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, this solar cell includes: silicon base, the back light surface of silicon base has P type area and N type area along the first direction alternate arrangement, interval region is arranged between P type area and N type area, several first nap structure are arranged in interval region, and first nap structure is four pyramid, wherein the inclination angle of at least two opposite conical surfaces of four pyramid is different. Improve the diffuse reflection effect, reduce the escape of light, and then improve the absorption efficiency of light of cell.

Description

Technical Field

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

[0002] In the field of solar cell technology, improving the light absorption efficiency of cells has always been a key research direction. Existing solar cells, after light shines on their surface, suffer from a lack of effective light processing structures, resulting in significant light reflection at the surface—a phenomenon known as light escape. This light escape drastically reduces the amount of light that can be absorbed by the cell and converted into electrical energy, leading to low light absorption and consequently affecting the cell's power generation efficiency.

[0003] Therefore, developing a battery structure that can effectively reduce light escape and improve light absorption efficiency is of great practical significance. Utility Model Content

[0004] This invention provides a solar cell, a battery module, and a photovoltaic system, aiming to solve the problems of light escape and low absorption rate.

[0005] This invention is achieved as follows: a solar cell, comprising:

[0006] A silicon substrate has P-type regions and N-type regions alternately arranged along a first direction on its back surface. An interval region is provided between the P-type regions and the N-type regions. A plurality of first textured structures are provided in the interval region. The first textured structures are in the shape of a quadrangular pyramid, wherein at least two opposite pyramidal faces have different inclination angles.

[0007] Optionally, the inclination angle of the cone surface of the square pyramid ranges from 10° to 80°.

[0008] Optionally, the difference in the inclination angles of the two opposite faces of the square pyramid is greater than 6°.

[0009] Optionally, the maximum diagonal length of the base of the square pyramid is 0.2 to 5 μm.

[0010] Optionally, the first textured structure is uniformly distributed on the surface of the silicon substrate.

[0011] Optionally, the height of some of the first velvet structures is 0.3 to 3 μm.

[0012] Optionally, at least part of the bottom portion of the first velvet structure overlaps.

[0013] Optionally, the spacing between adjacent first velvet structures is 0.5 to 6 μm.

[0014] Optionally, the first velvet structure is oriented in the same direction.

[0015] Optionally, the silicon substrate has a second textured surface on its light-facing surface, the second textured surface being in the shape of a regular square pyramid.

[0016] This invention also provides a battery assembly, including the aforementioned solar cell.

[0017] This utility model also provides a photovoltaic system, including the above-mentioned battery components.

[0018] The beneficial effects achieved by this utility model are due to the provision of a first velvet structure in the interval area between the P-type region and the N-type region. The first velvet structure is in the shape of a square pyramid, and the at least two opposite pyramidal faces have different inclination angles, which improves the diffuse reflection effect, reduces light escape, and thus improves the light absorption efficiency of the battery. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a solar cell structure provided by this utility model;

[0020] Figure 2 This is a top view electron microscope schematic diagram of the first textured surface structure provided by this utility model;

[0021] Figure 3 This is a side electron microscope schematic diagram of the first textured surface structure provided by this utility model;

[0022] Figure 4 This is a schematic diagram of the first velvet structure provided by this utility model;

[0023] Figure 5 This is a schematic diagram of the optical path of the first and second sets of solar cells;

[0024] Figure 6 This is another structural schematic diagram of the solar cell provided by this utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 100. Solar cell; 101. Silicon substrate; 110. N-type region; 111. First tunneling layer; 112. N-type doped layer; 120. P-type region; 121. Second tunneling layer; 122. P-type doped layer; 130. Spacer region; 131. First textured structure; 140. Second textured structure; 150. Passivation antireflection layer. 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 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 utility model, and should not be construed as limiting this utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this utility model and are not intended to limit this utility model.

[0028] In the description of this utility model, 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. 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] 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 utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] 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.

[0032] 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, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0033] This invention provides a first textured surface structure in the space between the P-type and N-type regions. The first textured surface structure is in the shape of a four-sided pyramid, and the at least two opposite pyramidal faces have different inclination angles, which improves the diffuse reflection effect, reduces light escape, and thus improves the light absorption efficiency of the battery.

[0034] Example 1

[0035] like Figures 1 to 4 As shown, this embodiment provides a solar cell 100, including:

[0036] A silicon substrate 101 has P-type regions 120 and N-type regions 110 arranged alternately along a first direction on its backlight surface. An interval region 130 is provided between the P-type regions 120 and N-type regions 110. A plurality of first textured structures 131 are provided in the interval region 130. The first textured structures 131 are in the shape of a quadrangular pyramid, wherein at least two opposite pyramidal faces have different inclination angles.

[0037] The silicon substrate 101 has two main surfaces: a light-facing surface and a back-lighting surface. The light-facing surface directly faces the sunlight, while the back-lighting surface is on the other side. The two surfaces are positioned opposite each other.

[0038] Two distinct regions, a P-type region 120 and an N-type region 110, are arranged alternately on the backlight surface of the silicon substrate 101. Specifically, a plurality of P-type regions 120 and a plurality of N-type regions 110 are arranged alternately along a first direction, and both P-type regions 120 and N-type regions 110 extend along a second direction, which intersects the first direction. The P-type regions 120 and N-type regions 110 can be arranged alternately along the lateral direction of the silicon substrate 101 and both extend along the longitudinal direction; that is, the first direction can be the lateral direction of the back contact battery, and the second direction can be the longitudinal direction of the back contact battery, and the two are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction can also be other directions, for example, they can be the diagonal directions of the silicon substrate 101, and no specific limitation is made here.

[0039] A P-type doped layer 122 is disposed within the P-type region 120, and an N-type doped layer 112 is disposed within the N-type region 110. The P-type doped layer 122 and the N-type doped layer 112 form regions with different electrical characteristics, supporting the formation of the PN junction and the separation of charge carriers. Specifically, the P-type region 120 has a first tunneling layer 111 and a P-type doped layer 122 stacked on the silicon substrate 101, and the N-type region 110 has a second tunneling layer 121 and an N-type doped layer 112 stacked on the silicon substrate 101. When photogenerated charge carriers (electrons and holes) move towards the electrode under the influence of an electric field, they encounter a potential barrier formed by the tunneling layer. Due to the tunneling effect, some charge carriers can pass through the tunneling layer to reach the corresponding electrode, where they are collected to form a current. This reduces the recombination of charge carriers at the interface and improves the photoelectric conversion efficiency of the battery.

[0040] The spacer region 130 is located between the P-type region 120 and the N-type region 110. Typically, the spacer region is a trench, preventing the P-type region 120 and the N-type region 110 from contacting each other, thus isolating them. This prevents unnecessary recombination of charge carriers between the P-type region 120 and the N-type region 110, thereby improving the photoelectric conversion efficiency of the cell.

[0041] The first textured structure 131 is in the shape of a square pyramid. A square pyramid is a solid geometric figure with four lateral faces and a base, the four lateral faces intersecting at a single vertex. At least two opposite pyramidal faces of the first textured structure 131 have different inclination angles. Specifically, a pyramidal face is formed by two adjacent pyramids and the base. When the angles between the two adjacent pyramids and the base are equal, the angle between the resulting pyramidal face and the base is a constant value; when the angles between the two adjacent pyramids and the base are unequal, the angle between the resulting pyramidal face and the base is a variable value. The fact that at least two opposite pyramidal faces have different inclination angles means that when the angles between the two opposite pyramidal faces and the base are constant values, the corresponding constant values ​​are different; when the angles between the two opposite pyramidal faces and the base are variable values, the corresponding extreme values ​​(maximum and / or minimum values) of the variable values ​​are different, and / or the patterns of change of the corresponding variable values ​​are different.

[0042] The conical surfaces with different tilt angles allow incident light to undergo multiple reflections and scatterings on the surface of the first textured structure 131. When light shines on different conical surfaces of the square pyramid, the light is reflected at different angles due to the difference in the tilt angle of the conical surfaces, thereby enhancing the diffuse reflection effect and increasing the propagation path of light inside the battery. This allows more light to be absorbed by the silicon substrate 101, improving the battery's light absorption efficiency.

[0043] The first textured structure 131 is disposed within the spacer region 130. On one hand, it can additionally increase the cell's light absorption without affecting the structure and performance of the P-type region 120 and the N-type region 110. On the other hand, it can also increase the propagation path of light in the spacer region 130, allowing more light to reach the P-type region 120 and the N-type region 110, promoting the generation of photogenerated carriers, and thus improving the cell's photoelectric conversion efficiency. Simultaneously, the main function of the spacer region 130 is to isolate the P-type region 120 and the N-type region 110, preventing carrier recombination. The presence of the first textured structure 131 can further improve the performance of the spacer region 130. Because the first textured structure 131 increases light absorption, the number of photogenerated carriers generated in the spacer region 130 increases. These carriers can move towards the P-type region 120 or the N-type region 110 through diffusion, thereby reducing the probability of recombination within the spacer region 130 and improving carrier collection efficiency.

[0044] Specifically, such as Figure 5As shown, two sets of solar cells 100 were compared and tested. The first set of solar cells 100 had a first textured surface structure 131 in the spacing region, while the second set of solar cells 100 had a regular square pyramidal textured surface structure in the spacing region. The photoelectric conversion efficiency (Bta), open-circuit voltage (Voc), short-circuit current (Isc), and fill factor (EF) of each solar cell 100 were measured, and the data obtained are recorded in the table below:

[0045] Group 1 26.65％ 0.7478 15.096 82.49 Group 2 26.53％ 0.7466 15.063 82.44

[0046] As can be seen from the table above, the photoelectric conversion efficiency of the first group of solar cells 100 is higher than that of the second group of solar cells 100, especially the short-circuit current of the first group of solar cells 100 is greater than that of the second group of solar cells 100. The main reason is that the spacing region 130 of the backlight surface of the first group of solar cells 100 adopts a first textured surface structure 131, which causes the transmitted light entering the cell from the light-receiving surface to be reflected at different angles on the backlight surface. When the reflected light returns to the light-receiving surface, it can be reflected back into the cell, increasing the cell's absorption of light, thereby increasing the short-circuit current and improving the conversion efficiency of the solar cell 100.

[0047] In this embodiment, a first textured surface structure 131 is provided in the interval region 130 between the P-type region 120 and the N-type region 110. The first textured surface structure 131 is in the shape of a square pyramid. The at least two opposite pyramidal faces have different tilt angles, which improves the diffuse reflection effect, reduces light escape, and thus improves the light absorption efficiency of the battery.

[0048] In some embodiments, the backlight surface of the silicon substrate 101 corresponding to the P-type region 120 and the N-type region 110 is a polished surface, which can effectively reduce parasitic absorption and enable more photogenerated carriers to reach the corresponding electrodes smoothly, thereby improving the carrier collection efficiency.

[0049] In some embodiments, the inclination angle of the cone face of the square pyramid ranges from 10° to 80°.

[0050] When the tilt angle is too small, less than 10°, the surface of the square pyramid becomes very flat, almost like a plane. This significantly reduces the reflection and scattering of light on the surface of the first textured structure 131, causing more light to be reflected near-specularly. This fails to effectively increase the light propagation path within the battery, leading to a decrease in the battery's light absorption efficiency and photoelectric conversion efficiency. If the tilt angle is too large, greater than 80°, the square pyramid becomes too sharp. On one hand, such a sharp structure is difficult to manufacture, easily resulting in structural damage or unevenness; on the other hand, an overly sharp structure causes some light to exit directly from the top of the pyramid during reflection, preventing multiple reflections and absorptions within the battery, also reducing light absorption efficiency.

[0051] By controlling the tilt angle within the range of 10° to 80°, the effective reflection and scattering of light inside the battery can be achieved while ensuring the ease of manufacturing the first textured surface structure 131. Conical surfaces with different tilt angles allow light to be reflected at different angles, increasing the propagation path of light inside the battery, thereby improving the battery's light absorption efficiency and ultimately enhancing the photoelectric conversion efficiency.

[0052] In some embodiments, the difference in the inclination angles of the two opposite faces of the square pyramid is greater than 6°.

[0053] When the difference in tilt angle between the relative conical surfaces is small, less than 6°, the shape of the square pyramid is relatively regular, and the difference in light reflection is not obvious, failing to fully utilize the scattering effect of conical surfaces with different tilt angles. The reflection and scattering effect of light on the surface of the first textured structure 131 is limited, and the increase in the light propagation path is not significant, resulting in a lack of significant improvement in the light absorption efficiency of the battery.

[0054] When the difference in tilt angle between two opposing faces of the square pyramid exceeds 6°, the differences in reflection characteristics between the different faces become more pronounced, and light undergoes more complex reflection and scattering phenomena on the surface of the first textured structure 131. This further increases the propagation path of light inside the battery, allowing more light to be absorbed by the silicon substrate 101, thereby improving the photoelectric conversion efficiency of the battery.

[0055] In some embodiments, the maximum diagonal length of the base of the square pyramid is 0.2–5 μm. Specifically, it can be 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, 1 μm, 1.5 μm, 2 μm, 2.6 μm, 3 μm, 3.4 μm, 4 μm, 4.5 μm, or 5 μm, or other values ​​within the range of 0.2–5 μm, which are not limited here.

[0056] The base of a square pyramid is a quadrilateral with two diagonals, the longer of which is the longest diagonal. The larger the base of the pyramid, the larger the pyramid's size. When the length of the longest diagonal of the pyramid's base is too small, less than 0.2 μm, the pyramid's size will be very small. On one hand, such a small structure requires higher precision and more advanced processes in manufacturing, increasing manufacturing difficulty and cost. On the other hand, a small pyramid may not effectively scatter light, as the wavelength of light is typically within a certain range, and a small structure has limited scattering effect, failing to fully utilize the light absorption-enhancing effect of the first textured surface structure 131. If the length of the longest diagonal of the pyramid's base is too large, greater than 5 μm, the pyramid's size will increase accordingly. This would result in the first textured surface structure 131 on the battery surface being too rough, potentially causing significant light loss during reflection. Furthermore, an excessively large structure may affect the flatness and uniformity of the battery surface, reducing the overall performance of the battery.

[0057] By controlling the maximum diagonal length of the square pyramidal base within the range of 0.2–5 μm, it is possible to ensure that the first textured structure 131 can effectively scatter light while avoiding excessive manufacturing difficulties and issues related to the flatness of the battery surface. Appropriate dimensions allow for ideal reflection and scattering of light on the surface of the first textured structure 131, increasing the light propagation path within the battery and improving its light absorption efficiency.

[0058] In some embodiments, the first textured structure 131 is uniformly distributed on the surface of the silicon substrate 101.

[0059] If the first textured surface structure 131 is unevenly distributed, it will lead to inconsistent light absorption and scattering effects in different areas of the battery surface. In areas where the first textured surface structure 131 is dense, the light absorption and scattering effects are better, but the excessive density of the structure may affect the flatness of the battery surface and the transport of charge carriers; in areas where the first textured surface structure 131 is sparse, the light absorption and scattering effects are poor, and the light energy cannot be fully utilized. This non-uniformity will lead to differences in photoelectric conversion efficiency inside the battery, reducing the overall performance and stability of the battery.

[0060] The uniform distribution of the first textured surface 131 on the surface of the silicon substrate 101 makes the absorption and scattering of light on the battery surface more uniform. This allows the entire battery surface to effectively absorb light, improving the battery's efficiency in utilizing light energy. Simultaneously, the uniform distribution helps ensure the uniformity of charge carrier generation and transport within the battery, improving the overall performance and stability of the battery and reducing performance fluctuations during use.

[0061] In some embodiments, the height of the plurality of first velvet structures 131 is 0.3 to 3 μm. Specifically, it can be 0.3 μm, 0.5 μm, 0.7 μm, 0.9 μm, 1.1 μm, 1.5 μm, 2 μm, 2.5 μm, or 3 μm, or other values ​​between 0.3 and 3 μm, which are not limited here.

[0062] The first textured structure 131 is a square pyramid shape, and its height refers to the vertical distance from the base to the vertex of the pyramid. When the height of the first textured structure 131 is too small, less than 0.3 μm, its scattering and light-trapping effects on light will be significantly weakened. When light is reflected from such a low structure, the propagation path increases only slightly, which cannot sufficiently increase the residence time of light inside the battery and the probability of absorption, resulting in low light absorption efficiency of the battery and thus affecting the photoelectric conversion efficiency. When the height of the first textured structure 131 is too large, greater than 3 μm, on the one hand, it is difficult to ensure the uniformity and stability of such a tall structure during manufacturing, which can easily lead to structural collapse or deformation. On the other hand, an excessively tall structure may increase the surface roughness of the battery too much, leading to an increase in the recombination rate on the battery surface and increased carrier loss during transport, which will also reduce the photoelectric conversion efficiency of the battery.

[0063] By controlling the height of the first textured structure 131 between 0.3 and 3 μm, the relationship between light scattering and trapping effects and the battery manufacturing process and surface properties can be effectively balanced. A suitable height allows light to be reflected and scattered multiple times between the first textured structures 131, increasing the light propagation path inside the battery and improving light absorption efficiency. Simultaneously, it ensures structural stability and good surface properties, which is beneficial for carrier collection and transport, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0064] In some embodiments, at least the bottom portions of adjacent first velvet structures 131 overlap.

[0065] Within the spacer region 130 of the silicon substrate 101, adjacent pyramidal first textured structures 131 are not completely independent; rather, at least some of the bottoms of adjacent structures partially overlap. This partial overlap at the bottom of adjacent first textured structures 131 enhances the continuity and synergy between them. When light shines on the overlapping area, more complex reflection and scattering phenomena occur, further increasing the light propagation path inside the battery and improving light absorption efficiency. Furthermore, this overlapping structure can also increase the mechanical strength of the battery surface to some extent, improving battery stability.

[0066] In some embodiments, the spacing between adjacent first velvet structures 131 is 0.5 to 6 μm. Specifically, it can be 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.6 μm, 3 μm, 3.4 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, or 6 μm, or other values ​​within the range of 0.5 to 6 μm, which are not limited here.

[0067] In some embodiments, the first velvet structure 131 is oriented in a consistent manner.

[0068] In other words, the vertices of the quadrangular pyramids in the first textured structure 131 all face the same direction. This consistent orientation of the first textured structure 131 allows light to exhibit a certain regularity during reflection and scattering. This facilitates the formation of an ordered light-trapping structure, causing light to be reflected and scattered multiple times along a specific path inside the battery, increasing the residence time and probability of absorption, thereby improving the battery's light absorption efficiency. Furthermore, the consistent orientation also contributes to a uniform distribution of the electric field on the battery surface, which is beneficial for the directional transport of charge carriers, reduces carrier recombination, and further improves the battery's photoelectric conversion efficiency.

[0069] In some embodiments, such as Figure 6 As shown, the solar cell 100 also includes a passivation antireflection layer 150. The passivation antireflection layer 150 is disposed on the outermost layer of the solar cell 100, covering all exposed surfaces along the existing functional layers, gaps, and the outer contour of the silicon substrate. The passivation antireflection layer 150, covering the outermost layer, protects the functional layers within its coverage. It can also saturate dangling bonds through chemical bonding and other methods, reducing the number of surface states, lowering the recombination probability of charge carriers on the surface, and improving the charge carrier collection efficiency. At the same time, by adjusting its refractive index and thickness, the passivation antireflection layer 150 utilizes the principle of light interference to cancel out reflected light, thereby reducing the energy of reflected light, increasing the cell's light absorption, and thus improving the cell's short-circuit current and photoelectric conversion efficiency.

[0070] The passivation antireflection layer 150 can be formed from a single film material or from a stack of multiple film materials. Specifically, it can be formed from silicon nitride (SiN). x Titanium dioxide (TiO2), aluminum oxide (Al2O3), silicon nitride (SiN) x One or more of the composite films, etc., are used to form a passivation and antireflection layer 150.

[0071] Example 2

[0072] like Figure 5 As shown, in some embodiments, the silicon substrate 101 has a second textured structure 140 on its light-facing surface, and the second textured structure 140 is in the shape of a regular square pyramid.

[0073] The first textured structure 131 and the second textured structure 140 work together to greatly improve the light absorption efficiency of the solar cell 100. On the light-facing side, the second textured surface, through its square pyramidal structure, causes multiple reflections and scattering of light, guiding it into the cell. After the light propagates to the first textured structure 131 on the back-facing side, the different tilt angles of at least two opposing pyramidal faces of the first textured structure 131 further increase the propagation path of the light inside the cell, giving the light more opportunities to be absorbed by the silicon substrate 101, reducing light reflection losses, and thus improving the photoelectric conversion efficiency.

[0074] Example 3

[0075] This embodiment provides a battery assembly, including the solar cell 100 in the above embodiment.

[0076] The battery module may include multiple solar cells 100. The multiple solar cells 100 in the battery module can be connected in series to form a battery string. The battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, the connection between the individual cells can be achieved by welding the welding strips, or the connection between the individual battery strings can be achieved by busbars.

[0077] The battery module may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulant film (not shown in the figures). The encapsulant film can be filled between the light-facing side of the solar cell 100 and the photovoltaic glass, the back-facing side and the backsheet, and adjacent cells. As a filler, it can be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulant film can be EVA film or POE film, and the specific choice can be made according to the actual situation. There are no restrictions here.

[0078] Photovoltaic glass can be applied to the encapsulating film on the light-facing side of the solar cell 100. The photovoltaic glass can be ultra-clear glass, which has 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 cell 100 while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell 100 together, providing sealing, insulation, waterproofing, and moisture protection for the solar cell 100.

[0079] The backsheet can be attached to the adhesive film on the back side of the solar cell 100. The backsheet provides protection and support for the solar cell 100, offering reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite adhesive film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell 100, adhesive film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0080] The beneficial effects of the battery module in this embodiment are equivalent to those of the solar cell 100 described above, and will not be repeated here.

[0081] Example 4

[0082] This embodiment provides a photovoltaic system, including the aforementioned battery module.

[0083] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in 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's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains grid before being connected to the mains grid to achieve solar power supply.

[0084] The beneficial effects of the photovoltaic system in this embodiment are equivalent to the beneficial effects of the battery module described above, and will not be repeated here.

[0085] The above description is only a preferred embodiment of the present utility model and is 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, include: A silicon substrate has P-type regions and N-type regions alternately arranged along a first direction on its back surface. An interval region is provided between the P-type regions and the N-type regions. A plurality of first textured structures are provided in the interval region. The first textured structures are in the shape of a quadrangular pyramid, wherein at least two opposite pyramidal faces have different inclination angles.

2. The solar cell as described in claim 1, characterized in that, The inclination angle of the pyramidal surface ranges from 10° to 80°.

3. The solar cell as described in claim 2, characterized in that, The difference in the inclination angle between the two opposite faces of the square pyramid is greater than 6°.

4. The solar cell as described in claim 1, characterized in that, The maximum diagonal length of the base of the square pyramid is 0.2 to 5 μm.

5. The solar cell as described in claim 1, characterized in that, The first textured surface is uniformly distributed on the surface of the silicon substrate.

6. The solar cell as claimed in claim 1, characterized in that, The height of some of the first velvet structures is 0.3 to 3 μm.

7. The solar cell according to claim 1, characterized in that, The bottom portions of the first velvet structure overlap at least partially.

8. The solar cell as claimed in claim 7, characterized in that, The spacing between adjacent first velvet structures is 0.5 to 6 μm.

9. The solar cell according to claim 1, characterized in that, The first velvet structure faces the same direction.

10. The solar cell according to claim 1, characterized in that, The silicon substrate has a second textured surface on its light-facing surface, and the second textured surface is in the shape of a regular square pyramid.

11. A battery assembly, characterized in that, Includes the solar cell described in any one of claims 1-10.

12. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 11.

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