Solar cell, cell assembly and photovoltaic system

Abstract

The present disclosure is applicable to the technical field of photovoltaics, and provides a solar cell, a cell assembly, and a photovoltaic system. The solar cell comprises a silicon substrate, the silicon substrate comprising a first region, the first region being provided with a plurality of first tower base structures and a plurality of second tower base structures, and at least some second tower base structures being arranged on the first tower base structures. Due to the composite arrangement of the first tower base structures and the second tower base structure, the complexity of the surface morphology of the first region increases, thereby significantly improving the photoelectric conversion efficiency and mechanical strength of solar cells.

Description

A solar cell, a solar module and a photovoltaic system

[0001] Cross-referencing

[0002] This disclosure claims priority to Chinese Patent Application No. 202410950720.8, filed on July 15, 2024, entitled “A Solar Cell, Battery Module and Photovoltaic System”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure pertains to the field of photovoltaic technology, and particularly relates to a solar cell, a solar module, and a photovoltaic system. Background Technology

[0004] Photovoltaic conversion efficiency and mechanical strength are two key performance indicators for solar cells. On the one hand, the feature size of existing textured surface structures is either too large or too small, which has a certain negative impact on subsequent film passivation and slurry contact interfaces, thus affecting cell performance.

[0005] On the other hand, traditional silicon wafers are prone to stress concentration during manufacturing and use, especially during polycrystalline silicon film growth at high temperatures, which can cause the wafers to bend. During automated production and transfer, silicon wafers are susceptible to mechanical damage such as microcracks, fragmentation, scratches, and edge chipping due to stress, affecting product yield and reliability. Summary of the Invention

[0006] This disclosure provides a solar cell, a solar module, and a photovoltaic system, aiming to solve the problems of significant deficiencies in mechanical performance, low photoelectric conversion efficiency, and poor product reliability in existing technologies.

[0007] This disclosure is implemented as follows: a solar cell includes:

[0008] A silicon substrate, the silicon substrate including a first region;

[0009] The first area is provided with a plurality of first tower base structures and a plurality of second tower base structures, with at least a portion of the second tower base structures placed on the first tower base structures.

[0010] Optionally, the longest diagonal length of the first tower base structure is greater than or equal to 2 μm and less than or equal to 60 μm.

[0011] Optionally, the longest diagonal length of the first tower base structure is greater than or equal to 5 μm and less than or equal to 40 μm.

[0012] Optionally, the longest diagonal length of the first tower base structure is greater than or equal to 10 μm and less than or equal to 30 μm.

[0013] Optionally, the longest diagonal length of the first tower base structure is greater than or equal to 15 μm and less than or equal to 30 μm.

[0014] Optionally, the longest diagonal length of the second tower base structure is greater than or equal to 0.5 μm and less than or equal to 30 μm.

[0015] Optionally, the longest diagonal length of the second tower base structure is greater than or equal to 1 μm and less than or equal to 30 μm.

[0016] Optionally, the longest diagonal length of the second tower base structure is greater than or equal to 1 μm and less than or equal to 20 μm.

[0017] Optionally, the longest diagonal length of the second tower base structure is greater than or equal to 5 μm and less than or equal to 20 μm.

[0018] Optionally, the ratio of the total area of ​​the orthographic projection of a plurality of the second tower base structures onto the first region to the area of ​​the first region is greater than 60%.

[0019] Optionally, it may also include a second region, which is located on the same side of the silicon substrate or on opposite sides of the silicon substrate.

[0020] Optionally, the second region may be provided with several third tower base structures.

[0021] Optionally, the longest diagonal length of the third tower base structure is greater than or equal to 2 μm and less than or equal to 60 μm.

[0022] Optionally, the longest diagonal length of the third tower base structure is greater than or equal to 5 μm and less than or equal to 40 μm.

[0023] Optionally, the longest diagonal length of the third tower base structure is greater than or equal to 10 μm and less than or equal to 30 μm.

[0024] Optionally, the longest diagonal length of the third tower base structure is greater than or equal to 15 μm and less than or equal to 30 μm.

[0025] Optionally, the longest diagonal length of the first tower base structure is greater than the longest diagonal length of the second tower base structure.

[0026] Optionally, the ratio of the longest diagonal length of the first tower base structure to the longest diagonal length of the third tower base structure is 0.5 to 2.

[0027] Optionally, the roughness of the first region is greater than the roughness of the second region.

[0028] Optionally, some of the first tower base structures are arranged in a linear array.

[0029] Optionally, some of the third tower base structures are arranged in a linear array.

[0030] Optionally, the first tower base structure and / or the second tower base structure are downwardly recessed structures.

[0031] Optionally, the depth of the downward indentation of the first tower base structure and / or the second tower base structure is greater than or equal to 0.05 μm and less than or equal to 2 μm.

[0032] Optionally, the third tower base structure is a downwardly recessed structure.

[0033] Optionally, the depth of the downward indentation of the third tower base structure is greater than or equal to 0.05 μm and less than or equal to 1.5 μm.

[0034] This disclosure also provides a battery assembly including the solar cell described above.

[0035] This disclosure also provides a photovoltaic system including the aforementioned battery module.

[0036] The beneficial effects achieved by this disclosure are that, due to the composite arrangement of the first and second tower base structures, the complexity of the surface morphology of the first region is increased, which can improve the photoelectric response and mechanical strength of the solar cell. Attached Figure Description

[0037] Figure 1 is a scanning electron microscope image of the first region of the solar cell provided in this disclosure at 1k magnification;

[0038] Figure 2 is a scanning electron microscope image of the first tower base structure of the solar cell provided in this disclosure at the first angle;

[0039] Figure 3 is a scanning electron microscope image of the first tower base structure of the solar cell provided in this disclosure at a second angle.

[0040] Figure 4 is a scanning electron microscope image of the first tower base structure of the solar cell provided in this disclosure at the third angle;

[0041] Figure 5 is a scanning electron microscope image of the second region of the solar cell provided in this disclosure at 1k magnification;

[0042] Figure 6 is a scanning electron microscope image of the third tower base structure of the solar cell provided in this disclosure at the first angle;

[0043] Figure 7 is a scanning electron microscope image of the third tower base structure of the solar cell provided in this disclosure at the third angle.

[0044] Explanation of reference numerals in the attached drawings: 101, First tower base structure; 102, Second tower base structure; 103, Third tower base structure. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the 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 this disclosure, and should not be construed as limiting this disclosure. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this disclosure and are not intended to limit this disclosure.

[0046] In the description of this disclosure, it should be understood that the terms “length”, “width”, “upper”, “lower”, “left”, “right”, “horizontal”, “top”, “bottom”, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0048] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0049] In this disclosure, unless otherwise expressly 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.

[0050] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. 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 this disclosure. 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, various specific examples of processes and materials are provided in this disclosure, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0051] The present invention discloses a composite arrangement of a first tower base structure and a second tower base structure, which increases the complexity of the surface morphology of the first region, thereby improving the photoelectric response and mechanical strength of the solar cell.

[0052] Example 1

[0053] As shown in Figures 1 to 3, this embodiment provides a solar cell, including:

[0054] A silicon substrate, the silicon substrate including a first region;

[0055] The first area is provided with a number of first tower base structures 101 and a number of second tower base structures 102, with at least some of the second tower base structures 102 placed on the first tower base structures 101.

[0056] A tower base structure refers to a microstructure disposed on a silicon substrate of a solar cell. These microstructures typically appear in the form of a tower or cone, with a planar top surface and a polygonal outer contour, specifically including at least one of rhombus, square, trapezoid, approximate rhombus, approximate square, and approximate trapezoid. A first tower base structure 101 and a second tower base structure 102 are formed on a first region of the silicon substrate through a certain process, with at least a portion of the second tower base structure 102 located on top of the first tower base structure 101.

[0057] The first tower base structure 101 and the second tower base structure 102 coexist. Specifically, the second tower base structure 102 and the first tower base structure 101 can be arranged side by side, or the second tower base structure 102 can be disposed on the top surface of the first tower base structure 101. This arrangement provides a more complex surface morphology, which is conducive to the subsequent deposition and formation of the film on the silicon substrate.

[0058] The combined presence of the first base structure 101 and the second base structure 102 increases the complexity of the surface morphology of the first region. The presence of these two structures causes multiple reflections and scatterings of incident light on the silicon substrate surface, increasing the optical path length within the silicon substrate. In particular, diffusely reflected light from the back side, after multiple reflections through the first and second base structures 101 and 102, can be more effectively absorbed by the silicon substrate. Due to the increased optical path length, photons travel a longer path within the silicon substrate, increasing the probability of absorption and thus improving the photoelectric response of the solar cell.

[0059] The composite texture of the first tower base structure 101 and the second tower base structure 102 also provides superior surface features, allowing the screen-printed metal paste to better fill the spaces between the tower base structures during electrode formation. This improved contact characteristic reduces the contact resistance between the electrode and the silicon substrate, thereby increasing the open-circuit voltage and fill factor of the battery.

[0060] Structurally, the combined arrangement of the first tower base structure 101 and the second tower base structure 102 helps to disperse and release the stress generated during the growth of polycrystalline silicon films on the silicon wafer under high-temperature conditions. The superposition of the first tower base structure 101 and the second tower base structure 102 provides multi-layered stress release paths, reducing stress concentration. By optimizing the shape and distribution of the tower base structure, the overall stress on the silicon wafer can be effectively reduced, decreasing its bending degree under high-temperature conditions. The improved stress distribution and reduced wafer bending make the silicon wafer less prone to mechanical damage such as fragmentation, scratches, and edge chipping during automated production and transfer, thereby improving production efficiency and product quality.

[0061] In this embodiment, by setting a first tower base structure 101 and a second tower base structure 102 on a silicon substrate, the photoelectric response and mechanical strength of the solar cell can be improved.

[0062] Example 2

[0063] Based on Example 1, the longest diagonal length of the first tower base structure 101 is greater than or equal to 2μm and less than or equal to 60μm.

[0064] Since the top surface of a tower base is mostly polygonal, the longest diagonal is the longest diagonal. Furthermore, experiments have shown that the top surface of a tower base is not excessively long and narrow; generally, the longer the longest diagonal, the larger the area of ​​the top surface of the tower base.

[0065] When measuring the longest diagonal length of the tower base, the surface calibration of the membrane layer can be directly measured using testing instruments such as optical microscopes, atomic force microscopes, scanning electron microscopes, and transmission electron microscopes.

[0066] The tower base structure is optimized by further limiting the longest diagonal dimension of the first tower base structure 101. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0067] Example 3

[0068] Based on Example 1, the longest diagonal length of the first tower base structure 101 is greater than or equal to 5 μm and less than or equal to 40 μm.

[0069] The tower base structure is optimized by further limiting the longest diagonal dimension of the first tower base structure 101. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0070] Example 4

[0071] Based on Example 1, the longest diagonal length of the first tower base structure 101 is greater than or equal to 10 μm and less than or equal to 30 μm.

[0072] The tower base structure is optimized by further limiting the longest diagonal dimension of the first tower base structure 101. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0073] Example 5

[0074] Based on Example 1, the longest diagonal length of the first tower base structure 101 is greater than or equal to 15 μm and less than or equal to 30 μm.

[0075] The tower base structure is optimized by further limiting the longest diagonal dimension of the first tower base structure 101. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0076] Example 6

[0077] Based on Example 1, the longest diagonal length of the second tower base structure 102 is greater than or equal to 0.5 μm and less than or equal to 30 μm.

[0078] The tower base structure is optimized by further limiting the longest diagonal dimension of the second tower base structure 102. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0079] Example 7

[0080] Based on Example 1, the longest diagonal length of the second tower base structure 102 is greater than or equal to 1 μm and less than or equal to 30 μm.

[0081] The tower base structure is optimized by further limiting the longest diagonal dimension of the second tower base structure 102. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0082] Example 8

[0083] Based on Example 1, the longest diagonal length of the second tower base structure 102 is greater than or equal to 1 μm and less than or equal to 20 μm.

[0084] The tower base structure is optimized by further limiting the longest diagonal dimension of the second tower base structure 102. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0085] Example 9

[0086] Based on Example 1, the longest diagonal length of the second tower base structure 102 is greater than or equal to 5 μm and less than or equal to 20 μm.

[0087] The tower base structure is optimized by further limiting the longest diagonal dimension of the second tower base structure 102. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the first region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0088] Example 10

[0089] Based on any one of Embodiments 5 to 10, the total area of ​​several second tower base structures 102 accounts for more than 60% of the area of ​​the first region.

[0090] Examples 5 to 10 further limit the longest diagonal length of the second tower base structure 102. It is not necessary for all second tower base structures 102 within the first region to conform to the limited dimensions; it is sufficient that the sum of the areas of all second tower base structures 102 conforming to the limited dimensions is greater than 60% of the total area of ​​the first region. Specifically, if the total area of ​​the first region is A, then the sum of the areas of all second tower base structures 102 conforming to the limited dimensions is greater than 0.6A. This ensures that the coverage of the second tower base structures 102 within the first region is sufficiently extensive, thereby achieving the desired optimization effect.

[0091] Example 11

[0092] Based on Embodiment 1, the solar cell further includes a second region, which is located on the same side of the silicon substrate or on opposite sides of the silicon substrate.

[0093] Specifically, the first and second regions can both be disposed on the same surface of the silicon substrate, meaning that the two regions coexist on the same side, possibly adjacent to each other or distributed on the surface in a specific manner. Alternatively, the first and second regions can be disposed on opposite sides of the silicon substrate, meaning that one region is located on the front side of the silicon substrate and the other region is located on the back side of the silicon substrate.

[0094] Example 12

[0095] As shown in Figures 5 to 7, based on Embodiment Twelve, a number of third tower base structures 103 are provided in the second region. Figures 6 and 7 are scanning electron microscope images of the third tower base structure 103 at the first angle and the third angle, respectively.

[0096] The inclusion of the third tower base structure 103 increases the complexity of the surface morphology of the second region, allowing the passivation layer to be more uniformly covered on the third tower base structure 103. This coverage effectively reduces surface density and lowers the recombination rate, thereby improving passivation quality.

[0097] The third tower base structure 103 provides superior surface characteristics, allowing the screen-printed metal paste to better fill the spaces between the tower base structures during electrode formation. This improved contact characteristic reduces the contact resistance between the electrode and the silicon substrate, thereby increasing the open-circuit voltage and fill factor of the battery.

[0098] The third tower base structure 103 can also be a downwardly recessed structure. It should be noted that, taking the third tower base structure 103 disposed on the surface of the second region of the silicon substrate as an example, the above-mentioned downwardly recessed structure can be understood as the third tower base structure 103 being recessed downward into the second region.

[0099] In some alternative embodiments, the third tower base structure is recessed to a depth greater than or equal to 0.05 μm and less than or equal to 1.5 μm. For example, as shown in FIG6, the third tower base structure 103 is recessed to a depth of 556 nm.

[0100] Example 13

[0101] Based on Example 13, the longest diagonal length of the third tower base structure 103 is greater than or equal to 2μm and less than or equal to 60μm.

[0102] The tower base structure is optimized by further limiting the longest diagonal dimension of the third tower base structure 103. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the second region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0103] Example 14

[0104] Based on Example 13, the longest diagonal length of the third tower base structure 103 is greater than or equal to 5 μm and less than or equal to 40 μm.

[0105] The tower base structure is optimized by further limiting the longest diagonal dimension of the third tower base structure 103. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the second region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0106] Example 15

[0107] Based on Example 13, the longest diagonal length of the third tower base structure 103 is greater than or equal to 10 μm and less than or equal to 30 μm.

[0108] The tower base structure is optimized by further limiting the longest diagonal dimension of the third tower base structure 103. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the second region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0109] Example 16

[0110] Based on Example 13, the longest diagonal length of the third tower base structure 103 is greater than or equal to 15 μm and less than or equal to 30 μm.

[0111] The tower base structure is optimized by further limiting the longest diagonal dimension of the third tower base structure 103. The optimized tower base structure can not only effectively release stress and reduce mechanical damage, but also further improve the passivation quality and electrode contact characteristics of the second region, thereby increasing the open circuit voltage and fill factor, and ultimately improving the overall conversion efficiency of the battery.

[0112] Example 17

[0113] Based on Embodiment 1, the longest diagonal length of the first tower base structure 101 is greater than the longest diagonal length of the second tower base structure 102.

[0114] The longest diagonal length of the first base structure 101 is greater than that of the second base structure 102, meaning that the first base structure 101 is larger than the second base structure 102. The larger size of the first base structure 101 helps to disperse stress on the silicon substrate, reducing stress concentration. The smaller size of the second base structure 102 can better adapt to changes in surface morphology, reducing the risk of mechanical damage. Simultaneously, the larger size of the first base structure 101 provides a larger coverage area for the passivation layer, improving passivation quality. The smaller size of the second base structure 102 allows for better contact with the electrode, reducing contact resistance and improving the open-circuit voltage and fill factor of the battery.

[0115] Example 18

[0116] Based on Embodiment Thirteen, the ratio of the longest diagonal length of the first tower base structure 101 to the longest diagonal length of the third tower base structure 103 is 0.5 to 2.

[0117] The longest diagonal length of the third tower base structure 103 can be greater than or equal to 0.5 times the longest diagonal length of the first tower base structure 101, while being less than or equal to 2 times the longest diagonal length of the first tower base structure 101. The design specifies a particular proportional relationship between the longest diagonal lengths of the first tower base structure 101 and the third tower base structure 103 to ensure that the tower base structures in the two regions can work together in coordination while leveraging their respective advantages.

[0118] Example 19

[0119] Based on Example 12, the roughness of the first region is greater than that of the second region.

[0120] Surface roughness refers to the degree of microscopic unevenness of a surface. Higher roughness means that the surface has more tiny protrusions or depressions. The first region has higher surface roughness, meaning that the surface in this region is more uneven and has more microstructures. The second region has lower surface roughness, and the surface is relatively smooth and flat.

[0121] This design of varying surface roughness can effectively improve photoelectric conversion efficiency, optimize electrode contact characteristics, reduce surface recombination effects, and contribute to improved mechanical properties.

[0122] Example 20

[0123] As shown in Figure 1, based on Embodiment 1, several first tower base structures 101 are arranged in a linear array.

[0124] Several first tower base structures 101 are arranged in a regular linear array within a first region, meaning they are arranged along a certain direction at a certain spacing and according to a certain pattern, forming a neat linear structure. The linear array arrangement of the first tower base structures 101 can be determined according to design requirements, with parameters such as array spacing, arrangement direction, and density to achieve optimal performance.

[0125] This configuration can distribute stress evenly, improve the simplicity and consistency of the manufacturing process, and thus further optimize the overall performance and reliability of solar cells.

[0126] Example 21

[0127] As shown in Figure 5, based on Embodiment 1, several third tower base structures 101 are arranged in a linear array.

[0128] Several third tower base structures 103 are arranged in a regular linear array within the second region, meaning they are arranged along a certain direction at a certain spacing and according to a certain pattern, forming a neat linear structure. The linear array arrangement of the third tower base structures 103 can be determined according to design requirements, with parameters such as array spacing, arrangement direction, and density to achieve optimal performance.

[0129] This configuration can distribute stress evenly, improve the simplicity and consistency of the manufacturing process, and thus further optimize the overall performance and reliability of solar cells.

[0130] Example 22

[0131] Based on Embodiment 1 and Embodiment 12, the first tower base structure 101 and / or the second tower base structure 102 are downwardly recessed structures, that is, the first tower base structure 101 and / or the second tower base structure 102 have downwardly recessed portions.

[0132] Specifically, both the first tower base structure 101 and the second tower base structure 102 may be recessed, or one of the first tower base structure 101 and the second tower base structure 102 may be recessed.

[0133] As shown in Figure 4, the first tower base structure 101 is a downwardly recessed structure. It should be noted that, taking the first tower base structure 101 being disposed on the surface of the first region of the silicon substrate as an example, the above-mentioned downwardly recessed structure can be understood as the first tower base structure 101 being recessed downward into the first region.

[0134] In some optional embodiments, the depth of the downward indentation of the first tower base structure and / or the second tower base structure is greater than or equal to 0.05 μm and less than or equal to 2 μm. For example, as shown in FIG4, the depth of the downward indentation of the first tower base structure 101 is 1.01 μm.

[0135] Example 23

[0136] This embodiment provides a battery assembly, including the solar cell of any of the above embodiments.

[0137] The beneficial effects obtained by the battery module in this embodiment are similar to those of the solar cell, and will not be described in detail here.

[0138] Example 24

[0139] This embodiment provides a photovoltaic system, including the battery module described in Embodiment 23 above.

[0140] The beneficial effects obtained by the photovoltaic system in this embodiment are similar to those of the battery module, and will not be described in detail here.

[0141] The above are merely preferred embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A solar cell, comprising: a silicon substrate, the silicon substrate comprising a first region; the first region is provided with a plurality of first pylon structures and a plurality of second pylon structures, at least part of the second pylon structures are disposed on the first pylon structures.

2. The solar cell of claim 1, wherein: a longest diagonal length of the first pylon structures is greater than or equal to 2 μm and less than or equal to 60 μm; or a longest diagonal length of the first pylon structures is greater than or equal to 5 μm and less than or equal to 40 μm; or a longest diagonal length of the first pylon structures is greater than or equal to 10 μm and less than or equal to 30 μm; or a longest diagonal length of the first pylon structures is greater than or equal to 15 μm and less than or equal to 30 μm.

3. The solar cell of claim 1, wherein: a longest diagonal length of the second pylon structures is greater than or equal to 0.5 μm and less than or equal to 30 μm; or a longest diagonal length of the second pylon structures is greater than or equal to 1 μm and less than or equal to 30 μm; or a longest diagonal length of the second pylon structures is greater than or equal to 1 μm and less than or equal to 20 μm; or a longest diagonal length of the second pylon structures is greater than or equal to 5 μm and less than or equal to 20 μm.

4. The solar cell as claimed in claim 2 or 3, wherein a ratio of a total area of a normal projection of the second pylon structures on the first region to an area of the first region is greater than 60%.

5. The solar cell of claim 1, wherein, further comprising a second region, the second region and the first region are located on the same side of the silicon substrate or on opposite sides of the silicon substrate.

6. The solar cell of claim 5, wherein, the second region is provided with a plurality of third pylon structures.

7. The solar cell of claim 6, wherein: a longest diagonal length of the third pylon structures is greater than or equal to 2 μm and less than or equal to 60 μm; or a longest diagonal length of the third pylon structures is greater than or equal to 5 μm and less than or equal to 40 μm; or a longest diagonal length of the third pylon structures is greater than or equal to 10 μm and less than or equal to 30 μm.

8. The solar cell of claim 1, wherein, a longest diagonal length of the first pylon structures is greater than a longest diagonal length of the second pylon structures.

9. The solar cell of claim 6, wherein, a ratio of a longest diagonal length of the first pylon structures to a longest diagonal length of the third pylon structures is 0.5 to 2.

10. The solar cell of claim 5, wherein, a roughness of the first region is greater than a roughness of the second region.

11. The solar cell of claim 1, wherein, the plurality of first pylon structures are in a linear array.

12. The solar cell of claim 6, wherein, the plurality of third pylon structures are in a linear array.

13. The solar cell of claim 1, wherein, the first pylon structures and / or the second pylon structures are downwardly recessed structures.

14. The solar cell of claim 13, wherein, a depth of the downward recess of the first pylon structures and / or the second pylon structures is greater than or equal to 0.05 μm and less than or equal to 2 μm.

15. The solar cell of claim 6, wherein, the third pylon structures are downwardly recessed structures.

16. The solar cell of claim 15, wherein, a depth of the downward recess of the third pylon structures is greater than or equal to 0.05 μm and less than or equal to 1.5 μm.

17. A battery assembly, wherein, comprising the solar cell of any one of claims 1 to 16.

18. A photovoltaic system, wherein, comprising the cell assembly of claim 17.

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