Solar cell manufacturing method and solar cell

Abstract

The present invention addresses the problem of providing a solar cell manufacturing method capable of obtaining high sticking force between a sealing resin and an upper support body in a solar cell in which a photoelectric conversion layer is sealed by a sealing resin and which furthermore has an upper support covering the sealing resin, and of providing a solar cell manufactured by the manufacturing method. The problem is solved by sealing a laminate formed on a lower support and including a lower electrode, a perovskite-type photoelectric conversion layer, and an upper electrode with a sealing resin, then irradiating the uncured sealing resin with an atmospheric-pressure plasma, then bonding the upper support to a part of the uncured sealing resin that is irradiated by the atmospheric-pressure plasma, and then curing the sealing resin.

Description

Method for manufacturing solar cell and solar cell

[0001] The present invention relates to a method for manufacturing a solar cell having a perovskite-type photoelectric conversion layer, and to a solar cell.

[0002] Perovskite solar cells are known that have a photoelectric conversion layer containing a perovskite compound. The photoelectric conversion layer constituting the perovskite solar cell is known to deteriorate upon contact with moisture. Therefore, various methods have been proposed to prevent moisture-induced deterioration of perovskite solar cells.

[0003] For example, Patent Document 1 describes a solar cell that includes a laminate having an electrode, a counter electrode, and a photoelectric conversion layer provided between the electrode and the counter electrode, and a sealing resin (resin sealing layer) that covers the counter electrode and seals the laminate, the photoelectric conversion layer being a perovskite-type photoelectric conversion layer, and the sealing resin being made of a resin having a solubility parameter (SP value) of 10 or less. In Patent Document 1, by sealing the laminate with a sealing resin using a resin having a solubility parameter of 10 or less, deterioration of the perovskite-type photoelectric conversion layer due to moisture is prevented.

[0004] On the other hand, Patent Document 2 describes a similar perovskite solar cell, which includes a first flexible support (flexible substrate), a first electrode, a photoelectric conversion layer having a perovskite layer, a second electrode, and a second flexible support. In the solar cell described in Patent Document 1, the laminate is also formed on a support (substrate). Therefore, in consideration of Patent Document 2, it is conceivable to cover the resin sealing layer with a second support in the solar cell described in Patent Document 1 as well, thereby protecting the resin sealing layer by ensuring weather resistance, for example.

[0005] International Publication No. 2016 / 060156 Japanese Patent Application Laid-Open No. 2022-117248

[0006] As described above, the solar cell described in Patent Document 1 prevents deterioration of the perovskite-type photoelectric conversion layer due to moisture by sealing the laminate with a sealing resin. That is, this sealing resin has so-called gas barrier properties. Here, this sealing resin has low reactivity due to its gas barrier properties. Therefore, even if the surface of this sealing resin is covered with a support such as a resin film, it is difficult to bond the resin sealing layer and the support with a high adhesive strength.

[0007] The object of the present invention is to solve the problems of the conventional technology and to provide a method for manufacturing a solar cell that has a lower support, a laminate having a lower electrode, a perovskite-type photoelectric conversion layer and an upper electrode, and a sealing resin that seals the laminate, and further has an upper support bonded to the sealing resin, and to provide a solar cell manufactured by this solar cell manufacturing method that can obtain high adhesion between the sealing resin and the upper support.

[0008] To achieve these objects, the present invention has the following configurations. [1] A method for manufacturing a solar cell, comprising: sealing a solar cell body having a lower support and a laminate including a lower electrode, a perovskite-type photoelectric conversion layer, and an upper electrode formed on the surface of the lower support, with a sealing resin; irradiating the sealing resin with atmospheric pressure plasma while the sealing resin is still uncured; irradiating the sealing resin with atmospheric pressure plasma, and then laminating an upper support to the part of the sealing resin irradiated with atmospheric pressure plasma while the sealing resin is still uncured; and then curing the sealing resin. [2] The method for manufacturing a solar cell according to [1], wherein an inorganic film is formed on the surface of the sealing resin by irradiating with atmospheric pressure plasma. [3] The method for manufacturing a solar cell according to [2], wherein the inorganic film is formed by irradiating with atmospheric pressure plasma so that the maximum thickness of the inorganic film is 10 nm or less. [4] The method for manufacturing a solar cell according to any of [1] to [3], wherein at least one of the lower support and the upper support is flexible. [5] A solar cell comprising a lower support, a laminate having a lower electrode formed on the surface of the lower support, a perovskite-type photoelectric conversion layer, and an upper electrode, a sealing resin for sealing the laminate, and an upper support laminated on the surface of the sealing resin opposite to the lower support, and further comprising a plurality of inorganic films spaced apart from each other between the sealing resin and the upper support. [6] The solar cell according to [5], wherein at least one of the lower support and the upper support is flexible.

[0009] According to the present invention, in a solar cell having a lower support, a laminate having a lower electrode, a perovskite-type photoelectric conversion layer and an upper electrode, and a sealing resin covering the laminate, in which the sealing resin is covered with an upper support, a high adhesive strength can be obtained between the sealing resin and the upper support.

[0010] Fig. 1 is a diagram conceptually showing an example of a solar cell manufactured by the solar cell manufacturing method of the present invention. Fig. 2 is a conceptual diagram for explaining an example of a solar cell manufacturing method of the present invention. Fig. 3 is a conceptual diagram for explaining an example of a solar cell manufacturing method of the present invention. Fig. 4 is a conceptual diagram for explaining an example of a solar cell manufacturing method of the present invention. Fig. 5 is a conceptual diagram for explaining an example of a solar cell manufacturing method of the present invention. Fig. 6 is a cross-sectional diagram conceptually showing an example of an irradiation type atmospheric pressure plasma source. Fig. 7 is a diagram conceptually showing an example of a parallel plate type atmospheric pressure plasma source.

[0011] The solar cell manufacturing method and solar cell of the present invention are described in detail below. The following description is based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the present invention, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in the present invention, angles such as "angle," "parallel," and "orthogonal" include the error range generally accepted in the relevant technical field unless otherwise specified. Furthermore, all of the figures shown below are conceptual diagrams for explaining the present invention. Therefore, the shape, size, thickness, and positional relationships, such as the placement position and spacing, of each component in each figure do not necessarily correspond to those of an actual device.

[0012] In addition, in the present invention, the terms "upper" and "lower" in the lower support and upper support, and the lower electrode and upper electrode are used for convenience in order to distinguish between similar members according to their positions in the drawings, and have no technical significance whatsoever. Therefore, in actual use, the lower support side may be located at the top in the vertical direction, and the upper support side may be located at the bottom in the vertical direction.

[0013] An example of a solar cell of the present invention manufactured by the solar cell manufacturing method of the present invention is conceptually shown in Figure 1. The solar cell 10 shown in Figure 1 has a lower support 12, a lower electrode 14, a photoelectric conversion layer 18, an upper electrode 24, a sealing resin 26 that seals the laminate having the lower electrode 14, the photoelectric conversion layer 18, and the upper electrode 24, and an upper support 28. In the present invention, the photoelectric conversion layer 18 is a perovskite-type photoelectric conversion layer.

[0014] In the solar cell manufacturing method of the present invention, first, a solar cell body is fabricated by forming a laminate including the lower support 12, the lower electrode 14, and the photoelectric conversion layer 18 on the lower support 12. Alternatively, such a solar cell body is prepared. Next, the laminate of the solar cell body, i.e., the lower support 12, the lower electrode 14, and the photoelectric conversion layer 18, is sealed with a sealing resin 26. Next, while the sealing resin 26 is in an uncured state, atmospheric pressure plasma is irradiated to at least the portion of the surface of the sealing resin 26 that contacts the upper support 28. Next, while the sealing resin 26 is in an uncured state, the upper support 28 is laminated and bonded to the atmospheric pressure plasma-irradiated surface of the sealing resin 26. Furthermore, after the upper support 28 is laminated on the sealing resin 26, the sealing resin 26 is cured to form a solar cell 10. As will be described in detail later, this configuration of the present invention allows the sealing resin 26 and the upper support 28 to be bonded with high adhesive strength.

[0015] The solar cell of the present invention is not limited to the configuration shown in FIG. 1 . That is, the solar cell of the present invention can utilize the configuration of various known solar cells as long as it has a perovskite-type photoelectric conversion layer. For example, the solar cell 10 of the present invention may have a blocking layer (short-circuit prevention layer) and a porous layer, as well as a layer formed in known solar cells, such as an electron transport layer, between the lower electrode 14 and the photoelectric conversion layer 18. The solar cell 10 of the present invention may also have a layer formed in known solar cells, such as a hole transport layer, between the photoelectric conversion layer 18 and the upper electrode 24. Furthermore, the solar cell 10 of the present invention is not limited in shape to the lower electrode 14, the photoelectric conversion layer 18, and the upper electrode 24, as well as the electron transport layer and hole transport layer, and can utilize shapes used in various known solar cells.

[0016] 1 shows one stacked body having the lower electrode 14, the photoelectric conversion layer 18, and the upper electrode 24 on the lower support 12, but the present invention is not limited to this. In other words, the present invention may correspond to a configuration having a plurality of stacked bodies having the lower electrode 14, the photoelectric conversion layer 18, and the upper electrode 24 on the lower support 12.

[0017] [Lower Support] In the present invention, the lower support 12 can be any of various known sheet-like materials (films, plate-like materials) used as supports (substrates) in solar cells, as long as it can support the layers formed on one surface. The lower support 12 may be flexible or inflexible. The lower support 12 is preferably flexible. In the present invention, a flexible support means that after being curved from a flat (planar) state, it can be returned to a flat state without deformation, breakage, or damage. Specifically, the above-mentioned curvature preferably allows for a curvature radius of 2 cm or less, and more preferably allows for a curvature radius of 1 cm or less.

[0018] Examples of such lower support 12 include a glass plate, a plastic film, and a gas barrier film. Examples of materials for forming the plastic film used for the lower support 12 include thermoplastic resins such as polyester resin, methacrylic resin, resin made of methacrylic acid-maleic acid copolymer, polystyrene resin, fluororesin, polyimide resin, fluorinated polyimide resin, polyamide resin, polyamideimide resin, polyetherimide resin, cellulose acylate resin, polyurethane resin, polyether ether ketone resin, polycarbonate resin, alicyclic polyolefin resin, polyarylate resin, polyethersulfone resin, polysulfone resin, resin made of cycloolefin copolymer, fluorene ring-modified polycarbonate resin, alicyclic ring-modified polycarbonate resin, fluorene ring-modified polyester resin, and acryloyl compound.

[0019] The plastic film preferably has heat resistance. Specifically, the plastic film preferably has at least one of the following physical properties: a glass transition temperature (Tg) of 100°C or higher and a linear thermal expansion coefficient of 40 ppm / K or lower. The Tg and linear expansion coefficient of the plastic film may be measured by the method for measuring the transition temperature of plastics described in JIS (Japanese Industrial Standards)-K7121 and the test method for linear expansion coefficient by thermomechanical analysis of plastics described in JIS-K7197.

[0020] The Tg or linear expansion coefficient of the plastic film can be adjusted by additives, etc. Examples of such thermoplastic resins having excellent heat resistance include polyethylene naphthalate (PEN: 120°C), polycarbonate (PC: 140°C), alicyclic polyolefins (e.g., Zeonor 1600 (trade name) manufactured by Nippon Zeon Co., Ltd.: 160°C), polyarylate (PAr: 210°C), polyethersulfone (PES: 220°C), polysulfone (PSF: 190°C), cycloolefin copolymers (C Examples include fluorene ring-modified polycarbonate (BCF-PC: compound of JP-A 2000-227603: 225°C), alicyclic modified polycarbonate (IP-PC: compound of JP-A 2000-227603: 205°C), acryloyl compounds (compounds of JP-A 2002-80616: 300°C or higher), and polyimide. The temperatures in parentheses are all "Tg". Of these, polyethylene naphthalate is preferred.

[0021] In the solar cell 10 of the present invention, at least one of the lower support 12 and the upper support 28 described below must be transparent to visible light. Specifically, the lower support 12 and / or the upper support 28 preferably have a light transmittance of 80% or more for light in the wavelength range of 400 to 800 nm. The light transmittance is more preferably 85% or more, and even more preferably 90% or more. The light transmittance can be calculated by the method described in JIS-K7105, that is, by measuring the total light transmittance and the amount of scattered light using an integrating sphere light transmittance measuring device and subtracting the diffuse transmittance from the total light transmittance.

[0022] There is no limitation on the thickness of the lower support 12, and it may be set appropriately depending on the material used to form the lower support 12 so as to support the solar cell (laminate) and ensure the necessary flexibility and strength. The thickness of the lower support 12 is, for example, 1 to 800 μm, and preferably 10 to 300 μm.

[0023] [Lower Electrode] In the solar cell 10 shown in Fig. 1, a lower electrode 14 is provided on one surface of the lower support 12. In the following description, the upper side in Fig. 1 will also be referred to as "upper," and the lower side will also be referred to as "lower." That is, in the solar cell 10 shown in Fig. 1, the lower electrode 14 is provided on the upper surface of the lower support 12.

[0024] In the solar cell 10, the lower electrode 14 is used to extract the power generated in the photoelectric conversion layer 18 (perovskite-type photoelectric conversion layer) to the outside. The material for forming the lower electrode 14 is not particularly limited, and examples thereof include metals, metal oxides, conductive polymers, and mixtures thereof. Among these, conductive polymers are preferred in terms of flexibility. Examples of metals include magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), strontium (Sr), silver (Ag), indium (In), tin (Sn), barium (Ba), and bismuth (Bi), as well as alloys thereof. Examples of metal oxides include tin oxide, fluorine-doped tin oxide (FTO), zinc oxide, antimony-doped zinc oxide (AZO), indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), and transparent conductive oxides (TCOs) such as indium tungsten oxide (IWO).

[0025] Conductive polymers are not particularly limited as long as they are polymeric compounds that are conductive. Therefore, the charge carriers to be transported may be either holes or electrons. Examples of conductive polymers include polythiophene, polypyrrole, polyaniline, polyphenylene vinylene, polyphenylene, polyacetylene, polyquinoxaline, polyoxadiazole, and polybenzothiadiazole, as well as polymeric compounds containing multiple conductive skeletons. Among these, polythiophene is preferred, with polyethylene dioxythiophene and polythienothiophene being more preferred. These polythiophenes are typically partially oxidized to achieve conductivity. The electrical conductivity of conductive polymers can be adjusted by the degree of partial oxidation (doping amount), with higher doping amounts resulting in higher electrical conductivity. Partial oxidation renders polythiophene cationic, requiring a counteranion to neutralize the charge. An example of such a polythiophene is polyethylene dioxythiophene (PEDOT-PSS) with polystyrene sulfonic acid as the counterion. As the conductive polymer, for example, the conductive polymer described in JP-A-2015-191916 can be used.

[0026] In the solar cell 10 of the present invention, the lower electrode 14 and the upper electrode 24 described below, whose corresponding supports are transparent to visible light, must also be transparent to visible light. However, if both the lower support 12 and the upper support 28 are transparent to visible light, only one of the lower electrode 14 and the upper electrode 24 may be transparent to visible light. Specifically, transparency to visible light is equivalent to the lower support 12 and upper support 28 described above.

[0027] The film thickness of the lower electrode 14 is not particularly limited, but is preferably 0.01 to 30 μm, for example. The layer structure of the lower electrode 14 is not particularly limited, and may be a single-layer structure or a multilayer structure.

[0028] As described above, the solar cell 10 may have an electron transport layer between the lower electrode 14 and the photoelectric conversion layer 18, i.e., on the upper surface of the lower electrode 14. The electron transport layer has the function of transporting electrons generated in the photoelectric conversion layer 18 to the lower electrode 14 (or the conductive support). The electron transport layer is formed of an electron transport material capable of transporting electrons. The electron transport material is not particularly limited, but an organic material (organic electron transport material) is preferred. Examples of organic electron transport materials include fullerene compounds such as [6,6]-phenyl-C61-butylic acid methyl ester (PC61BM), perylene compounds such as perylene tetracarboxylic diimide (PTCDI), and low-molecular-weight compounds or high-molecular-weight compounds such as tetracyanoquinodimethane (TCNQ). The thickness of the electron transport layer is not particularly limited, but is preferably 0.001 to 10 μm, and more preferably 0.01 to 1 μm.

[0029] As described above, the solar cell 10 may have a blocking layer, a porous layer, or the like instead of the electron transport layer.

[0030] [Photoelectric Conversion Layer] In the solar cell 10 shown in FIG. 1 , a photoelectric conversion layer 18 is provided on the lower electrode 14. The photoelectric conversion layer 18 has a photoelectric conversion function and obtains electric power from incident light. In the present invention, the photoelectric conversion layer 18 is a perovskite-type photoelectric conversion layer and therefore includes a perovskite compound. A perovskite compound is a compound having a perovskite-type crystal structure. The compound having a perovskite-type crystal structure is not particularly limited. For example, the perovskite compounds described in WO 2019 / 053967, JP 2017-17166, and JP 2015-191916 can be used in the photoelectric conversion layer 18. The method for forming the photoelectric conversion layer 18 is not particularly limited, and examples thereof include vacuum deposition, sputtering, gas phase reaction methods such as CVD, electrochemical deposition, and coating (printing) methods. Among these, coating methods are preferred. Forming the photoelectric conversion layer 18 by a coating method allows for the easy formation of large-area solar cells. The coating method is not particularly limited, and examples thereof include spin coating and casting. When a coating method is used, the photoelectric conversion layer 18 can be formed by roll-to-roll. The film thickness of the photoelectric conversion layer 18 is not particularly limited, and is preferably 0.001 to 100 μm, more preferably 0.01 to 10 μm, and even more preferably 0.01 to 5 μm.

[0031] As described above, the solar cell 10 may have a hole transport layer or the like between the photoelectric conversion layer 18 and the upper electrode 24, i.e., on the photoelectric conversion layer 18. The hole transport layer has the function of replenishing electrons in the oxidant of the photoelectric conversion layer 18 and is preferably a solid layer (solid hole transport layer). The hole transport material forming the hole transport layer may be either a liquid material or a solid material, and is not particularly limited. Examples of hole transport materials include inorganic materials such as CuI and CuNCS, and organic hole transport materials described in paragraphs

[0209] to

[0212] of JP 2001-291534 A. Examples of organic hole transport materials include conductive polymers such as polythiophene, polyaniline, polypyrrole, and polysilane; spiro compounds in which two rings share a central atom such as C or Si and form a tetrahedral structure; aromatic amine compounds such as triarylamine; triphenylene compounds; and nitrogen-containing heterocyclic compounds or liquid crystalline cyano compounds. The hole transport material is preferably a solution-coatable organic hole transport material that becomes a solid. Specific examples of such hole transport materials include 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamino)-9,9'-spirobifluorene (also known as spiro-MeOTAD), poly(3-hexylthiophene-2,5-diyl), 4-(diethylamino)benzaldehyde diphenylhydrazone, and polyethylenedioxythiophene (PEDOT). As the hole transport material for forming the hole transport layer, materials used for hole transport layers described in International Publication No. 2019 / 053967, JP 2017-17166 A, and JP 2015-191916 A can also be used. The film thickness of the hole transport layer is not particularly limited, but is preferably 50 μm or less, more preferably 1 nm to 10 μm, even more preferably 5 nm to 5 μm, and particularly preferably 10 nm to 1 μm.

[0032] [Upper Electrode] In the solar cell 10 shown in FIG. 1 , an upper electrode 24 is provided on the photoelectric conversion layer 18. The upper electrode 24 functions as a positive electrode in the solar cell 10. The upper electrode 24 is not particularly limited as long as it is conductive. The structure of the upper electrode 24 is preferably a structure with a high current collection effect. The upper electrode 24 may also be patterned, as described in Patent Document 1. In the solar cell 10, when the lower support 12 and the lower electrode 14 are transparent to light and sunlight or other light is incident from the lower support 12 side, it is preferable that the upper electrode 24 have a light-reflecting property.

[0033] The material for forming the upper electrode 24 is not particularly limited. Examples of materials for forming the upper electrode 24 include metals such as platinum (Pt), gold (Au), nickel (Ni), copper (Cu), silver (Ag), indium (In), ruthenium (Ru), palladium (Pd), rhodium (Rh), iridium (Ir), osnium (Os), and aluminum (Al), conductive metal oxides of these metals, carbon materials, and conductive polymers. Examples of carbon materials include conductive materials formed by bonding carbon atoms, such as fullerenes, carbon nanotubes, graphite, and graphene. The thickness of the upper electrode 24 is not particularly limited, but is preferably 0.01 to 100 μm, more preferably 0.01 to 10 μm, and even more preferably 0.01 to 1 μm.

[0034] [Sealing Resin] As described above, solar cell 10 of the present invention has sealing resin 26 that seals the laminate having lower electrode 14, photoelectric conversion layer 18, and upper electrode 24. As described above, in solar cell 10 of the present invention, the laminate may have other layers, such as an electron transport layer and a hole transport layer, which are provided in solar cells having a known perovskite-type photoelectric conversion layer, as long as it has lower electrode 14, photoelectric conversion layer 18, and upper electrode 24.

[0035] In the solar cell 10 of the present invention, the sealing resin 26 prevents moisture and the like from penetrating into the photoelectric conversion layer 18, thereby preventing the perovskite-type photoelectric conversion layer 18 from deteriorating due to moisture and the like. That is, the sealing resin 26 has gas barrier properties in a cured state. Specifically, when the sealing resin 26 has a thickness of 1 mm, the water vapor transmission rate (WVTR) in an environment of a temperature of 25°C and a relative humidity of 50% is 100 g / (m 2 ·day) or less, and 50 g / (m 2 ·day) or less, and 30 g / (m 2 It is more preferable that the sealing resin 26 has a water vapor permeability of 100 g·mm / (m 2 The water vapor transmission rate is preferably 1 / 2 day or less. The water vapor transmission rate may be measured by a known method such as the Mocon method or the calcium corrosion method. The calcium corrosion method is described in JP-A-2005-283561.

[0036] There are no limitations on the sealing resin 26, and various known resins can be used as long as they provide the required gas barrier properties. Here, the sealing resin 26 is preferably a curable (hardening) resin such as an ultraviolet-curable resin, a thermosetting resin, or an electron beam-curable resin. Among these, an ultraviolet-curable resin is preferably used as the sealing resin 26 because it provides high gas barrier properties. Examples of the sealing resin 26 include an olefin resin, an epoxy resin, a silicone resin, and a urethane resin.

[0037] The thickness of the sealing resin 26, i.e., the distance between the lower support 12 and the upper support 28, is not particularly limited, and may be set appropriately depending on the material used to form the sealing resin 26 so as to obtain the required gas barrier properties. The thickness of the sealing resin 26 is preferably 0.1 to 100 μm, more preferably 0.2 to 50 μm, and even more preferably 0.3 to 30 μm.

[0038] [Upper Support] The solar cell 10 of the present invention has an upper support 28 covering the sealing resin 26. There are no limitations on the upper support 28, and various known sheet-like materials can be used. As an example, various materials exemplified for the lower support 12 described above can be used. The preferred thickness and heat resistance of the upper support 28 are also similar to those of the lower support 12 described above. Note that if the lower support 12 described above is flexible, it is preferable that the upper support 28 also be flexible.

[0039] In the solar cell 10 of the present invention, the upper support 28 not only covers the encapsulating resin 26 but may also have functions such as protection of the encapsulating resin 26, weather resistance, light resistance to ultraviolet rays and the like, anti-reflection, anti-fogging properties, anti-fouling properties, and gas barrier properties. That is, the upper support 28 may be a sheet-like material having these functions. Various known sheet-like materials having such functions can also be used. Note that in the solar cell 10 of the present invention, these functions may be provided by the lower support 12 rather than the upper support 28, or by both the upper support 28 and the lower support 12.

[0040] The solar cell 10 of the present invention has a plurality of inorganic films spaced apart from one another between the sealing resin 26 and the upper support 28. This will be described in detail later.

[0041] The following describes a method for manufacturing a solar cell of the present invention for producing such a solar cell 10. In the following description, the "method for manufacturing a solar cell of the present invention" may also be simply referred to as the "manufacturing method of the present invention." The manufacturing method of the present invention may be performed by a sheet-by-sheet method using cut-sheet-shaped lower support 12 and upper support 28, or by a roll-to-roll method using flexible, long lower support 12 and upper support 28.

[0042] First, as conceptually shown in Figure 2, a solar cell body is fabricated by forming a laminate having a lower electrode 14, a photoelectric conversion layer 18, and an upper electrode 24 on the surface of a lower support 12. In the following description, for convenience, the "front surface" of the lower support 12 refers to the surface on which the laminate is formed, and the "back surface" refers to the surface opposite to the surface on which the laminate is formed. As described above, in the present invention, in the laminate having the lower electrode 14, the photoelectric conversion layer 18, and the upper electrode 24, an electron transport layer or the like may be formed between the lower electrode 14 and the photoelectric conversion layer 18, and a hole transport layer or the like may be formed between the photoelectric conversion layer 18 and the upper electrode.

[0043] There are no limitations on the method for forming each of these layers, and they may be formed by any known method suitable for the layer-forming material, such as coating, vapor-phase deposition methods (vapor-phase deposition layers) such as vapor deposition and CVD, lamination of sheet-like materials, and printing. In the present invention, CVD includes plasma CVD. As described above, multiple laminates may be formed on the lower support 12. Furthermore, as described above, the upper electrode 24 may be patterned after it is formed.

[0044] After fabricating the solar cell body having the laminate on the surface of the lower support 12, the laminate is then sealed with sealing resin 26a, as conceptually shown in Fig. 3. The sealing resin 26a in this state is uncured. In Fig. 3, the laminate is composed of the lower electrode 14, the photoelectric conversion layer 18, and the upper electrode 24. Note that the sealing (coating) with the sealing resin 26a may be limited to the front surface of the lower support 12, or the sealing resin 26a may cover the side surfaces of the lower support 12 as well, or the sealing resin 26a may cover the back surface of the lower support 12 as well.

[0045] There are no limitations on the method for forming the sealing resin 26a, and known methods can be used depending on the material for forming the sealing resin 26a. As described above, a curable resin is preferably used as the sealing resin 26a (sealing resin 26). Therefore, since the uncured sealing resin 26a is liquid, sealing of the laminate with the sealing resin 26a can be performed by a coating method. In the manufacturing method of the present invention, there are no limitations on the coating method (printing method), and various known methods can be used, such as curtain coating, dip coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, and wire bar coating.

[0046] After the sealing resin 26a is formed, atmospheric pressure plasma P is irradiated onto the uncured sealing resin 26a using an atmospheric pressure plasma source 32, as conceptually shown in FIG. 4 . That is, the sealing resin 26a is treated with atmospheric pressure plasma while it is still uncured. Note that, if the sealing resin 26a (sealing resin 26) is a curable resin, the uncured state of the sealing resin refers to the state before treatment for curing the resin. For example, if the sealing resin 26a is an ultraviolet-curable resin, the uncured state refers to the state before ultraviolet light is irradiated onto the sealing resin 26a to harden the resin. If the sealing resin 26a is a thermosetting resin, the uncured state refers to the state before heat treatment for hardening the resin is performed on the sealing resin 26a. If the sealing resin 26a is an electron beam-curable resin, the uncured state refers to the state before electron beams are irradiated onto the sealing resin 26a to harden the resin.

[0047] In the manufacturing method of the present invention, atmospheric pressure plasma P is applied to the uncured sealing resin 26a, thereby introducing functional groups, such as "-OH" groups, into the surface of the sealing resin 26a, which contribute to bonding with the upper support 28. Furthermore, the use of atmospheric pressure plasma makes it possible to efficiently introduce functional groups into the sealing resin 26a by utilizing moisture and oxygen in the air. As a result, the manufacturing method and solar cell of the present invention produce a solar cell 10 with high adhesive strength between the sealing resin 26 and the upper support 28. This point will be described in more detail below.

[0048] There is no limitation on the region of the sealing resin 26a that can be irradiated with the atmospheric pressure plasma P, as long as it is the surface of the sealing resin 26 that is in contact with the upper support 28. Here, the atmospheric pressure plasma P can be irradiated to at least a portion of the contact area of ​​the sealing resin 26 with the upper support 28, as long as sufficient adhesive strength between the sealing resin 26 and the upper support 28 is obtained. However, in the manufacturing method of the present invention, the atmospheric pressure plasma P is preferably irradiated to the entire contact area of ​​the sealing resin 26 with the upper support 28. Note that the atmospheric pressure plasma P can also be irradiated to the portion of the sealing resin 26 that is not in contact with the upper support 28 without causing any problems.

[0049] Furthermore, the atmospheric pressure plasma source 32 is moved (scanned) as needed to irradiate the sealing resin 26a with the atmospheric pressure plasma P over the entire required area of ​​the sealing resin 26a.

[0050] In the manufacturing method of the present invention, there are no limitations on the amount of atmospheric pressure plasma irradiated onto the sealing resin 26a, specifically, the amount of plasma gas supplied for irradiating the sealing resin 26a with atmospheric pressure plasma and the voltage applied to the electrode of the atmospheric pressure plasma source for generating the atmospheric pressure plasma P. That is, the amount of atmospheric pressure plasma irradiated onto the sealing resin 26a, in other words, the conditions for irradiating the sealing resin 26a with atmospheric pressure plasma, can be appropriately set depending on the plasma gas used, the desired adhesive strength between the sealing resin 26 and the upper support 28, and the like. This also applies to the case of forming an inorganic film during atmospheric pressure plasma irradiation, which will be described later. That is, the conditions for forming an inorganic film during atmospheric pressure plasma irradiation can also be appropriately set depending on the plasma gas and source gas used, the inorganic film to be formed, the desired inorganic film thickness, and the like.

[0051] In the manufacturing method of the present invention, an inorganic film may be formed on the surface of the sealing resin 26a when the sealing resin 26a is irradiated with atmospheric pressure plasma. Preferably, the inorganic film is not formed over the entire area irradiated with atmospheric pressure plasma P, but rather multiple inorganic films are spaced apart from one another in the planar direction of the surface of the sealing resin 26a. The solar cell of the present invention has multiple inorganic films that are spaced apart from one another between the sealing resin 26 and the upper support 28.

[0052] In the production method of the present invention, the inorganic film is preferably formed by atmospheric pressure plasma so that the maximum thickness of the inorganic film to be formed is 10 nm or less. That is, in the production method of the present invention, the inorganic film is preferably formed so that the thickness of all the inorganic films to be formed is 10 nm or less.

[0053] As described above, in the manufacturing method of the present invention, atmospheric pressure plasma is irradiated onto the uncured sealing resin 26a. Accordingly, in the manufacturing method of the present invention, the formation of an inorganic film on the sealing resin 26a using atmospheric pressure plasma is also performed on the surface of the uncured sealing resin 26a. That is, in the manufacturing method of the present invention, the formation of the inorganic film using atmospheric pressure plasma is performed while the sealing resin 26a is in a soft state. Thus, when a thin inorganic film with a maximum thickness of 10 nm or less is formed on the sealing resin 26a, i.e., the surface on which the inorganic film is formed, in a soft state, the inorganic film is not formed on the entire surface of the sealing resin 26a irradiated with atmospheric pressure plasma, but rather forms multiple inorganic films spaced apart from one another. That is, by forming the inorganic film under these conditions, multiple inorganic films spaced apart from one another form a so-called sea-island-like inorganic film.

[0054] Such an inorganic film is not a complete inorganic film but an incomplete inorganic film, and a large number of functional groups are introduced by atmospheric pressure plasma. As a result, in the present invention, by forming an inorganic film on the surface of the sealing resin 26a, i.e., by having multiple inorganic films spaced apart from each other between the sealing resin 26 and the upper support 28, the adhesive strength between the sealing resin 26 and the upper support 28 can be further improved.

[0055] As the inorganic film, various known films can be used as long as they can be formed by atmospheric pressure plasma. Examples include inorganic films made of inorganic compounds such as metal oxides such as aluminum oxide, magnesium oxide, tantalum oxide, zirconium oxide, titanium oxide, and indium tin oxide (ITO); metal nitrides such as aluminum nitride; metal carbides such as aluminum carbide; silicon oxides such as silicon oxide, silicon oxynitride, silicon oxycarbide, and silicon oxynitride carbide; silicon nitrides such as silicon nitride and silicon carbide nitride; silicon carbides such as silicon carbide; hydrides thereof; mixtures of two or more of these; and hydrogen-containing compounds thereof. Among these, inorganic films made of silicon oxides, nitrides, and oxynitrides such as silicon oxide, silicon nitride, and silicon oxynitride are preferred examples.

[0056] There are no limitations on the means for irradiating the sealing resin 26a with atmospheric pressure plasma P and the means for forming an inorganic film during irradiation with atmospheric pressure plasma P, and any known atmospheric pressure plasma irradiation method and method for forming an inorganic film using atmospheric pressure plasma can be used. One example is a method using an irradiation-type atmospheric pressure plasma source, which discharges plasma and a film-forming material from a nozzle to form a film using atmospheric pressure plasma.

[0057] An example of such a plasma source is conceptually shown in Figure 6. The irradiation-type atmospheric pressure plasma source 50 shown in Figure 6 has a double-tube structure, and includes an inner tube 52, an outer tube 54, a ground electrode 56, a high-voltage electrode 58, and a power supply 60.

[0058] The inner tube 52 and the outer tube 54 are nozzles in the irradiation-type atmospheric pressure plasma source. The inner tube 52 and the outer tube 54 are made of a high-melting-point insulating material (dielectric material), such as a glass material such as quartz or a ceramic material such as alumina. The inner tube 52 and the outer tube 54 are both circular tubes, and the inner tube 52 is inserted into the outer tube 54 with their centerlines aligned. In the irradiation-type atmospheric pressure plasma source 50, the gap 62 between the inner tube 52 and the outer tube 54 serves as a supply path for plasma gas (plasma generating gas) PG and a flow path for the generated atmospheric pressure plasma P.

[0059] The ground electrode 56 and the high-voltage electrode 58 are both cylindrical electrodes with an inner diameter substantially equal to the outer diameter of the outer tube 54, and are disposed so as to pass through the outer tube 54. The ground electrode 56 and the high-voltage electrode 58 are disposed spaced apart in the direction of the center line of the outer tube 54, with the high-voltage electrode 58 on the plasma irradiation side. The ground electrode 56 is also grounded (earthed). The high-voltage electrode 58 is connected to a power source 60. The power source 60 is, for example, a high-frequency pulse power source, and applies a pulsed voltage of a predetermined frequency to the high-voltage electrode 58.

[0060] In the projection-type atmospheric pressure plasma source 50, plasma gas PG is supplied from a supply source (not shown) into the gap 62 between the inner tube 52 and the outer tube 54. At this time, when a pulsed voltage is applied from the power supply 60 to the high-voltage electrode 58, a discharge region DA is formed between the ground electrode 56 and the high-voltage electrode 58, and this discharge acts on the plasma gas PG flowing in the discharge region DA, generating atmospheric pressure plasma P. The generated atmospheric pressure plasma P flows further through the gap 62 due to the flow of the plasma gas PG, and is irradiated onto the uncured sealing resin 26a from the end of the double tube consisting of the inner tube 52 and the outer tube 54, i.e., the end of the nozzle.

[0061] Here, the irradiating type atmospheric pressure plasma source 50 has a double-tube structure consisting of an inner tube 52 and an outer tube 54, and a source gas MG, which is a film-forming material, can be flowed inside the inner tube 52. That is, with the irradiating type atmospheric pressure plasma source 50, when irradiating the sealing resin 26a with atmospheric pressure plasma, the source gas MG can be supplied inside the inner tube 52, and the source gas MG can be irradiated onto the surface of the sealing resin 26a together with the atmospheric pressure plasma P. Therefore, with the irradiating type atmospheric pressure plasma source 50, when irradiating the sealing resin 26a with atmospheric pressure plasma P, the source gas MG is excited and decomposed by the atmospheric pressure plasma P, and an inorganic film can be formed on the uncured sealing resin 26a by the source gas MG.

[0062] In the present invention, the irradiation-type atmospheric pressure plasma source is not limited to the example shown in FIG. 6 , and various known irradiation-type atmospheric pressure plasma sources that discharge plasma and film-forming materials from a nozzle to form a film using atmospheric pressure plasma can be used.

[0063] Furthermore, in the manufacturing method of the present invention, the method of irradiating the uncured sealing resin 26a with atmospheric pressure plasma P and forming the inorganic film are not limited to the method using an irradiation-type atmospheric pressure plasma source, and various known methods can be used.

[0064] As an example, a parallel plate atmospheric pressure plasma source can be used, as conceptually shown in Fig. 7. In Fig. 7, the upper part is a cross-sectional view, and the lower part is a plan view of the cross-sectional view of the upper part as viewed from above (or below) in the figure.

[0065] The parallel-plate atmospheric pressure plasma source 70 shown in Figure 7 has two rectangular insulating plates 72 arranged parallel to and spaced apart from each other. The insulating plates 72 are formed, for example, from the same material as the inner tube 52 and outer tube 54 of the above-mentioned irradiation-type atmospheric pressure plasma source 50. A high-voltage electrode 74 is provided on the outer surface of one of the insulating plates 72, i.e., the side opposite to the facing side, and a ground electrode 76 is provided on the outer surface of the other insulating plate 72.

[0066] In the parallel-plate atmospheric-pressure plasma source 70 shown in FIG. 7 , plasma gas PG flows between insulating plates 72 while a pulsed voltage is applied to a high-voltage electrode 74 from a power supply (not shown). Plasma can be generated and exhausted between the insulating plates 72. In the illustrated example, for example, plasma gas PG flows from the left side of the figure, and uncured sealing resin 26a is placed near the right-hand end of the insulating plate 72. This allows atmospheric-pressure plasma P to be irradiated onto the sealing resin 26a. It is preferable to block the end between the two insulating plates 72, perpendicular to the flow direction of the plasma gas PG, with an insulating member 78 made of alumina or the like to prevent leakage of the plasma gas PG. Furthermore, by supplying source gas MG near the right-hand end of the insulating plates 72 while irradiating the atmospheric-pressure plasma P, the source gas MG can be excited by the plasma exhausted from between the insulating plates 72. Therefore, this supply of source gas MG allows an inorganic film to be formed on the surface of the sealing resin 26a.

[0067] As described above, when the sealing resin 26 a is irradiated with the atmospheric pressure plasma P, the irradiating type atmospheric pressure plasma source 50 and the atmospheric pressure plasma source 70 are moved (scanned) as necessary, so that the atmospheric pressure plasma P is irradiated onto the entire required area of ​​the surface of the sealing resin 26 a.

[0068] When irradiating the uncured sealing resin 26a with atmospheric pressure plasma P, there are no limitations on the plasma gas; various known substrates capable of generating atmospheric pressure plasma can be used. Examples include helium gas, argon gas, neon gas, nitrogen gas, and oxygen gas. Note that multiple plasma gases may be used in combination. When forming an inorganic film using atmospheric pressure plasma, there are no limitations on the plasma gas PG and source gas MG; known gases may be used depending on the inorganic film to be formed. For example, when forming a silicon oxide film as the inorganic film, helium gas is used as the plasma gas PG, and tetraethoxysilane (TEOS) and oxygen gas are used as the source gas MG. When forming a silicon nitride film as the inorganic film, helium gas is used as the plasma gas PG, and hexamethyldisilazane (HMDS) and nitrogen gas are used as the source gas MG.

[0069] After irradiating the sealing resin 26a with atmospheric pressure plasma or forming an inorganic film on it in this manner, an upper support 28 is laminated and bonded to the uncured sealing resin 26a at the position on the upper surface of the uncured sealing resin 26a in the drawing where the atmospheric pressure plasma P is irradiated. After laminating and bonding the upper support 28 to the uncured sealing resin 26a, the uncured sealing resin 26a is cured to form the sealing resin 26, thereby producing the solar cell 10. The manufacturing method and solar cell of the present invention, having such a configuration, enable bonding the sealing resin 26 having gas barrier properties to the upper support 28 with high adhesive strength (adhesion).

[0070] As described above, the sealing resin is required to have gas barrier properties in order to protect the perovskite-type photoelectric conversion layer, which is vulnerable to moisture, from moisture and the like. However, sealing resins with gas barrier properties have low reactivity due to their gas barrier properties. Therefore, even if the surface of this sealing resin is covered with an upper support such as a resin film, it is difficult to bond the resin sealing layer and the upper support with a high adhesive strength.

[0071] In contrast, as described above, in the manufacturing method of the present invention, the upper support 28 is laminated onto the uncured sealing resin 26a and then bonded. That is, in the manufacturing method of the present invention, the upper support 28 is laminated onto the soft uncured sealing resin 26a and then bonded. Therefore, in the present invention, the contact area between the sealing resin 26a and the upper support 28 can be significantly increased. Moreover, before laminating and bonding the upper support 28, the uncured sealing resin 26a is irradiated with atmospheric pressure plasma to introduce functional groups such as "-OH" groups into the surface, thereby improving adhesion (adhesion). Preferably, the uncured sealing resin 26a has multiple inorganic films formed on its surface by atmospheric pressure plasma, which are spaced apart from each other. Therefore, in the present invention, the upper support 28 can be bonded to the sealing resin 26a with improved adhesion over a large contact area. As a result, according to the present invention, a solar cell can be obtained in which the adhesive strength between the upper support 28 and the sealing resin 26 having gas barrier properties is high, due to the synergistic effect of the sealing resin 26a with improved adhesiveness and the large contact area, without using an adhesive such as an adhesive.

[0072] In the manufacturing method of the present invention, the uncured sealing resin 26a may be cured by a known method appropriate for the type of sealing resin. For example, if the sealing resin 26 is an ultraviolet-curable resin, the uncured sealing resin 26a may be cured by irradiating it with ultraviolet light. If the sealing resin 26 is a thermosetting resin, the uncured sealing resin 26a may be cured by heating it. If the sealing resin 26 is an electron-beam-curable resin, the uncured sealing resin 26a may be cured by irradiating it with electron beams. There are no limitations on the irradiation conditions for ultraviolet light and electron beams, as well as the heating conditions, for curing the uncured sealing resin 26a. Conditions that produce an appropriate effect may be set appropriately depending on the type of sealing resin 26.

[0073] The solar cell manufacturing method and the solar cell of the present invention have been described in detail above, but the present invention is not limited to the above examples, and various improvements and modifications may be made within the scope of the present invention.

[0074] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0075] Example 1 Preparation of Lower Support and Formation of Lower Electrode A lower support was prepared by forming, in this order, a 1 μm thick underlayer organic layer formed by polymerizing trimethylolpropane triacrylate (TMPTA) on the surface of a 100 μm thick polyethylene terephthalate film, a 50 nm thick silicon nitride layer formed by plasma CVD, and a 10 μm thick protective organic layer formed by polymerizing TMPTA. A 300 nm thick fluorine-doped tin oxide (SnO) layer was formed by a sol-gel method on the surface of the protective organic layer of this support to serve as the lower electrode.

[0076] <Preparation of Undercoat Layer Paint> Titanium (IV) isopropoxide (manufactured by Aldrich) was diluted with a mixed solvent of isopropanol and α-terpineol (99:1 (mass ratio)) to prepare a 0.02M undercoat layer paint.

[0077] <Formation of Underlayer> A coating material for the underlayer containing titanium (IV) isopropoxide at a concentration of 0.02 M was applied onto the lower electrode by spin coating. The coating was then heated in air from room temperature at a rate of 10°C / min until it reached 500°C, after which it was baked for 1 hour to form an underlayer (50 nm thick) made of titanium oxide on the lower electrode.

[0078] <Preparation of Titanium Oxide Paste> Ethyl cellulose, lauric acid, and terpineol were added to an ethanol dispersion of titanium oxide (anatase, average particle size 20 nm) to prepare a titanium oxide paste.

[0079] <Formation of Porous Layer> The prepared titanium oxide paste was applied to the underlayer by screen printing and then fired. This titanium oxide paste application and firing process was repeated twice. The first firing was performed at 130°C, and the second firing was performed at 500°C for 1 hour. The resulting fired titanium oxide body was immersed in a 40 mM TiCl4 aqueous solution, heated at 60°C for 1 hour, and then heated at 500°C for 30 minutes to form a porous layer made of TiO2 with a thickness of 300 nm.

[0080] <Formation of Photoelectric Conversion Layer> A 40% by mass methanol solution of methylamine (27.86 mL (liters)) and a 57% by mass aqueous solution of hydrogen iodide (hydroiodic acid, 30 mL) were stirred in a flask at 0°C for 2 hours and then concentrated to obtain crude CHNHI. The obtained crude CHNHI was dissolved in ethanol and recrystallized with diethyl ether. The precipitated crystals were collected by filtration and dried under reduced pressure at 60°C for 24 hours to obtain purified CHNHI. Next, purified CHNHI and PbI were mixed in a molar ratio of 2:1 in γ-butyrolactone at 60°C for 12 hours with stirring, and then filtered with a polytetrafluoroethylene (PTFE) syringe filter to prepare a 40% by mass light absorber coating material.

[0081] The prepared light-absorbing agent coating was applied onto the porous layer by spin coating (2000 rpm for 60 seconds, followed by 3000 rpm for 60 seconds), and the applied light-absorbing agent coating was dried on a hot plate at 100°C for 40 minutes to form a photoelectric conversion layer (thickness 350 nm (including the 300 nm porous layer thickness)) containing a perovskite compound. The obtained perovskite compound was CHNHPbI.

[0082] <Preparation of Hole Transport Material Coating> Spiro-OMeTAD (180 mg) as a hole transport material was dissolved in chlorobenzene (1 mL). To this chlorobenzene solution, an acetonitrile solution (37.5 μL) prepared by dissolving lithium-bis(trifluoromethanesulfonyl)imide (170 mg) in acetonitrile (1 mL) and t-butylpyridine (TBP, 17.5 μL) were added and mixed to prepare a hole transport material coating.

[0083] <Formation of Hole Transport Layer> The prepared hole transport material coating material was applied onto the photoelectric conversion layer by spin coating, and the applied hole transport material coating material was dried to form a hole transport layer with a thickness of 0.5 μm.

[0084] <Preparation of Upper Electrode> Carbon was dissolved in a solvent to prepare a coating material for the upper electrode. The prepared coating material for the upper electrode was applied to the hole transport layer by spin coating, and the applied coating material for the upper electrode was dried to prepare an upper electrode with a film thickness of 0.3 μm. A solar cell body was then prepared by forming a laminate on a lower support.

[0085] <Sealing with sealing resin> The produced laminate was sealed with a sealing resin having a thickness of 10 μm. The sealing resin used was an ultraviolet-curable olefin resin (3178, manufactured by ThreeBond Co., Ltd.). This sealing resin had a water vapor transmission rate of 15 g / (m) at a temperature of 25° C. and a relative humidity of 50% in a cured resin having a thickness of 1 mm. 2 ・day).

[0086] <Irradiation of atmospheric pressure plasma> Atmospheric pressure plasma was irradiated onto the surface of the uncured sealing resin using an irradiation-type atmospheric pressure plasma source 50 shown in Figure 6. Both the inner tube 52 and the outer tube 54 were made of quartz with a thickness of 1 mm, with the inner tube 52 having an outer diameter of 4 mm and the outer tube 54 having an outer diameter of 8 mm. The high-voltage electrode 58 was 30 mm long, the ground electrode 56 was 10 mm long, and the length of the discharge area DA between the two electrodes was 10 mm. Both electrodes were made of copper. The distance between the end of the high-voltage electrode 58 and the end of the outer tube 54 was 5 mm. The distance between the ends of the inner tube 52 and the outer tube 54 and the uncured sealing resin was 10 mm.

[0087] The plasma gas PG was a mixture of helium gas and oxygen gas, and "-OH" groups were introduced into the surface of the uncured sealing resin. The supply rate of helium gas was 10 L / min, and the supply rate of oxygen gas was 0.1 L / min. The atmospheric pressure plasma was irradiated at a depth of 1 cm. 2 The entire surface of the sealing resin was irradiated with atmospheric pressure plasma for 1 second per 1000 μm.

[0088] <Laminating the Upper Support and Curing the Sealing Resin> A polyethylene terephthalate film having a thickness of 100 μm was laminated as an upper support onto the uncured sealing resin that had been irradiated with atmospheric pressure plasma. Thereafter, the uncured sealing resin was irradiated with atmospheric pressure plasma at 30° C. and 100 mW / cm 2 The sealing resin was cured by irradiation with ultraviolet light of 1000 kJ for 10 seconds, thereby completing the production of a solar cell.

[0089] <Measurement of Adhesion Strength> For the fabricated solar cells, the peel strength (N / 25 mm) between the upper support and the sealing resin was measured in accordance with the 180° peel test of JIS Z 0237: 2009. As a result, the peel strength between the upper support and the sealing resin was 12 N / 25 mm.

[0090] Example 2 A solar cell was fabricated in the same manner as in Example 1, except that TEOS was further supplied as the source gas MG to the irradiating atmospheric pressure plasma source 50 to form an inorganic film during the irradiation of the uncured encapsulating resin with atmospheric pressure plasma. The amount of TEOS supplied was adjusted so that the thickness of the inorganic film formed was 5 nm. After the atmospheric pressure plasma irradiation, time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to confirm that multiple inorganic layers were formed, spaced apart from one another, on the surface of the uncured encapsulating resin. The peel strength between the upper support and the encapsulating resin was measured in the same manner as in Example 1, and was found to be 18 N / 25 mm, indicating a stronger adhesive strength between the upper support and the encapsulating resin than in Example 1.

[0091] [Comparative Example 1] A solar cell was produced in the same manner as in Example 1, except that the laminate was sealed with a sealing resin, the sealing resin was cured, and the cured sealing resin was irradiated with atmospheric pressure plasma. When the peel strength between the upper support and the sealing resin was measured in the same manner as in Example 1, it was 0.8 N / 25 mm, which was far weaker than in Example 1.

[0092] Comparative Example 2 A solar cell was manufactured in the same manner as in Example 1, except that uncured encapsulating resin was irradiated with atmospheric pressure plasma, the encapsulating resin was cured, and an upper support was laminated and attached to the cured encapsulating resin. When the peel strength between the upper support and the encapsulating resin was measured in the same manner as in Example 1, it was 0.7 N / 25 mm, which was a much weaker adhesive strength between the upper support and the encapsulating resin than in Example 1. From these results, the effects of the present invention are clear.

[0093] The present invention can be suitably used in the manufacture of solar cells.

[0094] REFERENCE SIGNS LIST 10 Solar cell 12 Lower support 14 Lower electrode 18 Photoelectric conversion layer 24 Upper electrode 26 Sealing resin 26a Sealing resin (uncured) 28 Upper support 32 Atmospheric pressure plasma source 50 Radiation type atmospheric pressure plasma source 52 Inner tube 54 Outer tube 56 Ground electrode 58 High voltage electrode 60 Power supply 70 Atmospheric pressure plasma source 72 Insulating plate 74 High voltage electrode 76 Ground electrode P Atmospheric pressure plasma PG Plasma gas MG Raw material gas DA Discharge region

Claims

1. A method for manufacturing a solar cell, comprising the steps of: sealing a solar cell body having a lower support and a laminate including a lower electrode, a perovskite-type photoelectric conversion layer, and an upper electrode formed on a surface of the lower support, with a sealing resin; irradiating the sealing resin with atmospheric pressure plasma while the sealing resin is in an uncured state; irradiating the sealing resin with atmospheric pressure plasma, and then laminating an upper support to the part irradiated with the atmospheric pressure plasma while the sealing resin is in an uncured state; and then curing the sealing resin.

2. The method for manufacturing a solar cell according to claim 1, wherein an inorganic film is formed on the surface of the sealing resin by irradiating the atmospheric pressure plasma.

3. The method for manufacturing a solar cell according to claim 2, wherein the inorganic film is formed by irradiating the atmospheric pressure plasma so that the maximum thickness of the inorganic film is 10 nm or less.

4. The method for manufacturing a solar cell according to claim 1 or 2, wherein at least one of the lower support and the upper support is flexible.

5. A solar cell comprising: a lower support; a laminate having a lower electrode formed on the surface of the lower support, a perovskite-type photoelectric conversion layer and an upper electrode; a sealing resin for sealing the laminate; and an upper support laminated on the surface of the sealing resin opposite the lower support, and further comprising a plurality of inorganic films spaced apart from each other between the sealing resin and the upper support.

6. The solar cell according to claim 5, wherein at least one of said lower support and said upper support is flexible.

Images