A solar cell, a cell assembly, and a photovoltaic system

Abstract

The utility model is suitable for photovoltaic technical field provides a kind of solar cell, battery component and photovoltaic system, solar cell includes silicon chip, the first surface of silicon chip is provided with several grooves, the first surface of silicon chip includes the non-groove area located at the outside of groove, groove includes bottom wall and inclined side wall, inclined side wall connects bottom wall and non-groove area, bottom wall is provided with first pyramid nap structure, non-groove area is provided with second pyramid nap structure, the included angle between inclined side wall and the bottom surface of first pyramid nap structure is 55°~85°. The utility model discloses solar cell can reduce the total reflectivity of first surface, and can guarantee the good passivation performance of passivation film layer of the first surface of solar cell.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a solar cell, a battery module and a photovoltaic system. Background Technology

[0002] Solar cells, also known as photovoltaic cells, are devices that directly convert light energy into direct current using the photovoltaic effect. To enhance the anti-reflective properties of solar cell surfaces, a textured surface is typically fabricated on the cell surface.

[0003] In related technologies, pyramidal textured surfaces are usually fabricated directly on the surface of solar cells. However, due to the limited area of ​​the silicon wafer surface, it is impossible to further improve the anti-reflection effect of the solar cell surface on sunlight, resulting in low utilization of sunlight by the solar cell and poor cell efficiency. Utility Model Content

[0004] This invention provides a solar cell designed to address the problem of low solar energy utilization and poor battery efficiency in existing solar cells.

[0005] This invention is implemented as follows: a solar cell is provided, including a silicon wafer. A first surface of the silicon wafer is provided with a plurality of grooves. The first surface of the silicon wafer includes a non-groove area located outside the grooves. The grooves include a bottom wall and an inclined side wall. The inclined side wall connects the bottom wall and the non-groove area. The bottom wall is provided with a first pyramidal textured surface structure. The non-groove area is provided with a second pyramidal textured surface structure. The angle between the inclined side wall and the bottom surface of the first pyramidal textured surface structure is 55° to 85°.

[0006] Preferably, the angle between the inclined sidewall and the bottom surface of the first pyramid velvet structure is the same as the bottom angle of the first pyramid velvet structure.

[0007] Preferably, the angle between the inclined sidewall and the bottom surface of the first pyramid velvet structure is 60° to 70°.

[0008] Preferably, the base angle of the first pyramid velvet structure is greater than or equal to the base angle of the second pyramid velvet structure.

[0009] Preferably, the base angle of the second pyramid velvet structure is 50° to 70°.

[0010] Preferably, the base angle of the second pyramid velvet structure is 50° to 60°.

[0011] Preferably, the plurality of grooves are arranged at intervals along a first direction, and the grooves penetrate the first surface of the silicon wafer along a second direction, wherein the first direction and the second direction intersect.

[0012] Preferably, the distance between the edges of two adjacent grooves is 20 to 1000 micrometers.

[0013] Preferably, the distance between the edges of two adjacent grooves is 20 to 200 micrometers.

[0014] Preferably, the width of the groove along the first direction is 20 to 200 micrometers.

[0015] Preferably, the bottom dimension of the first pyramid velvet structure is smaller than the bottom dimension of the second pyramid velvet structure.

[0016] Preferably, the diagonal length of the bottom of the first pyramid velvet structure is 0.8 to 2 micrometers; and the diagonal length of the bottom of the second pyramid velvet structure is 3 to 8 micrometers.

[0017] Preferably, the depth of the groove is 1 to 20 micrometers.

[0018] This invention provides a battery assembly, including the aforementioned solar cell.

[0019] This invention provides a photovoltaic system, including the aforementioned battery module.

[0020] This utility model provides a solar cell by forming several grooves on the first surface of a silicon wafer. The first surface of the silicon wafer includes a non-grooved area located outside the grooves. Each groove includes a bottom wall and an inclined sidewall. The inclined sidewall connects the bottom wall and the non-grooved area. The bottom wall is provided with a first pyramidal textured surface structure, and the non-grooved area is provided with a second pyramidal textured surface structure. The first pyramidal textured surface structure in the groove area and the second pyramidal textured surface structure in the groove area achieve an anti-reflection effect on the first surface of the solar cell. Moreover, because the first surface of the silicon wafer has grooves and the grooves have inclined sidewalls, the depth of the grooves allows for a height difference between the first pyramidal textured surface structure in the groove area and the second pyramidal textured surface structure in the groove area. The anti-reflection effect is further enhanced by utilizing the sloping sidewalls of the groove to absorb the reflected light from the first pyramidal textured structure within the groove, thereby reducing the total reflectivity of the first surface of the solar cell and improving the utilization rate of sunlight, thus increasing the cell conversion efficiency. Moreover, by controlling the angle between the sloping sidewalls of the groove and the bottom surface of the first pyramidal textured structure to be 55°–85°, the sloping sidewalls of the groove can effectively absorb the reflected light from the first pyramidal textured structure within the groove, while also ensuring the uniformity of the passivation film deposition on the first surface of the silicon wafer. This improves the optical performance of the solar cell while ensuring good passivation performance of the passivation film on the first surface of the solar cell. Attached Figure Description

[0021] Figure 1 A cross-sectional schematic diagram of a silicon wafer for a solar cell provided in an embodiment of this utility model;

[0022] Figure 2 A top view schematic diagram of a silicon wafer for a solar cell provided in an embodiment of this utility model;

[0023] Figure 3 for Figure 1 A magnified view of part B in the middle;

[0024] Figure 4 A microscopic schematic diagram of a silicon wafer for a solar cell under a scanning electron microscope, provided as an embodiment of this utility model;

[0025] Figure 5 Another microscopic schematic diagram of a silicon wafer of a solar cell under a scanning electron microscope, provided for an embodiment of this utility model;

[0026] Figure 6 Another microscopic schematic diagram of a silicon wafer of a solar cell provided in an embodiment of this utility model under a scanning electron microscope. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as limiting the present utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0028] In the description of this utility model, it should be understood that the terms "upper", "lower", "second surface", "front", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0031] Please refer to Figures 1-3 This utility model provides a solar cell including a silicon wafer 1. The first surface 11 of the silicon wafer 1 is provided with a plurality of grooves 13. The first surface 11 of the silicon wafer 1 includes a non-groove area 14 located outside the grooves 13. The grooves 13 include a bottom wall 131 and an inclined side wall 132. The inclined side wall 132 connects the bottom wall 131 and the non-groove area 14. The bottom wall 131 is provided with a first pyramidal textured surface structure 15. The non-groove area 14 is provided with a second pyramidal textured surface structure 16. The included angle A0 between the inclined side wall 132 and the bottom surface of the first pyramidal textured surface structure 15 is 55° to 85°.

[0032] In this embodiment of the present invention, the silicon wafer 1 includes a first surface 11 and a second surface 12 disposed opposite to each other. One of the first surface 11 and the second surface 12 is the front side of the silicon wafer 1, and the other is the back side of the silicon wafer 1. It can be understood that the first surface 11 can be the front side of the silicon wafer 1, that is, the side of the silicon wafer 1 facing sunlight when the solar cell is working; the first surface 11 can also be the back side of the silicon wafer 1, that is, the second surface 12 can be the side of the silicon wafer 1 facing away from sunlight when the solar cell is working. Preferably, the first surface 11 is the front side of the silicon wafer 1, and a plurality of grooves 13 are disposed on the front side of the silicon wafer 1. In some other embodiments, the first surface 11 is the back side of the silicon wafer 1, and a plurality of grooves 13 are disposed on the back side 12 of the silicon wafer 1; the present invention does not limit this. Of course, grooves 13 can also be disposed on both the first surface 11 and the second surface 12.

[0033] In this embodiment of the present invention, the number of grooves 13 is not limited, and the arrangement of the grooves 13 is not limited. The first surface 11 of the silicon wafer 1 is divided into an area with grooves 13 and a non-groove area 14 located outside the grooves 13. The non-groove area 14 is the area of ​​the first surface 11 other than the grooves 13.

[0034] This utility model provides a solar cell by forming a plurality of grooves 13 on the first surface 11 of a silicon wafer 1. The first surface 11 of the silicon wafer 1 includes a non-groove region 14 located outside the grooves 13. Each groove 13 includes a bottom wall 131 and an inclined side wall 132. The inclined side wall 132 connects the bottom wall 131 and the non-groove region 14. The bottom wall 131 is provided with a first pyramidal textured surface structure 15, and the non-groove region 14 is provided with a second pyramidal textured surface structure 16. By forming a plurality of grooves 13 on the first surface 11 of the silicon wafer 1, and providing the first pyramidal textured surface structure 15 in the area within the grooves 13, and providing the second pyramidal textured surface structure 16 in the area outside the grooves 14, the first surface 11 of the solar cell is equipped with a solar cell that provides solar energy to the first surface 11. The solar cell exhibits enhanced anti-reflection properties. Furthermore, by utilizing the depth of the groove 13, a height difference exists between the first pyramidal textured surface 15 within the groove 13 and the second pyramidal textured surface 16 outside the groove 13, forming two anti-reflection planes with a height difference. Additionally, the groove 13 features a sloping sidewall 132, which absorbs the reflected light from the first pyramidal textured surface 15 within the groove 13, further enhancing the anti-reflection effect of sunlight. This can further reduce the total reflectivity of the first surface 11 of the solar cell. Actual testing shows that, compared to existing solar cells where the first surface 11 lacks a groove structure, the first surface 11 of this solar cell can reduce reflectivity by 1-2%, thereby improving the utilization rate of sunlight and ultimately increasing the cell conversion efficiency.

[0035] Specifically, the inclined sidewall 132 of the groove 13 is the sidewall of the groove 13, and the opening size of the groove 13 is larger than the bottom size of the groove 13. The angle between the inclined sidewall 132 of the groove 13 and the bottom surface of the first pyramidal textured structure 15 is controlled to be 55° to 85°. The inclined sidewall 132 is inclined relative to the bottom surface of the first pyramidal textured structure 15, that is, the inclined sidewall 132 is also inclined relative to the bottom wall 131 of the groove 13. At this inclination angle, the inclined sidewall 132 of the groove 13 can effectively absorb the reflected light from the first pyramidal textured structure 15 in the groove 13, and can also ensure the uniformity of the deposition of the passivation film layer on the first surface 11 of the silicon wafer 1. While improving the optical performance of the solar cell, it can also ensure the good passivation performance of the passivation film layer on the first surface 11 of the solar cell. The passivation film layer on the first surface 11 can be one or a stack of silicon oxide layer, silicon oxynitride layer, or aluminum oxide layer. The angle between the inclined sidewall 132 of the groove 13 and the bottom surface of the first pyramid velvet structure 15 is 55° to 85°, which also facilitates the formation of the groove 13 by chemical etching.

[0036] For example, the included angle A0 between the inclined sidewall 132 of the groove 13 and the bottom surface of the first pyramid velvet structure 15 can be any value among 55°, 58°, 60°, 62°, 65°, 70°, 73°, 75°, 80°, 84°, and 85°.

[0037] Please refer to the reference. Figures 3-6 In this embodiment of the invention, a plurality of first pyramidal velvet structures 15 are provided in the groove 13 area. The arrangement of the first pyramidal velvet structures 15 is not limited; they can be arranged in a linear array or in an irregular arrangement. Adjacent first pyramidal velvet structures 15 can be spaced apart and can partially overlap. A plurality of second pyramidal velvet structures 16 are provided in the non-groove area 14. The arrangement of the second pyramidal velvet structures 16 is not limited; they can be arranged in a linear array or in an irregular arrangement. Adjacent second pyramidal velvet structures 16 can be spaced apart and can partially overlap.

[0038] In this embodiment of the present invention, the first pyramid velvet structure 15 and the second pyramid velvet structure 16 are both pyramid-like structures with a top or pyramid structures with the top truncated; wherein, the first pyramid velvet structure 15 and the second pyramid velvet structure 16 can be pyramid structures with four sides and one bottom.

[0039] As an embodiment of the present invention, the included angle A0 between the inclined sidewall 132 and the bottom surface of the first pyramid velvet structure 15 is the same as the bottom angle A1 of the first pyramid velvet structure 15.

[0040] In this embodiment, the bottom angle A1 of the first pyramidal velvet structure 15 is the angle between the side surface and the bottom surface of the first pyramidal velvet structure 15. The angle A0 between the inclined sidewall 132 and the bottom surface of the first pyramidal velvet structure 15 is the same as the bottom angle A1 of the first pyramidal velvet structure 15. That is, the inclination angle of the inclined sidewall 132 is the same as the inclination angle of the side surface of the first pyramidal velvet structure 15. This allows the inclined sidewall 132 and the first pyramidal velvet structure 15 of the groove 13 to be formed by chemical etching in one step, which facilitates the one-time processing of the inclined sidewall 132 and the first pyramidal velvet structure 15 of the groove 13.

[0041] As an embodiment of this utility model, the included angle A0 between the inclined sidewall 132 and the bottom surface of the first pyramid velvet structure 15 is 60° to 70°.

[0042] In this embodiment, the included angle A0 between the inclined sidewall 132 and the bottom surface of the first pyramid textured structure 15 is further controlled to be 60° to 70°. By controlling the inclined sidewall 132 within this angle range, the inclined sidewall 132 can better absorb the reflected light from the first pyramid textured structure 15, and can ensure the uniformity of the passivation film deposition on the first surface 11 of the silicon wafer 1. Under the premise of improving the optical performance of the solar cell, the good performance of the passivation film on the first surface 11 of the solar cell can be guaranteed.

[0043] As an embodiment of the present invention, the base angle A1 of the first pyramid velvet structure 15 is greater than or equal to the base angle A2 of the second pyramid velvet structure 16.

[0044] In this embodiment, the base angle A1 of the first pyramidal velvet structure 15 is the angle between the side surface and the bottom surface of the first pyramidal velvet structure 15, and the base angle A2 of the second pyramidal velvet structure 16 is the angle between the side surface and the bottom surface of the second pyramidal velvet structure 16. Controlling the base angle of the first pyramidal velvet structure 15 to be greater than or equal to the base angle of the second pyramidal velvet structure 16 facilitates better reflection of light from the first pyramidal velvet structure 15 onto the inclined sidewall 132, and facilitates secondary absorption of the reflected light from the first pyramidal velvet structure 15, thereby further improving optical performance. Preferably, the base angle A1 of the first pyramidal velvet structure 15 is greater than the base angle A2 of the second pyramidal velvet structure 16, allowing the inclined sidewall 132 to better absorb the reflected light from the first pyramidal velvet structure 15.

[0045] As an embodiment of this utility model, the base angle A2 of the second pyramid velvet structure 16 is 50° to 70°.

[0046] In this embodiment, the bottom angle A2 of the second pyramid velvet structure 16 is controlled to be 50° to 70°, which can achieve a good anti-reflection effect of the second pyramid velvet structure 16 and ensure the uniformity of the deposition of the passivation film layer on the first surface 11 of the non-groove area 14, thereby giving the passivation film layer on the first surface 11 of the non-groove area 14 good passivation performance.

[0047] As an embodiment of this utility model, the base angle A2 of the second pyramid velvet structure 16 is 50° to 60°.

[0048] In this embodiment, the bottom angle A2 of the second pyramid velvet structure 16 is controlled to be 50° to 60°, which further achieves a good anti-reflection effect of the second pyramid velvet structure 16 and better ensures the uniformity of the deposition of the passivation film layer on the first surface 11 of the non-groove area 14, so that the passivation film layer on the first surface 11 of the non-groove area 14 has good passivation performance at the same time.

[0049] As an embodiment of the present invention, a plurality of grooves 13 are arranged at intervals along the first direction X, and the grooves 13 penetrate the first surface 11 of the silicon wafer 1 along the second direction Y, wherein the first direction X and the second direction Y intersect.

[0050] In this embodiment, the first direction X and the second direction Y can be perpendicular or not. Preferably, the first direction X and the second direction Y are perpendicular. For example, the first direction X can be the length direction of the solar cell, and the second direction Y can be the width direction of the solar cell. Figure 2 As shown, from the top view of the solar cell, multiple grooves 13 are arranged sequentially at intervals along the first direction X, and the grooves 13 penetrate the first surface 11 of the silicon wafer 1 along the second direction Y, making the grooves 13 elongated. This allows the oblique sidewalls 132 of the grooves 13 to be longer along the second direction Y, which facilitates better secondary absorption of reflected light from the first pyramidal textured structure 15, further improving optical performance. In other embodiments, from the top view of the solar cell, the grooves 13 can also be any of the following shapes: triangular, circular, square, rhomboid, or polygonal. Of course, the grooves 13 can also be other irregular shapes.

[0051] As one embodiment of this utility model, the distance D between the edges of two adjacent grooves 13 is 20 to 1000 micrometers.

[0052] In this embodiment, the distance between the edges of the two grooves 13 is the distance between the closest edges of two adjacent grooves 13. Controlling the distance between the edges of two adjacent grooves 13 to be 20-1000 micrometers can not only improve the optical performance of the solar cell, but also facilitate the processing of the grooves 13.

[0053] As one embodiment of this utility model, the distance D between the edges of two adjacent grooves 13 is 20 to 200 micrometers.

[0054] In this embodiment, the distance between the edges of two adjacent grooves 13 is controlled to be 20 to 1000 micrometers to avoid the distance between the edges of two adjacent grooves 13 being too large or too small. This can not only improve the optical performance of the solar cell, but also facilitate the processing of the grooves 13.

[0055] As one embodiment of the present invention, the width W of the groove 13 along the first direction X is 20 to 200 micrometers.

[0056] In this embodiment, the width of the groove 13 along the first direction X is controlled to be 20 to 200 micrometers to avoid the width W of the groove 13 along the first direction X being too large or too small. This can not only improve the optical performance of the solar cell, but also prevent the width W of the groove 13 from being too large, thus ensuring the good passivation performance of the first surface 11 of the solar cell.

[0057] As an embodiment of the present invention, the bottom dimension of the first pyramid velvet structure 15 is smaller than the bottom dimension of the second pyramid velvet structure 16.

[0058] In this embodiment, the bottom dimension of the first pyramidal textured structure 15 can be either the diagonal dimension or the side length of the bottom surface of the first pyramidal textured structure 15. The bottom dimension of the second pyramidal textured structure 16 can be either the diagonal dimension or the side length of the bottom surface of the second pyramidal textured structure 16. That is, the diagonal dimension of the bottom surface of the first pyramidal textured structure 15 is smaller than the diagonal dimension of the bottom surface of the second pyramidal textured structure 16, or the side length of the bottom surface of the first pyramidal textured structure 15 is smaller than the side length of the bottom surface of the second pyramidal textured structure 16. Controlling the bottom dimension of the first pyramidal textured structure 15 to be smaller than the bottom dimension of the second pyramidal textured structure 16 makes the textured surface of the non-grooved area 14 flatter than the textured surface of the grooved area 13, making the film deposition on the first surface 11 on the second pyramidal textured structure 16 in the non-grooved area 14 more uniform, which is beneficial to improving the passivation effect of the first surface 11.

[0059] As an embodiment of the present invention, the diagonal length of the bottom of the first pyramid velvet structure 15 is 0.8 to 2 micrometers; the diagonal length of the bottom of the second pyramid velvet structure 16 is 3 to 8 micrometers.

[0060] In this embodiment, the diagonal length of the bottom of the first pyramid textured structure 15 is controlled to be 0.8 to 2 micrometers; the diagonal length of the bottom of the second pyramid textured structure 16 is controlled to be 3 to 8 micrometers. This not only achieves good solar anti-reflection effect for both the first pyramid textured structure 15 and the second pyramid textured structure 16, but also ensures that the passivation film layer on the first surface 11 of the first pyramid textured structure 15 and the second pyramid textured structure 16 is deposited more uniformly, thus guaranteeing a good passivation effect for the passivation film layer on the first surface 11 of the solar cell.

[0061] Please refer to this again. Figure 3 As an embodiment of this utility model, the depth H of the groove 13 is 1 to 20 micrometers.

[0062] In this embodiment, the height difference between the first pyramidal textured structure 15 in the inner region of the groove 13 and the second pyramidal textured structure 16 in the outer region of the groove 13 is H. The depth H of the groove 13 is controlled to be 1 to 20 micrometers to avoid the groove 13 being too deep or too shallow. On the one hand, this avoids the groove 13 being too deep, which would affect the structural strength of the silicon wafer 1 and ensure good structural strength of the silicon wafer 1. On the other hand, it avoids the groove 13 being too shallow, ensuring that the inclined sidewall 132 of the groove 13 has a good light absorption effect on the first pyramidal textured structure 15.

[0063] This invention also provides a battery assembly including the solar cell described in the above embodiments. It should be noted that this battery assembly has the same or similar beneficial effects as the solar cell described above, and the related aspects between the two can be referred to each other; to avoid repetition, they will not be repeated here.

[0064] In this embodiment, multiple solar cells in the battery module can be connected in series to form a battery string, thereby achieving series current output. For example, the battery cells can be connected in series by setting solder strips (busbars, interconnecting strips), conductive backplates, etc.

[0065] It is understood that in such embodiments, the battery assembly may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back of the solar cells, the photovoltaic glass, and adjacent cells. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0066] Photovoltaic glass can be applied to the encapsulating film on the front of solar cells. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cells while minimizing impact on their efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cells together, providing sealing, insulation, and waterproofing / moisture protection for the solar cells.

[0067] The backsheet can be attached to the encapsulating film on the back of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, aluminum alloy TPT composite encapsulating film, etc., and the specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell, encapsulating film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire solar cell module, providing stable support and installation. For example, the solar cell module can be installed at the desired location using the metal frame.

[0068] This utility model embodiment also provides a photovoltaic system, which includes the battery module of the above embodiment. It should be noted that the photovoltaic system has the same or similar beneficial effects as the above-described solar cell module, and the related parts between the two can be referred to each other. To avoid repetition, they will not be described again here.

[0069] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple solar cell modules; for example, multiple solar cell modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0070] In the description of this specification, references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A solar cell, characterized in that, The device includes a silicon wafer, the first surface of which is provided with a plurality of grooves, the first surface of which includes a non-groove area located outside the grooves, the grooves including a bottom wall and an inclined side wall, the inclined side wall connecting the bottom wall and the non-groove area, the bottom wall being provided with a first pyramidal textured surface structure, the non-groove area being provided with a second pyramidal textured surface structure, and the angle between the inclined side wall and the bottom surface of the first pyramidal textured surface structure being 55° to 85°.

2. The solar cell according to claim 1, characterized in that, The angle between the inclined sidewall and the bottom surface of the first pyramid velvet structure is the same as the bottom angle of the first pyramid velvet structure.

3. The solar cell according to claim 1, characterized in that, The angle between the sloping sidewall and the bottom surface of the first pyramid velvet structure is 60° to 70°.

4. The solar cell according to claim 1, characterized in that, The base angle of the first pyramid velvet structure is greater than or equal to the base angle of the second pyramid velvet structure.

5. The solar cell according to claim 1, characterized in that, The base angle of the second pyramid velvet structure is 50° to 70°.

6. The solar cell according to claim 1, characterized in that, The base angle of the second pyramid velvet structure is 50° to 60°.

7. The solar cell according to claim 1, characterized in that, The plurality of grooves are arranged at intervals along a first direction, and the grooves penetrate the first surface of the silicon wafer along a second direction, wherein the first direction and the second direction intersect.

8. The solar cell according to claim 7, characterized in that, The distance between the edges of two adjacent grooves is 20 to 1000 micrometers.

9. The solar cell according to claim 7 or 8, characterized in that, The distance between the edges of two adjacent grooves is 20 to 200 micrometers.

10. The solar cell according to claim 7, characterized in that, The width of the groove along the first direction is 20 to 200 micrometers.

11. The solar cell according to claim 1, characterized in that, The bottom dimension of the first pyramid velvet structure is smaller than the bottom dimension of the second pyramid velvet structure.

12. The solar cell according to claim 1, characterized in that, The diagonal length of the bottom of the first pyramid velvet structure is 0.8 to 2 micrometers; the diagonal length of the bottom of the second pyramid velvet structure is 3 to 8 micrometers.

13. The solar cell according to claim 1, characterized in that, The depth of the groove is 1 to 20 micrometers.

14. A battery assembly, characterized in that, Including the solar cell as described in any one of claims 1 to 13.

15. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 14.

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