A method for preparing a solar cell, a solar cell, and a photovoltaic module.

Abstract

This application relates to a method for fabricating a solar cell, a solar cell, and a photovoltaic module, comprising: forming a first antireflection layer on a first surface of a substrate, wherein the reflectivity of the first surface after forming the first antireflection layer is R1; forming a second antireflection layer on a second surface of the substrate, wherein the reflectivity of the second surface after forming the second antireflection layer is R2; forming a mask layer on a side of the first antireflection layer away from the substrate, a side of the second antireflection layer away from the substrate, and a third surface intersecting the first and second surfaces; forming electrode grid lines on the first and second surfaces, wherein after forming the electrode grid lines, the reflectivity R3 of the mask layer corresponding to the first surface satisfies the following condition with respect to R1: 0.95R1≤R3≤1.05R1; and the reflectivity R4 of the mask layer corresponding to the second surface satisfies the following condition with respect to R2: 0.95R2≤R4≤1.05R2. By setting the mask layer, it is beneficial to reduce the possibility of background electroplating and edge leakage phenomena on the substrate, and also beneficial to improve the optical performance of the solar cell.

Description

Technical Field

[0001] This application relates to the field of photovoltaic cell technology, and in particular to a method for preparing a solar cell, a solar cell, and a photovoltaic module. Background Technology

[0002] With the development of technology, the application range of solar cells is becoming more and more widespread. During the preparation of solar cells, the damaged areas on the substrate surface are prone to background plating during the electroplating process. At the same time, the substrate is also prone to edge leakage during the electroplating process. These phenomena will affect the production quality and performance of solar cells. Summary of the Invention

[0003] This application provides a method for preparing a solar cell, a solar cell, and a photovoltaic module, which solves the problems of background electroplating and edge leakage in solar cells.

[0004] This application provides a method for preparing a solar cell, including:

[0005] A first antireflection layer is formed on the first surface of the substrate, and the reflectivity of the first surface after the formation of the first antireflection layer is R1;

[0006] A second antireflection layer is formed on the second surface of the substrate, and the reflectivity of the second surface after the formation of the second antireflection layer is R2;

[0007] A mask layer is formed on the side of the first antireflective layer away from the substrate, the side of the second antireflective layer away from the substrate, and a third surface that intersects with the first surface and the second surface;

[0008] Electrode grid lines are formed on the first surface and the second surface. After the electrode grid lines are formed, the reflectivity R3 and R1 of the mask layer corresponding to the first surface satisfy the following condition: 0.95R1≤R3≤1.05R1; the reflectivity R4 and R2 of the mask layer corresponding to the second surface satisfy the following condition: 0.95R2≤R4≤1.05R2.

[0009] In one possible implementation, the mask layer comprises at least one of silicon nitride, magnesium fluoride, titanium oxide, silicon oxynitride, and silicon oxide.

[0010] In one possible implementation, the mask layer is silicon nitride, magnesium fluoride, or titanium oxide, and the mask layer thickness d satisfies: 1nm ≤ d ≤ 30nm.

[0011] In one possible implementation, the mask layer is silicon oxynitride, and the mask layer thickness d satisfies: 1nm≤d≤100nm.

[0012] In one possible implementation, the mask layer is silicon oxide, and the mask layer thickness d satisfies: 10nm ≤ d ≤ 100nm.

[0013] In one possible implementation, the thickness of the mask layer is d, and the thickness of the substrate surface etched after the electrode grid lines are formed is D, where d and D satisfy: dD≥0.

[0014] In one possible implementation, the step of forming electrode grid lines on the first surface and the second surface includes:

[0015] The electrode grid lines with an average height of T are formed on the first surface and the second surface, wherein the average height T satisfies: 5um≤T≤20um.

[0016] In one possible implementation, in the plurality of solar cells, the average height of the electrode grid lines of each solar cell ranges from 0.7T to 1.3T.

[0017] In one possible implementation, the step of forming electrode grid lines on the first surface and the second surface includes:

[0018] Etching is performed on the first surface and the second surface;

[0019] The first surface and the second surface are pretreated;

[0020] A first growth layer, a second growth layer, and a third growth layer are sequentially formed on the first surface and the second surface.

[0021] In one possible implementation, the step of etching the first surface and the second surface includes:

[0022] Laser etching, paste etching, or ion etching are performed on the first surface and the second surface.

[0023] In one possible implementation, the step of sequentially forming a first growth layer, a second growth layer, and a third growth layer on the first surface and the second surface includes:

[0024] The first growth layer, the second growth layer, and the third growth layer are electroplated or chemically plated on the first surface and the second surface.

[0025] This application also provides a solar cell, which is prepared by any of the above methods for preparing solar cells.

[0026] This application also provides a photovoltaic module, including an encapsulation layer, a cover plate, and at least one battery string, wherein the battery string is composed of multiple solar cells electrically connected together, the encapsulation layer is used to cover the surface of the battery string, and the cover plate is used to cover the surface of the encapsulation layer away from the battery string.

[0027] This application provides a method for fabricating a solar cell, a solar cell, and a photovoltaic module. The method for fabricating the solar cell includes: forming a first antireflection layer on a first surface of a substrate, wherein the reflectivity of the first surface after forming the first antireflection layer is R1; forming a second antireflection layer on a second surface of the substrate, wherein the reflectivity of the second surface after forming the second antireflection layer is R2; forming a mask layer on a side of the first antireflection layer away from the substrate, a side of the second antireflection layer away from the substrate, and a third surface intersecting the first and second surfaces; forming electrode grid lines on the first and second surfaces, wherein after forming the electrode grid lines, the reflectivity R3 of the mask layer corresponding to the first surface satisfies the following condition with respect to R1: 0.95R1≤R3≤1.05R1; and the reflectivity R4 of the mask layer corresponding to the second surface satisfies the following condition with respect to R2: 0.95R2≤R4≤1.05R2. By setting the mask layer, the mask layer protects the substrate surface, thereby reducing the possibility of background electroplating at damaged areas. Simultaneously, the mask layer can isolate the substrate surface from the chemical solution, thus reducing the possibility of corrosion. Furthermore, placing the mask layer on the third surface helps reduce the possibility of edge leakage in the solar cell, thereby improving the production quality. On the other hand, the mask layer can also be designed to match the reflectivity with other films on the substrate surface, which helps improve the optical performance of the solar cell, ultimately enhancing its performance and efficiency.

[0028] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0029] Figure 1 A flowchart illustrating a method for fabricating a solar cell according to an embodiment of this application;

[0030] Figure 2 This is a partial schematic diagram of the substrate in a method for fabricating a solar cell according to an embodiment of this application;

[0031] Figure 3 This is a schematic diagram of a photovoltaic module provided in an embodiment of this application.

[0032] Figure label:

[0033] 1-Base;

[0034] 11-First surface;

[0035] 12-Second surface;

[0036] 13-Third surface;

[0037] 2-Mask layer;

[0038] 3-First growth layer;

[0039] 4-Second growth layer;

[0040] 5-Third growth layer;

[0041] 10-Solar cells;

[0042] 100-battery string;

[0043] 200-Encapsulation layer;

[0044] 300 - Cover plate.

[0045] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0046] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0047] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0048] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0049] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0050] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0051] like Figure 1 and Figure 2 As shown, this application embodiment provides a method for fabricating a solar cell 10, including:

[0052] S1, a first antireflection layer is formed on the first surface 11 of the substrate 1, and the reflectivity of the first surface 11 after the formation of the first antireflection layer is R1;

[0053] S2, a second antireflection layer is formed on the second surface 12 of the substrate 1, and the reflectivity of the second surface 12 after the second antireflection layer is formed is R2;

[0054] S3, a mask layer 2 is formed on the side of the first antireflective layer away from the substrate 1, the side of the second antireflective layer away from the substrate 1, and the third surface 13 intersecting with the first surface 11 and the second surface 12;

[0055] S4, electrode grid lines are formed on the first surface 11 and the second surface 12. After the electrode grid lines are formed, the reflectivity R3 and R1 of the mask layer 2 corresponding to the first surface 11 satisfy the following: 0.95R1≤R3≤1.05R1; the reflectivity R4 and R2 of the mask layer 2 corresponding to the second surface 12 satisfy the following: 0.95R2≤R4≤1.05R2.

[0056] The substrate 1 of the solar cell 10 can be a silicon substrate, including but not limited to monocrystalline silicon substrates, polycrystalline silicon substrates, and quasi-monocrystalline silicon substrates. The substrate 1 has a first surface 11 and a second surface 12 disposed opposite each other along its thickness direction. The first surface 11 can be a light-receiving surface facing the sun, while the second surface 12 can be the back surface of the solar cell 10. Before forming the first and second antireflection layers, the fabrication method of the solar cell 10 can also include processes such as texturing, boron diffusion, deposition of polycrystalline or amorphous silicon, and phosphorus diffusion. In S1 and S2, plasma-enhanced chemical vapor deposition (PECVD) can be used to prepare the first antireflection layer on the first surface 11 and the second antireflection layer on the second surface 12. The first and second antireflection layers can passivate the surface of the substrate 1, which is beneficial to improving the performance of the solar cell 10. Specifically, the first and second antireflection layers can include components such as silicon nitride, silicon oxide, and silicon oxynitride. The reflectance of the first surface 11 after the formation of the first antireflection layer is R1, and the reflectance of the second surface 12 after the formation of the second antireflection layer is R2. R1 can be the average reflectance of several points on the first surface 11, and R2 can be the average reflectance of several points on the second surface 12. The values ​​of R1 and R2 can be different. In step S3, chemical vapor deposition (CVD) or physical vapor deposition (PVD) can be used to form the mask layer 2. The mask layer 2 can be formed on the first surface 11, the second surface 12, and the third surface 13. The third surface 13 can be formed by the sides of the substrate 1, thus achieving full coverage of the substrate 1 surface. The mask layer 2 possesses good corrosion resistance and insulation properties, thereby protecting and insulating the substrate 1 surface. After the mask layer 2 is formed, an electrode grid line can be formed on the surface of the substrate 1 using an electroplating process. In step S4, the mask layer 2 will be etched by the chemical solution. After the electrode grid line is formed, the reflectivity of the mask layer 2 after being etched by the chemical solution can be tested. R3 can be the average reflectivity of several points in the mask layer 2 on the first surface 11, and R4 can be the average reflectivity of several points in the mask layer 2 on the second surface 12. The relationship between R1 and R3 satisfies 0.95R1≤R3≤1.05R1, and the relationship between R4 and R2 satisfies 0.95R2≤R4≤1.05R2.

[0057] The specific testing methods for R1, R2, R3, and R4 are as follows. Taking the first surface 11 as an example, after the first antireflection layer is formed on the first surface 11, nine test points can be uniformly set within the first surface 11. The reflectance of these nine points is tested, and the average reflectance result of the nine points is obtained as R1. Then, a mask layer 2 is formed on the first surface 11. After the mask layer 2 has been completely etched by the chemical solution, the reflectance of the mask layer 2 is tested at the positions of the aforementioned nine test points, and the average reflectance result of the nine points is obtained as R3. Furthermore, R1 and R3 satisfy the condition 0.95R1≤R3≤1.05R1. The testing method for the second surface 12 is similar, and the reflectance R4 of the mask layer 2 on the second surface 12 satisfies the condition 0.95R2≤R4≤1.05R2. During the testing process, the number of test points can be four, six, or ten, and there is no limitation in this embodiment.

[0058] In current technologies, the substrate surface of solar cells is damaged during the formation of antireflection layers and electrode grid lines. For example, corrosive solutions are used in the formation of electrode grid lines, which damage the substrate surface. During subsequent electroplating, these damaged areas experience background plating. Background plating refers to non-ideal plating at damaged and defective areas on the substrate surface, affecting the performance and quality of solar cells. Simultaneously, edge leakage can occur during electroplating, where abnormal current shunting occurs around the edges of the substrate. Edge leakage also affects the plating process, potentially leading to poor deposition and impacting the production quality of the solar cell. Furthermore, the optical properties of the substrate surface degrade after electroplating, further affecting the performance of the solar cell.

[0059] In this embodiment, before forming the electrode grid lines, a mask layer 2 is applied to the surface of the substrate 1. Damage to the substrate 1 surface caused by the formation of the anti-reflection layer or other reasons can be covered by the mask layer 2, thus protecting the substrate 1 surface and reducing the possibility of background plating at the damaged areas. Simultaneously, during the formation of the electrode grid lines, the high corrosion resistance of the mask layer 2 isolates the substrate 1 surface from the chemical solution, reducing the possibility of corrosion and thus minimizing the likelihood of surface damage leading to background plating. Furthermore, the mask layer 2 also acts as an insulator. Placing the mask layer 2 on the third surface 13 helps reduce the possibility of edge leakage in the solar cell 10, thereby improving the production quality of the solar cell 10. On the other hand, the mask layer 2 can also be designed to match the reflectivity of other films on the surface of the substrate 1, so that the mask layer 2 has a suitable reflectivity. This allows the mask layer 2 to passivate the surface of the substrate 1, which helps reduce light reflection and thus improves the light transmittance of the solar cell 10 surface, enhances the concentration of surface charge carriers, and improves the cell efficiency of the solar cell 10. The films on the first surface 11 and the second surface 12 of the substrate 1 are different, resulting in differences in optical properties and reflectivity. The reflectivity of the mask layer 2 can be designed to match the first surface 11 and the second surface 12 respectively. That is, the reflectivity of the mask layer 2 can be adjusted according to the different positions of the mask layer 2 to meet the optical performance requirements of different surfaces of the substrate 1. This design ensures that the surface of the substrate 1 still has a suitable reflectivity after the electroplating process, reducing the possibility of a decrease in the optical performance of the solar cell 10 due to the electroplating process. This improves the optical performance of the solar cell 10, thereby improving its cell efficiency and ultimately enhancing its production quality.

[0060] In one possible implementation, the mask layer 2 includes at least one of silicon nitride, magnesium fluoride, titanium oxide, silicon oxynitride, and silicon oxide.

[0061] The mask layer 2 may include one or more of silicon nitride, magnesium fluoride, titanium oxide, silicon oxynitride, and silicon oxide. The components of the mask layer 2 may be the same as or different from those of the first and second antireflection layers. Using these materials enables the mask layer 2 to possess good corrosion resistance and insulation properties, thereby protecting and insulating the surface of the substrate 1, reducing the possibility of background plating and edge leakage, and thus improving the production quality of the solar cell 10. Furthermore, using these materials also helps to ensure that the mask layer 2 has a suitable reflectivity, allowing its reflectivity to match that of other layers, thereby improving the optical performance of the solar cell 10 and ultimately increasing its efficiency.

[0062] like Figure 2 As shown, in one possible implementation, the mask layer 2 is silicon nitride, magnesium fluoride, or titanium oxide, and the thickness d of the mask layer 2 satisfies: 1nm ≤ d ≤ 30nm.

[0063] When the mask layer 2 is one of silicon nitride, magnesium fluoride, or titanium oxide, the thickness d of the mask layer 2 can be 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, or 30 nm, or other values ​​within the above range. This application does not impose any limitations on these values. By limiting the thickness and material of the mask layer 2, it is beneficial to ensure that the mask layer 2 has a suitable reflectivity. This allows for the improvement of the optical performance of the solar cell 10 by setting the mask layer 2, thereby enhancing the overall performance and efficiency of the solar cell 10.

[0064] like Figure 2 As shown, in one possible implementation, the mask layer 2 is silicon oxynitride, and the thickness d of the mask layer 2 satisfies: 1nm≤d≤100nm.

[0065] When the mask layer 2 is silicon oxynitride, the thickness d of the mask layer 2 can be 1 nm, 10 nm, 50 nm, 80 nm or 100 nm, or other values ​​within the above range. No limitation is made in the embodiments of this application. By limiting the thickness and material of the mask layer 2, the mask layer 2 can have a suitable reflectivity, which is beneficial to make the reflectivity of the mask layer 2 match the reflectivity of other films on the surface of the substrate 1, thereby improving the optical performance of the solar cell 10.

[0066] like Figure 2 As shown, in one possible implementation, the mask layer 2 is silicon oxide, and the thickness d of the mask layer 2 satisfies: 10nm≤d≤100nm.

[0067] When the mask layer 2 is silicon oxide, the thickness d of the mask layer 2 can be 10nm, 30nm, 50nm, 80nm or 100nm, or other values ​​within the above range. No limitation is made in the embodiments of this application. By limiting the thickness and material of the mask layer 2, the mask layer 2 can have a suitable reflectivity, which is beneficial to make the reflectivity of the mask layer 2 match the reflectivity of other films on the surface of the substrate 1, thereby improving the optical performance of the solar cell 10.

[0068] like Figure 2 As shown, in one possible implementation, the thickness of the mask layer 2 is d, and the thickness of the surface of the substrate 1 after the electrode grid lines are formed is D, where d and D satisfy: dD≥0.

[0069] In step S4, mask layer 2 is etched by the chemical solution. After step S4, if dD > 0, it indicates that some mask layer 2 remains and has not been completely etched. If dD = 0, it indicates that mask layer 2 is completely etched away, while the other layers beneath it remain un-etched. This design helps mask layer 2 protect the surface of substrate 1, reducing the possibility of damage caused by chemical corrosion and thus minimizing the likelihood of background plating on the substrate 1 surface.

[0070] In one possible implementation, step S4 includes:

[0071] S41, electrode grid lines with a mean height of T are formed on the first surface 11 and the second surface 12, where the mean height T satisfies: 5um≤T≤20um.

[0072] The height direction of the electrode grid lines can be parallel to the thickness direction of the substrate 1. The average height T of the electrode grid lines can be 5 μm, 10 μm, 15 μm, or 20 μm, or other values ​​within the above range. This embodiment does not impose any limitations. During the formation of the electrode grid lines, multiple growth layers need to be deposited on the surface of the substrate 1. By setting the mask layer 2, the possibility of background electroplating and edge leakage on the surface of the substrate 1 is reduced. This helps to ensure that each growth layer can be deposited stably during the formation of the electrode grid lines, thereby keeping the height of the electrode grid lines within a reasonable range. This is beneficial to improving the production quality and performance of the solar cell 10.

[0073] In one possible implementation, among the plurality of solar cells 10, the average height of the electrode grid lines of each solar cell 10 ranges from 0.7T to 1.3T.

[0074] In the mass production of solar cells 10, the average height of the electrode grid lines on each solar cell 10 will fluctuate to some extent. In the prior art, the average height of the electrode grid lines on a single solar cell is A. Therefore, in multiple solar cells, the average height of the electrode grid lines can fluctuate within the range of 0.2A to 1.8A. In this embodiment, by setting a mask layer 2, the occurrence of background plating and edge leakage in the solar cells 10 is reduced, thereby improving the stability of the deposition of each growth layer in the electrode grid lines and reducing the possibility of poor deposition of the growth layers. This helps to reduce the possibility of a smaller deposition amount of the growth layer due to background plating and edge leakage. Therefore, in this embodiment, the average height T of the electrode grid lines can be greater than A, and the average height of the electrode grid lines of each solar cell 10 can fluctuate stably within the range of 0.7T to 1.3T. Thus, the fluctuation range of the average height of the electrode grid lines in this embodiment is converged compared to the prior art. This is beneficial to improving the production quality of the solar cells 10, that is, improving the yield of the solar cell 10 products, and also improving the efficiency and performance stability of the solar cells 10.

[0075] like Figure 2 As shown, in one possible implementation, step S4 includes;

[0076] S42, etch the first surface 11 and the second surface 12;

[0077] S43, pre-process the first surface 11 and the second surface 12;

[0078] S44, a first growth layer 3, a second growth layer 4 and a third growth layer 5 are formed sequentially on the first surface 11 and the second surface 12.

[0079] In step S42, an electrode grid pattern is formed on the surface of substrate 1 by etching. The pattern of the electrode grid pattern can be designed according to the actual application requirements of solar cell 10. In step S43, the surface of substrate 1 can be pretreated with a corresponding solution. This pretreatment removes impurities such as silicon oxide generated at the etching sites, thereby improving the stability of the electrical connection between the electrode grid and substrate 1 in subsequent steps. The electrode grid includes a first growth layer 3, a second growth layer 4, and a third growth layer 5. In step S44, the first growth layer 3, the second growth layer 4, and the third growth layer 5 are deposited sequentially in a direction away from substrate 1. Each growth layer can be deposited according to the pattern formed in step S42. The first growth layer 3 can be metallic nickel, the second growth layer 4 can be metallic copper, serving as the main conductive part of the electrode grid, and the third growth layer 5 can be metallic silver, providing anti-oxidation protection. After each growth layer is formed, it needs to be acid-washed or water-washed in the corresponding tank to improve the quality of each growth layer.

[0080] In one possible implementation, step S42 includes:

[0081] Laser etching, paste etching, or ion etching are performed on the first surface 11 and the second surface 12.

[0082] The above etching methods can be used to form the electrode grid lines required for solar cell 10 on the surface of substrate 1. The etching method can be selected according to the actual production needs. This design is beneficial to improving the flexibility of electrode grid line preparation, thereby benefiting the entire preparation process of solar cell 10.

[0083] In one possible implementation, step S44 includes:

[0084] A first growth layer 3, a second growth layer 4, and a third growth layer 5 are electroplated or chemically plated on the first surface 11 and the second surface 12.

[0085] In step S44, electroplating or electroless plating can be used to form each growth layer. By setting the mask layer 2, it is beneficial to improve the stability of each growth layer during electroplating or electroless plating, and reduce the possibility of poor deposition of each growth layer due to damage to the surface of the substrate 1. This is beneficial to improve the quality of the electrode grid lines, and thus to improve the production quality of the solar cell 10.

[0086] This application also provides a solar cell 10, which is prepared by any of the above methods for preparing solar cells 10.

[0087] The first surface 11 can be the front side of the substrate 1, and an emitter can be formed on the first surface 11. The emitter can form a PN junction structure with the substrate 1. The second surface 12 can be the back side of the substrate 1, and a tunneling layer and a doped conductive layer can be formed on the second surface 12. The tunneling layer can be a silicon oxide layer, which can act as a tunneling layer for majority carriers and chemically passivate the surface of the substrate 1, thereby reducing interface states. The doped conductive layer can form band bending on the back side of the substrate 1, enabling selective carrier transport, reducing recombination losses, and ensuring carrier transport efficiency. The above preparation method is beneficial to improving the quality of the solar cell 10, thereby improving the yield of the solar cell 10, and also improving the performance and efficiency of the solar cell 10.

[0088] like Figure 3 As shown in the embodiment of this application, a photovoltaic module is also provided, including an encapsulation layer 200, a cover plate 300 and at least one battery string 100. The battery string 100 is composed of a plurality of solar cells 10 as described above that are electrically connected. The encapsulation layer 200 is used to cover the surface of the battery string 100, and the cover plate 300 is used to cover the surface of the encapsulation layer 200 away from the battery string 100.

[0089] In the cell string 100, multiple solar cells 10 are electrically connected in series and / or parallel. A laminated module is obtained by pressing the cover plate 300, encapsulation layer 200, and cell string 100 in a specific order using a lamination process. A frame can then be installed on the laminated module to form a photovoltaic module. The photovoltaic module, through the cell string 100, performs photoelectric conversion, that is, it converts the light energy absorbed by the solar cells 10 into electrical energy.

[0090] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a solar cell, characterized in that, include; A first antireflection layer is formed on the first surface (11) of the substrate (1), and the reflectance of the first surface (11) after the formation of the first antireflection layer is R1; A second antireflection layer is formed on the second surface (12) of the substrate (1), and the reflectance of the second surface (12) after the formation of the second antireflection layer is R2; A mask layer (2) is formed on the side of the first antireflection layer away from the substrate (1), the side of the second antireflection layer away from the substrate (1), and a third surface (13) intersecting with the first surface (11) and the second surface (12); Electrode grid lines are formed on the first surface (11) and the second surface (12). After the electrode grid lines are formed, the reflectivity R3 and R1 of the mask layer (2) corresponding to the first surface (11) satisfies: 0.95R1≤R3≤1.05R1; the reflectivity R4 and R2 of the mask layer (2) corresponding to the second surface (12) satisfies: 0.95R2≤R4≤1.05R2.

2. The method for preparing a solar cell according to claim 1, characterized in that, The mask layer (2) includes at least one of silicon nitride, magnesium fluoride, titanium oxide, silicon oxynitride, and silicon oxide.

3. The method for preparing a solar cell according to claim 2, characterized in that, The mask layer (2) is silicon nitride, magnesium fluoride, or titanium oxide, and the thickness d of the mask layer (2) satisfies: 1nm≤d≤30nm.

4. The method for preparing a solar cell according to claim 2, characterized in that, The mask layer (2) is silicon oxynitride, and the thickness d of the mask layer (2) satisfies: 1nm≤d≤100nm.

5. The method for preparing a solar cell according to claim 2, characterized in that, The mask layer (2) is silicon oxide, and the thickness d of the mask layer (2) satisfies: 10nm≤d≤100nm.

6. The method for preparing a solar cell according to claim 2, characterized in that, The thickness of the mask layer (2) is d, and the thickness of the surface of the substrate (1) after the electrode grid line is formed is D, where d and D satisfy: dD≥0.

7. The method for preparing a solar cell according to claim 6, characterized in that, The step of forming electrode grid lines on the first surface (11) and the second surface (12) includes: The electrode grid lines with an average height of T are formed on the first surface (11) and the second surface (12), and the average height T satisfies: 5um≤T≤20um.

8. The method for preparing a solar cell according to claim 7, characterized in that, In the plurality of solar cells (10), the average height of the electrode grid lines of each solar cell (10) ranges from 0.7T to 1.3T.

9. The method for preparing a solar cell according to any one of claims 1 to 8, characterized in that, The step of forming electrode grid lines on the first surface (11) and the second surface (12) includes: The first surface (11) and the second surface (12) are etched; The first surface (11) and the second surface (12) are pretreated; A first growth layer (3), a second growth layer (4), and a third growth layer (5) are sequentially formed on the first surface (11) and the second surface (12).

10. The method for preparing a solar cell according to claim 9, characterized in that, The steps of etching the first surface (11) and the second surface (12) include: Laser etching, paste etching, or ion etching are performed on the first surface (11) and the second surface (12).

11. The method for preparing a solar cell according to claim 9, characterized in that, The steps of sequentially forming a first growth layer (3), a second growth layer (4), and a third growth layer (5) on the first surface (11) and the second surface (12) include: The first growth layer (3), the second growth layer (4), and the third growth layer (5) are electroplated or chemically plated on the first surface (11) and the second surface (12).

12. A solar cell, characterized in that, The solar cell (10) is prepared by the method for preparing the solar cell (10) according to any one of claims 1 to 11.

13. A photovoltaic module, characterized in that, include: At least one battery string (100) is formed by electrically connecting a plurality of solar cells (10) as described in claim 12; An encapsulation layer (200) is provided to cover the surface of the battery string (100); A cover plate (300) is used to cover the surface of the encapsulation layer (200) away from the battery string (100).

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