealing portion of the first sealing member so as to seal the first sealing portion of the first sealing member and the second filling material. At this time, the leads were maintained in a state where they penetrated the second sealing member and were led out to the outside.

[0194] In this manner, a photoelectric conversion module was produced using Sample 12. That is, the photoelectric conversion module using Sample 12 corresponds to a photoelectric conversion module in which the photoelectric conversion module using Sample 1 is further provided with a second filling material and a second sealing member.

[0195] (Sample 13) A photoelectric conversion module according to Sample 13 was fabricated in the same manner as Sample 12, except that a 205°C melt of polyvinyl alcohol (JF-05 manufactured by Nippon Vinyl Acetate & Poval Co., Ltd., saponification degree 98 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member. The photoelectric conversion module according to Sample 13 corresponds to a photoelectric conversion module in which the photoelectric conversion module according to Sample 2 is further equipped with a second filler and a second sealing member.

[0196] (Sample 14) A photoelectric conversion module according to Sample 14 was fabricated in the same manner as Sample 12, except that a 220°C melt of polyvinyl alcohol (VC-10 manufactured by Japan Vinyl Acetate & Poval Co., Ltd., degree of polymerization 1000, degree of saponification 99.5 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member. The photoelectric conversion module according to Sample 14 corresponds to a photoelectric conversion module in which the photoelectric conversion module according to Sample 3 is further equipped with a second filler and a second sealing member.

[0197] (Sample 15) A photoelectric conversion module according to Sample 15 was fabricated in the same manner as Sample 12, except that a 240°C melt of ethylene-vinyl alcohol (L171B manufactured by Kuraray Co., Ltd., ethylene 27 mol %, saponification degree 100 mol %) was used as the first sealing material constituting the first sealing portion of the first sealing member. The photoelectric conversion module according to Sample 15 corresponds to a photoelectric conversion module in which the photoelectric conversion module according to Sample 4 is further equipped with a second filler and a second sealing member.

[0198] (Sample 16) A photoelectric conversion module according to Sample 16 was fabricated in the same manner as Sample 12, except that a 200°C melt of ethylene-vinyl alcohol (E105B manufactured by Kuraray Co., Ltd., ethylene 44 mol%, saponification degree 100 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member. The photoelectric conversion module according to Sample 16 corresponds to a photoelectric conversion module in which the photoelectric conversion module according to Sample 5 is further equipped with a second filler and a second sealing member.

[0199] (Sample 17) A photoelectric conversion module of Sample 17 was produced in the same manner as Sample 12, except that a 195°C melt of butylenediol-vinyl alcohol (BVE8049Q manufactured by Nippon Synthetic Chemical Industry Co., Ltd., saponification degree 99 mol%) was used as the first sealing material constituting the first sealing portion of the first sealing member. The photoelectric conversion module of Sample 17 corresponds to a photoelectric conversion module in which the photoelectric conversion module of Sample 6 is further equipped with a second filler and a second sealing member.

[0200] (Sample 18) A photovoltaic conversion module according to Sample 18 was fabricated in the same manner as Sample 12, except that a 220°C melt of rice-grain-sized solid raw materials, polyvinyl alcohol (VC-10 manufactured by Japan Vinyl Acetate & Poval Co., Ltd., polymerization degree 1000, saponification degree 99.5 mol%) and ethylene-vinyl alcohol (L171B manufactured by Kuraray Co., Ltd., ethylene 27 mol%, saponification degree 100 mol%), mixed at a mass ratio of 1:1, was used as the first sealing material constituting the first sealing portion of the first sealing member. The photovoltaic conversion module according to Sample 18 corresponds to a photovoltaic conversion module in which the photovoltaic conversion module according to Sample 7 is further equipped with a second filler and a second sealing member.

[0201] (Sample 19) A photovoltaic conversion module according to Sample 19 was fabricated in the same manner as Sample 12, except that a 240°C melt of rice-grain-sized solid raw materials of polyvinyl alcohol (VC-10 manufactured by Nippon Vinyl Acetate & Poval Co., Ltd., polymerization degree 1000, saponification degree 99.5 mol%) and butylenediol-vinyl alcohol (BVE8049Q manufactured by Nippon Synthetic Chemical Industry Co., Ltd., saponification degree 99 mol%) mixed at a mass ratio of 1:1 was used as the first sealing material constituting the first sealing portion of the first sealing member. The photovoltaic conversion module according to Sample 19 corresponds to a photovoltaic conversion module in which the photovoltaic conversion module according to Sample 8 is further equipped with a second filler and a second sealing member.

[0202] (Sample 20) (Fabrication of photoelectric conversion element) In the same manner as in Sample 12, that is, in the same manner as in Sample 1, a photoelectric conversion element was fabricated on a substrate, and terminals and leads were bonded to the first electrode and the second electrode, respectively.

[0203] (Attachment of first filling material and preparation of first sealing member) The first filler and the second sealing portion of the first sealing member were installed in the same manner as Sample 12, except that iron powder (JIP 303A-60 manufactured by JFE Steel Corporation) was added as an oxygen absorber between the four polyolefin sheets in a mass ratio of polyolefin sheet:iron powder = 9:1 when installing the first filler.

[0204] Similar to Sample 15, a first sealing member was produced in the same manner as Sample 12, i.e., Sample 1, except that a 240°C melt of ethylene-vinyl alcohol (L171B manufactured by Kuraray Co., Ltd., ethylene 27 mol %, saponification degree 100 mol %) was used as the first sealing material constituting the first sealing portion of the first sealing member.

[0205] Thereafter, a second filling material and a second sealing member were prepared in the same manner as in Sample 12. In this manner, a photoelectric conversion module according to Sample 20 was prepared. That is, the photoelectric conversion module according to Sample 20 corresponds to a photoelectric conversion module in which the photoelectric conversion module according to Sample 9 is further provided with a second filling material and a second sealing member.

[0206] (Sample 21) A photovoltaic conversion module using sample 21 was fabricated in the same manner as sample 15, except that the second filler used was a melt of ethylene-vinyl acetate copolymer (EVA) to which calcium oxide powder was added at a mass ratio of 5%.

[0207] (Sample 22) A photovoltaic conversion module according to Sample 22 was fabricated in the same manner as Sample 12, except that the first sealing portion of the first sealing member was not fabricated. That is, the photovoltaic conversion module according to Sample 22 corresponds to a photovoltaic conversion module in which the photovoltaic conversion module according to Sample 10 is further equipped with a second filling material and a second sealing member.

[0208] (Sample 23) A photovoltaic conversion module according to Sample 23 was fabricated in the same manner as Sample 12, except that the first sealing portion and second sealing member of the first sealing member were not fabricated. That is, the photovoltaic conversion module according to Sample 23 corresponds to a photovoltaic conversion module in which the photovoltaic conversion module according to Sample 10 is further provided with a second filling material.

[0209] (Sample 24) A photoelectric conversion module of Sample 24 was fabricated in the same manner as Sample 14, except that a second sealing member was not fabricated. That is, the photoelectric conversion module of Sample 24 corresponds to a photoelectric conversion module in which the photoelectric conversion module of Sample 3 is further provided with a second filling material.

[0210] (Sample 25) A photovoltaic conversion module of Sample 25 was fabricated in the same manner as Sample 15, except that the second sealing member was not fabricated. That is, the photovoltaic conversion module of Sample 25 corresponds to a photovoltaic conversion module in which the photovoltaic conversion module of Sample 4 is further provided with a second filling material.

[0211] (Sample 26) A photoelectric conversion module of Sample 26 was fabricated in the same manner as Sample 12, except that a 220°C melt of polyvinylidene chloride (223-0255 manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the first sealing material constituting the first sealing portion of the first sealing member. In other words, the photoelectric conversion module of Sample 26 corresponds to a photoelectric conversion module in which the photoelectric conversion module of Sample 11 is further equipped with a second filler and a second sealing member.

[0212] (Evaluation of photoelectric conversion modules) The photoelectric conversion modules of Samples 12 to 26 were stored in the following environment, and the storage time and the output of the photoelectric conversion module after the storage time had elapsed were recorded.

[0213] The storage environment was atmospheric gas, with a temperature of 85°C and a relative humidity of 85%. The photoelectric conversion output was determined as the maximum output value calculated from the results of measuring the current value when irradiating light from a low-intensity light source (fluorescent lamp, illuminance 200lx) and changing the voltage from -0.2V to 1.0V in 0.02V steps using a curve tracer (ADCDC Source Meter 2242).

[0214] The change over time in the maximum output of the photovoltaic conversion modules of Samples 12 to 26 was measured. The composition of each sample is shown in Table 3, and the evaluation results are shown in Table 4. The output maintenance rate shown in Table 4 is the percentage of the maximum output after the storage time has elapsed, with the maximum output before exposure to the storage environment being taken as 100%.

[0215] [Table 3]

[0216] [Table 4]

[0217] (Consideration) The output maintenance rates for each storage time of the photovoltaic conversion modules made of Samples 12 to 21 shown in Table 4 were almost the same as those of the photovoltaic conversion modules made of Samples 1 to 9 stored in a dry environment shown in Table 2. From the above, it can be seen that by further providing a second sealing member, the photovoltaic conversion module can be used even in a high-temperature, high-humidity environment.

[0218] Samples 12 to 21 maintained an output maintenance rate of 88% or more even after 40 days. In particular, Samples 13 to 21 maintained an output maintenance rate of 90% or more even after 40 days. However, Sample 22, which did not have a first sealing portion made of a first sealing material, had an output maintenance rate below 90% after 4 days. Sample 23, which did not have a first sealing member or a second sealing member, had an output maintenance rate below 90% after 2 hours or less. Furthermore, Sample 26, which used polyvinylidene chloride as the first sealing material, had an output maintenance rate below 90% after 8 days.

[0219] From these results, it can be said that the second sealing member and the first sealing member used in Samples 12 to 21 are effective in a high-temperature, high-humidity environment.

[0220] Furthermore, Samples 24 and 25, which do not have a second sealing member, have a configuration equivalent to Samples 3 and 4 with a second filler added, but in a humid environment, their output maintenance rate fell below 90% after 2 hours or less. In other words, in a humid environment, Samples 12 to 21, which further include a second sealing member, exhibited a superior output maintenance rate than Samples 24 and 25. These results demonstrate that the inclusion of a second sealing member in addition to the first sealing member makes the photovoltaic conversion module durable even in a humid environment.

[0221] There were no problems with sealing performance in Sample 18, in which the first sealing material was polyvinyl alcohol VC-10 and ethylene-vinyl alcohol copolymer L171B (mixed mass ratio 1:1), and in Sample 19, in which the first sealing material was polyvinyl alcohol VC-10 and butylenediol-vinyl alcohol copolymer BVE8049Q (mixed mass ratio 1:1). It can be said that these vinyl alcohol-based polymer materials can be mixed and used even in high-temperature, high-humidity environments.

[0222] Furthermore, a comparison of Sample 15 with Samples 20 and 21 showed that adding an oxygen scavenger to the first filler and adding calcium oxide as a moisture absorbent to the second filler had a further effect on maintaining output. [Industrial Applicability]

[0223] The photovoltaic conversion module of the present disclosure is useful because it exhibits improved performance in terms of short-term and long-term reliability compared to conventional photovoltaic conversion modules.

Claims

1. a first substrate; a second substrate facing the first substrate in a thickness direction of the first substrate; a first sealing portion that is provided between the first substrate and the second substrate so as to be in contact with the first substrate and the second substrate in a cross-sectional view in the thickness direction, and that seals a region formed between the first substrate and the second substrate; a second sealing member provided between the first substrate and the second substrate so as to be in contact with the first substrate and the second substrate, and disposed outside the first sealing portion, in a cross-sectional view in the thickness direction; a photoelectric conversion element, the photoelectric conversion element is disposed in a sealed region sealed by the first substrate, the second substrate, and the first sealing portion; the first sealing portion includes a first sealing material; the second sealing member includes a second sealing material different from the first sealing material; the first sealing portion is provided spaced apart from the photoelectric conversion element in a cross-sectional view in the thickness direction; Photoelectric conversion module.

2. Further, a first filler material is provided so as to fill the sealed area, The photovoltaic conversion module according to claim 1 , wherein the first filling material includes a material different from the first sealing material and the second sealing material.

3. The photovoltaic conversion module according to claim 2 , wherein the first filler material includes at least one selected from the group consisting of an oxygen absorbent and a moisture absorbent.

4. further comprising a lead electrically connected to the photoelectric conversion element; The photovoltaic conversion module according to claim 1 , wherein the lead passes through the first sealing portion and the second sealing member.

5. The photoelectric conversion module according to claim 1 , wherein the photoelectric conversion element includes a perovskite compound.

6. The photovoltaic conversion module according to claim 5 , wherein the perovskite compound contains Pb.

7. The perovskite compound has the chemical formula APbX 3 is represented by where A is CH 3 NH 3 , N.H. 2 CH 2 NH 2 , K, Cs, and Rb; 7. The photoelectric conversion module according to claim 6, wherein X is at least one selected from the group consisting of Cl, Br, and I.

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