solar cells

Abstract

To improve the conversion efficiency of solar cell modules. [Solution] The solar cell module 11 is a film-like structure in which a substrate portion 20 and a sealing sheet portion 24 are superimposed in such a manner that a photoelectric conversion unit 22 is placed between them. The base sheet portion 30, which is the superimposed portion of the substrate portion 20 and the sealing sheet portion 24, is the portion in which the photoelectric conversion unit 22 is not placed between them and includes a peripheral portion 32, which is the outer edge of the solar cell module 11 when viewed from the light-receiving surface 11A side. The solar cell module 11 has a bent portion 32A in which the outer edge portion of the peripheral portion 32 is curved toward the back surface 11B, which is located opposite the light-receiving surface 11A.

Description

Technical Field

[0001] The present invention relates to a solar cell.

Background Art

[0002] In recent years, film-shaped solar cells have been proposed (for example, Patent Document 1). The solar cell described in Patent Document 1 is a perovskite solar cell. This solar cell includes a photoelectric conversion unit that converts light into electricity and contains a perovskite layer. In order to improve durability and weather resistance, the above solar cell has a structure in which the photoelectric conversion unit is sealed between a pair of sheet members (for example, a flexible substrate and a sealing agent layer) having flexibility and forming a sheet shape.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a film-shaped solar cell, in order to seal or wire the photoelectric conversion unit, a portion where a pair of sheet members are bonded to each other (hereinafter, the peripheral portion) is formed around the photoelectric conversion unit. Although this peripheral portion constitutes a part of the light-receiving portion of the solar cell, it does not contribute to the power generation by the solar cell. In the above solar cell, the formation of such a peripheral portion causes a decrease in the module conversion efficiency.

Means for Solving the Problems

[0005] Each aspect of the device for solving the above problems will be described. [Aspect 1] A film-shaped solar cell comprising a photoelectric conversion unit that converts light into electricity, and a pair of flexible sheet members, wherein the pair of sheet members are superimposed in such a manner that the photoelectric conversion unit is positioned between them, and the pair of sheet members include a peripheral portion which is the portion in which the photoelectric conversion unit is not positioned between them and which is the outer edge of the solar cell when viewed from the light-receiving surface, and the solar cell has a bent portion in which the outer edge portion of the peripheral portion is curved toward the back side which is located opposite the light-receiving surface.

[0006] According to the above configuration, at least a portion of the peripheral parts of the pair of sheet members, i.e., the parts that do not contribute to power generation, can be bent towards the back side of the solar cell so that they are difficult to see from the light-receiving surface side of the solar cell. This makes it possible to increase the proportion of the area occupied by the central part of the solar cell, more specifically the part sandwiching the photoelectric conversion section, when viewed from the light-receiving surface side, relative to the total area of ​​the light-receiving portion when viewed from the light-receiving surface side. Therefore, the module conversion efficiency of the solar cell can be improved compared to a solar cell without the above-mentioned bent portion.

[0007] [Aspect 2] The solar cell according to [Aspect 1], wherein the pair of sheet members include a central portion which is the portion in which the photoelectric conversion unit is positioned and which is the central portion of the solar cell when viewed from the light-receiving surface, and the bent portion has a bending angle of 90 degrees or more with respect to the central portion.

[0008] According to the above configuration, at least a portion of the peripheral part of the pair of sheet members can be bent towards the back side so that it is not visible from the light-receiving surface side. This makes it possible to suitably increase the ratio of the area of ​​the central part, which sandwiches the photoelectric conversion part, to the total area of ​​the light-receiving part when viewed from the light-receiving surface side.

[0009] [Aspect 3] The solar cell according to [Aspect 1], wherein the bent portion is folded back toward the central part of the solar cell when viewed from the light-receiving surface.

[0010] According to the above configuration, in order to realize a structure in which the peripheral portions of the pair of sheet members bend toward the back side, the increase in the thickness dimension of the solar cell can be suppressed, and thus the size of the solar cell can be kept down.

[0011] [Aspect 4] The solar cell according to [Aspect 3], wherein the pair of sheet members include a central portion which is the portion in which the photoelectric conversion unit is positioned and which is the central portion of the solar cell when viewed from the light-receiving surface, and the bent portion and the central portion overlap in the thickness direction of the solar cell.

[0012] With the above configuration, compared to a case where the bent portion and the central portion do not overlap, the peripheral portions of the pair of sheet members can be bent towards the back side over a wider area. Therefore, when viewed from the light-receiving surface, the proportion of the area occupied by the central portion, in which the photoelectric conversion portion is positioned, relative to the total area of ​​the light-receiving portion can be increased.

[0013] [Aspect 5] The peripheral portion has an adhesive portion where the pair of sheet members are bonded to each other, and a non-adhesive portion which constitutes a portion where the pair of sheet members are not bonded to each other at a position further away from the edges of the pair of sheet members than the adhesive portion, and the bent portion is bent with the non-adhesive portion as the starting point, the solar cell according to any one of [Aspect 1] to [Aspect 4].

[0014] When creating a bent section, if a pair of sheet members are bent using the bonded portion as a starting point, the other sheet member will deform in accordance with the deformation of the other, which may result in the deformation of one being restricted by the other.

[0015] According to the above configuration, since the pair of sheet members are bent with the non-adhesive portion as the starting point, it becomes possible to deform the pair of sheet members individually in a way that does not restrict their deformation from one another. Therefore, since the pair of sheet members can be deformed with a high degree of freedom, a bent portion can be easily created.

[0016] [Aspect 6] The photoelectric conversion unit and the pair of sheet members have a rectangular shape when viewed from the light-receiving surface, and the bent portions are provided corresponding to each of the four sides of the rectangular shape, as described in any one of [Aspect 1] to [Aspect 4].

[0017] According to the above configuration, in a solar cell with a rectangular shape when viewed from the light-receiving surface, the parts corresponding to each of the four sides of the rectangular shape can be made into a shape where a part of the peripheral portion of the pair of sheet members is bent towards the back side. Therefore, compared to the case where the bent portion is provided corresponding to only a part of the four sides, the proportion of the area of ​​the central part of the solar cell when viewed from the light-receiving surface, more specifically the area of ​​the part sandwiching the photoelectric conversion section, can be increased relative to the total area of ​​the light-receiving portion when viewed from the light-receiving surface.

[0018] [Aspect 7] The solar cell according to [Aspect 6], wherein the peripheral portion has notches in which parts corresponding to the four corners of the rectangular shape are cut out, and the bent portion has a shape in which the part sandwiched between two adjacent notches in the peripheral portion is bent toward the back side.

[0019] If a pair of rectangular sheet members are used in their unfolded state, and a bent section is adopted in which each of the four sides of the rectangular shape is folded back, the structure of the four corners of the rectangular shape becomes complex.

[0020] According to the above configuration, since the cutouts are provided in the portions corresponding to such four corners, the shape of each of the four bending portions can be made to bend in one direction on the back side of the solar cell. As a result, compared with those without cutouts, the structure of the portions corresponding to the four corners of the square shape can be simplified. Therefore, the solar cell can be formed relatively easily.

Effects of the Invention

[0021] According to the present invention, the module conversion efficiency of the solar cell can be improved.

Brief Description of the Drawings

[0022] [Figure 1] FIG. 1 is a plan view showing a solar cell panel including a solar cell according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of a solar cell unit constituting the solar cell panel. [Figure 3] FIG. 3 is an enlarged cross-sectional view of a bending portion of the solar cell unit and its periphery. [Figure 4] FIG. 4 is a plan view of a base sheet portion when the peripheral portion including the bending portion is developed in the extending direction of the photoelectric conversion portion. [Figure 5] FIG. 5 is a plan view of a base sheet portion having a shape in which the peripheral portion is folded back as viewed from the back side. [Figure 6] FIG. 6 is an explanatory view for explaining the first step and the second step. [Figure 7] FIG. 7 is an explanatory view for explaining the third step. [Figure 8] FIG. 8 is an explanatory view for explaining the fourth step and the fifth step.

Embodiments for Carrying Out the Invention

[0023] Hereinafter, an embodiment of the solar cell will be described with reference to FIGS. 1 to 8. As shown in Figure 1, the solar panel 10 is composed of 12 solar cell modules 11. In the solar panel 10, the solar cell modules 11 are arranged in a row of three vertically in Figure 1 and in a row of four horizontally in Figure 1. Each solar cell module 11 is a perovskite solar cell and has 10 solar cells.

[0024] As shown in Figure 2, the solar cell constituting the solar cell module 11 comprises a substrate portion 20, a first electrode 21, a photoelectric conversion portion 22, and a second electrode 23. The solar cell has a basic structure in which the substrate portion 20, the first electrode 21, the photoelectric conversion portion 22, and the second electrode 23 are stacked in that order from the light-receiving surface 11A side of the solar cell module 11 (upper side in Figure 2).

[0025] The substrate portion 20 is formed from a transparent synthetic resin material. Examples of synthetic resin materials include polyimide (PI) and polyethylene terephthalate (PET). The substrate portion 20 is flexible and forms a sheet. The substrate portion 20 is composed of, for example, a flexible substrate.

[0026] The first electrode 21 is made of a transparent material that has conductivity. For example, the first electrode 21 is made of a film of indium tin oxide (ITO). The photoelectric conversion unit 22 constitutes the part of the solar cell that converts light into electricity. The photoelectric conversion unit 22 has an electron transport layer made of zinc oxide, tin oxide, etc., a perovskite layer made of a perovskite compound, and a hole transport layer made of a semiconductor, hole transport material, etc. The photoelectric conversion unit 22 has a structure in which the electron transport layer, the perovskite layer, and the hole transport layer are stacked in that order from the light-receiving surface 11A side.

[0027] The second electrode 23 is made of a conductive material. For example, the second electrode 23 is made of a gold (Au) film. <Sealing sheet section 24> The solar cell module 11 includes a sealing sheet portion 24. The sealing sheet portion 24 is formed from a synthetic resin material and is flexible, forming a sheet. The sealing sheet portion 24 is formed from, for example, polyester-based resin materials such as polyimide (PI), polyethylene terephthalate (PET), polycarbonate, and polyethersulfone, or from a fluorine film or triacetate.

[0028] In this embodiment, the photoelectric conversion unit 22 of each solar cell is arranged between the sealing sheet portion 24 and the substrate portion 20, and the sealing sheet portion 24 and the substrate portion 20 are superimposed as a single unit. In the solar cell module 11, an adhesive layer (not shown) is provided to cover the entire surface on the back surface 11B, which is located opposite to the light-receiving surface 11A of the photoelectric conversion unit 22 and its surrounding area. This adhesive layer is made of, for example, epoxy resin or acrylic resin. The sealing sheet portion 24 is superimposed on and bonded to the substrate portion 20 via the adhesive layer. The solar cell module 11 is in the form of a film, and has a structure in which the photoelectric conversion unit 22 of each solar cell is sealed between the substrate portion 20 and the sealing sheet portion 24. In this embodiment, the substrate portion 20 and the sealing sheet portion 24 correspond to a pair of sheet members.

[0029] As shown in Figure 1, in the solar cell module 11, the portion where a pair of sheet members, namely the substrate portion 20 and the sealing sheet portion 24, are superimposed (hereinafter referred to as the base sheet portion 30), has a roughly rectangular shape when viewed from the light-receiving surface 11A side. In addition, in the solar cell module 11, the photoelectric conversion portion 22 of each solar cell has a roughly rectangular shape when viewed from the light-receiving surface 11A side.

[0030] <Central part 31, peripheral part 32> As shown in Figures 1 and 2, the base sheet portion 30 includes a central portion 31, which is the part in which the photoelectric conversion unit 22 is positioned and is the center of the solar cell module 11 when viewed from the light-receiving surface 11A side. The base sheet portion 30 also includes a peripheral portion 32, which is the part in which the photoelectric conversion unit 22 is not positioned and is the outer edge of the solar cell module 11 when viewed from the light-receiving surface 11A side. In this embodiment, both the outer shape of the central portion 31 when viewed from the light-receiving surface 11A side and the outer shape of the peripheral portion 32 when viewed from the light-receiving surface 11A side are substantially rectangular.

[0031] <Adhesive part P1, non-adhesive part P2> As shown in Figure 3, the base sheet portion 30 has an adhesive portion P1 in which the substrate portion 20 and the sealing sheet portion 24 are bonded to each other, and a non-adhesive portion P2 in which the substrate portion 20 and the sealing sheet portion 24 are not bonded to each other. The adhesive portion P1 extends in an annular shape along the edge of the base sheet portion 30 to seal the gap between the substrate portion 20 and the sealing sheet portion 24 at the edge of the base sheet portion 30. In the adhesive portion P1, the substrate portion 20 and the sealing sheet portion 24 are bonded using an adhesive made of epoxy resin or acrylic resin. In the solar cell module 11, the intrusion of moisture and air between the substrate portion 20 and the sealing sheet portion 24 is suppressed in the adhesive portion P1. The non-adhesive portion P2 is the portion in which the adhesive is not provided. The non-adhesive portion P2 is located further away from the edge of the base sheet portion 30 than the adhesive portion P1, specifically between the adhesive portion P1 and the adhesive layer, and extends along the adhesive portion P1.

[0032] <Bent section 32A> As shown in Figures 2 to 5, the peripheral portion 32 of the base sheet portion 30 has a bent portion 32A which is a curved shape toward the back surface 11B. The bent portion 32A is the outer edge portion of the peripheral portion 32 and is a curved shape toward the back surface 11B (lower side in Figure 2). The bent portion 32A is folded back toward the central part of the solar cell module 11 when viewed from the light-receiving surface 11A side. The bending angle of the bent portion 32A with respect to the central portion 31 is 180 degrees. More specifically, the bent portion 32A is curved so that the first surface of the bent portion 32A toward the light-receiving surface 11A and the second surface of the base sheet portion 30 adjacent to the bent portion 32A toward the back surface 11B are facing each other.

[0033] In this embodiment, since a bent portion 32A is provided, the gap between the substrate portion 20 and the sealing sheet portion 24, that is, the path that could allow moisture and air to enter, becomes a folded passage shape. As a result, compared to the case where the bent portion 32A is not provided and the path extends in a straight line, it is possible to make it more difficult for moisture and air to pass through the path, thereby suppressing the intrusion of moisture and air into the interior of the solar cell module 11.

[0034] The bent portion 32A (more specifically, the majority of the base sheet portion 30 excluding both ends in the direction along the edge) is bent with the non-adhesive portion P2 in the peripheral portion 32 as the starting point. In the base sheet portion 30, the edge portion of the bent portion 32A and the outer edge portion of the central portion 31, where the photoelectric conversion portion 22 is positioned between them, overlap in the thickness direction of the solar cell module 11.

[0035] <Notch 33> As shown in Figure 1, in the solar cell module 11, the photoelectric conversion unit 22 and the base sheet unit 30 have a roughly rectangular shape when viewed from the light-receiving surface 11A side.

[0036] As shown in Figure 4, the base sheet portion 30 has notches 33 at positions corresponding to the four corners of the rectangular shape. Figure 4 shows the planar structure of the base sheet portion 30 when the peripheral portion 32, including the bent portion 32A, is unfolded in the extending direction of the photoelectric conversion portion 22. As shown by the dashed lines in Figure 4, the basic shape of the base sheet portion 30 is approximately rectangular. The notches 33 are formed by cutting out the parts corresponding to the four corners of this approximately rectangular shape. Each notch 33 is a part that corresponds to a corner of the base sheet portion 30, which has a basic shape of approximately rectangular, and is composed of a part that is cut out in the shape of an equilateral triangle.

[0037] As shown in Figure 5, the bent portion 32A has a shape in which the portion sandwiched between two adjacent notches 33 in the peripheral portion 32 is bent toward the back surface 11B. More specifically, the portion sandwiched between two adjacent notches 33 in the peripheral portion 32 has a shape in which it is folded back toward the back surface 11B. In this embodiment, this folded portion constitutes the bent portion 32A. The bent portions 32A are provided corresponding to each of the four sides of the roughly rectangular basic shape described above. The four bent portions 32A are provided so as not to overlap each other in the thickness direction of the solar cell module 11 and so as to be arranged in a rectangular ring shape along the edge of the base sheet portion 30.

[0038] As shown in Figures 1 and 2, the solar cell module 11 has a frame 40. The frame 40 is for supporting the base sheet portion 30. The frame 40 is rectangular in shape and is attached to the base sheet portion 30 so as to cover the entire outer surface of the base sheet portion 30. As shown in Figure 1, by integrally connecting the frames 40 of adjacent solar cell modules 11, 12 solar cell modules 11 are formed into a single panel. As shown in Figure 2, the solar cell module 11 has wiring wires 41. The wires 41 are connected to the base sheet portion 30, specifically to the first electrode 21 and the second electrode 23.

[0039] The solar cell module 11 of this embodiment can be formed, for example, by the procedure described below. The process of forming the solar cell module 11 is carried out in the following order: first step, second step, third step, fourth step, and fifth step.

[0040] In the first step, a separately formed solar cell and a sealing sheet portion 24 are prepared. Then, as shown in Figure 6, the solar cell and the sealing sheet portion 24 are superimposed. At this time, the substrate portion 20 of the solar cell and the sealing sheet portion 24 are bonded together via an adhesive layer.

[0041] In the second step, the substrate portion 20 and the sealing sheet portion 24 are bonded together with adhesive at the edge of the base sheet portion 30, specifically at the adhesive portion P1. In the third step, as shown by the white arrow in Figure 7, the outer edge portion of the peripheral portion 32 of the base sheet portion 30 is folded back towards the back surface 11B. This forms the bent portion 32A.

[0042] In the fourth step, as shown in Figure 8, wiring wires 41 are attached to the base sheet portion 30, specifically to the first electrode 21 and the second electrode 23. In the fifth step, the frame 40 is attached to the base seat section 30.

[0043] <Operation and Effects of This Embodiment> The operation and effects of this embodiment will now be described. (1) The solar cell module 11 is a film-like structure in which a substrate portion 20 and a sealing sheet portion 24 are superimposed in such a manner that a photoelectric conversion unit 22 is placed between them. The base sheet portion 30, which is the superimposed portion of the substrate portion 20 and the sealing sheet portion 24, is the portion in which the photoelectric conversion unit 22 is not placed between them and includes a peripheral portion 32, which is the outer edge of the solar cell module 11 when viewed from the light-receiving surface 11A side. The solar cell module 11 has a bent portion 32A in which the outer edge portion of the peripheral portion 32 is curved toward the back surface 11B, which is located opposite the light-receiving surface 11A.

[0044] With the above configuration, as shown in Figures 4 and 5, at least a portion of the peripheral portion 32 of the base sheet portion 30, i.e., the portion that does not contribute to power generation, can be bent towards the back surface 11B so that it is difficult to see from the light-receiving surface 11A side. This makes it possible to increase the proportion of the area occupied by the central portion of the solar cell module 11 when viewed from the light-receiving surface 11A side, specifically the central portion 31 sandwiching the photoelectric conversion portion 22, relative to the total area of ​​the light-receiving portion when viewed from the light-receiving surface 11A side. Therefore, the module conversion efficiency of the solar cell module 11 can be improved compared to one that does not have the bent portion 32A.

[0045] (2) The bent portion 32A is folded back toward the center of the solar cell module 11 when viewed from the light-receiving surface 11A side. According to the above configuration, in order to realize a structure in which the peripheral portion 32 of the base sheet portion 30 bends toward the back surface 11B, it is possible to suppress an increase in the thickness dimension of the solar cell module 11. Therefore, it is possible to suppress an increase in the size of the solar cell module 11.

[0046] (3) The bent portion 32A and the central portion 31 of the base sheet portion 30 overlap in the thickness direction of the solar cell module 11. With the above configuration, compared to the case where the bent portion 32A and the central portion 31 do not overlap, the peripheral portion 32 of the base sheet portion 30 can be bent towards the back surface 11B over a wider area. Therefore, the proportion of the area of ​​the central portion 31, in which the photoelectric conversion portion 22 is positioned, to the total area of ​​the light-receiving portion when viewed from the light-receiving surface 11A can be increased. Consequently, the module conversion efficiency of the solar cell module 11 can be suitably improved.

[0047] (4) The peripheral portion 32 has an adhesive portion P1 in which the substrate portion 20 and the sealing sheet portion 24 are bonded to each other, and a non-adhesive portion P2 in which the substrate portion 20 and the sealing sheet portion 24 are not bonded to each other at a position further away from the edge of the base sheet portion 30 than the adhesive portion P1. The bent portion 32A is bent with the non-adhesive portion P2 in the peripheral portion 32 as the starting point.

[0048] When creating the bent portion 32A, if the base sheet portion 30 is bent using the portion where the substrate portion 20 and the sealing sheet portion 24 are bonded to each other as the starting point, the other portion will deform in accordance with the deformation of the other portion, which may restrict the deformation of one portion. In this embodiment, however, since the base sheet portion 30 is bent using the non-bonded portion P2 as the starting point, the substrate portion 20 and the sealing sheet portion 24 can be deformed separately in a manner that does not easily restrict the deformation of the other portion. Therefore, since the substrate portion 20 and the sealing sheet portion 24 can be deformed with a high degree of freedom, the bent portion 32A can be easily created.

[0049] (5) The photoelectric conversion unit 22 and the base sheet unit 30 have an outer shape that is approximately rectangular when viewed from the side of the light-receiving surface 11A. The bent portion 32A is provided corresponding to each of the four sides of this approximately rectangular shape.

[0050] According to the above configuration, in a solar cell module 11 whose outer shape is approximately rectangular when viewed from the light-receiving surface 11A side, the parts corresponding to each of the four sides of the rectangular shape can be made into a shape in which a part of the peripheral part 32 of the base sheet part 30 is bent toward the back surface 11B side. Therefore, compared to the case in which the bent part 32A is provided corresponding to only a part of the four sides, the proportion of the area of ​​the central part 31 when viewed from the light-receiving surface 11A side to the total area of ​​the light-receiving part when viewed from the light-receiving surface 11A side can be made larger.

[0051] (6) The peripheral portion 32 has notches 33 which are cut out in the way that the four corners of the roughly rectangular solar cell module 11 are cut out. The bent portion 32A has a shape in which the portion sandwiched between two adjacent notches 33 in the peripheral portion 32 is bent toward the back surface 11B.

[0052] If a pair of rectangular sheet members are used in their unfolded state, and a bent section 32A is adopted in which each of the four sides of the rectangular shape is folded back, the structure of the parts corresponding to the four corners of the rectangular shape becomes complex.

[0053] According to the above configuration, since notches 33 are provided in the parts corresponding to the four corners, the shape of each of the four bent parts 32A can be made to be bent in one direction toward the back surface 11B. As a result, the structure of the parts corresponding to the four corners of the square shape can be simplified compared to a design without notches 33. Therefore, the solar cell module 11 can be formed relatively easily.

[0054] Furthermore, the notch 33 is located at the corner of the base sheet portion 30, which has a roughly rectangular basic shape, and is composed of a portion cut out in the shape of an equilateral triangle. Therefore, as shown in Figure 5, a simple structure can be achieved in which two adjacent bent portions 32A do not overlap. Consequently, the thickness dimension of the solar cell module 11 can be reduced compared to a structure in which two adjacent bent portions 32A overlap.

[0055] <Variation> The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0056] The frame 40 and the wires 41 can be omitted. The notch 33 may be made up of a portion cut into any shape other than an equilateral triangle, such as a triangle or a square. With this configuration, although two adjacent bent portions 32A may overlap, it becomes possible to make the shape of each of the four bent portions 32A curved in one direction toward the back surface 11B. As a result, the structure of the four corners of the roughly square-shaped base sheet portion 30 can be simplified compared to a version without the notch 33.

[0057] The bent portion 32A may be provided only on two opposing sides of the base sheet portion 30, which has a roughly rectangular shape when viewed from the light-receiving surface 11A. Alternatively, the bent portion 32A may be provided only on three sides, two sides, or one side of the base sheet portion 30, which has a roughly rectangular shape when viewed from the light-receiving surface 11A.

[0058] The non-adhesive portion P2 in the base sheet portion 30 can be omitted. That is, the substrate portion 20 and the sealing sheet portion 24 may be bonded together over their entire surface in such a manner that the photoelectric conversion portion 22 is positioned between them. In this case as well, the base sheet portion 30 may be heated to soften it, and then the portion of the peripheral portion 32 of the base sheet portion 30 that constitutes the outer edge may be bent toward the back surface 11B to form the bent portion 32A.

[0059] The structure of the base sheet portion 30 can be such that the central portion 31, where the photoelectric conversion portion 22 is positioned, and the bent portion 32A do not overlap in the thickness direction. With this configuration, a portion of the peripheral portion 32 can be bent towards the back surface 11B, so that the proportion of the area of ​​the central portion 31 to the total area of ​​the light-receiving portion when viewed from the light-receiving surface 11A side can be increased.

[0060] - If the bent portion 32A is bent toward the back surface 11B, the bending angle of the bent portion 32A relative to the central portion 31 is not limited to 180 degrees and can be changed as desired. In order to improve the module conversion efficiency of the solar cell module 11, it is preferable that the bending angle be 90 degrees or more. By setting the bending angle to 90 degrees or more, at least a part of the peripheral portion 32 of the base sheet portion 30 is bent toward the back surface 11B so that it is not visible from the light-receiving surface 11A side. This makes it possible to suitably increase the proportion of the area of ​​the central portion 31, which is the part that sandwiches the photoelectric conversion portion 22, to the total area of ​​the light-receiving portion when viewed from the light-receiving surface 11A side. It is also possible to set the bending angle to less than 90 degrees.

[0061] The solar cell according to the above embodiment can also be applied to a solar cell module in which a pair of sheet members, separate from the solar cells, are superimposed in such a manner that one or more solar cells are sandwiched between them.

[0062] The number of solar cells included in one solar cell module 11 can be arbitrarily changed, such as setting it to 1 to 9 cells or 11 or more cells. The solar cell according to the above embodiment can be applied to solar cells other than perovskite solar cells, such as cadmium telluride solar cells and CIS solar cells, as long as it is a film-type solar cell in which a pair of sheet members are superimposed with a photoelectric conversion unit placed between them. [Explanation of Symbols]

[0063] 10…Solar panels 11… Solar cell modules 11A... Light receiving surface 11B…Back side 20... Circuit board section 21...1st electrode 22... Photoelectric conversion unit 23…Second electrode 24... Sealing sheet section 30...Base seat section 31...Central part 32… Peripheral area 32A...Bent section 33... Notch 40...frames 41...Electric wire

Claims

1. A film-shaped solar cell comprising a photoelectric conversion unit that converts light into electricity, and a pair of flexible sheet members that are in the shape of a sheet, wherein the pair of sheet members are superimposed in such a manner that the photoelectric conversion unit is positioned between them, The pair of sheet members includes a peripheral portion which is the portion in which the photoelectric conversion unit is not positioned between them and which corresponds to the outer edge of the solar cell when viewed from the light-receiving surface side. The solar cell has a curved portion in which the outer edge of the peripheral portion is bent toward the back side, which is located opposite to the light-receiving surface. Solar cell.

2. The pair of sheet members includes a central portion which is the portion in which the photoelectric conversion unit is positioned and which is the portion that corresponds to the center of the solar cell when viewed from the light-receiving surface side. The bent portion has a bending angle of 90 degrees or more relative to the central portion. The solar cell according to claim 1.

3. The bent portion has a shape that is folded back toward the center of the solar cell when viewed from the light-receiving surface. The solar cell according to claim 1.

4. The pair of sheet members includes a central portion which is the portion in which the photoelectric conversion unit is positioned and which is the portion that corresponds to the center of the solar cell when viewed from the light-receiving surface side. The bent portion and the central portion overlap in the thickness direction of the solar cell. The solar cell according to claim 3.

5. The peripheral portion has an adhesive portion where the pair of sheet members are bonded to each other, and a non-adhesive portion which constitutes a portion where the pair of sheet members are not bonded to each other at a position further away from the edges of the pair of sheet members than the adhesive portion. The bent portion is bent with the non-adhesive portion as the starting point. A solar cell according to any one of claims 1 to 4.

6. The photoelectric conversion unit and the pair of sheet members have a rectangular shape when viewed from the light-receiving surface side. The bent portion is provided corresponding to each of the four sides of the rectangular shape. A solar cell according to any one of claims 1 to 4.

7. The peripheral portion has notches in which parts corresponding to the four corners of the rectangular shape are cut out. The bent portion has a shape in which the portion sandwiched between two adjacent notches in the peripheral area is bent toward the back side. The solar cell according to claim 6.

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