Solar cell element coating composition, and solar cell module and production method therefor

Abstract

Provided is a solar cell element coating composition comprising (A) an organopolysiloxane which is represented by the following average unit formula (1): (R1R3 2SiO1 / 2)2(Ar2SiO2 / 2)a(R2 2SiO2 / 2)b [where R1 is an alkenyl group, R2 is a monovalent saturated hydrocarbon group, R3 is a monovalent saturated hydrocarbon group or an aryl group, Ar is an aryl group, a is an integer of 1-100, b is an integer of 0-1,000, and a / (a+b) is a number of 0.01 to 1.0)], (B) an organic silicon compound which has a hydrogen atom bonded to at least two silicon atoms in one molecule, and (C) a platinum group metal catalyst which is activated by light of a wavelength of 200-500 nm. The solar cell element coating composition can be applied directly onto a solar cell element in an organic thin film solar cell, a perovskite solar cell, and the like.

Description

Coating composition for solar cell elements, solar cell module, and method for producing the same

[0001] The present invention relates to a coating composition for a solar cell element, a solar cell module, and a method for producing the same.

[0002] In recent years, research and development has been progressing on flexible solar cells that emphasize cost reduction and design, see-through solar cells, lightweight and easy-to-handle organic thin-film solar cells, and solar cells with a perovskite compound in the power generation layer (hereinafter referred to as "perovskite solar cells") that combine low cost and high efficiency. Perovskite solar cells can be manufactured more inexpensively than crystalline silicon solar cells and have high power generation efficiency. Perovskite solar cells are obtained by sequentially stacking, from the light-receiving side, a light-transmitting substrate or film, a transparent conductive film, an electron transport layer, a power generation layer, a hole transport layer, and a back electrode. In the so-called modularization process for sealing the above-mentioned elements, a structure in which an encapsulant is applied to the back side of the back electrode and the backmost side is sealed with a substrate or film has been investigated. Various proposals have been made, including a structure using glass or the like for the light-receiving side light-transmitting substrate and the backmost side substrate, and a flexible structure using a light-transmitting film on the light-receiving side and a film on the backmost side.

[0003] However, perovskite compounds are susceptible to water vapor, and because solar cells are exposed to harsh outdoor environments for long periods of time, perovskite solar cell modules are required to have a high level of water vapor blocking capability.

[0004] For electronic devices susceptible to water vapor, various techniques have been introduced to form a water vapor barrier layer on the element prior to the sealing process. For example, Patent Document 1 introduces a three-layer barrier coating technology containing silicon, oxygen, and carbon. A flexible and mechanically strong water vapor barrier film is formed using plasma-enhanced chemical vapor deposition (CVD). However, plasma-enhanced CVD requires the device to be placed in a vacuum chamber and processed in a vacuum environment, making it difficult to scale up the device. Furthermore, the process involves vacuum and atmospheric exposure, which inevitably increases the complexity and cost of the process. Patent Document 2 also introduces a technology for forming a ZnO-SiO2-Al2O3 film using direct current (DC) sputtering. DC sputtering also requires a vacuum environment and presents similar challenges in terms of process complexity.

[0005] JP 2014-100806 A JP 2013-147710 A

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solar cell element coating composition that can be applied directly to a solar cell element, such as an organic thin-film solar cell or a perovskite solar cell, and that cures under atmospheric pressure to form a protective film with high water vapor barrier properties.

[0007] As a result of intensive research aimed at solving the above problems, the present inventors have found that the following solar cell element coating composition can be applied directly to a solar cell element, cures under atmospheric pressure, and provides a protective film with high water vapor barrier properties, thereby completing the present invention.

[0008] That is, the present invention provides: 1. (A) an organopolysiloxane represented by the following average unit formula (1) (R 1 R 3 2SiO 1 / 2 )2(Ar2SiO 2 / 2 ) a (R 2 2SiO 2 / 2 ) b (1) [wherein, R 1 are each independently an alkenyl group, and R2 are each independently a substituted or unsubstituted monovalent saturated hydrocarbon group, R 3 are each independently a substituted or unsubstituted monovalent saturated hydrocarbon group or a substituted or unsubstituted aryl group, and Ar is a substituted or unsubstituted aryl group. a is an integer of 1 to 100, b is an integer of 0 to 1,000, and a / (a+b) is a number of 0.01 to 1.0.] A solar cell element coating composition comprising: (B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule; and (C) a platinum group metal catalyst that is activated by light having a wavelength of 200 to 500 nm. 2. The solar cell element coating composition according to 1, wherein the component (B) is at least one selected from the following (i) to (iii): (i) an organohydrogenpolysiloxane represented by the following average composition formula (2): R 4 c H d SiO (4-c-d) / 2 (2) (wherein, R 4 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms other than an alkenyl group, and c and d are numbers that satisfy 0.7≦c≦2.1, 0.01≦d≦1, and 0.8≦c+d≦2.7.) (ii) an addition reaction product of vinylnorbornene and / or diallylbisphenol A with a cyclic organohydrogenpolysiloxane (iii) a SiH group-containing silane compound 3. The component (C) is (η 5 the solar cell element coating composition according to 1 or 2, which contains a (β-cyclopentadienyl)trialiphatic platinum compound or a bis(β-diketonato)platinum compound; 4. a solar cell module comprising a solar cell element and a water vapor barrier layer consisting of a cured product of the solar cell element coating composition according to any one of 1 to 3; 5. the solar cell module according to 4, wherein the solar cell element is an organic thin film type or perovskite type solar cell element; 6. a method for producing a solar cell module, which comprises the steps of contacting the solar cell element coating composition according to any one of 1 to 3 with a solar cell element directly or via at least one other layer, irradiating the composition with light having a wavelength of 200 to 500 nm under atmospheric pressure, and then curing the composition by heating.

[0009] The solar cell element coating composition of the present invention can be applied directly to a solar cell element, and is cured under atmospheric pressure to give a cured product with high water vapor barrier properties. The solar cell element coating composition of the present invention having such properties is useful as a protective film for organic thin-film solar cells, perovskite solar cells, etc.

[0010] The present invention relates to a perovskite solar cell module and a method for manufacturing the same.

[0011] The present invention will be specifically described below. [1] Coating Composition (1) Component (A) Component (A) in the solar cell element coating composition of the present invention is an organopolysiloxane represented by the following average unit formula (1): (R 1 R 3 2SiO 1 / 2 )2(Ar2SiO 2 / 2 ) a (R 2 2SiO 2 / 2 ) b (1)

[0012] In the formula, R 1 are each independently an alkenyl group, and R 2 are each independently a substituted or unsubstituted monovalent saturated hydrocarbon group, R 3 are each independently a substituted or unsubstituted monovalent saturated hydrocarbon group or a substituted or unsubstituted aryl group, and each Ar is independently a substituted or unsubstituted aryl group.

[0013] R 1 The alkenyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms. Specific examples thereof include vinyl, allyl, butenyl, pentenyl, and hexenyl groups, with vinyl being particularly preferred.

[0014] R 2The monovalent saturated hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms, and may be linear, branched, or cyclic. Specific examples include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, and n-heptyl; and cycloalkyl groups such as cyclohexyl. Some or all of the hydrogen atoms in these groups may be substituted with halogen atoms such as chlorine, fluorine, and bromine; specific examples include halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl. Among these, a methyl group is preferred in terms of heat resistance.

[0015] R 3 The monovalent saturated hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms, and may be linear, branched, or cyclic. Specific examples thereof include R 2 The same groups as those exemplified in R 3 The aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms. Specific examples thereof include phenyl, naphthyl, tolyl, xylyl, and mesityl groups. Also included are halogen-substituted aryl groups such as chlorophenyl groups in which some or all of the hydrogen atoms in these groups have been substituted with halogen atoms such as chlorine, fluorine, and bromine. Of these, methyl and phenyl groups are preferred.

[0016] The aryl group of Ar preferably has 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms. Specific examples thereof include R 3 Examples of the groups include the same as those exemplified in the above, and a phenyl group is preferred.

[0017] All hydrocarbon groups (R 1 , R 2 , R 3and Ar), the methyl group content is preferably 20 to 99 mol %, more preferably 40 to 97 mol %, and particularly preferably 60 to 95 mol %. If the content is within this range, a cured product with excellent heat resistance can be obtained.

[0018] a is an integer of 1 to 100, preferably an integer of 1 to 50, and more preferably an integer of 20 to 40; b is an integer of 0 to 1,000, preferably an integer of 1 to 1,000, more preferably an integer of 1 to 500, and even more preferably an integer of 100 to 400; a / (a+b) is a number of 0.01 to 1.0, preferably a number of 0.01 to 0.4, and more preferably a number of 0.05 to 0.3.

[0019] The molecular weight of component (A) is not particularly limited, but the weight average molecular weight (Mw) calculated in terms of standard polystyrene as determined by gel permeation chromatography (GPC) using a THF solvent is preferably 500 to 100,000, more preferably 700 to 50,000, and particularly preferably 1,000 to 30,000.

[0020] Specific examples of component (A) include, but are not limited to, those represented by the following formula: In the following formula, Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group (the same applies hereinafter). Component (A) may be used alone or in combination of two or more types. (ViMeSiO 1 / 2 )2(Ph2SiO 2 / 2 ) a (MeSiO 2 / 2 ) b (ViMePhSiO 1 / 2 )2(Ph2SiO 2 / 2 ) a (MeSiO 2 / 2 ) b (ViMeSiO 1 / 2 )2(Ph2SiO 2 / 2 ) a (ViMePhSiO 1 / 2 )2(Ph2SiO 2 / 2 ) a (In the formula, a and b are the same as above.)

[0021] (2) Component (B) Component (B) in the solar cell element coating composition of the present invention is an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms per molecule. The SiH groups in component (B) undergo a hydrosilylation reaction with the addition-reactive carbon-carbon double bonds in component (A) to give a cured product with a three-dimensional network structure. For example, the following compounds (i) to (iii) can be used as component (B):

[0022] (i) Organohydrogenpolysiloxane R represented by the following average composition formula (2): 4 c H d SiO (4-c-d) / 2 (2)

[0023] In the formula, R 4 are each independently a substituted or unsubstituted monovalent hydrocarbon group other than an alkenyl group having 1 to 12 carbon atoms, particularly 1 to 6 carbon atoms, and c and d are numbers that satisfy the conditions 0.7≦c≦2.1, 0.01≦d≦1, and 0.8≦c+d≦2.7.

[0024] In the average composition formula (2), R 4 The monovalent hydrocarbon group having 1 to 12 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, and sec-hexyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, o-, m-, and p-tolyl; aralkyl groups such as benzyl and 2-phenylethyl; and halogenated alkyl groups in which one or more hydrogen atoms bonded to carbon atoms in these groups have been substituted with halogen atoms, cyano, epoxy ring-containing groups, or the like, such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl; 2-cyanoethyl; and 3-glycidoxypropyl. Of these, methyl and phenyl groups are particularly preferred because of their ease of industrial production and availability.

[0025] c is a number that satisfies 0.7≦c≦2.1, but preferably 1≦c≦1.8. d is a number that satisfies 0.01≦d≦1, but preferably 0.02≦d≦1, and more preferably 0.1≦d≦1. Furthermore, c+d is a number that satisfies 0.8≦c+d≦2.7, but preferably 1≦c+d≦2.4, and more preferably 1.6≦c+d≦2.2.

[0026] The kinematic viscosity of component (i) is not particularly limited, but it is preferred that the kinematic viscosity at 23°C measured by an Ostwald viscometer is 0.1 to 100,000 mm 2 / s is preferable, and more preferably 0.5 to 500 mm 2 / s.

[0027] Specific examples of component (i) include, but are not limited to, those represented by the following formula: (MeSiO 1 / 2 )2(HMeSiO 2 / 2 ) 45 (MeSiO 2 / 2 ) 17 (HMeSiO 1 / 2 )2(HMeSiO 2 / 2 )2(Ph2SiO 2 / 2 ) 2

[0028] (ii) Addition reaction product of vinylnorbornene and / or diallylbisphenol A with cyclic organohydrogenpolysiloxane. Furthermore, as component (B), for example, an addition reaction product obtained by subjecting vinylnorbornene or diallylbisphenol A to a hydrosilylation reaction with a cyclic organohydrogenpolysiloxane, as represented by the following structural formula (3) or (4), can be used.

[0029]

[0030] In the formula, Z is a group represented by the following structural formula (5), (6), or (7), or a group represented by the following structural formula (10), and Z' is a group represented by the following structural formula (8) or (9), or a group represented by the following structural formula (11): s is an integer of 0 to 100, preferably 1 to 10, t is an integer of 1 to 100, preferably 1 to 20, q and r are each independently an integer of 0 to 3, and the sum of q and r in each cyclic siloxane moiety is independently 2 or 3.

[0031] (In formulas (5) to (9), an asterisk (*) indicates a bonding site to the silicon atom, and the configuration at each asymmetric carbon may be either cis (exo) or trans (endo).)

[0032] (In the formula, an asterisk (*) indicates a bonding site with a silicon atom.)

[0033] There are no particular restrictions on the viscosity of component (ii), but the viscosity at 25°C measured with a rotational viscometer is preferably 10 to 100,000 mPa·s, and more preferably 100 to 10,000 mPa·s.

[0034] The compound represented by formula (3) or (4) can be obtained by addition reaction of 5-vinylbicyclo[2.2.1]hept-2-ene and / or diallylbisphenol A represented by the following structural formula (12) with a cyclic siloxane represented by the following formula (13) in the presence of a hydrosilylation reaction catalyst. The compound represented by the following structural formula (12) may be a single structure or a mixture of two or more isomers.

[0035] (In the formula, q and r are the same as above.)

[0036] Known hydrosilylation catalysts can be used. Examples include platinum-based catalysts such as platinum metal-supported carbon powder, platinum black, platinic chloride, chloroplatinic acid, reaction products of chloroplatinic acid and monohydric alcohols, complexes of chloroplatinic acid and olefins, and platinum group metal catalysts such as platinum bisacetoacetate; palladium-based catalysts; and rhodium-based catalysts. The addition reaction conditions, the solvent used, and the like are not particularly limited, and the reaction may be carried out under known conditions.

[0037] In the above reaction, the amounts of diallyl bisphenol A and the cyclic siloxane represented by the formula (13) used are preferably such that the number of moles of the cyclic siloxane represented by the formula (13) is 1.05 times the number of moles of allyl groups contained in diallyl bisphenol A, and when 5-vinylbicyclo[2.2.1]hept-2-ene is used, the amount used is preferably such that the number of moles of the cyclic siloxane represented by the formula (13) is 1.05 times the number of moles of the olefin contained in 5-vinylbicyclo[2.2.1]hept-2-ene.

[0038] (iii) SiH Group-Containing Silane Compounds In addition to components (i) and (ii), the following silane compounds can also be used as component (B).

[0039]

[0040] The kinematic viscosity of component (iii) is not particularly limited, but it is preferred that the kinematic viscosity at 23°C measured by an Ostwald viscometer is 0.1 to 100,000 mm 2 / s is preferable, and more preferably 0.5 to 500 mm 2 / s.

[0041] The component (B) of the present invention may use either a single compound or a combination of two or more compounds.

[0042] The amount of component (B) to be blended is not particularly limited, but is preferably an amount such that the number of silicon-bonded hydrogen atoms per mole of addition-reactive carbon-carbon double bonds of component (A) in the composition of the present invention is 0.5 to 2.0 moles, and more preferably 0.8 to 1.5 moles.

[0043] (3) Component (C) The platinum group metal catalyst for hydrosilylation reactions of component (C) is inactive when shielded from light, and is converted into an active platinum catalyst upon irradiation with light having a wavelength of 200 to 500 nm, thereby accelerating the hydrosilylation reaction between the addition-reactive carbon-carbon double bond in component (A) and the silicon-bonded hydrogen atom in component (B).

[0044] Specific examples of such component (C) include (η 5 -cyclopentadienyl)trialiphatic platinum compounds and derivatives thereof. Particularly preferred among these are cyclopentadienyltrimethylplatinum complex, methylcyclopentadienyltrimethylplatinum complex, and their derivatives in which the cyclopentadienyl group is modified. Bis(β-diketonato)platinum compounds are also cited as suitable examples of component (C), and particularly preferred among these are bis(acetylacetonato)platinum compounds and their derivatives in which the acetylacetonato group is modified.

[0045] There are no particular restrictions on the amount of component (C) that may be added, provided it is an amount that promotes curing (hydrosilylation reaction) of the composition. Preferably, the amount of platinum group metal atoms in component (C) is 0.01 to 500 ppm by mass, more preferably 0.05 to 100 ppm, and even more preferably 0.01 to 50 ppm, relative to the combined mass of components (A) and (B) in the composition.

[0046] The component (C) may be used alone or in combination of two or more.

[0047] (4) Component (D) A reaction inhibitor as component (D) may be added to the solar cell element coating composition of the present invention as needed to prevent thickening or gelation before heat curing when the composition is formulated or applied to a substrate. Specific examples thereof include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclohexanol, ethynylmethyldecylcarbinol, 3-methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butynoxy)dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and 1,1,3,3-tetramethyl-1,3-divinyldisiloxane. Of these, 1-ethynylcyclohexanol, ethynylmethyldecylcarbinol, 3-methyl-1-butyn-3-ol, and bis(2,2-dimethyl-3-butynoxy)dimethylsilane are preferred.

[0048] When component (D) is used, the amount of component (D) added is preferably 0.01 to 2.0 parts by mass, and more preferably 0.01 to 0.1 parts by mass, per 100 parts by mass of the total of components (A) and (B).Within this range, the reaction control effect is sufficiently exhibited.

[0049] (5) Other Components In addition to the above components (A) to (C) and the optional component (D), the solar cell element coating composition of the present invention may contain other components exemplified below, as long as the components do not impair the object of the present invention. Examples include adhesion promoters having one or more functional groups selected from alkenyl groups, (meth)acrylic groups, carbonyl groups, epoxy groups, alkoxysilyl groups, and amide groups per molecule; thixotropy control agents such as fumed silica; reinforcing agents such as crystalline silica; antioxidants such as hindered phenols and hindered amines; light stabilizers; heat resistance improvers such as metal oxides and metal hydroxides; colorants such as titanium oxide; thermal conductivity fillers such as alumina and crystalline silica; viscosity modifiers such as nonreactive silicone oils that do not have reactive functional groups; conductivity imparting agents such as metal powders of silver, gold, etc.; and pigments and dyes for coloring.

[0050] The solar cell element coating composition of the present invention has excellent light transmittance and is easy to obtain as a thin film cured product, and is therefore suitable as a transparent protective material for organic thin film solar cell elements, perovskite solar cell elements, etc. By using the solar cell element coating composition of the present invention, it is possible to prepare, for example, a cured product having a thickness of 50 μm and a total light transmittance of 90% or more as measured by a method in accordance with JIS K 7361-1:1997.

[0051] [2] Solar Cell Module Next, one embodiment of the solar cell module according to the present invention will be described with reference to the drawings. Figure 1 shows an example of a perovskite solar cell module according to one embodiment of the present invention. The perovskite solar cell module 10 is configured to include a light-receiving-surface light-transmitting substrate or light-receiving-surface light-transmitting film 1, a perovskite solar cell element 2 laminated on the back surface of the light-receiving-surface light-transmitting substrate or light-receiving-surface light-transmitting film, a water vapor barrier layer 3 formed on the back surface of the perovskite solar cell element 2, an encapsulant 4 formed on the back surface of the perovskite solar cell element 2, and a back-side substrate or back-side film 5 laminated on the backmost portion of the encapsulant 4.

[0052] Here, the light-receiving surface light-transmitting substrate or light-receiving surface light-transmitting film 1 is a transparent member that serves as the side through which sunlight is incident, and is required to have long-term reliability for outdoor use, including transparency, weather resistance, and impact resistance. Specific examples of this light-receiving surface light-transmitting substrate 1 include transparent glass, with blue plate glass and white plate tempered glass being preferred. Furthermore, examples of the light-receiving surface light-transmitting film 1 include resin films, with the use of a light-transmitting film having high water vapor barrier properties being preferred.

[0053] The perovskite solar cell element 2 generally has a structure in which an electron transport layer, a power generation layer formed of a perovskite compound, a hole transport layer, and a back electrode are laminated on a light-receiving surface light-transmitting substrate or a light-receiving surface light-transmitting film 1, but is not limited to this structure.

[0054] The water vapor barrier layer 3 is disposed by applying the solar cell element coating composition of the present invention to the back surface of the perovskite solar cell element 2 so as to cover the solar cell element 2 without any gaps, and it is desirable that the water vapor barrier layer 3 adheres well to the light-receiving surface light-transmitting substrate or light-receiving surface light-transmitting film 1 and the perovskite solar cell element 2.

[0055] The encapsulant 4 placed on the back side of the perovskite solar cell element 2 is preferably flexible, transparent, and durable. White plate glass, blue plate glass, or the like can be used as the back substrate 5. Examples of the back film 5 include films with controlled water vapor permeation, such as a laminated film combining a fluororesin film and a polyethylene terephthalate (PET) film, a laminated film combining a thin metal film and a PET film, or a film in which a thin metal layer is vapor-deposited on a polyethylene naphthalate (PEN) film or the like. When the back substrate or back film 5 is light-transmitting, the resulting solar cell module becomes a see-through type, expanding the range of applications.

[0056] [3] Method for manufacturing a solar cell module A water vapor barrier layer can be formed by directly contacting the solar cell element coating composition of the present invention with a solar cell element and curing the composition through a curing step. The method for contacting the solar cell element coating composition is not particularly limited, but examples of methods that can be used include dispensing, casting, dipping, roll coating, spraying, and screen printing. The film thickness of the water vapor barrier layer is not particularly limited, but when applied to organic thin-film solar cells and perovskite solar cells, for example, it is preferably 1 to 3,000 μm, more preferably 10 to 1,000 μm, and even more preferably 20 to 500 μm.

[0057] Furthermore, the solar cell element coating composition of the present invention may be applied, if necessary, via one or more other layers formed on the solar cell element, such as inorganic layers of SiO, SiN, AlO, etc. When multiple layers are laminated on the solar cell element, it is also possible to use a cured product of the solar cell element coating composition of the present invention as a buffer film between the layers. Furthermore, a method such as laminating a film obtained by curing the solar cell element coating composition of the present invention can be used.

[0058] When curing the solar cell element coating composition of the present invention, the platinum group metal catalyst is activated by irradiation with light having a wavelength of 200 to 500 nm, preferably 200 to 370 nm. For light irradiation, a UV-LED lamp, a metal halide lamp, a mercury lamp, or the like can be used. From the viewpoints of the curing speed of the composition and prevention of discoloration, the irradiation intensity is set to 30 to 2,000 mW / cm. 2 The irradiation dose is preferably 3,000 to 100,000 mJ / cm 2 The temperature during irradiation is not particularly limited as long as it does not adversely affect the solar cell element, but is preferably 10 to 60°C, more preferably 20 to 40°C.

[0059] After the light irradiation, the solar cell element may be heated to a temperature of preferably 50 to 80° C., more preferably 50 to 70° C. The heating time is preferably 1 to 60 minutes, more preferably 10 to 30 minutes.

[0060] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group. The kinematic viscosity is measured using an Ostwald viscometer, and the viscosity is measured using a rotational viscometer.

[0061] [1] Preparation of Coating Compositions [Examples 1-1 to 1-5, Comparative Examples 1-1 to 1-3] The following components (A) to (D) were mixed in the amounts (parts by mass) shown in Table 1 to prepare coating compositions for solar cell elements.

[0062] Component (A) (A-1) Organopolysiloxane (Mw: 28,000) represented by the following average unit formula (14) (ViMeSiO 1 / 2 )2(Me2SiO 2 / 2 ) 300 (PhSiO 2 / 2 ) 30 (14) (A-2) Organopolysiloxane (Mw: 11,200) represented by the following average unit formula (15) (ViMeSiO 1 / 2 )2(Me2SiO 2 / 2 ) 68 (PhSiO 2 / 2 ) 30 (15) (A-3) Organopolysiloxane (Mw: 905) represented by the following average unit formula (16) (ViMePhSiO 1 / 2 )2(Ph2SiO 2 / 2 ) 3 (16)

[0063] Component (B) (B-1) A compound represented by the following average unit formula (17) (kinematic viscosity at 23°C: 45 mm 2 / s, silicon-bonded hydrogen atom content: 0.0112 mol / g) (MeSiO 1 / 2 )2(HMeSiO 2 / 2 ) 45 (MeSiO 2 / 2 ) 17 (17) (B-2) A compound represented by the following average unit formula (18) (kinematic viscosity at 23°C: 21 mm 2 / s, silicon-bonded hydrogen atom content: 0.0061 mol / g) (HMeSiO1 / 2 )2(HMeSiO 2 / 2 )2(Ph2SiO 2 / 2 ) 2 (18) (B-3) A siloxane compound represented by the following structural formula (19) (kinematic viscosity at 25°C: 1,000 mPa·s, content of silicon-bonded hydrogen atoms: 0.0066 mol / g) (B-4) A compound represented by the following structural formula (20) (kinematic viscosity at 23°C: 1.8 mm 2 / s, silicon-bonded hydrogen atom content: 0.0092 mol / g)

[0064] Component (C) (C-1) Toluene solution of methylcyclopentadienyltrimethylplatinum complex (platinum concentration 0.5% by mass) (C'-2) Toluene solution of platinum 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum concentration 0.5% by mass)

[0065] Component (D) (D-1) 1.0 mass% toluene solution of bis(2,2-dimethyl-3-butynoxy)dimethylsilane (D-2) bis(2,2-dimethyl-3-butynoxy)dimethylsilane

[0066]

[0067] [2] Production of Solar Cell Modules [Examples 2-1 to 2-5, Comparative Examples 2-1 to 2-3] Solar cell modules were produced using the solar cell element coating compositions obtained in Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-3 according to the following procedure.

[0068] As shown in Figure 2, a perovskite solar cell element 2 (size 25 x 25 mm) having a transparent conductive film, an electron transport layer, a perovskite layer, and a hole transport layer sequentially laminated on a glass substrate (size 50 x 50 mm, thickness 3.2 mm) serving as a light-receiving surface light-transmitting substrate 1, with a positive electrode formed on the hole transport layer, was laminated so as to be positioned at the center of the light-receiving surface light-transmitting substrate 1, thereby obtaining a perovskite solar cell cell for evaluation 11. Next, as shown in Figure 3, a fluororesin adhesive tape (thickness 0.25 mm, width 3 x 3 mm, Chukoh Chemical Industry Co., Ltd.) was provided as a dam material 6 around the outer periphery of the light-receiving surface light-transmitting substrate 1. A solar cell element coating composition was then applied to the perovskite solar cell element 2 to a thickness of 0.1 mm.

[0069] In Examples 1-1 to 1-5, the solar cell element coating composition was applied onto the perovskite solar cell element 2, and then ultraviolet light was irradiated from above at 25°C with an intensity of 100 mW / cm using a metal halide lamp (HANDY UV-100, manufactured by Oak Manufacturing Co., Ltd. (OCR)). 2 The cumulative irradiation dose is 3,000 mJ / cm 2 The coating composition was then heated at 60°C for 1 hour to cure the solar cell element coating composition, thereby obtaining a water vapor barrier layer 3. A glass back substrate 5 (size: 50 × 50 mm, thickness: 3.2 mm) was then placed on top of the dam material 6, and the back surface was fixed with polyimide tape 7 so that the back substrate 5 would not come off, thereby obtaining a perovskite solar cell module 12 for evaluation.

[0070] In Comparative Examples 1-1 to 1-3, the solar cell element coating composition was applied onto the perovskite solar cell element 2, and then the solar cell element coating composition was cured by heating for 1 hour at 100° C. Thereafter, a glass substrate (size 50×50 mm, thickness 3.2 mm) serving as the rear substrate 5 was placed on top of the dam material 6, and the rear surface was fixed with polyimide tape 7 so that the rear substrate 5 would not come off, thereby obtaining a perovskite solar cell module 12 for evaluation.

[0071] [Initial Output Maintenance Rate] The obtained perovskite solar cell evaluation body was irradiated with light from the surface direction of the light-transmitting substrate 1 using a simulated solar light irradiation device, and the output (W1) of the evaluation perovskite solar cell module 12 was measured. The output (W1) of the evaluation perovskite solar cell module 12 and the output (W1) of the evaluation perovskite solar cell 11 before modularization were measured. c ) and the initial output maintenance rate (%) was calculated. The initial output maintenance rate was evaluated as ◯ when it was 95% or more, and x when it was less than 95%. The results are shown in Table 2. Initial output maintenance rate (%) = (W1 / W c ) x 100

[0072] [Output Maintenance Rate After Moisture Resistance Test] Furthermore, the output (W2) of the perovskite solar cell module 12 for evaluation after 500 hours of exposure to an environment of 60°C and 90% RH was measured in the same manner as above, and the output maintenance rate (%) after the moisture resistance test was calculated. The output maintenance rate after the moisture resistance test was evaluated as ◯ when it was 80% or more, and x when it was less than 80%. The results are shown in Table 2. Output maintenance rate after moisture resistance test (%) = (W2 / W c ) x 100

[0073]

[0074] As shown in Table 2, the perovskite solar cells having a water vapor barrier layer made of the cured product of the solar cell element coating composition of Examples 1-1 to 1-5 exhibited good output retention even when exposed to an environment of 60°C and 90% RH for 500 hours. On the other hand, the perovskite solar cells using the compositions of Comparative Examples 1-1 to 1-3 exhibited low initial output retention and were not suitable for conducting a humidity resistance test. This is thought to be because the perovskite solar cell elements, which are sensitive to heat, were damaged by heating to 100°C when the water vapor barrier layer was formed, resulting in a decrease in output.

[0075] REFERENCE SIGNS LIST 1 Light-receiving surface light-transmitting substrate / light-receiving surface light-transmitting film 2 Perovskite solar cell element 3 Water vapor barrier layer 4 Sealant 5 Rear substrate / rear film 6 Dam material 7 Polyimide tape 10 Perovskite solar cell module 11 Perovskite solar cell for evaluation 12 Perovskite solar cell module for evaluation

Claims

1. (A) An organopolysiloxane represented by the following average unit formula (1): (R 1 R 3 2 SiO 1 / 2 ) 2 (Ar 2 SiO 2 / 2 ) a (R 2 2 SiO 2 / 2 ) b (1) [In the formula, R 1 are each independently an alkenyl group; R 2 are each independently a substituted or unsubstituted monovalent saturated hydrocarbon group; R 3 are each independently a substituted or unsubstituted monovalent saturated hydrocarbon group or a substituted or unsubstituted aryl group, and Ar is a substituted or unsubstituted aryl group. a is an integer from 1 to 100, b is an integer from 0 to 1,000, and a / (a+b) is a number from 0.01 to 1.

0. (B) an organosilicon compound having at least two hydrogen atoms bonded to silicon atoms in one molecule, and (C) A platinum group metal catalyst activated by light having a wavelength of 200 to 500 nm. A solar cell coating composition comprising:

2. 2. The coating composition for a solar cell element according to claim 1, wherein the component (B) is at least one selected from the following (i) to (iii): (i) An organohydrogenpolysiloxane represented by the following average composition formula (2): R 4 c H d SiO (4-c-d) / 2 (2) (In the formula, R 4 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms other than an alkenyl group, and c and d are numbers that satisfy 0.7≦c≦2.1, 0.01≦d≦1, and 0.8≦c+d≦2.

7. (ii) Addition reaction products of vinylnorbornene and / or diallylbisphenol A with cyclic organohydrogenpolysiloxanes (iii) SiH group-containing silane compound

3. The component (C) is (η 5 2. The solar cell coating composition of claim 1, comprising a bis(β-cyclopentadienyl)trialiphatic platinum compound or a bis(β-diketonato)platinum compound.

4. A solar cell module comprising a solar cell element and a water vapor barrier layer comprising a cured product of the solar cell element coating composition according to any one of claims 1 to 3.

5. 5. The solar cell module according to claim 4, wherein the solar cell element is an organic thin film type or a perovskite type solar cell element.

6. A method for producing a solar cell module, comprising the steps of contacting the solar cell element coating composition according to any one of claims 1 to 3 with a solar cell element directly or via at least one other layer, irradiating the solar cell element with light having a wavelength of 200 to 500 nm under atmospheric pressure, and then curing the solar cell element by heating.

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