Solar cell

Abstract

[PROBLEM] To reduce the radius of curvature of a bent portion of a film-like substrate which is used in a solar cell. [SOLUTION] A solar cell (100) comprises: a film-like substrate (10) that includes a main region (10A) and a terminal region (10B) and that has a surface (11) and a surface (12) located on the side opposite the surface (11); photoelectric conversion layers (21-24) that are provided on the surface (11) of the main region (10A) of the substrate (10); an electrode layer (31) that is provided on the surface (12) of the terminal region (10B) of the substrate (10); and a via conductor (51) that is provided so as to penetrate the substrate (10) and that connects the photoelectric conversion layer (21) and the electrode layer (31). The substrate (10) is provided, on the surface (11) thereof, with a half-cut groove (71) at a position which overlaps the electrode layer (31).

Description

solar cells

[0001] The present disclosure relates to a solar cell, and more particularly to a solar cell using a film-like substrate.

[0002] Patent Document 1 discloses a solar cell using a film-like substrate. In the solar cell described in Patent Document 1, the end of the substrate is bent 180 degrees so that the terminal electrodes face the back surface.

[0003] Japanese Unexamined Patent Publication No. 123073 / 1983

[0004] However, when a material that is difficult to deform elastically is used as the substrate material, there is a problem in that when the substrate is bent, the radius of curvature of the bent portion becomes large.

[0005] This disclosure describes a technique for reducing the radius of curvature of a folded portion of a substrate in a solar cell that uses a film-like substrate.

[0006] A solar cell according to one aspect of the present disclosure comprises a film-like substrate including a main region and a terminal region, and having a first surface and a second surface located opposite the first surface, a photoelectric conversion layer provided on the first surface of the main region of the substrate, a first electrode layer provided on the second surface of the terminal region of the substrate, and a first via conductor that penetrates the substrate and connects the photoelectric conversion layer and the first electrode layer, and a first half-cut groove is provided on the first surface of the substrate at a position that overlaps with the first electrode layer.

[0007] According to the present disclosure, a technique is provided for reducing the radius of curvature of the bent portion of a substrate in a solar cell using a film-like substrate.

[0008] FIG. 1( a) is a schematic plan view showing the appearance of a solar cell 100 according to an embodiment of the technology disclosed herein. FIG. 1( b) is a schematic cross-sectional view taken along line A-A in FIG. 1( a). FIG. 2 is a schematic cross-sectional view of the solar cell 100. FIG. 3 is a schematic cross-sectional view showing an example in which a laminate of a conductive adhesive 91 and a metal foil 92 is used as the material for the electrode layer. FIG. 4 is a schematic cross-sectional view showing the solar cell 100 in a folded state. FIG. 5( a) is a schematic plan view showing the appearance of a solar cell 101 according to a first modified example. FIG. 5( b) is a schematic cross-sectional view taken along line A-A in FIG. 5( a). FIG. 6 is a schematic plan view showing the appearance of a solar cell 102 according to a second modified example. FIG. 7 is a schematic plan view showing the appearance of a solar cell 103 according to a third modified example. FIG. 8 is a schematic plan view showing the appearance of a solar cell 104 according to a fourth modified example. FIG. 9 is a schematic plan view showing the appearance of a solar cell 105 according to a fifth modified example.

[0009] Hereinafter, embodiments of the technology according to the present disclosure will be described in detail with reference to the accompanying drawings.

[0010] Fig. 1(a) is a schematic plan view showing the appearance of a solar cell 100 according to an embodiment of the technology disclosed herein, and Fig. 1(b) is a schematic cross-sectional view taken along line AA shown in Fig. 1(a).

[0011] As shown in FIG. 1( a), a solar cell 100 according to this embodiment has a film-like substrate 10 and photoelectric conversion layers 21 to 24 provided on a surface 11 of the substrate 10. The substrate 10 is a flexible film-like member made of an insulating material such as polyethylene naphthalate, and functions as a support for the photoelectric conversion layers 21 to 24. The thickness of the substrate 10 is, for example, 75 to 90 μm. The substrate 10 includes a main region 10A and terminal regions 10B and 10C. The photoelectric conversion layers 21 to 24 are provided on the surface 11 of the main region 10A of the substrate 10.

[0012] FIG. 2 is a schematic cross-sectional view of the solar cell 100.

[0013] As shown in Fig. 2, photoelectric conversion layers 21 to 24 and a sealing resin layer 80 covering the photoelectric conversion layers 21 to 24 are provided on the surface 11 of the substrate 10. The photoelectric conversion layers 21 to 24 and the sealing resin layer 80 are omitted in Fig. 1(b). The photoelectric conversion layers 21 to 24 are semiconductor elements that convert incident light into electricity, and are formed on almost the entire surface 11 of the main region 10A of the substrate 10 except for the outer periphery. The sealing resin layer 80 is a protective member that protects the light-receiving surfaces of the photoelectric conversion layers 21 to 24, and is made of a thermosetting resin material such as polyimide.

[0014] The photoelectric conversion layers 21 to 24 are connected in series, for example, in this order. A terminal 50 of the photoelectric conversion layer 21 is connected to a via conductor 51 provided to penetrate the substrate 10. A terminal (not shown) of the photoelectric conversion layer 24 is also connected to a via conductor (not shown) provided to penetrate the substrate 10. The terminals of the photoelectric conversion layers 21 and 24 are concealed by being covered with colored resins 61 and 62. The connection portion connecting the photoelectric conversion layer 21 and the photoelectric conversion layer 22 and the connection portion connecting the photoelectric conversion layer 23 and the photoelectric conversion layer 24 may also be concealed with colored resins 63 and 64.

[0015] In the terminal region 10B of the substrate 10, an electrode layer 41 is provided on the surface 11 side, and an electrode layer 31 is provided on the surface 12 side, which is located opposite the surface 11. Similarly, in the terminal region 10C of the substrate 10, an electrode layer 42 is provided on the surface 11 side, and an electrode layer 32 is provided on the surface 12 side. One end of the electrode layer 31 reaches the main region 10A and is connected to a terminal 50 of the photoelectric conversion layer 21 through a via conductor 51. Similarly, one end of the electrode layer 32 reaches the main region 10A and is connected to a terminal (not shown) of the photoelectric conversion layer 24 through a via conductor (not shown). Furthermore, the other end of the electrode layer 31 is connected to the electrode layer 41 through a via conductor 52 provided through the substrate 10. Similarly, the other end of the electrode layer 32 is connected to the electrode layer 42 through a via conductor (not shown) provided through the substrate 10.

[0016] The material of the electrode layers 31, 32, 41, 42 may be a flexible conductive paste, or may be a laminate of a conductive adhesive 91 and a metal foil 92 as shown in FIG.

[0017] In this embodiment, half-cut grooves 71 and 72 are provided on the surface 11 of the substrate 10. The half-cut groove 71 is provided between the photoelectric conversion layer 21 and the electrode layer 41, and the half-cut groove 72 is provided between the photoelectric conversion layer 24 and the electrode layer 42. In the example shown in FIG. 1( a), the half-cut groove 71 is provided along the boundary between the main region 10A and the terminal region 10B, and the half-cut groove 72 is provided along the boundary between the main region 10A and the terminal region 10C. The depths of the half-cut grooves 71 and 72 are within a range that ensures the strength of the substrate 10 in the portions where the half-cut grooves 71 and 72 are provided, and are, for example, approximately half the thickness of the substrate 10.

[0018] By providing such half-cut grooves 71, 72, even when the substrate 10 is made of a material that is not easily elastically deformed, such as polyethylene naphthalate, it becomes possible to easily bend the substrate 10 along the half-cut grooves 71, 72. In other words, by bending the substrate 10 along the half-cut grooves 71, 72, it becomes possible to significantly reduce the radius of curvature of the bent portion. Furthermore, even when the substrate 10 is bent along the half-cut grooves 71, 72, the main region 10A is hardly deformed, and therefore the photoelectric conversion layers 21-24 are less likely to be damaged.

[0019] FIG. 4 is a schematic cross-sectional view showing the solar cell 100 according to this embodiment in a bent state.

[0020] In the example shown in FIG. 4 , the terminal region 10B is bent approximately 90° along the half-cut groove 71 and inserted between the substrates 210 and 220. The electrode layer 31 of the solar cell 100 is connected to the electrode pattern 211 provided on the substrate 210, and the electrode layer 41 of the solar cell 100 is connected to the electrode pattern 221 provided on the substrate 220. In this manner, the solar cell 100 according to the embodiment can be connected from both sides of the terminal region 10B. However, this is not essential to the present invention, and the electrode layers 41 and 42 on the front surface 11 of the substrate 10 may be omitted. Furthermore, the half-cut grooves 71 and 72 do not necessarily need to be located along the boundary between the main region 10A and the terminal regions 10B and 10C; they only need to be located in positions that overlap at least the electrode layers 31 and 32. Therefore, the half-cut grooves 71 and 72 may be located within the terminal regions 10B and 10C, respectively.

[0021] Fig. 5(a) is a schematic plan view showing the appearance of a solar cell 101 according to a first modified example, and Fig. 5(b) is a schematic cross-sectional view taken along line AA shown in Fig. 5(a).

[0022] 5(a) and 5(b), the solar cell 101 according to the first modification differs from the solar cell 100 shown in Figures 1(a) and 1(b) in that additional half-cut grooves 73 and 75 are further provided on the surface 11 of the terminal region 10B, and additional half-cut grooves 74 and 76 are further provided on the surface 11 of the terminal region 10C. The other basic configuration is the same as that of the solar cell 100 shown in Figures 1(a) and 1(b), and therefore the same elements are designated by the same reference numerals and redundant explanations will be omitted.

[0023] The half-cut grooves 71, 73, and 75 extend parallel to one another, and the half-cut grooves 72, 74, and 76 extend parallel to one another. This allows the terminal areas 10B and 10C to be bent in multiple stages in the same direction. As a result, not only can the terminal areas 10B and 10C be bent more greatly, but the bending angles of the half-cut grooves 71 to 76 can also be relaxed.

[0024] FIG. 6 is a schematic plan view showing the appearance of a solar cell 102 according to a second modified example.

[0025] As shown in Figure 6, the solar cell 102 according to the second modification differs from the solar cell 100 shown in Figures 1(a) and 1(b) in that another half-cut groove 77 is further provided on the surface 11 of the terminal region 10B. Since the other basic configuration is the same as that of the solar cell 100 shown in Figures 1(a) and 1(b), the same elements are denoted by the same reference numerals and redundant explanations will be omitted.

[0026] The half-cut grooves 71 and 77 extend perpendicular to each other. The symbol S in Fig. 6 denotes a slit, where the substrate 10 is cut. This allows the terminal region 10B to be bent in multiple stages in different directions.

[0027] FIG. 7 is a schematic plan view showing the appearance of a solar cell 103 according to a third modified example.

[0028] As shown in Fig. 7, solar cell 103 according to the third modification differs from solar cell 102 shown in Fig. 6 in that another half-cut groove 78 is further provided on surface 11 of terminal region 10B. Since the other basic configuration is the same as solar cell 102 shown in Fig. 6, the same elements are denoted by the same reference numerals and redundant explanations will be omitted.

[0029] The half-cut grooves 77 and 78 extend parallel to each other, which allows the terminal area 10B to be bent in multiple stages along the half-cut grooves 71, 77, and 78.

[0030] FIG. 8 is a schematic plan view showing the appearance of a solar cell 104 according to a fourth modified example.

[0031] As shown in Figure 8, a solar cell 104 according to the fourth modification differs from the solar cell 100 shown in Figures 1(a) and 1(b) in that the terminal region 10B is surrounded by the main region 10A and a half-cut groove 79 is provided along the boundary between the terminal region 10B and the main region 10A. Since the other basic configuration is the same as that of the solar cell 100 shown in Figures 1(a) and 1(b), the same elements are designated by the same reference numerals and redundant explanations will be omitted.

[0032] 8 denotes slits where the substrate 10 is cut. That is, the terminal region 10B, which is surrounded by the main region 10A, has three sides separated from the main region 10A by the slits S, and one side connected to the main region 10A via the half-cut groove 79. This makes it possible to bend the terminal region 10B along the half-cut groove 79.

[0033] FIG. 9 is a schematic plan view showing the appearance of a solar cell 105 according to a fifth modified example.

[0034] 9, solar cell 105 according to the fifth modification differs from solar cell 100 shown in Figures 1(a) and 1(b) in that slits S are provided in parts of main region 10A located on extensions of edges of terminal regions 10B and 10C. The other basic configuration is the same as that of solar cell 100 shown in Figures 1(a) and 1(b), and therefore the same elements are designated by the same reference numerals and redundant explanations will be omitted.

[0035] The slits S are formed from the ends of the half-cut grooves 71, 72 located at the boundaries between the main region 10A and the terminal regions 10B, 10C toward the main region 10A. As a result, when the substrate 10 is bent along the half-cut grooves 71, 72, the bent portions of the substrate 10 move inward by the amount of the slits S formed, and therefore, protrusion of the bent portions in a plan view is suppressed.

[0036] The length of the slit S is preferably equal to or greater than the thickness of the substrate 10. This is because if the length of the slit S is shorter than the thickness of the substrate 10, the bent portion will protrude from the main region 10A in plan view, even when the slit S is bent at a substantially right angle. Furthermore, the length of the slit S is more preferably 1.1 to 1.5 times the thickness of the substrate 10. This is because, by making the length of the slit S 1.1 times or more the thickness of the substrate 10, the bent portion will hardly protrude, and, by making the length of the slit S 1.5 times or less the thickness of the substrate 10, it is possible to minimize the reduction in the area of ​​the photoelectric conversion layer.

[0037] The above describes embodiments of the technology according to the present disclosure, but the technology according to the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the technology, and it goes without saying that these modifications are also included within the scope of the technology according to the present disclosure.

[0038] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0039] A solar cell according to one aspect of the present disclosure includes a film-like substrate including a main region and a terminal region, and having a first surface and a second surface opposite the first surface, a photoelectric conversion layer provided on the first surface of the main region of the substrate, a first electrode layer provided on the second surface of the terminal region of the substrate, and a first via conductor provided through the substrate and connecting the photoelectric conversion layer and the first electrode layer, wherein a first half-cut groove is provided on the first surface of the substrate at a position overlapping with the first electrode layer. By bending the substrate along the first half-cut groove, it is possible to reduce the radius of curvature of the bent portion.

[0040] In the solar cell described above, the first half-cut groove may be provided along the boundary between the main region and the terminal region, and by bending the substrate along the first half-cut groove, the planar size of the substrate can be reduced.

[0041] The solar cell may further include a second electrode layer provided on the first surface of the terminal region of the substrate, and a second via conductor provided through the substrate to connect the first electrode layer and the second electrode layer, thereby enabling connection from both sides of the substrate.

[0042] In the solar cell described above, the first half-cut groove may be provided between the photoelectric conversion layer and the second electrode layer, so that the second electrode layer is not divided by the first half-cut groove.

[0043] In the solar cell described above, a second half-cut groove may be further provided on the first surface of the terminal region of the substrate. This allows the substrate to be bent in multiple stages. In this case, the first half-cut groove and the second half-cut groove may extend parallel to each other or in different directions. The former not only allows the terminal region to be bent more greatly, but also makes it possible to reduce the bending angle of the first and second half-cut grooves. The latter allows the terminal region to be bent in multiple stages in different directions.

[0044] In the solar cell described above, the terminal region may be surrounded by the main region, which allows the electrode layer to be disposed directly below the photoelectric conversion layer.

[0045] In the solar cell described above, the substrate may have a slit extending from the boundary between the main region and the terminal region toward the main region on an extension of the edge of the terminal region, which makes it possible to prevent the bent portion from protruding in a plan view when the substrate is bent along the half-cut groove.

[0046] This application claims the benefit of Japanese Patent Application No. 2024-006541, filed on January 19, 2024, the entire disclosure of which is incorporated herein by reference.

[0047] 10 Substrate 10A Main region 10B, 10C Terminal region 11, 12 Surface of substrate 21 to 24 Photoelectric conversion layer 31, 32, 41, 42 Electrode layer 50 Terminal 51, 52 Via conductor 61 to 64 Resin 71 to 79 Half-cut groove 80 Sealing resin layer 91 Conductive adhesive 92 Metal foil 100 to 105 Solar cell 210, 220 Substrate 211, 221 Electrode pattern S Slit

Claims

1. A film-like substrate including a main region and a terminal region, having a first surface and a second surface located on the opposite side of the first surface; a photoelectric conversion layer provided on the first surface of the main region of the substrate; a first electrode layer provided on the second surface of the terminal region of the substrate; and a first via conductor provided through the substrate to connect the photoelectric conversion layer and the first electrode layer. A first half-cut groove is provided at a position overlapping the first electrode layer on the first surface of the substrate. A solar cell.

2. The solar cell according to claim 1, wherein the first half-cut groove is provided along the boundary between the main region and the terminal region.

3. Further comprising: a second electrode layer provided on the first surface of the terminal region of the substrate; and a second via conductor provided through the substrate to connect the first electrode layer and the second electrode layer. The solar cell according to claim 1.

4. The solar cell according to claim 3, wherein the first half-cut groove is provided between the photoelectric conversion layer and the second electrode layer.

5. The solar cell according to any one of claims 1 to 4, wherein a second half-cut groove is further provided on the first surface of the terminal region of the substrate.

6. The solar cell according to claim 5, wherein the first half-cut groove and the second half-cut groove extend parallel to each other.

7. The solar cell according to claim 5, wherein the first half-cut groove and the second half-cut groove extend in different directions from each other.

8. The solar cell according to any one of claims 1 to 4, wherein the terminal region is surrounded by the main region.

9. The solar cell according to any one of claims 1 to 4, wherein the substrate has a slit formed on an extension line of an edge of the terminal region from the boundary between the main region and the terminal region toward the main region side.

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