Solar cell and solar cell module

Abstract

To provide a solar cell that has high designability.SOLUTION: A solar cell comprises a coating layer formed at least at a linear part of a peripheral edge part of a light reception surface of the solar cell, and has an antireflection film on its light reception surface, wherein the coating layer is formed on the antireflection film, and the color of the coating layer is the same as or similar to the color of the light reception surface of the solar cell.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a solar cell and a solar cell module. [Background technology]

[0002] In recent years, solar cells have been used in a variety of places other than on residential roofs, solar power plants, etc. For example, solar cell modules installed on vehicle roofs are more visible to users than those installed on residential roofs or power plants, so they require a much higher level of design quality than before. In order to improve the design of a solar cell module, a solar cell module is known in which a black pattern is provided on the light-receiving side protective member so as to overlap the gaps between the solar cells, thereby making the gaps between the solar cells invisible (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2020 / 121693A1 Summary of the Invention [Problem to be solved by the invention]

[0004] Solar cells typically have an anti-reflective coating and / or an anti-reflective textured structure on their light-receiving surfaces, resulting in a dark blue or black color. If a solar cell has chipping (a chip at the corner between the light-receiving surface and the peripheral side) on its periphery, the anti-reflective coating and / or anti-reflective textured structure disappears in the chipped area, revealing the original semiconductor surface and reflecting light. For solar cell modules installed on residential roofs or solar power plants, chipping is inconspicuous because they are installed at high altitudes or in places with little foot traffic. However, for solar cell modules mounted on vehicles, chipping is highly noticeable because the solar cell can be viewed up close. For example, even chipping as small as 0.1 mm to 1.0 mm in size is easily noticeable in solar cell modules mounted on vehicles. Therefore, high requirements are placed on the appearance of solar cell modules installed in close proximity to users, such as those mounted on vehicles, and high design quality is required for the solar cells that make up the solar cell module. Furthermore, dirt, watermarks, color unevenness, etc. on the light-receiving surface of a solar cell degrade the design quality of the solar cell, just like chipping. When high requirements are placed on the appearance of solar cells, those with poor design qualities are removed from the production line during appearance inspection, resulting in a decrease in appearance yield. As mentioned above, defects that detract from the design quality of solar cells include chipping, dirt, watermarks, and color unevenness, all of which tend to occur more frequently around the periphery of solar cells. For example, chipping is likely to occur during the solar cell manufacturing process when semiconductor substrates are placed in cassettes or deposition trays, or when the edge of a transported semiconductor substrate or solar cell strikes a guide pin. Small chipping (e.g., chips of 3 mm or less) occurs frequently. Furthermore, when a semiconductor substrate is placed in a cassette or deposition tray, or when the edge of a transported semiconductor substrate or solar cell strikes a guide pin, dirt (oil, etc.) may adhere to the periphery of the semiconductor substrate or solar cell. Furthermore, during the drying process after wet processing of a semiconductor substrate, water droplets remaining between the cassette guide and the semiconductor substrate may cause watermarks around the periphery of the semiconductor substrate. Furthermore, when an anti-reflective coating is deposited on the surface of a semiconductor substrate, uneven film formation is likely to occur around the periphery of the semiconductor substrate, and color unevenness may occur due to differences in the thickness of the anti-reflective coating. One possible method for using solar cells with defects in the peripheral area that reduce the design is to provide a black pattern on the light-receiving-side protective member so that it overlaps the edge of the solar cell, as in Patent Document 1. However, it is necessary to consider the positional accuracy when placing the solar cell on the light-receiving-side protective member, tolerances such as the amount of cell misalignment during lamination, and the appearance from an oblique angle, and it is therefore necessary to increase the area of ​​the black pattern by an amount corresponding to the margin. This results in a problem of reduced light reception by the solar cell and reduced power generation by the solar cell. The present invention has been made in view of the above circumstances, and provides a solar cell with high designability. [Means for solving the problem]

[0005] The present invention provides a solar cell characterized in that it has a paint layer applied to at least a linear portion of the periphery of the light-receiving surface of the solar cell, the solar cell has an anti-reflection film on its light-receiving surface, the paint layer is formed on the anti-reflection film, and the color of the paint layer is the same color or a similar color to the color of the light-receiving surface of the solar cell. [Effects of the Invention]

[0006] According to the present invention, the design of the solar cell is improved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1(a) is a schematic plan view of a solar cell according to one embodiment of the present invention, and FIG. 1(b) is a schematic rear view of this solar cell. [Figure 2] 1(a) and 1(b) are schematic plan views of a solar cell according to one embodiment of the present invention. [Figure 3] 2(a) is a schematic cross-sectional view of a solar cell taken along dashed line AA in FIG. 1, and FIG. 2(b) is a schematic cross-sectional view of a solar cell having a semiconductor substrate with chipping at its edge. [Figure 4] FIG. [Figure 5] 1 is a schematic plan view of a solar cell module according to one embodiment of the present invention. [Figure 6] 6 is a schematic cross-sectional view of the solar cell module taken along dashed line BB in FIG. 5. [Figure 7] 1(a) to 1(d) are explanatory diagrams of a method for manufacturing a solar cell module according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] The solar cell of the present invention is characterized in that it has a paint layer applied to at least a linear portion of the peripheral edge of the light-receiving surface of the solar cell, and the color of the paint layer is the same color or a similar color to the color of the light-receiving surface of the solar cell. Furthermore, the solar cell of the present invention is characterized in that it comprises a coating layer applied to at least a linear portion of the periphery of the light-receiving surface of the solar cell, the solar cell has an anti-reflection film on its light-receiving surface, the coating layer is formed on the anti-reflection film, and the color of the coating layer is the same color or a similar color to the color of the light-receiving surface of the solar cell. The solar cell of the present invention is also characterized in that it has a paint layer applied to at least a linear portion of the periphery of the light-receiving surface of the solar cell, electrodes are arranged only on the back surface of the solar cell, and the color of the paint layer is the same color or a similar color to the color of the light-receiving surface of the solar cell.

[0009] Preferably, the solar cell includes a silicon substrate, and the color of the coating layer is black or dark blue. It is preferable that the electrodes are placed only on the back surface of the solar cell (back-contact solar cell). In a back-contact solar cell, where no electrodes are placed on the light-receiving surface of the solar cell, there are no electrodes on the light-receiving surface, which improves the design of the solar cell. The width of the coating layer provided along the edge of the light-receiving surface of the solar cell is preferably 3 mm or less, which enhances the design of the solar cell and prevents a decrease in the light-receiving area. When the shape of the solar cell is a rectangle with at least two rounded corners in a plan view, the coating layer may be disposed on the linear portions of the four sides of the periphery of the light-receiving surface of the solar cell, but may not be disposed on the rounded corners of the periphery of the light-receiving surface of the solar cell. This improves the design of the solar cell and makes it easy to form the coating layer.

[0010] The present invention also provides a solar cell module comprising a plurality of solar cells of the present invention, a light-receiving surface protection member, and a back surface protection member. The solar cell module of the present invention has high designability because it is composed of solar cells with high designability. The present invention also provides a solar cell module comprising a plurality of solar cells of the present invention, wiring, a light-receiving surface protection member, a back surface protection member, and a wiring cover that covers at least a portion of the wiring, the wiring connecting two adjacent solar cells, the plurality of solar cells being arranged between the light-receiving surface protection member and the back surface protection member, the color of the surface of the back surface protection member facing the solar cells being the same color or a similar color to the color of the light-receiving surface of the solar cells, and the color of the surface of the wiring cover facing the light-receiving surface being the same color or a similar color to the color of the light-receiving surface of the solar cells. The solar cell module of the present invention has a high designability because the light-receiving surface appears to be a single color.

[0011] The present invention will be described in more detail below with reference to several embodiments. The configurations shown in the drawings and the following description are examples, and the scope of the present invention is not limited to those shown in the drawings and the following description.

[0012] First embodiment Fig. 1(a) is a schematic plan view of a solar cell of this embodiment, and Fig. 1(b) is a schematic back view of this solar cell. Fig. 2(a) and (b) are schematic plan views of solar cells of modified examples of this embodiment. Fig. 3(a) is a schematic cross-sectional view of a solar cell taken along dashed line AA in Fig. 1, and Fig. 3(b) is a schematic cross-sectional view of a solar cell including a semiconductor substrate having a chipping at its edge. A solar cell 40 of this embodiment includes a semiconductor substrate 2, a light-receiving surface 12, a back surface 13, a first electrode 3, a second electrode 4, and a coating layer 5 applied to at least a linear portion of the periphery of the light-receiving surface 12. The semiconductor substrate 2 has a first-conductivity-type region or first-conductivity-type diffusion region 6 and a second-conductivity-type region or second-conductivity-type diffusion region 7. The first electrode 3 is connected to the first-conductivity-type region or first-conductivity-type diffusion region 6, and the second electrode 4 is connected to the second-conductivity-type region or second-conductivity-type diffusion region 7. The solar cell 40 has at least one of an anti-reflection coating 9 and an anti-reflection textured structure 10 on the light-receiving surface 12. The anti-reflection coating 9 is a film laminated on the light-receiving surface of the semiconductor substrate 2. The anti-reflection textured structure 10 is an uneven structure formed on the light-receiving surface of the semiconductor substrate 2. The color of the coating layer 5 is the same color or a similar color to the color of the light-receiving surface 12 of the solar cell 40. The colors of the light-receiving surface 12, the paint layer 5, etc. can be quantified using a colorimeter.

[0013] The semiconductor substrate 2 is a semiconductor substrate, such as a single crystal silicon substrate, a polycrystalline silicon substrate, a CIS semiconductor substrate, a CIGS semiconductor substrate, or a III-V compound semiconductor substrate. The solar cell 40 includes the semiconductor substrate 2 and has a p-n junction capable of generating photovoltaic power. The semiconductor substrate 2 included in the solar cell 40 is not particularly limited. The semiconductor substrate 2 of this embodiment includes, for example, a first-conductivity-type region or a first-conductivity-type diffusion region 6 and a second-conductivity-type region or a second-conductivity-type diffusion region 7. The first or second-conductivity-type region may be a base material region of the semiconductor substrate (e.g., when a p-type semiconductor substrate is used as the base material, the p-type semiconductor region inherent in this substrate), or may be a deposited film deposited on the base material substrate. The semiconductor substrate may also have both a diffusion region and a deposited film. One of the first and second conductivity types is n-type (majority carriers are electrons), and the other is p-type (majority carriers are holes). These regions form a p-n junction in the semiconductor substrate 2. When the semiconductor substrate 2 is a silicon substrate, the p-type diffusion region (one of the first conductivity type diffusion region 6 and the second conductivity type diffusion region 7) is a region in which a p-type dopant such as boron (B) is diffused, and the n-type diffusion region (the other of the first conductivity type diffusion region 6 and the second conductivity type diffusion region 7) is a region in which an n-type dopant such as phosphorus (P) is diffused.

[0014] The solar cell 40 has an anti-reflection structure on the light-receiving surface 12. For example, the solar cell 40 has at least one of an anti-reflection film 9 and an anti-reflection textured structure 10 on the light-receiving surface 12. This makes the light-receiving surface 12 of the solar cell 40 dark blue or black. The anti-reflection textured structure 10 is a concave-convex structure called a texture, and this concave-convex structure guides light incident on the light-receiving surface 12 into the semiconductor. The anti-reflection textured structure 10 is formed on the light-receiving surface of the semiconductor substrate 2. The anti-reflection film 9 is a dielectric film such as a silicon nitride film or a silicon oxide film. The anti-reflection film 9 may also have a structure in which multiple dielectric films with different refractive indices are stacked. The anti-reflection film 9 is stacked on the light-receiving surface of the semiconductor substrate 2. The solar cell 40 may also have a passivation film 23 on the back surface. The passivation film 23 is stacked on the surface (back surface) of the semiconductor substrate 2 opposite the light-receiving surface.

[0015] The shape of the semiconductor substrate 2 (solar cell 40) may be a square with rounded corners as shown in Figures 1 and 2(a), a rectangle, or a shape obtained by dividing a square semiconductor substrate with rounded corners into two as shown in Figure 2(b).

[0016] The first electrode 3 and the second electrode 4 are electrodes for extracting photovoltaic power generated in the semiconductor substrate 2. The first electrode 3 is connected to a first conductivity type region or a first conductivity type diffusion region 6, and the second electrode 4 is connected to a second conductivity type region or a second conductivity type diffusion region 7. One of the first electrode 3 and the second electrode 4 may be provided on the light-receiving surface 12 of the semiconductor substrate 2, and the other may be provided on the back surface of the semiconductor substrate 2 (double-sided electrode solar cell). 1 to 3, both the first electrode 3 and the second electrode 4 may be provided on the back surface of the semiconductor substrate 2 (back-contact solar cell). A back-contact solar cell has high design flexibility because it does not have an electrode on the light-receiving surface 12. The first electrode 3 is linear, and the second electrode 4 is linear. The linear first electrodes 3 and second electrodes 4 are alternately arranged on the back surface of the semiconductor substrate 2. The linear first electrodes 3 are connected to first cell terminals 25 provided on the back surface of the semiconductor substrate 2, and the linear second electrodes 4 are connected to second cell terminals 26 provided on the back surface of the semiconductor substrate 2. Photovoltaic power generated in the semiconductor substrate 2 can be extracted to the outside via the first cell terminals 25 and second cell terminals 26.

[0017] The semiconductor substrate 2 included in the back-contact type solar cell can have a structure in which linear first-conductivity-type diffusion regions 6, in which a first-conductivity-type dopant is linearly diffused on the back surface side of a semiconductor region 8 (p-type semiconductor region, n-type semiconductor region, or intrinsic semiconductor region), and linear second-conductivity-type diffusion regions 7, in which a second-conductivity-type dopant is diffused on the back surface side of the semiconductor region 8, are arranged alternately. The linear first electrode 3 can be connected to the linear first-conductivity-type diffusion region 6 through a linear opening provided in the passivation film 23 on the rear surface 13 of the semiconductor substrate 2. The linear second electrode 4 can be connected to the linear second-conductivity-type diffusion region 7 through a linear opening provided in the passivation film 23 on the rear surface 13 of the semiconductor substrate 2.

[0018] The coating layer 5 is a layer formed by applying a paint onto the light-receiving surface of the solar cell 40. The coating layer 5 may contain a pigment and a resin. The pigment contained in the coating layer 5 is preferably a light-resistant pigment. This makes it possible to prevent discoloration of the coating layer 5. The coating used to form the coating layer 5 contains, for example, a pigment, a resin, and a solvent. The method for applying the paint onto the light-receiving surface of the solar cell 40 to form the coating layer 5 is not particularly limited, but examples include an inkjet method, a spray coating method, a transfer method, and a screen printing method. The coating layer 5 may be provided so as to be in contact with the anti-reflection film 9.

[0019] The coating layer 5 is a layer applied to at least linear portions of the periphery of the light-receiving surface 12 of the solar cell 40. In this embodiment, the coating layer 5 is provided on an anti-reflection film 9 formed on the semiconductor substrate 2. By providing such a coating layer 5, even if chipping 28 (chips at the corners between the light-receiving surface 12 and the peripheral side surface 14; see FIGS. 4(a) and 4(b)), dirt, watermarks, color unevenness, etc., occurs on the periphery of the light-receiving surface 12 of the solar cell 40, these are hidden by the coating layer 5, so that a reduction in the design quality of the solar cell 40 can be prevented. Furthermore, even if chipping 28, dirt, watermarks, color unevenness, etc. occurs on the periphery of the light-receiving surface 12 of the solar cell 40, these are hidden by the coating layer 5, so they do not cause appearance defects of the solar cell 40, and the appearance yield can be improved. The coating layer 5 may be provided over the entire periphery of the light-receiving surface 12, as shown in FIG. 1(a).

[0020] As shown in FIGS. 2(a) and 2(b), the coating layer 5 is applied to the linear portions of the periphery of the light-receiving surface 12, but does not necessarily have to be applied to the rounded corners of the periphery of the light-receiving surface 12. Chipping, stains, watermarks, color unevenness, etc. are likely to occur on the linear portions of the periphery of the light-receiving surface 12, but are less likely to occur on the rounded corners (for example, because the linear portions of the semiconductor substrate 2 come into contact with guide pins, etc., during the manufacturing process). Therefore, by applying the coating layer 5 to the linear portions of the periphery of the light-receiving surface 12, it is possible to prevent a decrease in the design of the solar cell 40 and improve the appearance yield. It also makes it possible to prevent a decrease in the amount of light incident on the solar cell 40. Furthermore, since it is necessary to apply coating only to the linear portions of the periphery of the light-receiving surface 12, coating is easy.

[0021] The color of the coating layer 5 is the same color or a similar color to the color of the light-receiving surface 12 of the solar cell 40. Therefore, the light-receiving surface of the solar cell 40 (excluding the electrodes, if provided) appears to be a single color, improving the design of the solar cell 40 and increasing the appearance yield. The light-receiving surface 12 of the solar cell 40, which includes a semiconductor substrate 2 (silicon substrate) and has an anti-reflection film 9 or anti-reflection texture structure 10 on its light-receiving surface, is usually black to dark blue. Therefore, the color of the coating layer 5 is black to dark blue. Alternatively, the color of the coating layer 5 may be a single color. L * a * b * The color difference ΔE between the color of the paint layer 5 and the color of the light-receiving surface 12 of the solar cell 40 in the color space (color system) * is, for example, from 0.0 to 10.0, preferably from 0.0 to 5.0, and more preferably from 0.0 to 2.0. The color difference can be measured using a colorimeter, a colorimeter, a color difference meter, or the like.

[0022] The coating layer 5 is linear and provided in a linear region between the edge (end) of the light-receiving surface 12 of the solar cell 40 and a line along the edge (end) of the light-receiving surface 12 of the solar cell 40. The width (distance from the edge of the light-receiving surface) of the linear coating layer 5 is 3 mm or less, preferably 2 mm or less, preferably 1 mm or less, and more preferably 0.5 mm or less. This makes it possible to conceal chipping, dirt, watermarks, color unevenness, etc., and to suppress a decrease in the amount of light incident on the semiconductor substrate 2, thereby suppressing a decrease in power generation. It also makes it possible to conceal chipping of 3 mm or less, which occurs frequently. The thickness of the coating layer 5 is, for example, not less than 0.5 μm and not more than 10 μm.

[0023] Second embodiment FIG. 5 is a schematic plan view of the solar cell module of this embodiment, and FIG. 6 is a schematic cross-sectional view of the solar cell module taken along dashed line BB in FIG. The solar cell module 50 includes a plurality of solar cell cells 40 of the first embodiment, wiring 16, a light-receiving surface side protection member 17, a back surface side protection member 18, and a wiring cover 20 that covers at least a portion of the wiring 16. The solar cell 40 has been described in the first embodiment, so a description thereof will be omitted here. The number of solar cells 40 included in the solar cell module 50 is not particularly limited. For example, the solar cell module 50 shown in FIGS. 5 and 6 has six solar cell strings, each of which has five solar cells 40 connected in series, and each solar cell string is connected in series. All of the solar cells 40 included in the solar cell module 50 can have substantially the same shape. Furthermore, the coating layers 5 of all of the solar cells 40 included in the solar cell module 50 can have substantially the same pattern. This allows the solar cells 40 to have a uniform appearance, improving the design of the solar cell module 50. Furthermore, the light-receiving areas of the cells can be made uniform, reducing variations in the output current values ​​of the solar cells 40.

[0024] Of two adjacent solar cells 40 included in a solar cell string, a first cell terminal 25 of one solar cell 40 and a second cell terminal 26 of the other solar cell 40 are connected by a wiring 16. Furthermore, the cell terminals at both ends of the solar cell string are connected to different bus bars 15 by the wiring 16. Furthermore, the bus bars 15 are connected to terminal boxes provided on the rear surface of the adjacent solar cell string and / or the solar cell module 50.

[0025] At least the inter-cell wiring of the wiring 16 is covered at least on the light receiving surface side with the wiring cover 20. Furthermore, at least the light receiving surface side of the bus bar 15 may be covered with the wiring cover 20. The wiring cover 20 may be in the form of a sheet, or may be a coating layer for the wiring 16. In the solar cell module 50 shown in Figs. 5 and 6, the wiring cover 20 is a coating layer for the wiring 16 and the bus bar 15. The color of the surface on the light-receiving side of the wiring cover 20 is the same color or a similar color as the color of the light-receiving surface 12 of the solar cell 40. The color of the surface on the light-receiving side of the wiring cover 20 is, for example, black or dark blue. In addition, L * a * b * The color difference ΔE between the color of the surface of the light-receiving side of the wiring cover 20 and the color of the light-receiving surface of the solar cell 40 in the color space (color system) * is, for example, from 0.0 to 10.0, preferably from 0.0 to 5.0, and more preferably from 0.0 to 2.0. The color difference can be measured using a colorimeter, a colorimeter, a color difference meter, or the like.

[0026] The plurality of solar cells 40 are disposed between a light-receiving surface protection member 17 and a back surface protection member 18, and are sealed with a sealing material 22. The light-receiving surface protection member 17 is a translucent protection member disposed on the light-receiving surface side of the plurality of solar cells 40, and is, for example, a glass plate such as thermally strengthened white glass or chemically strengthened glass. The back surface protection member 18 (backsheet) is a protection member disposed on the back surface of the plurality of solar cells 40. The material of the back surface protection member 18 is, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), PVF, PVDF, etc. The color of the surface of the back surface protection member 18 on the solar cell side is the same color or a similar color to the color of the light receiving surface 12 of the solar cell 40. The color of the surface of the back surface protection member 18 on the solar cell side is, for example, black or dark blue. In addition, L * a * b * The color difference ΔE between the color of the surface of the rear surface protection member 18 on the solar cell side and the color of the light receiving surface of the solar cell 40 in the color space (color system) *is, for example, 0.0 or more and 10.0 or less, preferably 0.0 or more and 5.0 or less, and more preferably 0.0 or more and 2.0 or less. The color difference can be measured using a colorimeter, colorimeter, color difference meter, or the like. For example, the back surface protection member 18 may have a paint layer of the same color or a similar color as the color of the light-receiving surface 12 of the solar cell 40 (external coloring). Furthermore, the back surface protection member 18 may be in the form of a sheet or a resin plate such as glass or polycarbonate. In this case, the back surface protection member may be colored with a pigment of the same color or a similar color as the color of the light-receiving surface 12 of the solar cell 40, or may be transparent and light-transmitting without being colored.

[0027] By making the color of both the light-receiving surface of the wiring cover 20 and the color of the solar cell-side surface of the back protection member 18 the same color or a similar color as the color of the light-receiving surface 12 of the solar cell 40, the color of the light-receiving surface of the solar cell module 50 appears to be a single color. This makes it possible to improve the design of the solar cell module 50. Sealant 22 is a material that seals multiple solar cells 40 between light-receiving surface protection member 17 and back surface protection member 18. Sealant 22 is, for example, ethylene vinyl acetate copolymer resin (EVA), polyolefin resin, polyvinyl butyral resin, silicone resin, or the like.

[0028] FIG. 7 is an explanatory diagram of a manufacturing method for a solar cell module 50. The manufacturing method for a solar cell module 50 includes the steps of forming a coating layer 5 on the periphery of the light-receiving surface 12 of each solar cell 40, inspecting the appearance of the solar cell 40 with the coating layer 5 formed thereon, and sealing multiple solar cells 40 between a light-receiving surface protection member 17 and a back surface protection member 18. First, as shown in FIG. 7(a), a solar cell is received, including a semiconductor substrate 2 having a first conductivity-type diffusion region 6 and a second conductivity-type diffusion region 7, a first electrode 3, a second electrode 4, and the like. Next, as shown in FIG. 7(b), paint is printed on the periphery of the light-receiving surface 12 of each solar cell 40 to form a coating layer 5. Next, the appearance of the solar cell 40 is inspected, and solar cells 40 with visible chipping, dirt, watermarks, color unevenness, etc. are removed from the production line. Because the solar cell 40 has the coating layer 5, most chipping, dirt, watermarks, color unevenness, etc. are no longer visible. Therefore, the number of solar cells 40 removed from the production line during this visual inspection can be reduced, and visual yield can be improved.

[0029] 7(c), the plurality of solar cells 40 are connected in series using wiring 16. The wiring 16 is provided with a wiring cover 20 that is the same color as or similar to the color of the light-receiving surface 12 of the solar cell 40. 7(d), the back surface protection member 18, the sealant sheet, the plurality of solar cells 40 with the wiring 16 and wiring cover 20 attached, the sealant sheet, and the light-receiving surface protection member 17 are stacked in this order, and then laminated, etc. Heat is applied to the sealant sheet to promote the cross-linking reaction of the sealant. Next, a terminal box is attached to the back surface of back surface protection member 18, and wiring 16 is connected to the terminal box with a wire. In this manner, solar cell module 50 is manufactured. Thereafter, IV measurement, insulation inspection, module appearance inspection, etc. are carried out, and then the solar cell module 50 is shipped.

[0030] As described above, the solar cell 40 of the present invention has a coating layer 5 on the peripheral edge of the light-receiving surface 12 of the semiconductor substrate 2. Therefore, even if chipping, dirt, watermarks, or color unevenness occurs on the peripheral edge of the semiconductor substrate during the solar cell manufacturing process, including the step of forming an anti-reflection structure on the semiconductor substrate 2, the coating layer can cover the chipping, dirt, watermarks, color unevenness, etc., preventing the chipping, dirt, watermarks, color unevenness, etc. from becoming noticeable. Therefore, the solar cell 40 of the present invention has high designability. Furthermore, it is possible to increase the appearance yield of solar cells for installation in locations where high designability is required, thereby reducing manufacturing costs. Note that such appearance defects, such as chipping, dirt, watermarks, and color unevenness, occur more frequently on the peripheral edge of the semiconductor substrate (solar cell), especially in linear portions. Therefore, forming a coating layer on at least the linear portion of the peripheral edge of the light-receiving surface of the solar cell improves the appearance yield of the solar cell. Designability may also be further improved by applying a coating layer to rounded corners on the peripheral edge of the light-receiving surface of the solar cell. Furthermore, the coating layer application process may be simplified by not applying a coating layer to the rounded corners of the periphery of the light-receiving surface of the solar cell.

[0031] Because the paint layer is formed by painting directly onto the solar cell, the paint layer will not shift even if the solar cell is misaligned during the lamination process when manufacturing the solar cell module. This means that no margin is needed to prevent the solar cell from shifting position, and the paint area can be minimized. In addition, because there is no gap between the solar cell and the paint layer, chipping of the semiconductor substrate is not visible even when viewed from an angle. The solar cell 40 of the present invention may be either a double-sided electrode type or a back-side electrode type. In the back-side electrode type, which has no electrode on the light-receiving surface, defects in appearance are very noticeable, so the effect of the coating layer is significant.

[0032] The method for manufacturing solar cell module 50 of the present invention includes a step of inspecting the appearance of solar cell 40 on which coating layer 5 has been formed before the step of sealing multiple solar cell 40 between light-receiving surface protection member 17 and back surface protection member 18, and solar cell 40 with poor appearance is removed from the manufacturing line before forming solar cell module 50. By inspecting the appearance of solar cell 40 after forming coating layer 5, it is possible to increase the appearance yield of the solar cell. Furthermore, a step of visually inspecting the solar cells may be included before the step of forming the paint layer 5. In this case, solar cells with visual defects are extracted, and a paint layer 5 is formed on the peripheral portion of the light-receiving surface 12 of the semiconductor substrate 2 of the solar cell, and the solar cells 40 are visually inspected again after the paint layer 5 is formed. By painting the solar cells with visual defects, the number of solar cells to be painted can be reduced. The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention. [Explanation of symbols]

[0033] 2: Semiconductor substrate 3: First electrode 4: Second electrode 5: Paint layer 6: First conductivity type diffusion region 7: Second conductivity type diffusion region 8: Semiconductor region 9: Anti-reflection film 10: Anti-reflection texture structure 12: Light receiving surface 13: Back surface 14: Peripheral side surface 15: Bus bar 16: Wiring 17: Light receiving surface side protective member 18: Back surface side protective member 20: Wiring cover 22: Sealant 23: Passivation film 25: First cell terminal 26: Second cell terminal 28: Chipping 40: Solar cell 50: Solar cell module

Claims

1. a coating layer applied to at least a linear portion of the periphery of the light-receiving surface of the solar cell; the solar cell has an anti-reflection film on its light-receiving surface, the coating layer is formed on the anti-reflection film, A solar cell characterized in that the color of the paint layer is the same color or a similar color to the color of the light-receiving surface of the solar cell.

2. a coating layer applied to at least a linear portion of the periphery of the light-receiving surface of the solar cell; An electrode is disposed only on the back surface of the solar cell; A solar cell characterized in that the color of the paint layer is the same color or a similar color to the color of the light-receiving surface of the solar cell.

3. The solar cell according to claim 1 , wherein the anti-reflection film is a dielectric film.

4. the solar cell includes a silicon substrate; 4. The solar cell according to claim 1, wherein the color of the coating layer is black or dark blue.

5. 4. The solar cell according to claim 1, wherein an electrode is disposed only on the rear surface of the solar cell.

6. 4. The solar cell according to claim 1, wherein the coating layer is provided along the edge of the light-receiving surface of the solar cell and has a width of 3 mm or less.

7. The solar cell has a rectangular shape with at least two rounded corners, The solar cell according to any one of claims 1 to 3, wherein the coating layer is disposed on the linear portions of the four sides of the periphery of the light-receiving surface of the solar cell, and is not disposed on the rounded corners of the periphery of the light-receiving surface of the solar cell.

8. A solar cell module comprising: a plurality of solar cells according to any one of claims 1 to 3; a light-receiving surface protection member; and a back surface protection member; The solar cell module includes a plurality of solar cells disposed between the light-receiving surface protection member and the back surface protection member.

9. A solar cell assembly comprising: a plurality of solar cells according to any one of claims 1 to 3; wiring; a light-receiving surface protection member; a back surface protection member; and a wiring cover that covers at least a portion of the wiring; the wiring connects two adjacent solar cells; a plurality of solar cells are disposed between the light-receiving surface protection member and the back surface protection member; the color of the surface of the back surface side protection member facing the solar cell is the same color or a similar color to the color of the light-receiving surface of the solar cell; A solar cell module in which the color of the surface on the light-receiving side of the wiring cover is the same color or a similar color to the color of the light-receiving surface of the solar cell.

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