Solar cell and its manufacturing method, photovoltaic module, and photovoltaic system

Abstract

To provide a solar cell and its manufacturing method, a photovoltaic module, and a photovoltaic system.SOLUTION: A solar cell includes: a base substrate including a first surface and a second surface arranged oppositely, and a plurality of adjacent side faces between the first surface and the second surface; a dope conductive layer and a first passivation film layer sequentially installed in lamination on the first surface to cover only the first surface; an antireflection film layer installed in lamination on the first passivation film layer and for covering the first surface so as to cover at least the first passivation film layer; a passivation contact layer provided on the second surface; and a second passivation film layer installed in lamination on the passivation contact layer and for covering the second surface so as to cover at least the passivation contact layer. The antireflection film layer covers at least a portion of each side face, or the second passivation film layer covers at least a portion of each side face.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technical field of solar cells, and in particular to a solar cell and a method for manufacturing the same, a photovoltaic module and a photovoltaic system. [Background technology]

[0002] With the rapid development of photovoltaic industry technology, domestic and international markets are placing increasingly higher demands on solar cell conversion efficiency, leading many manufacturers in the industry to actively research and develop high-efficiency cells. Surface passivation contact technology has become a focus of research in recent years. TOPCon (Tunnel Oxide Passivated Contact) technology involves fabricating an ultra-thin tunnel oxide layer and a thin doped polycrystalline silicon layer on the cell surface, which together form a passivation contact structure, significantly reducing the metal contact recombination current and improving the cell's open-circuit voltage and short-circuit current. However, in related TOPCon cells, a large amount of carrier recombination exists on the cell's peripheral surface, resulting in low solar cell efficiency. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the above problems, the present application provides a solar cell and a manufacturing method thereof, a photovoltaic module, and a photovoltaic system that can improve the efficiency of the solar cell. [Means for solving the problem]

[0004] An embodiment of the present invention is an underlying substrate including a first surface and a second surface disposed opposite to each other and a plurality of side surfaces adjacent to the first surface and the second surface; a doped conductive layer and a first passivation film layer sequentially stacked on the first surface and covering only the first surface; an anti-reflection coating layer disposed on the first passivation film layer, the anti-reflection coating layer covering the first surface so as to cover at least the first passivation film layer; a passivation contact layer disposed on the second surface; a second passivation film layer disposed on the passivation contact layer, the second passivation film layer covering the second surface so as to cover at least the passivation contact layer; Including, The anti-reflective coating layer further covers at least a portion of at least one side surface, or the second passivation layer further covers at least a portion of at least one side surface. Solar cells are provided.

[0005] By further covering at least a portion of at least one side surface with an anti-reflection film layer or further covering at least a portion of at least one side surface with a second passivation film layer, at least a portion of the area of ​​at least one side surface of the base substrate is protected by the anti-reflection film or the second passivation film layer, thereby passivating the edge surface of the solar cell corresponding to that side surface, reducing carrier recombination on the edge surface of the solar cell and improving the efficiency of the solar cell.

[0006] Preferably, the anti-reflection coating layer covers at least a portion of each side surface, or the second passivation coating layer covers at least a portion of each side surface.

[0007] Preferably, the anti-reflective coating layer completely covers at least each side surface, and At least the surface of the passivation contact layer located on the same side as the side in question is completely covered.

[0008] Preferably, the anti-reflective coating layer further covers at least a portion of the second surface adjacent to the side surface, Alternatively, the edge of the anti-reflective coating layer proximate the second surface is flush with the surface of the passivation contact layer remote from the underlying substrate.

[0009] Preferably, the second passivation film layer covers at least a portion of the anti-reflective coating layer.

[0010] Preferably, the side surface of the base substrate is flush with edges of the doped conductive layer, the first passivation film layer, and the anti-reflection film layer that are located on the same side as the side surface in a normal direction of the side surface; the second passivation film layer has a partial structure on each side surface and completely covers at least each side surface; The doped conductive layer, the first passivation film layer, and the edges of the anti-reflection film layer on the same side as the side surfaces of the doped conductive layer and the first passivation film layer are completely covered.

[0011] Preferably, the second passivation film layer further covers at least a portion of the first surface adjacent to each side thereof; Alternatively, the edge of the second passivation film layer near the first surface is flush with the outer surface of the underlying substrate of the anti-reflection film layer along the thickness direction.

[0012] The embodiment of the present invention further comprises: providing a substrate including: an underlying substrate having first and second surfaces opposite to each other and a plurality of side surfaces adjacent to the first and second surfaces; a doped conductive layer and a first passivation film layer sequentially stacked on the first surface and covering only the first surface; and a passivation contact layer provided on the second surface; forming an anti-reflective coating layer on the first passivation film layer, the anti-reflective coating layer covering the first surface, at least overlying the first passivation film layer; forming a second passivation film layer on the passivation contact layer, the second passivation film layer covering the second surface, so as to completely cover the passivation contact layer; The anti-reflective coating layer or the second passivation coating layer further covers at least a portion of at least one side surface. A method for manufacturing a solar cell is provided.

[0013] Preferably, the step of forming an anti-reflective coating layer on the first passivation film layer includes: The substrate is placed between the positioning protrusions on the positioning boat with the passivation contact layer of the substrate facing the positioning boat, and an anti-reflection material is formed on the first unshielded surface area of ​​the substrate; adjusting the relative positions of each positioning protrusion and the side surface of the underlying substrate to form a second unshielded surface area of ​​the substrate, and forming an anti-reflective material on the second unshielded surface area of ​​the substrate to form an anti-reflective film layer on the first passivation film layer; The anti-reflection film layer covers at least the first passivation film layer, each side surface, and the surface of the passivation contact layer located on the same side as the side surface.

[0014] Preferably, when the passivation contact layer of the substrate is attached to the positioning boat, an edge of the formed anti-reflection film layer close to the second surface is flush with a surface of the passivation contact layer that is farther from the underlying substrate; With the passivation contact layer of the substrate spaced apart from the alignment board, the formed anti-reflection film layer further covers at least a portion of the area adjacent to the side surface of the passivation contact layer.

[0015] Preferably, the side surface of the base substrate is flush with edges of the doped conductive layer, the first passivation film layer, and the anti-reflection film layer that are located on the same side as the side surface in a normal direction of the side surface; the first structure is a substrate on which an anti-reflection film layer is formed, The step of forming a second passivation film layer on the passivation contact layer includes: The first structure is placed between the positioning protrusions on the positioning boat with the anti-reflection coating layer facing the positioning boat, and a second passivation material is formed on the first unshielded surface area of ​​the first structure; adjusting the relative positions of each positioning protrusion and the side surface of the underlying substrate to form a second unshielded surface area of ​​the first structure, and forming a second passivation material on the second unshielded surface area of ​​the first structure to form a second passivation film layer on the passivation contact layer; The second passivation layer completely covers at least each side surface of the underlying substrate, and completely covers at least the edges of the doped conductive layer, the first passivation layer, and the anti-reflective coating layer on the same side as each side surface.

[0016] Preferably, when the anti-reflection coating layer is attached to the positioning boat, an edge of the formed second passivation film layer close to the first surface is flush with an outer surface of the base substrate of the anti-reflection coating layer along the thickness direction; With the anti-reflective coating layer spaced apart from the positioning boat, the formed second passivation layer further covers at least a portion of the area adjacent to each side of the first surface.

[0017] Preferably, the step of providing a substrate comprises: forming a doped conductive layer on a first surface of an underlying substrate; forming a passivation contact layer on the second surface of the underlying substrate; forming a first passivation film layer over the doped conductive layer.

[0018] An embodiment of the present invention further provides a photovoltaic module including at least one cell string including the solar cell described above.

[0019] An embodiment of the present invention further provides a photovoltaic system including the photovoltaic module described above. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram illustrating the configuration of a solar cell provided in an example of the present application. [Figure 2] FIG. 2 is a schematic diagram illustrating the configuration of a solar cell according to another embodiment of the present application. [Figure 3] FIG. 2 is a schematic diagram illustrating the configuration of a solar cell according to another embodiment of the present application. [Figure 4] FIG. 2 is a schematic diagram illustrating the configuration of a solar cell according to another embodiment of the present application. [Figure 5]1 is a flow diagram of a solar cell manufacturing method provided by an embodiment of the present invention. [Figure 6] 1 is a schematic diagram illustrating the configuration of a positioning device in a solar cell manufacturing method according to an embodiment of the present invention; [Figure 7] 1 is a structural schematic diagram of a substrate in a solar cell manufacturing method provided by an embodiment of the present invention. [Figure 8] 2 is a schematic diagram illustrating the formation of an anti-reflection coating layer in the solar cell manufacturing method provided by the embodiment of the present invention. FIG. [Figure 9] FIG. 2 is a schematic diagram illustrating the formation of a second passivation film layer in the solar cell manufacturing method provided by an embodiment of the present invention. [Figure 10] FIG. 2 is a schematic diagram illustrating the formation of an anti-reflection coating layer in a method for manufacturing a solar cell according to another embodiment of the present invention. [Figure 11] FIG. 4 is a schematic diagram illustrating the formation of a second passivation film layer in a method for manufacturing a solar cell according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below with reference to the drawings. In order to fully understand the present invention, various specific details will be set forth in the following description. However, the present invention can be embodied in various forms different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] Furthermore, the terms "first" and "second" are for descriptive purposes only and should not be understood to denote or suggest relative importance or to implicitly indicate the number of technical features presented. Thus, a feature qualified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, unless otherwise expressly and specifically limited, "plurality" means at least two, e.g., two, three, etc.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "attached," "coupled," "connected," "fixed," etc. should be interpreted broadly, and unless otherwise clearly limited, they may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, an internal communication between two elements, or an interactive relationship between two elements. Those skilled in the art may understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0024] Hereinafter, a solar cell and a manufacturing method thereof, a photovoltaic module, and a photovoltaic system according to the present embodiment will be described with reference to the accompanying drawings.

[0025] In the related art, there is a problem that the recombination loss on the edge surface of the solar cell is relatively large, resulting in low solar cell efficiency. In the present invention, by adjusting the contact position between the base substrate and the positioning device during the film formation process, the anti-reflection coating layer or the second passivation coating layer is deposited on a position such as the side surface of the base substrate, thereby reducing the recombination on the edge surface of the solar cell and improving the photoelectric conversion efficiency.

[0026] Referring to FIG. 1, an embodiment of the present invention provides a solar cell 1, which includes a base substrate 2, a doped conductive layer 3, a first passivation film layer 4, an anti-reflective coating layer 5, a passivation contact layer 6, and a second passivation film layer 7.

[0027] The base substrate 2 includes a first surface 11 and a second surface 12 disposed opposite each other, and a plurality of side surfaces 13 adjacent to the first surface 11 and the second surface 12. The doped conductive layer 3 and the first passivation film layer 4 are sequentially stacked on the first surface 11 and cover only the first surface 11. The anti-reflection film layer 5 is stacked on the first passivation film layer 4. The anti-reflection film layer 5 covers the first surface 11 so as to cover at least the first passivation film layer 4. The passivation contact layer 6 is provided on the second surface 12. The second passivation film layer 7 is stacked on the passivation contact layer 6. The second passivation film layer 7 covers the second surface 12 so as to cover at least the passivation contact layer 6. Furthermore, the anti-reflection film layer 5 further covers at least a portion of at least one side surface 13, or the second passivation film layer 7 further covers at least a portion of at least one side surface 13. In the present invention, one film layer covering another structural layer includes a case where the film layer is directly stacked on the other structural layer, or a case where the film layer is provided on the other structural layer via another structural layer, and the term "covering" is used only to limit the installation range of the one film layer.

[0028] At least a portion of the area of ​​at least one side surface 13 of the base substrate 2 is protected by the anti-reflection coating layer 5 or the second passivation coating layer 7, thereby passivating the edge surface of the solar cell 1 corresponding to that side surface 13, thereby reducing recombination on the edge surface of the solar cell 1 and improving the efficiency of the solar cell 1. In some embodiments, the anti-reflection coating layer 5 covers at least a portion of each side surface 13, or the second passivation coating layer 7 covers at least a portion of each side surface 13.

[0029] The doped conductive layer 3 is used to form a PN junction with the base substrate 2. In this embodiment, the doped conductive layer 3 is a P-type doped conductive layer 3 (doped with boron) as an example, and other doped conductive layers 3 are similar to this, so repeated explanations will be omitted here.

[0030] The first passivation film layer 4 serves as a surface passivation layer, and may be, for example, an aluminum oxide passivation layer, which is used to provide good passivation for the dangling bonds on the surface of the underlying substrate 2 .

[0031] The doped conductive layer 3 and the first passivation film layer 4 being stacked in order on the first surface 11 means that the doped conductive layer 3 is provided on the first surface 11, and the first passivation film layer 4 is stacked on the side of the doped conductive layer 3 that is away from the first surface 11. The doped conductive layer 3 and the first passivation film layer 4 covering only the first surface 11 means that the installation range of the doped conductive layer 3 and the first passivation film layer 4 is limited to only the first surface 11, and is not provided on other surfaces of the base substrate 2.

[0032] The anti-reflective coating layer 5 covers the first surface 11 and also covers at least a portion of at least one side surface 13, for example, it covers at least a portion of each side surface 13, for example, the installation range of the anti-reflective coating layer 5 not only covers the first surface 11 but may also extend further and be directly laminated on each side surface 13 of the base substrate 2. The anti-reflective coating layer 5 reduces reflection loss of light on the surface of the solar cell 1, improving the cell conversion efficiency. The anti-reflective coating layer 5 may have a single layer or a multi-layer structure and may be made of one or more of the following materials: silicon oxide, silicon nitride, and silicon oxynitride.

[0033] In another possible embodiment, the second passivation film layer 7 covers the second surface 12 and also covers at least a portion of at least one side surface 13, for example, covering at least a portion of each side surface 13. For example, the second passivation film layer 7 may not only cover the second surface 12 but also extend directly to each side surface 13 of the base substrate 2. The second passivation film layer 7 may similarly have a single-layer or multi-layer structure. The material of the second passivation film layer 7 may be one or more of silicon oxide, silicon nitride, or silicon oxynitride. The second passivation film layer 7 may include at least one anti-reflection material layer laminated on the passivation contact layer 6. In this way, the reflectivity of the back surface of the solar cell 1 to sunlight is reduced and the absorption of the back surface of the solar cell 1 to sunlight is improved, thereby the second passivation film layer 7 simultaneously performs passivation and anti-reflection functions.

[0034] As described above, the anti-reflection coating layer 5 may be directly laminated on each side surface 13 of the base substrate 2, or the anti-reflection coating layer 5 may completely cover at least each side surface 13 and at least the surface of the passivation contact layer 6 located on the same side as the side surface 13 to provide full passivation of the side surface 13 in the area where the anti-reflection coating layer 5 is installed on the side surface 13 of the base substrate 2. In this way, it is possible to cover all locations on the edge surface of the solar cell 1 where carrier recombination may occur, preventing carrier recombination and electrical leakage on the edge surface of the solar cell 1 and improving the efficiency of the solar cell 1.

[0035] For example, referring to FIG. 1 , in a possible embodiment, the edge of the anti-reflective coating layer 5 near the second surface 12 is flush with the surface of the passivation contact layer 6 away from the underlying substrate 2, i.e., flush with the outer surface of the passivation contact layer 6 in the thickness direction along the underlying substrate 2.

[0036] 2 , the anti-reflection coating layer 5 further covers at least a portion of the area adjacent to the side surface 13 of the second surface 12. In this case, the anti-reflection coating layer 5 is partially stacked on the passivation contact layer 6, thereby protecting the side surface 13 of the entire underlying substrate 2 and the side surfaces of the passivation contact layer 6. As can be seen, in this case, a passivation field can be similarly formed at the edge of the second surface 12, thereby effectively reducing the recombination centers on the second surface 12 of the underlying substrate 2.

[0037] Furthermore, the second passivation film layer 7 covers at least a portion of the anti-reflection film layer 5. In the case shown in FIG. 1, the second passivation film layer 7 covers the edge of the anti-reflection film layer 5 on the side closer to the second surface 12. In the case shown in FIG. 2, the second passivation film layer 7 has a partial structure stacked on the anti-reflection film layer 5, and the thickness of the stacked region of the solar cell 1 between the second passivation film layer 7 and the anti-reflection film layer 5 is greater than the thickness of the central portion of the solar cell 1, and the thickness difference here may be, for example, 5 nm to 1 μm (including end points). In this way, it is possible to ensure that the film layer is effectively deposited on the side surface 13 and the edge of the second surface 12 of the base substrate 2, forming a passivation field and reducing carrier recombination on the surface of the base substrate 2.

[0038] In some embodiments, the side surface 13 of the base substrate 2 is flush with the edge of the passivation contact layer 6 located on the same side as the side surface 13 in the normal direction of the side surface 13. That is, the installation range of the passivation contact layer 6 is limited to the second surface 12 only and does not extend to the side surface 13 of the base substrate 2. The passivation contact layer 6 may include a tunnel oxide layer 61 and a doped polysilicon conductive layer 62 stacked in this order on the second surface. The tunnel oxide layer 61 is also used to perform interface passivation of the second surface 12 of the base substrate 2 and achieves the effect of chemical passivation. The material of the tunnel oxide layer 61 may be a dielectric material, such as silicon oxide.

[0039] 3 and 4 , the side surface 13 of the base substrate 2 is flush with the edges of the doped conductive layer 3, the first passivation film layer 4, and the anti-reflective coating layer 5 on the same side as the side surface 13 in the normal direction of the side surface 13, and the second passivation film layer 7 has a partial structure on each side surface 13, completely covering at least each side surface 13 and at least the edges of the doped conductive layer 3, the first passivation film layer 4, and the anti-reflective coating layer 5 on the same side as the side surface 13. For example, the second passivation film layer 7 is directly stacked on each side surface 13 to protect the side surfaces 13 and also completely cover the edges of the doped conductive layer 3, the first passivation film layer 4, and the anti-reflective coating layer 5 on the same side as the side surface 13, thereby providing good passivation to the side surfaces of the solar cell 1.

[0040] In a specific implementation, as shown in FIG. 3, the edge of the second passivation film layer 7 close to the first surface 11 may be flush with the outer surface of the anti-reflection film layer 5 along the thickness direction of the underlying substrate 2.

[0041] Alternatively, as shown in FIG. 4 , the second passivation film layer 7 may further cover at least a portion of the area adjacent to each side surface 13 of the first surface 11. In this case, a portion of the second passivation film layer 7 is laminated on the edge of the anti-reflection film layer 5 on the first surface 11, and the thickness of the laminated area of ​​the second passivation film layer 7 and the anti-reflection film layer 5 of the solar cell 1 is greater than the thickness of the central portion of the solar cell 1, with the thickness difference being, for example, 5 nm to 1 μm (including end points). As can be seen, in this case, a passivation field is similarly formed at the edge of the first surface 11, effectively reducing the number of recombination centers on the first surface 11 of the base substrate 2. Furthermore, a film layer is effectively deposited on the edge between the side surface 13 of the base substrate 2 and the first surface 11, forming a passivation field that protects the surface of the base substrate 2 and reduces carrier recombination.

[0042] An embodiment of the present invention further provides a method for manufacturing a solar cell, the method including:

[0043] S1 provides a substrate 10. The substrate 10 includes a base substrate 2, a doped conductive layer 3, a first passivation film layer 4, and a passivation contact layer 6. The base substrate 2 includes a first surface 11 and a second surface 12 facing each other, and a plurality of side surfaces 13 adjacent to the first surface 11 and the second surface 12. The doped conductive layer 3 and the first passivation film layer 4 are stacked in order on the first surface 11 and cover only the first surface 11, and the passivation contact layer 6 is provided on the second surface 12.

[0044] In S2, an anti-reflection coating layer 5 is formed on the first passivation film layer 4 so as to cover at least the first passivation film layer 4 and the first surface 11.

[0045] In step S3, a second passivation film layer 7 is formed on the passivation contact layer 6 to cover the second surface 12 so as to completely cover the passivation contact layer 6. The anti-reflection coating layer 5 or the second passivation film layer 7 further covers at least a portion of at least one side surface 13.

[0046] At least a portion of at least one side surface 13 of the base substrate 2 is protected by the anti-reflection coating layer 5 or the second passivation coating layer 7, and the edge surface corresponding to the side surface 13 of the solar cell 1 can be passivated, reducing recombination on the edge surface of the solar cell 1 and improving the efficiency of the solar cell 1. In some embodiments, the anti-reflection coating layer 5 covers at least a portion of each side surface 13, or the second passivation coating layer 7 covers at least a portion of each side surface 13.

[0047] In some embodiments, during the manufacturing process of the solar cell 1, the substrate 10 is positioned using a positioning device. The positioning device may include a plurality of positioning boats 8 and a plurality of positioning protrusions 9 arranged in parallel. FIG. 6 is a schematic diagram of one of the positioning boats 8. As shown in FIG. 6, the substrate 10 can be fixed to the positioning boat 8 by a plurality of positioning protrusions 9 provided around the substrate 10. While being fixed to the positioning boat 8, the positioning protrusions 9 also contact each side surface 13 of the substrate 10 and the surface of the substrate 10 that faces away from the positioning boat 8, thereby positioning the substrate 10. Here, the positioning device may be a graphite boat.

[0048] Furthermore, step S3 includes the step of forming a second passivation film layer 7 on the passivation contact layer 6, and then forming electrodes on the anti-reflection coating layer 5 and the second passivation film layer 7, respectively.

[0049] Further, in step S1, the step of providing a substrate 10 includes: forming a doped conductive layer 3 on a first surface 11 of an underlying substrate 2; forming a passivation contact layer 6 on the second surface 12 of the underlying substrate 2; forming a first passivation layer 4 on the doped conductive layer 3.

[0050] Further, referring to FIGS. 6, 7 and 8, in step S2, the step of forming the anti-reflection coating layer 5 on the first passivation film layer 4 includes: The substrate 10 is placed between the positioning protrusions 9 on the positioning board 8 with the passivation contact layer 6 of the substrate 10 facing the positioning board 8, and an anti-reflection material is formed on the first unshielded surface area of ​​the substrate 10; adjusting the relative positions of each positioning protrusion 9 and the side surface 13 of the base substrate 2 to form a second unshielded surface area of ​​the substrate 10, and forming an anti-reflection material on the second unshielded surface area of ​​the substrate 10, and forming an anti-reflection film layer 5 on the first passivation film layer 4; The anti-reflection film layer 5 covers at least the first passivation film layer 4, each side surface 13, and the surface of the passivation contact layer 6 located on the same side as the side surface 13.

[0051] 6, the relative position of each positioning protrusion 9 and the side surface 13 of the base substrate 2 can be adjusted, and the positioning protrusions 9 can be moved relative to their original positions, i.e., the areas originally shielded by the positioning protrusions 9 are exposed, forming second unshielded surface areas, and the anti-reflection coating layer 5 can be manufactured. For example, the positioning protrusions 9 located on both the left and right sides of the substrate 10 in FIG. 6 (on both the left and right sides of the drawing in FIG. 6) can be lowered or raised, and the positioning protrusions 9 located on the bottom side of the substrate 10 in FIG. 6 (on the bottom side of the drawing in FIG. 6) can be moved to both the left and right sides. Such position adjustments may be made once or multiple times.

[0052] The substrate 10 may be completely attached to the positioning boat 8, or may be spaced apart from the positioning boat 8. Specifically, when the passivation contact layer 6 of the substrate 10 is attached to the positioning boat 8, the edge of the formed anti-reflection coating layer 5 close to the second surface 12 is flush with the surface of the passivation contact layer 6 away from the underlying substrate 2, i.e., the anti-reflection coating layer 5 is not formed on the passivation contact layer 6 (is not blocked by the positioning boat 8).

[0053] With the passivation contact layer 6 of the substrate 10 spaced apart from the positioning boat 8, the formed anti-reflection coating layer 5 further covers at least a portion of the area adjacent to the side surface 13 of the passivation contact layer 6, and a portion of the edge of the passivation contact layer 6 is exposed to the reaction gas atmosphere, so that the anti-reflection coating layer 5 is also formed on a portion of the edge of the passivation contact layer 6, as shown in Fig. 2. Naturally, in this case, in the subsequent step of forming the second passivation film layer 7, the second passivation film layer 7 will cover the film layer on the side located at the second surface 12 of the anti-reflection coating layer 5.

[0054] After the step of forming the passivation contact layer 6, the method further includes the step of forming a second passivation film layer 7 on the passivation contact layer 6, thereby forming the structure shown in FIG.

[0055] Hereinafter, a specific example will be taken to describe the manufacturing method of the solar cell of this embodiment, and the method includes the following:

[0056] In step (A), the base substrate 2 is subjected to texturing, boron doping, and alkaline polishing to form a textured structure and a doped conductive layer 3 on the first surface 11 of the base substrate 2 .

[0057] Step (B) is depositing a tunnel material layer and an amorphous silicon material layer on the underlying substrate 2, doping with phosphorus element and etching to form a passivation contact layer 6 on the second surface 12 of the underlying substrate 2, and depositing aluminum oxide on the doped conductive layer 3 to form a first passivation film layer 4, thereby forming the substrate 10 shown in FIG. 7.

[0058] In step (C), with the passivation contact layer 6 of the substrate 10 facing the positioning board 8 and spaced apart from the positioning board 8, the substrate 10 is engaged and placed between each of the positioning protrusions 9 provided on the positioning board 8, and an anti-reflective material is formed on the unshielded surface area of ​​the substrate 10.

[0059] The relative positions of each positioning protrusion 9 and the side surface 13 of the base substrate 2 are adjusted, and then an anti-reflection material is formed on the unobstructed surface area of ​​the substrate 10 to form an anti-reflection coating layer 5 on the first passivation film layer 4. As shown in Figure 8, the anti-reflection coating layer 5 covers the first passivation film layer 4, each side surface 13, the surface of the passivation contact layer 6 located on the same side as the side surface 13, and a portion of the surface of the passivation contact layer 6 adjacent to the side surface 13 of the base substrate 2.

[0060] In step (D), a second passivation film layer 7 is formed on the passivation contact layer 6, and electrodes are formed on the anti-reflection film layer 5 and the second passivation film layer 7, as shown in FIG. 9, and electrical injection is performed, followed by test screening.

[0061] In some other embodiments, referring to Figures 3, 4, 10 and 11, when the side surface 13 of the base substrate 2 is flush with the edges of the doped conductive layer 3, the first passivation film layer 4 and the anti-reflection film layer 5 located on the same side as the side surface 13 in the normal direction of the side surface 13, i.e., when the formed anti-reflection film layer 5 covers only the first surface 11, the step of forming the second passivation film layer 7 on the passivation contact layer 6 includes:

[0062] With the anti-reflection film layer 5 facing the positioning boat 8, the first structure is engaged and placed between the positioning protrusions 9 provided on the positioning boat 8, and a second passivation material is formed on the first unshielded surface area of ​​the first structure. The first structure is a substrate 10 on which an anti-reflection coating layer 5 is formed.

[0063] The relative positions of each positioning protrusion 9 and the side surface 13 of the base substrate 2 are adjusted to form a second unshielded surface area of ​​the first structure, and a second passivation material is subsequently deposited to form a second passivation material on the second unshielded surface area of ​​the first structure, thereby forming a second passivation film layer 7 on the passivation contact layer 6. The second passivation film layer 7 completely covers at least each side surface 13 of the base substrate 2, and also completely covers at least the edges of the doped conductive layer 3, the first passivation film layer 4, and the anti-reflection film layer 5 that are located on the same side as each side surface 13.

[0064] 6, in this process, the relative position of each positioning protrusion 9 and the side surface 13 of the base substrate 2 is adjusted, and the positioning protrusions 9 are moved relative to their original positions, i.e., the portions that were shielded by the positioning protrusions 9 are exposed, forming second unshielded surface regions and manufacturing the second passivation film layer 7. For example, the positions of the positioning protrusions 9 located on both the left and right sides of the substrate 10 in FIG. 6 (on both the left and right sides of the drawing in FIG. 6) can be lowered or raised, and the positioning protrusions 9 located on the bottom side of the substrate 10 in FIG. 6 (on the bottom side of the drawing in FIG. 6) can be moved to both the left and right sides. Such position adjustments may be made once or multiple times.

[0065] The substrate 10 may be completely attached to the positioning boat 8, or may be spaced apart from the positioning boat 8. Specifically, when the anti-reflection coating layer 5 is attached to the positioning boat 8, the edge of the formed second passivation film layer 7 close to the first surface 11 is flush with the outer surface of the anti-reflection coating layer 5 along the thickness direction of the base substrate 2, forming the structure shown in FIG.

[0066] With the anti-reflective coating layer 5 spaced apart from the positioning board 8, the formed second passivation layer 7 further covers at least a portion of the area adjacent to each side 13 of the first surface 11, forming the structure shown in Figure 4.

[0067] Hereinafter, another method for manufacturing the solar cell 1 will be described by taking one specific example, which includes the following:

[0068] In step (E), the base substrate 2 is textured, boron doped, and alkaline polished to form a textured structure and a doped conductive layer 3 on the first surface 11 of the base substrate 2 .

[0069] Step (F) is depositing a tunnel material layer and an amorphous silicon material layer on the underlying substrate 2, doping with phosphorus element and etching to form a passivation contact layer 6 on the second surface 12 of the underlying substrate 2, and depositing aluminum oxide on the doped conductive layer 3 to form a first passivation film layer 4, thereby forming the substrate 10 shown in FIG. 7.

[0070] In step (G), an anti-reflection coating layer 5 is formed on the first passivation film layer 4. As shown in Fig. 10, a side surface 13 of the base substrate 2 is flush with edges of the doped conductive layer 3, the first passivation film layer 4, and the anti-reflection coating layer 5 that are located on the same side as the side surface 13 in the normal direction of the side surface 13.

[0071] In step (H), the first structure is placed between the positioning protrusions 9 on the positioning boat 8 with the anti-reflection coating layer 5 facing the positioning boat 8 and spaced apart from the positioning boat 8, and a second passivation material is formed on the unshielded surface area of ​​the first structure. The first structure is a substrate 10 on which an anti-reflection coating layer is formed.

[0072] The relative positions of the positioning projections 9 and the side surfaces 13 of the base substrate 2 are adjusted, and then the first structure 11 , a second passivation material is formed on the unshielded surface area of ​​the base substrate 2 to form a second passivation film layer 7 on the passivation contact layer 6. As shown in FIG. 11 , the second passivation film layer 7 completely covers each side surface 13 of the base substrate 2, completely covers edges of the doped conductive layer 3, the first passivation film layer 4, and the anti-reflection coating layer 5 on the same side as each side surface 13, and also covers a portion of the anti-reflection coating layer 5 adjacent to the side surface 13 of the base substrate 2.

[0073] In step (I), electrodes are formed on the anti-reflection film layer 5 and the second passivation film layer 7, electricity is injected, and test screening is performed.

[0074] 6, in this embodiment, the adjustment of the gap between the substrate 10 and the positioning boat 8 can be performed, for example, by adjusting the positions of the positioning protrusions 9 on both sides of the substrate 10 in the height direction H of the positioning boat 8. By moving the positioning protrusions 9 downward in the height direction H of the positioning boat 8 according to the direction of the arrow shown in FIG. 6, the gap between the substrate 10 and the positioning boat 8 can be increased, or conversely, the gap can be decreased.

[0075] This embodiment further provides a photovoltaic module, which includes at least one cell string, and the cell string includes at least two of the above-mentioned solar cells 1, and each solar cell 1 is connected together by a series welding method.

[0076] For example, the photovoltaic module further includes a sealing layer and a cover plate. The sealing layer is used to cover the surface of the battery string, and the cover plate is used to cover the surface of the sealing layer away from the battery string. The solar cells 1 are electrically connected in the form of a single or multi-cell to form a battery string, and multiple battery strings are electrically connected in series and / or parallel. The sealing layer may be an organic sealing film such as an ethylene-vinyl acetate copolymer film, a polyethylene octene copolymer elastomer rubber film, or a polyethylene terephthalate film. The cover plate may be a light-transmitting cover plate such as a glass cover plate or a plastic cover plate.

[0077] This embodiment further provides a photovoltaic system, which includes the above-mentioned photovoltaic module. The configurations, functions, and working principles of the photovoltaic module and solar cell have been described in detail above, so further description will be omitted here.

[0078] The technical features of the above embodiments can be combined in any way, and for the sake of simplicity, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of these technical features are not contradictory, they should all be considered within the scope described in this specification.

[0079] The above examples merely represent some embodiments of the present invention, and although the descriptions are relatively specific and detailed, they should not be construed as limitations on the scope of the patent claims. It should be noted that those skilled in the art can make minor modifications and improvements without departing from the concept of the present invention, and all such modifications and improvements are within the scope of protection of the present invention. Therefore, the scope of protection of the patent of the present invention is determined by the appended claims.

Claims

1. A solar cell, an underlying substrate including a first surface and a second surface disposed opposite to each other and a plurality of side surfaces adjacent to the first surface and the second surface; a doped conductive layer and a first passivation film layer sequentially stacked on the first surface and covering only the first surface; an anti-reflection film layer disposed on the first passivation film layer, the anti-reflection film layer covering the first surface so as to cover at least the first passivation film layer; a passivation contact layer disposed on the second surface; a second passivation film layer disposed on the passivation contact layer, the second passivation film layer covering the second surface so as to cover at least the passivation contact layer; Including, the second passivation film layer further covers at least a portion of each of the side surfaces; a side surface of the base substrate is flush with edges of the doped conductive layer, the first passivation film layer, and the anti-reflection film layer that are located on the same side as the side surface in a normal direction of the side surface; The second passivation film layer comprises: a portion of the structure is provided on each side and completely covers each of the sides; and completely covering the edges of the doped conductive layer, the first passivation film layer, and the anti-reflection film layer located on the same side as each of the side surfaces; and further covering an edge portion of the anti-reflection coating layer on the first surface. A solar cell characterized by:

2. A method for manufacturing a solar cell, comprising: providing a substrate including: an underlying substrate having a first surface and a second surface opposite to each other and a plurality of side surfaces adjacent to the first surface and the second surface; a doped conductive layer and a first passivation film layer sequentially stacked on the first surface and covering only the first surface; and a passivation contact layer provided on the second surface; forming an anti-reflective coating layer on the first passivation film layer, the anti-reflective coating layer covering the first surface, at least covering the first passivation film layer; forming a second passivation film layer on the passivation contact layer, the second passivation film layer covering the second surface so as to completely cover the passivation contact layer; the second passivation film layer further covers at least a portion of each of the side surfaces; a side surface of the base substrate is flush with edges of the doped conductive layer, the first passivation film layer, and the anti-reflection film layer that are located on the same side as the side surface in a normal direction of the side surface; The step of forming a second passivation film layer on the passivation contact layer includes: a first structure, which is the substrate on which the anti-reflection film layer is formed, is engaged and installed between positioning protrusions provided on a positioning boat with the anti-reflection film layer facing the positioning boat, and a second passivation material is formed on an unshielded surface of the first structure; adjusting the relative positions of each positioning protrusion and the side surface of the base substrate, and then forming a second passivation material on the unshielded surface of the first structure to form a second passivation film layer on the passivation contact layer; the second passivation film layer completely covers at least each of the side surfaces of the base substrate, and completely covers at least edges of the doped conductive layer, the first passivation film layer, and the anti-reflection film layer that are located on the same side as each of the side surfaces; A method for manufacturing a solar cell comprising the steps of:

3. when the anti-reflection film layer is attached to the positioning boat, an edge of the formed second passivation film layer along the thickness direction of the base substrate is flush with an outer surface of the anti-reflection film layer along the thickness direction of the base substrate; the second passivation film layer formed while the anti-reflection film layer is spaced apart from the positioning boat further covers at least a portion of an area adjacent to each of the side surfaces of the first surface; The method for manufacturing a solar cell according to claim 2 .

4. The step of providing a substrate comprises: forming the doped conductive layer on a first surface of the base substrate; forming the passivation contact layer on a second surface of the underlying substrate; forming the first passivation film layer on the doped conductive layer.

4. The method for manufacturing a solar cell according to claim 2 or 3.

5. 1. A photovoltaic module comprising: at least one battery string; The battery string includes at least two solar cells according to claim 1. A photovoltaic module characterized by:

6. 1. A photovoltaic system comprising:

6. A photovoltaic module comprising: A photovoltaic system comprising:

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