Method for manufacturing a solar cell

Abstract

The application relates to the technical field of solar cells. The application relates to a manufacturing method of a solar cell. The manufacturing method of the solar cell comprises the following steps: providing a substrate; the substrate comprises a base and a doped conductive material layer; a part of the surface of the first side and the first surface of the base has a texture structure; the doped conductive material layer is arranged on the part of the surface of the first side and the first surface to cover the texture structure; a passivation contact material layer is formed on each surface of the substrate; the substrate on which the passivation contact material layer is formed is cut along the thickness direction of the base to form at least two sub-substrates, so that the doped conductive material layer forms a doped conductive layer; the passivation contact material layer on the surface of the first side and each side of the sub-substrate is etched and removed to form a passivation contact layer on the sub-substrate; the first side is one side of the first surface of the base; and a first passivation film layer is formed on the doped conductive layer. The application can improve the efficiency of the solar cell.

Description

Technical Field

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

[0002] With the rapid development of photovoltaic technology, the conversion efficiency of crystalline silicon solar cells has been increasing year by year. Currently, TOPCon cells stand out due to their high efficiency and mature industrial manufacturing processes, leading many manufacturers in the industry to accelerate their R&D efforts. In the manufacturing process of TOPCon cells, doping processes are involved on both the front and back sides, resulting in strong lateral carrier transport capabilities on both sides. This leads to significant recombination on the sides of the cell and can easily cause leakage current, thus reducing the efficiency of the solar cell. Summary of the Invention

[0003] Therefore, it is necessary to provide a method for manufacturing a high-efficiency solar cell.

[0004] The first aspect of this application provides a solar cell, comprising:

[0005] The substrate includes a first surface and a second surface disposed opposite to each other, and a plurality of first side surfaces adjacent to the first surface and the second surface; wherein, at least a portion of the first surface and the first side surfaces of the substrate are provided with a velvet structure;

[0006] A doped conductive layer is disposed at least on a portion of the first surface and the first side surface to cover the textured structure;

[0007] A first passivation film layer is stacked on a doped conductive layer, and the first passivation film layer covers at least a portion of the first surface and the first side surface, so as to at least cover the doped conductive layer.

[0008] A passivated contact layer is disposed on the second surface; and

[0009] A second passivation film layer is stacked on the passivation contact layer, and the second passivation film layer covers the second surface to cover the passivation contact layer.

[0010] In one embodiment, the first side includes a velvety area with a velvety structure and a flat area adjacent to the velvety area.

[0011] The first passivation film layer completely covers the textured area on the first side and at least a portion of the flat area.

[0012] In one embodiment, the first passivation film layer is located at the edge of the film layer on the first side along the thickness direction of the substrate, and is flush with the surface of the passivation contact layer away from the substrate.

[0013] In one embodiment, the substrate further includes at least one cut-edge side adjacent to the first and second surfaces;

[0014] The textured surface is only disposed on a portion of the first surface and the first side surface, and the doped conductive layer is only disposed on a portion of the first surface and the first side surface to cover the textured surface.

[0015] In one embodiment, the cut edge side is flush with the edge of the doped conductive layer, the first passivation film layer, the passivation contact layer, and the second passivation film layer that is located on the same side as the cut edge side in the normal direction of the cut edge side.

[0016] In one embodiment, the first passivation film layer also covers at least a portion of the side of the cut edge.

[0017] In one embodiment, the second passivation film layer also covers at least a portion of the side of the cut edge to at least partially cover the first passivation film layer on the side of the cut edge.

[0018] In one embodiment, the substrate further includes at least one cut-edge side adjacent to the first and second surfaces;

[0019] The cut edge side also has a textured structure; a doped conductive layer is disposed on a portion of the first surface, a portion of the first side surface, and a portion of the cut edge side surface to cover the textured structure;

[0020] The first passivation film layer also covers at least a portion of the side of the cut edge to at least cover the doped conductive layer.

[0021] In one embodiment, the second passivation film layer also covers at least a portion of the side of the cut edge to at least partially cover the first passivation film layer on the side of the cut edge.

[0022] In one embodiment, the second passivation film layer also covers at least a portion of the first side surface to at least partially cover the first passivation film layer on the first side surface.

[0023] In one embodiment, the first side includes a velvety area with a velvety structure and a flat area adjacent to the velvety area.

[0024] The first passivation film layer located on the first side includes a first portion covering the flat area;

[0025] The second passivation film layer at least covers the first portion.

[0026] In one embodiment, the first passivation film layer located on the first side also includes a second portion covering the textured area;

[0027] The second passivation film layer covers at least a portion of the first and second portions.

[0028] In one embodiment, the second passivation film is located in the film layer on the first portion and the second portion, with its edge along the thickness direction of the substrate flush with the outer surface of the first passivation film along the thickness direction of the substrate.

[0029] In one embodiment, the textured structure on the first surface of the substrate and the textured structure on the first side surface are continuous structures; or, there is a gap between the textured structure on the first surface of the substrate and the textured structure on the first side surface.

[0030] In one embodiment, the first passivation film layer includes a first passivation layer and a first antireflection layer stacked on the doped conductive layer; and / or

[0031] The second passivation film layer includes at least one second antireflection layer stacked on the passivation contact layer.

[0032] A second aspect of this application provides a method for manufacturing a solar cell, comprising:

[0033] A substrate is provided; the substrate includes a base and a doped conductive layer; the base includes a first surface and a second surface disposed opposite to each other, and a plurality of first side surfaces adjacent to the first surface and the second surface; a textured structure is provided on at least a portion of the first surface and the first side surfaces of the base; the doped conductive layer is provided on at least a portion of the first surface and the first side surfaces to cover the textured structure;

[0034] A passivation contact layer is formed on the second surface of the substrate;

[0035] A first passivation film is formed on the doped conductive layer; wherein the first passivation film covers at least a portion of the first surface and the first side surface, so as to at least cover the doped conductive layer;

[0036] A second passivation film layer is formed on the passivation contact layer to form a solar cell substrate; wherein the second passivation film layer covers the second surface to cover the passivation contact layer.

[0037] In one embodiment, after the step of forming a second passivation film layer on the passivation contact layer, the method further includes:

[0038] Laser cutting is performed along the thickness direction of the solar cell substrate to form at least two solar cells.

[0039] In one embodiment, providing a substrate includes:

[0040] At least the first surface and the first side surface of the substrate are texturized and doped with element diffusion.

[0041] The substrate is etched to expose the second surface of the substrate and the first target area on each of the first side surfaces;

[0042] The first target region is the region on each of the first sides of the base that is adjacent to and connected to the second side.

[0043] In one embodiment, the step of providing a substrate includes:

[0044] The base blank is cut along the thickness direction to form at least two bases, and the cut edge side is formed on the base;

[0045] At least the first surface, the first side surface, and the cut edge side surface of the substrate are texturized and doped with element diffusion.

[0046] The substrate is etched to expose the second surface of the substrate, the first target area on each first side surface, and the second target area on each cut edge side surface; so that a textured structure and a doped conductive layer covering the textured structure are formed on a portion of the first surface of the substrate, a portion of the first side surface, and a portion of the cut edge side surface.

[0047] The first target area is the area on each first side that is adjacent to and connected to the second side; the second target area is the area on each cutting edge side that is adjacent to and connected to the second side.

[0048] In one embodiment, the step of forming a passivation contact layer on the second surface of the substrate includes:

[0049] A tunneling material layer, a polysilicon doped material layer, and an oxide material layer are sequentially stacked on each surface of the substrate.

[0050] Etching removes the oxide material layer on the surface of the first side of the substrate and on each side of the substrate;

[0051] Etching removes the polysilicon doped material layer and tunneling material layer on the first side surface and the side surface of the substrate;

[0052] The first side is one side of the first surface of the base.

[0053] In one embodiment, after the step of forming a second passivation film layer on the passivation contact layer, the method further includes:

[0054] Electrodes are fabricated on the first passivation film layer and the second passivation film layer, respectively.

[0055] A third aspect of this application provides a photovoltaic module, including at least one battery string, wherein the battery string includes at least two of the above-described solar cells.

[0056] A fourth aspect of this application provides a photovoltaic system including the photovoltaic module described above.

[0057] The fifth aspect of this application provides a method for manufacturing a solar cell, comprising:

[0058] A substrate is provided; the substrate includes a base and a doped conductive material layer; the base includes a first surface and a second surface disposed opposite to each other, and a plurality of first side surfaces adjacent to the first surface and the second surface; a portion of the first surface and the first side surfaces of the base have a textured structure; the doped conductive material layer is disposed on a portion of the first surface and the first side surfaces to cover the textured structure;

[0059] A passivation contact material layer is formed on each surface of the substrate;

[0060] The substrate forming the passivation contact material layer is cut along the thickness direction of the substrate to form at least two sub-substrates, so that the doped conductive material layer forms a doped conductive layer.

[0061] Etching removes the passivation contact material layer on the surface of the first side and each side of the sub-substrate to form a passivation contact layer on the sub-substrate, wherein the first side is one side of the first surface of the substrate;

[0062] A first passivation film is formed on the doped conductive layer; wherein the first passivation film covers at least a portion of the first surface and the first side surface to at least cover the doped conductive layer; the first passivation film also covers at least a portion of the cut edge side surface, wherein the cut edge side surface is a side surface cut out in the sub-substrate.

[0063] In one embodiment, providing the substrate includes:

[0064] At least the first surface and the first side surface of the substrate are texturized and doped with element diffusion.

[0065] The substrate is etched to expose the second surface of the substrate and the first target area on each of the first side surfaces;

[0066] The first target region is the region on each of the first sides of the base that is adjacent to and connected to the second side.

[0067] In one embodiment, the step of etching the substrate to expose the first target regions on the second surface and each of the first side surfaces includes:

[0068] The substrate after texturing and doping element diffusion is etched to expose the texturing structure on the second surface and each first target region.

[0069] The exposed textured surface is etched away to expose the second surface of the substrate and the first target area on each of the first side surfaces.

[0070] In one embodiment, the step of forming a passivation contact material layer on each surface of the substrate includes:

[0071] A tunneling material layer, a polysilicon doped material layer, and an oxide material layer are sequentially stacked on each surface of the substrate.

[0072] In one embodiment, the step of etching away the passivation contact material layer on the surface of the first side of the sub-substrate and on each side side to form a passivation contact layer on the sub-substrate includes:

[0073] Etching removes the oxide material layer on the surface of the first side of the sub-substrate and on each side of the sub-substrate;

[0074] The polysilicon doped material and tunneling material layer on the first side surface and each side surface of the sub-substrate are etched away; and the cut edge sides of the sub-substrate are etched and polished.

[0075] In one embodiment, the step of etching away the oxide material layer is performed using a chain machine;

[0076] The polycrystalline silicon doped material and tunneling material layer are removed using a tank mill.

[0077] In one embodiment, the step of etching away the polysilicon doped material and tunneling material layer on the surface of the first side of the sub-substrate and on each side of the sub-substrate further includes:

[0078] The oxide material layer on the surface of the second side of the sub-substrate is etched away; wherein the second side is one side of the second surface of the substrate.

[0079] In one embodiment, after forming the first passivation film layer on the doped conductive layer, the method further includes:

[0080] A second passivation film is formed on the passivation contact layer; wherein the second passivation film covers at least a portion of the second surface, at least a portion of the first side surface, and at least a portion of the cut edge side surface, to cover at least a portion of the passivation contact layer and the first passivation film layer.

[0081] In one embodiment, after the step of forming a second passivation film layer on the passivation contact layer, the method further includes:

[0082] Electrodes are fabricated on the first passivation film layer and the second passivation film layer respectively to form a solar cell.

[0083] In one embodiment, the step of cutting the substrate into which the passivation contact material layer is formed along the thickness direction of the substrate to form at least two sub-substrates includes:

[0084] The substrate to form the passivation contact material layer is laser-cut along the thickness direction of the substrate to form two sub-substrates of the same size.

[0085] The beneficial effects of the aforementioned solar cells, their manufacturing methods, photovoltaic modules, and photovoltaic systems are as follows:

[0086] By providing a textured structure on a portion of the first surface and a portion of the first side surface of the substrate, a doped conductive layer is disposed on a portion of the first surface and a portion of the first side surface to cover the textured structure. Since the portion of the first side surface has a textured structure, and a doped conductive layer is disposed on the textured structure, the doped conductive layer at this location helps reduce recombination at the interface where the first side surface is located, achieving a better passivation effect on the edge surface of the solar cell corresponding to the first side surface. Furthermore, the textured structure on the first side surface increases the light absorption area of ​​the solar cell, improves the photocurrent of the solar cell, and helps to improve the efficiency of the solar cell.

[0087] On the other hand, a first passivation film layer is stacked on the doped conductive layer, and the first passivation film layer covers at least a portion of the first surface and the first side surface, so as to at least cover the doped conductive layer. Since the first passivation film layer covers at least a portion of the first surface and the first side surface, it protects at least a portion of the first side surface, which not only increases the passivation effect on the edge surface of the solar cell corresponding to the first side surface and alleviates recombination on the edge surface of the solar cell corresponding to the first side surface, but also, as the first passivation film layer is an insulating film layer, it can better prevent leakage current from occurring on the edge surface of the solar cell corresponding to the first side surface. Thus, while improving the cell conversion efficiency, it also increases the power output of the solar cell. Attached Figure Description

[0088] Figure 1 This is a schematic diagram of the structure of a solar cell provided in Embodiment 1 of this application;

[0089] Figure 2 This is a schematic diagram of another structure of the solar cell provided in Embodiment 1 of this application;

[0090] Figure 3 This is a schematic diagram of another structure of the solar cell provided in Embodiment 1 of this application;

[0091] Figure 4 This is a schematic diagram of another structure of the solar cell provided in Embodiment 1 of this application;

[0092] Figure 5 This is a schematic diagram of the structure of the solar cell provided in Embodiment 2 of this application;

[0093] Figure 6 This is a schematic diagram of another structure of the solar cell provided in Embodiment 2 of this application;

[0094] Figure 7 This is a schematic diagram of another structure of the solar cell provided in Embodiment 2 of this application;

[0095] Figure 8 This is a schematic diagram of another structure of the solar cell provided in Embodiment 2 of this application;

[0096] Figure 9 This is a schematic diagram of the structure of the solar cell provided in Embodiment 3 of this application;

[0097] Figure 10 This is a schematic diagram of another structure of the solar cell provided in Embodiment 3 of this application;

[0098] Figure 11 This is a schematic diagram of another structure of the solar cell provided in Embodiment 3 of this application;

[0099] Figure 12 This is a schematic diagram of another structure of the solar cell provided in Embodiment 3 of this application;

[0100] Figure 13 This is a schematic flowchart illustrating the method for manufacturing a solar cell according to Embodiment 4 of this application;

[0101] Figure 14 This is a schematic diagram of the substrate structure in the method for manufacturing a solar cell provided in Embodiment 4 of this application;

[0102] Figure 15 This is a schematic diagram of the structure in which a textured surface structure and a doped conductive layer are formed on a substrate in the method for fabricating a solar cell provided in Embodiment 4 of this application;

[0103] Figure 16 This is a schematic diagram of the structure for forming the passivation contact layer in the method for manufacturing a solar cell according to Embodiment 4 of this application;

[0104] Figure 17 This is a schematic diagram of the formation of the first passivation film layer in the method for manufacturing a solar cell according to Embodiment 4 of this application;

[0105] Figure 18 This is a schematic diagram of the formation of the second passivation film layer in the method for manufacturing a solar cell according to Embodiment 4 of this application;

[0106] Figure 19 This is a schematic diagram of the solar cell formed in the method for manufacturing the solar cell provided in Embodiment 4 of this application;

[0107] Figure 20 This is a schematic diagram of the structure of the first side of the substrate in the method for manufacturing a solar cell provided in Embodiment 4 of this application;

[0108] Figure 21 This is a schematic diagram of the substrate structure in another method for manufacturing a solar cell provided in Embodiment 4 of this application;

[0109] Figure 22 This is a schematic diagram of forming a passivation contact layer on a substrate in another method for manufacturing a solar cell provided in Embodiment 4 of this application;

[0110] Figure 23 This is a schematic diagram of forming a first passivation film layer on a doped conductive layer in another method for fabricating a solar cell provided in Embodiment 4 of this application;

[0111] Figure 24 This is a schematic diagram of forming a second passivation film layer on the passivation contact layer in another method of manufacturing a solar cell provided in Embodiment 4 of this application;

[0112] Figure 25 This is a schematic diagram of forming electrodes on the first passivation film layer and the second passivation film layer in another method of fabricating a solar cell provided in Embodiment 4 of this application;

[0113] Figure 26 This is a schematic diagram of the structure of a solar cell formed in another method of manufacturing a solar cell according to Embodiment 4 of this application;

[0114] Figure 27 This image shows a cut surface of a solar cell obtained by cutting the solar cell in another method of manufacturing a solar cell provided in Embodiment 4 of this application.

[0115] Figure 28 This is a schematic flowchart illustrating the method for manufacturing a solar cell according to Embodiment 5 of this application;

[0116] Figure 29 This is a schematic diagram of the substrate structure in the method for manufacturing a solar cell provided in Embodiment 5 of this application;

[0117] Figure 30 This is a schematic diagram of the structure of the substrate in the method for fabricating a solar cell provided in Embodiment 5 of this application;

[0118] Figure 31 This is a schematic diagram of the formation of the first passivation film layer in the method for manufacturing a solar cell according to Embodiment 5 of this application;

[0119] Figure 32 This is a schematic diagram illustrating the formation of the second passivation film layer in the method for fabricating a solar cell according to Embodiment 5 of this application;

[0120] Figure 33 This is a schematic diagram of the solar cell formed in the method for manufacturing the solar cell provided in Embodiment 5 of this application;

[0121] Figure 34 This is a schematic diagram of the structure of the photovoltaic module provided in Embodiment Six of this application;

[0122] Figure 35 This is a structural schematic diagram of the manufacturing process of the photovoltaic module provided in Embodiment Six of this application.

[0123] Explanation of icon numbers:

[0124] 100, Solar cell; 101, 101', Substrate; 102, Sub-substrate; 103, Solar cell substrate; F, First surface; S, Second surface; C1, First side surface; C11, First target area; C12, Second target area; C2, Cut edge side surface; CQ, Cut surface; P, Flat area; R, Textured area; H, Thickness direction of the substrate;

[0125] 10. Substrate; 11. Boundary line; 20. Textured surface; 30. Doped conductive layer; 30'. Doped conductive material layer; 40. First passivation film layer; 41. First portion; 42. Second portion; 50. Passivation contact layer; 51. Tunneling oxide layer; 52. Polysilicon doped conductive layer; 60. Second passivation film layer;

[0126] 70. Electrode;

[0127] 200. Photovoltaic modules; 210. Battery strings. Detailed Implementation

[0128] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways 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.

[0129] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0130] 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 at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0131] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0132] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0133] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0134] The following description, in conjunction with the accompanying drawings, illustrates the solar cells and their manufacturing methods, photovoltaic modules, and photovoltaic systems according to embodiments of this application.

[0135] Example 1

[0136] Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of this application. Figure 2 This is a schematic diagram of another structure of the solar cell provided in Embodiment 1 of this application. Figure 3 This is a schematic diagram of another structure of the solar cell provided in Embodiment 1 of this application. Figure 4 This is a schematic diagram of another structure of the solar cell provided in Embodiment 1 of this application.

[0137] Reference Figure 1 This application provides a solar cell 100, including a substrate 10, a doped conductive layer 30, a first passivation film layer 40, a passivation contact layer 50, and a second passivation film layer 60. The substrate 10 includes a first surface F and a second surface S disposed opposite to each other, and a plurality of first side surfaces C1 adjacent to the first surface F and the second surface S.

[0138] The substrate 10 is used to receive incident light and generate photogenerated carriers. For example, the solar cell 100 can be a TOPCon cell (Tunnel Oxide Passivated Contact), and both the first surface F and the second surface S of the substrate 10 can be used to receive incident light. In some embodiments, the substrate 10 further includes at least one cut edge side surface C2 adjacent to the first surface F and the second surface S, the cut edge side surface C2 being a cut side surface formed by cutting.

[0139] In this embodiment, a textured structure 20 is provided on at least a portion of the first surface F and the first side surface C1 of the substrate 10. A doped conductive layer 30 is disposed at least on a portion of the first surface F and the first side surface C1 to cover the textured structure 20. A first passivation film layer 40 is stacked on the doped conductive layer 30, and the first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1 to at least cover the doped conductive layer 30. A passivation contact layer 50 is disposed on the second surface S. A second passivation film layer 60 is stacked on the passivation contact layer 50, and the second passivation film layer 60 covers the second surface S to cover the passivation contact layer 50.

[0140] By providing a textured structure 20 on a portion of the first surface F and the first side surface C1 of the substrate 10, a doped conductive layer 30 is disposed on a portion of the first surface F and the first side surface C1 to cover the textured structure 20. Since the portion of the first side surface C1 has a textured structure 20, and the textured structure 20 has a doped conductive layer 30, the doped conductive layer 30 at this location helps reduce recombination at the interface where the first side surface C1 is located, achieving a better passivation effect on the edge surface of the solar cell 100 corresponding to the first side surface C1. Furthermore, the textured structure 20 provided on the first side surface C1 increases the light absorption area of ​​the solar cell 100, improves the photocurrent of the solar cell 100, and helps to improve the efficiency of the solar cell 100.

[0141] On the other hand, a first passivation film layer 40 is stacked on the doped conductive layer 30. The first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1, thereby covering at least the doped conductive layer 30. Since the first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1, it protects at least a portion of the first side surface C1. This not only increases the passivation effect on the edge surface of the solar cell 100 corresponding to the first side surface C1 and alleviates recombination on the edge surface of the solar cell 100 corresponding to the first side surface C1, but also, as an insulating film layer, the first passivation film layer 40 can better prevent leakage on the edge surface of the solar cell 100 corresponding to the first side surface C1. Thus, while improving the cell conversion efficiency, it also increases the power output of the solar cell 100.

[0142] In this embodiment, the first surface F and the second surface S of the substrate 10 can be, for example, two end faces in the thickness direction H of the substrate. Multiple first side surfaces C1 adjacent to the first surface F and the second surface S mean that the two ends of each first side surface C1 are respectively connected to the first surface F and the second surface S. At least one cutting edge side surface C2 adjacent to the first surface F and the second surface S means that the two ends of each cutting edge side surface C2 are respectively connected to the first surface F and the second surface S. Exemplarily, when the substrate 10 includes both first side surfaces C1 and cutting edge side surfaces C2, multiple first side surfaces C1 and at least one cutting edge side surface C2 can be arranged around the circumference of the first surface F and sequentially connected to each other. When the substrate 10 is viewed from above as a quadrilateral, the total number of first side surfaces C1 and cutting edge side surfaces C2 is four. The shape of the substrate 10 can also be set to other shapes as needed. The relative positions of multiple first side surfaces C1 and at least one cutting edge side surface C2 along the circumferential direction of the first surface F can be, for example, each first side surface C1 can be connected to each other and then connected to the cutting edge side surface C2, or the first side surface C1 and the cutting edge side surface C2 can be arranged alternately. Of course, this application is not limited to this, and the relative positions of the first side surface C1 and the cutting edge side surface C2 can be set as needed.

[0143] Parts of the first surface F and the first side surface C1 of the substrate 10 have a textured structure 20. For example, the textured structure 20 on the first surface F and the textured structure 20 on the first side surface C1 of the substrate 10 can be a continuous structure, or there can be a gap between the textured structure 20 on the first surface F and the textured structure 20 on the first side surface C1 of the substrate 10, that is, the two can also be discontinuous structures.

[0144] In practice, the solar cell 100 may include N-type and P-type cells. The N-type cell has a substrate 10 doped with N-type elements and a doped conductive layer 30 doped with P-type elements. The P-type cell has a substrate 10 doped with P-type elements and a doped conductive layer 30 doped with N-type elements. The doped conductive layer 30 is used to form a PN junction with the substrate 10. In this embodiment, the substrate 10 is an N-type substrate, which can be a P-type doped conductive layer, for example, a boron-doped conductive layer 30 (also called a P+ type emitter).

[0145] A portion of the doped conductive layer 30 is disposed on the first surface F, and another portion is disposed on a portion of the surface of the first side surface C1. The disposed area covers the textured surface structure 20. In some embodiments, the disposed area of ​​the doped conductive layer 30 may be larger than that of the textured surface structure 20. In this embodiment, the example given is that the disposed area of ​​the doped conductive layer 30 is equivalent to that of the textured surface structure 20, i.e., the doped conductive layer 30 exactly completely covers the textured surface structure 20.

[0146] Continue to refer to Figure 1 A passivation contact layer 50 is disposed on the second surface S. For example, the passivation contact layer 50 can be directly stacked on the second surface S of the substrate 10. The passivation contact layer 50 can reduce the recombination of charge carriers on the surface of the substrate 10, thereby increasing the open-circuit voltage of the solar cell 100 and improving the photoelectric conversion efficiency of the solar cell 100. The passivation contact layer 50 may include a tunneling oxide layer 51 and a polycrystalline silicon doped conductive layer 52 sequentially stacked on the second surface S. For example, the tunneling oxide layer 51 is used to achieve interface passivation of the second surface S of the substrate 10, achieving the effect of chemical passivation. Specifically, by saturating the dangling bonds on the surface of the substrate 10, the interface defect state density of the second surface S of the substrate 10 is reduced, thereby reducing the recombination centers on the second surface S of the substrate 10 and reducing the carrier recombination rate. The material of the tunneling oxide layer 51 can be a dielectric material, such as at least one of silicon oxide, magnesium fluoride, silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide, or titanium oxide.

[0147] The first passivation film layer 40 is stacked on the doped conductive layer 30. The first passivation film layer 40 plays a role in surface passivation and anti-reflection in the solar cell 100. It can effectively passivate the dangling bonds on the surface of the substrate 10 and has an anti-reflection effect on the front side of the solar cell 100.

[0148] For example, the first passivation film layer 40 includes a first passivation layer (not shown) and a first antireflection layer (not shown) sequentially stacked on the doped conductive layer 30.

[0149] The first antireflective film is located on the first surface F of the substrate 10, that is, on the side of the solar cell 100 that receives incident light (referred to as the front side or light-receiving surface), and plays an antireflective role on the front side of the solar cell 100. The first antireflective film can adopt a multi-layer structure. In the multi-layer structure of the first antireflective layer, the material of each layer can be silicon oxide, silicon nitride, or silicon oxynitride.

[0150] The first passivation layer can be a single-layer or multi-layer structure, and the material of the first passivation layer can be at least one of alumina, silicon oxide, silicon nitride, or silicon oxynitride. Alternatively, the first passivation layer can be formed by chemical deposition.

[0151] The first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1 to at least cover the doped conductive layer 30. Specifically, the first passivation film layer 40 can continuously cover at least a portion of the first surface F and the first side surface C1 adjacent to the first surface F, thus covering the doped conductive layer 30. In this case, the first passivation film layer 40 includes a portion covering the first surface F and another portion extending continuously from the portion covering the first surface F to the first side surface C1.

[0152] The second passivation film layer 60 is stacked on the passivation contact layer 50. The second passivation film layer 60 can also be a single-layer or multi-layer structure, and the material of the second passivation film layer 60 can be silicon oxide, silicon nitride, or silicon oxynitride. Furthermore, the second passivation film layer 60 is disposed on the back side of the solar cell 100, also known as the backlight side. With the development of solar cell 100 technology, the back side of the solar cell 100 also receives sunlight energy, mainly from reflected or scattered light from the surrounding environment. The second passivation film layer 60 includes at least one second antireflection layer (not shown) stacked on the passivation contact layer 50. In this way, the reflectivity of the back side of the solar cell 100 to sunlight can be reduced, and the absorption rate of the back side of the solar cell 100 to sunlight can be increased, so that the second passivation film layer 60 simultaneously performs the functions of passivation and antireflection.

[0153] In the embodiments of this application, reference is made to Figure 1 , Figure 2 The first side surface C1 includes a velvet area R with a velvet structure 20 and a flat area P adjacent to the velvet area R. Here, the flat area P refers to the area on the first side surface C1 where the velvet structure 20 is not formed.

[0154] In this embodiment of the application, as described above, the first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1. For the setting range of the first passivation film layer 40 on the first side surface C1, for example, the edge of the first passivation film layer 40 along the thickness direction H of the substrate may be flush with the edge of the doped conductive layer 30, or the aforementioned edge of the first passivation film layer 40 may extend beyond the edge of the doped conductive layer 30.

[0155] When the first passivation film layer 40 extends beyond the edge of the doped conductive layer 30 along the thickness direction H of the substrate, the first passivation film layer 40 can completely cover the textured region R on the first side surface C1, and at least a portion of the flat region P. This provides better coverage and passivation of the edge surface of the solar cell 100 corresponding to the first side surface C1.

[0156] Of course, the first passivation film layer 40 completely covering the textured area R on the first side surface C1 and covering at least part of the flat area P also includes the following situation: during the manufacturing process of the solar cell 100, the contact points such as the positioning points with the first side surface C1 of the substrate 10 may fail to form a film layer, so that the first passivation film layer 40 does not completely cover the first side surface C1.

[0157] exist Figure 2 The diagram illustrates a case where the edge of the first passivation film 40, disposed on the first side surface C1, (the thickness direction H edge of the substrate) lies within a flat region P. Figure 1 The image shows the first passivation film 40 located on the first side surface C1, with its edge along the thickness direction H of the substrate flush with the surface of the passivation contact layer 50 away from the substrate 10. It is understood that... Figure 1 In the scenario shown, the passivation effect is the best.

[0158] For the case where the edge of the first passivation film layer 40 along the thickness direction H of the substrate is flush with the edge of the doped conductive layer 30, for example, refer to Figure 3 , Figure 4 The edge of the first passivation film layer 40 along the thickness direction H of the substrate does not extend to the flat region P, that is, the setting range of the first passivation film layer 40 is consistent with that of the doped conductive layer 30.

[0159] In this embodiment, the second passivation film layer 60 also covers at least a portion of the first side surface C1, so that the first passivation film layer 40 is at least partially covered on the first side surface C1. Since the first passivation film layer 40 covers at least a portion of the first side surface F and the first side surface C1, and the second passivation film layer 60 at least partially covers the first passivation film layer 40, the first passivation film layer 40 and the second passivation film layer 60 together protect at least a portion of the first side surface C1. This not only increases the passivation effect of at least a portion of the edge surface of the solar cell 100 corresponding to the first side surface C1, and alleviates recombination generated on the edge surface of the solar cell 100 corresponding to the first side surface C1, but also, since the second passivation film layer 60 is an insulating film layer, it can better prevent leakage current from occurring on the edge surface of the solar cell 100 corresponding to the first side surface C1. Thus, while improving the battery conversion efficiency, it also increases the power output of the solar cell 100.

[0160] The second passivation film layer 60 covers at least a portion of the second surface S and the first side surface C1, thereby covering at least a portion of the passivation contact layer 50 and the first passivation film layer 40. Specifically, the second passivation film layer 60 continuously covers at least a portion of the second surface S and the first side surface C1 adjacent to the second surface S, thus encompassing the passivation contact layer 50 and the first passivation film layer 40. In this case, the second passivation film layer 60 includes a portion covering the second surface S and another portion extending continuously from the portion covering the second surface S to the first side surface C1.

[0161] The following is combined with Figures 1-4 The setting range of the second passivation film layer 60 on the first side surface C1 is described.

[0162] For the case where the edge of the first passivation film layer 40 extends beyond the edge of the doped conductive layer 30 along the thickness direction H of the substrate, refer to... Figure 1 , Figure 2 The first passivation film layer 40 located on the first side surface C1 may include a first portion 41 covering the flat region P, and the second passivation film layer 60 may at least cover the first portion 41. In this way, it can be ensured that the second passivation film layer 60 can reliably cover the first passivation film layer 40, avoiding the situation where the passivation film layer is not covered at the junction of the two.

[0163] Furthermore, the first passivation film layer 40 located on the first side surface C1 also includes a second portion 42 covering the textured area R, and the second passivation film layer 60 covers at least a portion of the first portion 41 and the second portion 42. Thus, the second passivation film layer 60 has a larger coverage area over the first passivation film layer 40, resulting in a better passivation effect on the side surface of the solar cell 100.

[0164] like Figure 2The case shown is where the second passivation film layer 60 covers all of the first portion 41 and part of the second portion 42. Of course, it is also possible that the second passivation film layer 60 only covers the first portion 41 (not shown), or the second passivation film layer 60 only covers the first portion 41 and all of the second portion 42 (not shown).

[0165] Furthermore, referring to Figure 1 Alternatively, the second passivation film 60 can be located within the film layers on the first portion 41 and the second portion 42, with its edge along the thickness direction H of the substrate flush with the outer surface of the first passivation film 40 along the thickness direction H of the substrate. This provides better passivation of the sides of the solar cell 100. If the first passivation film 40 cannot be deposited due to contact points with the quartz boat during formation, or if its uniformity is poor due to process fluctuations, further increasing the formation range of the second passivation film 60 can further improve the passivation reliability of the sides of the solar cell 100.

[0166] Combination Figure 3 and Figure 4 When the edge of the first passivation film 40 along the thickness direction H of the substrate is flush with the edge of the doped conductive layer 30, as previously described, the first passivation film 40 on the first side surface C1 only covers the textured region R. In this case, the second passivation film 60 covers at least a portion of the textured region R on the first side surface C1; for example, it could be... Figure 4 The second passivation film layer 60 shown covers a portion of the textured area R on the first side surface C1.

[0167] Or, it can be like Figure 3 As shown, the second passivation film layer 60 is located in the film layer on the first side surface C1, and its edge along the thickness direction H of the substrate is flush with the outer surface of the first passivation film layer 40 along the thickness direction H of the substrate. This provides a better passivation effect on the side of the solar cell 100. In cases where the first passivation film layer 40 cannot be deposited due to contact with the quartz boat during formation, or where the uniformity of the first passivation film layer 40 is poor due to process fluctuations, further increasing the formation range of the second passivation film layer 60 can further improve the passivation reliability of the side edges of the solar cell 100.

[0168] Of course, the second passivation film layer 60 covering at least part of the textured area R on the first side surface C1 also includes the following situation: during the manufacturing process of the solar cell 100, the contact points used for positioning and the first passivation film layer 40 on the first side surface C1 and the cut edge side surface C2 of the substrate 10 may fail to form a film layer, so that the second passivation film layer 60 does not completely cover the first passivation film layer 40.

[0169] In this embodiment of the application, as described above, the substrate 10 further includes at least one cut edge side surface C2 adjacent to the first surface F and the second surface S.

[0170] Furthermore, referring to Figures 1-4 The textured structure 20 is only disposed on a portion of the surface of the first surface F and the first side surface C1, and the doped conductive layer 30 is only disposed on a portion of the surface of the first surface F and the first side surface C1 to cover the textured structure 20.

[0171] For example, the cut edge side C2 is flush with the edges of the doped conductive layer 30, the first passivation film layer 40, the passivation contact layer 50, and the second passivation film layer 60 located on the same side as the cut edge side C2 in the normal direction of the cut edge side C2. In this case, no film layer is provided on the edge surface of the solar cell 100 corresponding to the cut edge side C2. This can be, for example, a structure obtained by slicing the cell structure at the end of the manufacturing process of the solar cell 100.

[0172] Example 2

[0173] Figure 5 This is a schematic diagram of the structure of a solar cell provided in Embodiment 2 of this application. Figure 6 This is a schematic diagram of another structure of the solar cell provided in Embodiment 2 of this application. Figure 7 This is a schematic diagram of another structure of the solar cell provided in Embodiment 2 of this application. Figure 8 This is a schematic diagram of another structure of the solar cell provided in Embodiment 2 of this application.

[0174] Reference Figures 5-8 This embodiment improves upon Embodiment 1 by modifying the film structure at the cut edge side C2 position of the solar cell 100. It is understood that the film structure on the first surface F of the substrate 10, the film structure on the first side C1, and the range of their arrangement are the same as in Embodiment 1, and will not be repeated here.

[0175] For example, Figure 5 , Figure 6 This illustrates the case where, on the first side C1, the first passivation film layer 40 extends beyond the edge of the doped conductive layer 30 along the thickness direction H of the substrate. Figure 7 , Figure 8 This illustrates the case where, on the first side surface C1, the edge of the first passivation film layer 40 along the thickness direction H of the substrate is flush with the edge of the doped conductive layer 30.

[0176] exist Figure 5 , Figure 7The diagram shows the second passivation film 60 located on the first side surface C1, with its edge along the thickness direction H of the substrate flush with the outer surface of the first passivation film 40 along the thickness direction H of the substrate; Figure 6 , Figure 8 The diagram shows the second passivation film 60 extending to cover a portion of the second portion 42 (where the second portion 42 is the portion of the first passivation film 40 located on the first side surface C1 that covers the textured area R).

[0177] The details regarding the film layer setup on the side C2 of the cut edge are as follows:

[0178] Reference Figures 5-8 The textured surface 20 is only disposed on a portion of the first surface F and the first side surface C1, and the doped conductive layer 30 is only disposed on a portion of the first surface F and the first side surface C1 to cover the textured surface 20. Thus, the textured surface 20 and the doped conductive layer 30 are not disposed on the cutting edge side surface C2.

[0179] In this embodiment, the first passivation film layer 40 also covers at least a portion of the cut edge side surface C2. The cut edge side surface C2 corresponds to the cut surface formed by cutting in the solar cell 100. Thus, the first passivation film layer 40 protects at least a portion of the cut edge side surface C2, which not only increases the passivation effect of the cut surface of the solar cell 100 corresponding to the cut edge side surface C2 and alleviates recombination generated on the cut surface of the solar cell 100 corresponding to the cut edge side surface C2, but also, as the first passivation film layer 40 is an insulating film layer, can better prevent leakage current from occurring on the cut surface of the solar cell 100 corresponding to the cut edge side surface C2. Therefore, while improving the battery conversion efficiency, it also increases the power output of the solar cell 100.

[0180] Furthermore, the coverage area of ​​the first passivation film layer 40 on the cutting edge side C2 can be, for example, as shown in the figure. Figure 5 As shown, the first passivation film layer 40 is located at the edge of the film layer on the cutting edge side C2 along the thickness direction H of the substrate, and is flush with the surface of the passivation contact layer 50 away from the substrate 10. Alternatively, it can be as follows: Figure 6 , Figure 7 , Figure 8 As shown, the edge of the first passivation film 40 located on the cutting edge side C2 along the thickness direction H of the substrate is within the range of the cutting edge side C2.

[0181] Of course, the edges of the first passivation film layer 40 on the first side surface C1 and the cutting edge side surface C2 can be flush with each other, or they can be uneven.

[0182] In this embodiment, the second passivation film layer 60 also covers at least a portion of the cutting edge side surface C2, so as to at least partially cover the first passivation film layer 40 on the cutting edge side surface C2.

[0183] Specifically, it can be like Figure 5 , Figure 7 In this case, the second passivation film 60 is located in the film layer on the cutting edge side C2, with its edge along the thickness direction H of the substrate flush with the outer surface of the first passivation film 40 along the thickness direction H of the substrate. Alternatively, it can be as follows... Figure 6 , Figure 8 In this way, the second passivation film layer 60 extends to cover a portion of the first passivation film layer 40.

[0184] Of course, the edges of the second passivation film 60 on the first side C1 and the cutting edge side C2 can be flush with each other, or they can be uneven.

[0185] Example 3

[0186] Figure 9 This is a schematic diagram of the structure of a solar cell provided in Embodiment 3 of this application. Figure 10 This is a schematic diagram of another structure of the solar cell provided in Embodiment 3 of this application. Figure 11 This is a schematic diagram of another structure of the solar cell provided in Embodiment 3 of this application. Figure 12 This is a schematic diagram of another structure of the solar cell provided in Embodiment 3 of this application.

[0187] Reference Figures 9-12 This embodiment improves upon Embodiment 1 by modifying the film structure at the cut edge side C2 position of the solar cell 100. It is understood that the film structure on the first surface F of the substrate 10, the film structure on the first side C1, and the range of their arrangement are the same as in Embodiment 1, and will not be repeated here.

[0188] For example, Figure 9 , Figure 10 This illustrates the case where, on the first side C1, the first passivation film layer 40 extends beyond the edge of the doped conductive layer 30 along the thickness direction H of the substrate. Figure 11 , Figure 12 This illustrates the case where, on the first side surface C1, the edge of the first passivation film layer 40 along the thickness direction H of the substrate is flush with the edge of the doped conductive layer 30.

[0189] exist Figure 9 , Figure 11 The diagram shows the second passivation film 60 located on the first side surface C1, with its edge along the thickness direction H of the substrate flush with the outer surface of the first passivation film 40 along the thickness direction H of the substrate; Figure 10 , Figure 12 The image shows the second passivation film layer 60 extending to cover a portion of the second portion 42.

[0190] The details regarding the film layer setup on the side C2 of the cut edge are as follows:

[0191] Reference Figures 9-12 In this embodiment, the cut edge side surface C2 also has a textured structure 20; the doped conductive layer 30 is disposed on a portion of the surface of the first surface F, a portion of the surface of the first side surface C1, and a portion of the surface of the cut edge side surface C2 to cover the textured structure 20; the first passivation film layer 40 also covers at least a portion of the cut edge side surface C2 to at least cover the doped conductive layer 30.

[0192] Thus, by increasing the passivation effect on the edge surface of the solar cell 100 corresponding to the first side C1 and alleviating recombination on the edge surface of the solar cell 100 corresponding to the first side C1, and by providing a textured structure 20 on a portion of the structure on the cut edge side C2, a doped conductive layer 30 is provided on the textured structure 20. This doped conductive layer 30 at this location helps reduce recombination at the interface where the cut edge side C2 is located, achieving a better passivation effect on the cut surface of the solar cell 100 corresponding to the cut edge side C2. Furthermore, the textured structure 20 provided on the cut edge side C2 increases the light absorption area of ​​the solar cell 100, improves the photocurrent of the solar cell 100, and helps to improve the efficiency of the solar cell 100.

[0193] On the other hand, the first passivation film layer 40 covers at least a portion of the cut edge side surface C2 to at least cover the doped conductive layer 30, so that the first passivation film layer 40 protects at least a portion of the cut edge side surface C2. This not only increases the passivation effect of the cut surface of the solar cell 100 corresponding to the cut edge side surface C2 and alleviates the recombination generated on the cut surface of the solar cell 100 corresponding to the cut edge side surface C2, but also, since the first passivation film layer 40 is an insulating film layer, it can better prevent leakage current from occurring on the cut surface of the solar cell 100 corresponding to the cut edge side surface C2. Thus, while improving the cell conversion efficiency, it also increases the power output of the solar cell 100.

[0194] Furthermore, the coverage area of ​​the first passivation film layer 40 on the cutting edge side C2 can be, for example, as shown in the figure. Figure 9 As shown, the first passivation film layer 40 is located at the edge of the film layer on the cutting edge side C2 along the thickness direction H of the substrate, and is flush with the surface of the passivation contact layer 50 away from the substrate 10. Alternatively, it can be as follows: Figure 11 , Figure 12As shown, on the cutting edge side C2, the edge of the first passivation film layer 40 along the thickness direction H of the substrate is flush with the edge of the doped conductive layer 30. Alternatively, it can be as follows: Figure 10 As shown, the aforementioned edge of the first passivation film layer 40 extends beyond the edge of the doped conductive layer 30, within the range of the cut edge side surface C2.

[0195] Of course, the edges of the first passivation film layer 40 on the first side surface C1 and the cutting edge side surface C2 can be flush with each other, or they can be uneven.

[0196] In this embodiment, the second passivation film layer 60 also covers at least a portion of the cutting edge side surface C2, so as to at least partially cover the first passivation film layer 40 on the cutting edge side surface C2.

[0197] Specifically, it can be like Figure 9 , Figure 11 In this case, the second passivation film 60 is located in the film layer on the cutting edge side C2, with its edge along the thickness direction H of the substrate flush with the outer surface of the first passivation film 40 along the thickness direction H of the substrate. Alternatively, it can be as follows... Figure 10 , Figure 12 In this way, the second passivation film layer 60 extends to cover a portion of the first passivation film layer 40.

[0198] Of course, the edges of the second passivation film 60 on the first side C1 and the cutting edge side C2 can be flush with each other, or they can be uneven.

[0199] Example 4

[0200] Figure 13 This is a schematic flowchart illustrating the method for manufacturing a solar cell according to Embodiment 4 of this application.

[0201] This embodiment provides a method for manufacturing a solar cell, which is used to produce the solar cell in any of the above embodiments. The structure, function, and working principle of the solar cell 100 have been described in detail in Embodiment 1, and will not be repeated here.

[0202] Methods for manufacturing solar cells include:

[0203] S10. A substrate 101 is provided. The substrate 101 includes a base 10 and a doped conductive layer 30. The base 10 includes a first surface F and a second surface S disposed opposite to each other, and a plurality of first side surfaces C1 adjacent to the first surface F and the second surface S. A textured structure 20 is provided on at least a portion of the first surface F and the first side surfaces C1 of the base 10. The doped conductive layer 30 is provided on at least a portion of the first surface F and the first side surfaces C1 to cover the textured structure 20.

[0204] S20, A passivation contact layer 50 is formed on the second surface S of the substrate 10.

[0205] S30. A first passivation film layer 40 is formed on the doped conductive layer 30; wherein the first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1, so as to at least cover the doped conductive layer 30.

[0206] S40. A second passivation film layer 60 is formed on the passivation contact layer 50 to form a solar cell substrate 103; wherein the second passivation film layer 60 covers the second surface S to cover the passivation contact layer 50.

[0207] In the above scheme, by making a textured structure 20 on a portion of the first surface F and the first side surface C1 of the substrate 10, a doped conductive layer 30 is disposed at least on a portion of the first surface F and the first side surface C1 to cover the textured structure 20. Since a textured structure 20 is present on a portion of the first side surface C1, and a doped conductive layer 30 is provided on the textured structure 20, the doped conductive layer 30 in the first side surface C1 helps to reduce recombination at the interface where the first side surface C1 is located, achieving a better passivation effect on the edge surface of the solar cell 100 corresponding to the first side surface C1. Furthermore, the textured structure 20 provided on the first side surface C1 increases the light absorption area of ​​the solar cell 100, improves the photocurrent of the solar cell 100, and helps to improve the efficiency of the solar cell 100.

[0208] On the other hand, a first passivation film layer 40 is formed on the doped conductive layer 30. The first passivation film layer 40 covers at least a portion of the first side surface F and the first side surface C1, so as to at least cover the doped conductive layer 30. This allows the first passivation film layer 40 to protect at least a portion of the first side surface C1. This not only increases the passivation effect on the edge surface of the solar cell 100 corresponding to the first side surface C1 and alleviates recombination on the edge surface of the solar cell 100 corresponding to the first side surface C1, but also, since the first passivation film layer 40 is an insulating material layer, it can better prevent leakage on the edge surface of the solar cell 100 corresponding to the first side surface C1. Thus, while improving the cell conversion efficiency, it also increases the power output of the solar cell 100.

[0209] It is understood that the structure, material, and placement range of the textured structure 20, the doped conductive layer 30, the first passivation film layer 40, the passivation contact layer 50, and the second passivation film layer 60 have been described in detail in the aforementioned Embodiments 1, 2, and 3, and will not be repeated here.

[0210] In this embodiment, step S20, which involves forming a passivation contact layer 50 on the second surface S of the substrate 10, includes:

[0211] A tunneling material layer, a polysilicon doped material layer, and an oxide material layer (not shown) are sequentially stacked on each surface of the substrate 101.

[0212] Etching removes the oxide material layer on the surface of the first side of the substrate 101 and on each side of the substrate 101;

[0213] Etching removes the polysilicon doped material layer and tunneling material layer on the surface of the first side of the substrate 101 and on each side of the substrate 101; wherein, the first side is one side of the first surface F of the substrate 10.

[0214] Thus, only the tunneling material layer, the polysilicon doped material layer, and the oxide material layer remain on the second surface S. Of course, the oxide material layer here (e.g., a silicon oxide layer) can serve as a mask in subsequent processes and can be removed later by etching or other processes. In this way, a passivation contact layer 50 can be formed on the second surface S.

[0215] For example, the etching to remove the oxide material layer is performed by a chain machine, and the etching to remove the tunneling material layer and the polysilicon doped material layer is performed by a tank machine.

[0216] In this embodiment, after forming the second passivation film layer 60 on the passivation contact layer 50 in step S40, the method further includes:

[0217] Electrodes 70 are fabricated on the first passivation film layer 40 and the second passivation film layer 60, respectively. Among them, the electrode 70 located on the first surface F side of the substrate 10 is connected to the doped conductive layer 30, and the electrode 70 located on the second surface S side of the substrate 10 penetrates the second passivation film layer 60 and is connected to the passivation contact layer 50.

[0218] Understandably, to improve efficiency, the photovoltaic module 200 can be packaged using half-cell or multi-cell technology. That is, standard-sized cells can be cut in half or into multiple parts and then connected in series to form a module.

[0219] In the method for manufacturing a solar cell according to the embodiments of this application, the cutting step can be set at different locations.

[0220] For example, the cutting can be performed in step S10 or after step S40.

[0221] In the case of cutting in step S10, for example, the substrate blank is cut into substrate 10 of the corresponding size according to the required size of the solar cell 100.

[0222] It is understood that in the method provided in this embodiment, the substrate preform is cut into substrates 10 of appropriate size (corresponding to the actual size of the solar cell 100) before doping and texturing. By introducing the cutting step in advance and integrating it into the subsequent single-sided etching process and interface passivation process, the edge surfaces of the solar cell 100 (including the cut edge side surface C2) can be effectively passivated, reducing recombination and improving efficiency. Furthermore, no further cutting is performed in subsequent steps, meaning no new cut surfaces are generated, effectively avoiding the problem of a large amount of recombination on the cut surfaces in related technologies.

[0223] Figure 14 This is a schematic diagram of the substrate structure in the method for fabricating a solar cell provided in Embodiment 4 of this application. Figure 15 This is a schematic diagram of the structure in which a textured surface structure and a doped conductive layer are formed on a substrate in the method for fabricating a solar cell according to Embodiment 4 of this application. Figure 16 This is a schematic diagram of the structure for forming the passivation contact layer in the method for manufacturing a solar cell according to Embodiment 4 of this application. Figure 17 This is a schematic diagram illustrating the formation of the first passivation film layer in the method for fabricating a solar cell according to Embodiment 4 of this application. Figure 18 This is a schematic diagram illustrating the formation of the second passivation film layer in the method for fabricating a solar cell according to Embodiment 4 of this application. Figure 19 This is a schematic diagram of the solar cell formed in the method for manufacturing a solar cell provided in Embodiment 4 of this application. Figure 20 This is a schematic diagram of the structure of the first side of the substrate in the method for manufacturing a solar cell provided in Embodiment 4 of this application.

[0224] Specifically, refer to Figure 14 , Figure 15 In step S10, the step of providing a substrate 101 includes:

[0225] The base blank (not shown) is cut along the thickness direction to form at least two bases 10, and the cut edge side surface C2 is formed on the base 10;

[0226] At least the first surface F, the first side surface C1, and the cut edge side surface C2 of the substrate 10 are texturized and doped with element diffusion.

[0227] The substrate 10 is etched to expose the second surface S of the substrate 10, the first target area C11 on each first side surface C1, and the second target area C12 on each cut edge side surface C2; ​​so that a textured structure 20 and a doped conductive layer 30 covering the textured structure 20 are formed on a portion of the first surface F of the substrate 10, a portion of the first side surface C1, and a portion of the cut edge side surface C2.

[0228] Wherein, the first target area C11 is the area on each first side surface C1 that is adjacent to and connected to the second side surface S; the second target area C12 is the area on each cutting edge side surface C2 that is adjacent to and connected to the second side surface S.

[0229] In the above steps, the texturing process forms a textured surface on each surface of the substrate 10. Then, doping element diffusion is performed on the substrate 10. Since the diffusion process deposits some doped elements onto the first side surface C1, the cut edge side surface C2, and the second surface S of the substrate 10, a single-sided etching process is used to etch the first side surface C1, the cut edge side surface C2, and the second surface S of the substrate 10. This exposes the second surface S, the first target area C11 on the first side surface C1, and the second target area C12 on the cut edge side surface C2, preventing leakage. At this point, a textured structure 20 and a doped conductive layer 30 are formed on a portion of the surfaces of the first side surface F, the first side surface C1, and the cut edge side surface C2.

[0230] In a specific implementation, the step of etching the substrate 10 to expose the second surface S of the substrate 10, the first target area C11 on each first side surface C1, and the second target area C12 on each cutting edge side surface C2 includes:

[0231] Step D: Etch the substrate 10 after texturing and doping element diffusion to expose the texturized structures on the second surface S, the first target area C11 on each first side surface C1, and the second target area C12 on each cut edge side surface C2. Specifically, a chain etching machine can be used for etching. Of course, during the etching process, the liquid level of the chain etching machine must be controlled to prevent the etching solution from adhering to the texturized structure 20 and the doped conductive layer 30 on the first surface F of the substrate 10, while preserving the textured structure formed on the second surface S. Figure 20 The irregular shape shown.

[0232] Step E: Etch away the exposed textured surface on the second surface S, the first target area C11, and the second target area C12 to expose the second surface S of the substrate 10, the first target area C11 on each first side surface C1, and the second target area C12 on each cutting edge side surface C2. Specifically, a trough etching machine can be used. It can be understood that etching away the exposed textured surface is equivalent to etching and polishing the exposed textured surface to a non-textured morphology. Figure 20 In the middle, the boundary line 11 between the doped conductive layer 30 and the first target region C11 is irregularly wavy.

[0233] In this embodiment of the application, the step of cutting the base blank (not shown) along the thickness direction to form at least two bases 10 includes:

[0234] The base blank is laser-cut along the thickness direction H to form two bases 10 of the same size. Of course, the number of bases 10 cut out is not limited to this, and can be set to others as needed.

[0235] The following is a specific example to illustrate the method for fabricating the cut solar cell in step S10 above:

[0236] Step SJ: Refer to Figure 14 The base blank is cut along the thickness direction H to form at least two bases 10; the base 10 includes a first surface F and a second surface S disposed opposite to each other, and a plurality of first side surfaces C1 adjacent to the first surface F and the second surface S and at least one cut edge side surface C2 formed by cutting.

[0237] Step SK: Refer to Figure 15 The substrate 10 is texturized and boron diffused on each surface; and the substrate 10 is etched to expose the second surface S, the first target area C11 on each first side surface C1, and the second target area C12 on each cut edge side surface C2 of the substrate 10, thereby forming a textured structure 20 on a portion of the first surface F, the first side surface C1, and the cut edge side surface C2 of the substrate 10, and forming a doped conductive layer 30 (boron conductive layer) covering the textured structure 20 on a portion of the first surface F, the first side surface C1, and the cut edge side surface C2 of the substrate 10, to form a substrate 101.

[0238] Step SL: A tunneling material layer, a polysilicon doped material layer, and an oxide material layer are formed on each surface of the substrate 101. The oxide material layer on the first side surface of the substrate 101 and each side surface of the substrate 101 (including each first side surface C1 and each cut edge side surface C2) is etched away. The polysilicon doped material layer and tunneling material layer on the first side surface of the substrate 101 and each side surface of the substrate 101 are also etched away. The first side is one side of the first surface F of the substrate 10. Thus, only the tunneling material layer, polysilicon doped material layer, and oxide material layer remain on the second surface S. Of course, the oxide material layer here (e.g., a silicon oxide layer) can serve as a mask in subsequent processes and can be removed by etching or other processes. In this way, a structure like... Figure 16 The passivation contact layer 50 shown is disposed on the second surface S.

[0239] Step SM: Refer to Figure 17 A first passivation film layer 40 is formed on the doped conductive layer 30; wherein the first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1, and at least a portion of the cut edge side surface C2 is covered to at least cover the doped conductive layer 30.

[0240] Step SN: Refer to Figure 18 A second passivation film layer 60 is formed on the passivation contact layer 50; wherein the second passivation film layer 60 covers at least a portion of the second surface S and the first side surface C1, and at least a portion of the cut edge side surface C2, to cover at least a portion of the passivation contact layer 50 and the first passivation film layer 40.

[0241] Step SO: Refer to Figure 19 Electrodes 70 are fabricated on the first passivation film layer 40 and the second passivation film layer 60 respectively to form a solar cell 100.

[0242] The solar cell 100 produced in steps SJ-SO is denoted as solar cell A1.

[0243] The comparative method for manufacturing solar cells includes:

[0244] Step SP: Clean and texturize the silicon wafer, and then perform boron diffusion on the front side of the cleaned and texturized silicon wafer.

[0245] Step SQ: Remove the borosilicate glass (BSG) wrapped around the back and sides of the silicon wafer, and perform alkaline polishing on the sides and back of the silicon wafer.

[0246] Step SR: Form a tunneling oxide layer and a polysilicon-doped conductive layer on the back side of the silicon wafer.

[0247] Step SS: Deposit passivation antireflection films on both the front and back sides of the silicon wafer.

[0248] Step ST: Electrodes are fabricated on both the front and back sides of the silicon wafer.

[0249] Step SU: Laser cutting in half.

[0250] The solar cell 100 produced through comparative steps SP-ST is designated as solar cell B1, and the solar cell 100 produced through comparative steps SP-SU is designated as solar cell B2.

[0251] Solar cells A1, B1, and B2 were tested for cell performance, and the results are recorded in Table 1. Where Uoc is the open-circuit voltage; FF is the fill factor; Eta is the conversion efficiency; Isc is the short-circuit current; and IRev2 is the reverse current.

[0252] Table 1: Performance test results of solar cell A1 and solar cells B1 and B2

[0253] Group Isc_A Uoc_mV FF_% Eta_% IRev2_A A1 7.79 712.9 82.95 24.13 0.05 B1 15.56 713.3 82.98 24.12 0.08 B2 7.76 712.2 82.21 23.80 0.09

[0254] The experimental results above show that the efficiency of the solar cell A1 (after dicing) prepared by the method of this embodiment is basically the same as that of the whole solar cell B1 (undicated) in the comparative example. However, compared with the diced solar cell B2 in the comparative example, the open-circuit voltage of the cell increases by 0.7mV, the fill factor increases by about 0.74%, the cell conversion efficiency increases by about 0.33%, and the reverse current decreases from 0.09A to 0.05. Therefore, it can be concluded that the solar cell A1 prepared by the method of this embodiment has a higher efficiency.

[0255] For cases where cutting is performed after step S40, such as after each film layer has been fabricated, cutting is performed last.

[0256] Figure 21 This is a schematic diagram of the substrate structure in another method for manufacturing a solar cell provided in Embodiment 4 of this application. Figure 22 This is a schematic diagram illustrating the formation of a passivation contact layer on a substrate in another method for fabricating a solar cell provided in Embodiment 4 of this application. Figure 23 This is a schematic diagram illustrating the formation of a first passivation film layer on a doped conductive layer in another method for fabricating a solar cell provided in Embodiment 4 of this application. Figure 24 This is a schematic diagram illustrating the formation of a second passivation film layer on the passivation contact layer in another method for fabricating a solar cell provided in Embodiment 4 of this application. Figure 25 This is a schematic diagram illustrating the formation of electrodes on the first passivation film layer and the second passivation film layer in another method for fabricating a solar cell provided in Embodiment 4 of this application. Figure 26 This is a schematic diagram of the structure of a solar cell formed in another method of manufacturing a solar cell according to Embodiment 4 of this application. Figure 27 This image shows a cut surface of a solar cell obtained by cutting the solar cell in another method of manufacturing a solar cell provided in Embodiment 4 of this application.

[0257] In this embodiment, after the step of forming the second passivation film layer 60 on the passivation contact layer 50 in step S40, the method further includes:

[0258] Along the solar cell substrate 103 (e.g. Figure 25 Laser cutting is performed along the thickness direction of (as shown) to form at least two solar cells 100.

[0259] For example, the solar cell substrate 103 can be cut into two equal halves along the thickness direction H to form two solar cells 100 (e.g., Figure 26 (As shown).

[0260] For example, the step of forming the electrode 70 on the first passivation film layer 40 and the second passivation film layer 60 can be performed before the cutting step described above.

[0261] Furthermore, in the case of final cutting, step S10, providing a substrate 101 includes:

[0262] At least the first surface F and the first side surface C1 of the substrate 10 are texturized and doped with element diffusion.

[0263] The substrate 10 is etched to expose the second surface S of the substrate 10 and the first target area C11 on each of the first side surfaces C1.

[0264] The first target region C11 is the region on each first side surface C1 of the base 10 that is adjacent to and connected to the second surface S.

[0265] In the above steps, the texturing process forms a textured surface on each surface of the substrate 10. Then, dopant diffusion is performed on the substrate 10. Since the diffusion process deposits some dopant onto the first side surface C1 and the second side surface S of the substrate 10, a single-sided etching process is used to etch the first side surface C1 and the second side surface S of the substrate 10, exposing the first target area C11 on the second side surface S and each of the first side surfaces C1, thus preventing leakage. At this point, a textured structure 20 and a doped conductive material layer 30 are formed on a portion of the surfaces of the first side surface F and the first side surface C1.

[0266] In specific implementation, the step of etching the substrate 10 to expose the second surface S and the first target region C11 on each of the first side surfaces C1 of the substrate 10 includes:

[0267] Step D': Etch the substrate 10 after texturing and doping element diffusion to expose the textured structure on the second surface S and each first target region C11. Specifically, a chain etching machine can be used for etching. Of course, during the etching process, the liquid level of the chain etching machine must be controlled to prevent the etching solution from adhering to the textured structure 20 and the doped conductive material layer 30 on the first surface F of the substrate 10, thereby preserving the textured structure formed as shown in the image. Figure 20 The irregular shape shown.

[0268] Step E': The exposed textured structure is etched away to expose the second surface S of the substrate 10 and the first target area C11 on each of the first side surfaces C1. Specifically, a trough etching machine can be used. It can be understood that etching away the exposed textured structure on the surface of the substrate 10 is equivalent to etching and polishing the textured structure 20 in the first target area C11 and the second surface S of the substrate 10 to a non-textured morphology. Figure 20 In the middle, the boundary line 11 between the doped conductive layer 30 and the first target region C11 is irregularly wavy.

[0269] In this embodiment, since the solar cell 100 is formed by cutting the solar cell substrate 103 formed in step S40, the final size of the solar cell 100 is ( Figure 26 (As shown) compared to the solar cell substrate 103 ( Figure 25 (It is) small in size.

[0270] It is understandable that after cutting the solar cell substrate 103, a new cut surface CQ will be generated, such as... Figure 27 As shown.

[0271] The following is a specific example illustrating the cutting process after step S40.

[0272] At this point, the methods for manufacturing solar cells include:

[0273] Step SJ': Refer to Figure 21 Texturing and boron diffusion are performed on each surface of the substrate 10 in the substrate 101; and etching is performed on the substrate 10 to expose the second surface S and the first target area C11 on each first side surface C1 of the substrate 10, thereby forming a textured structure 20 on a portion of the first surface F and the first side surface C1 of the substrate 10, and forming a doped conductive layer 30 (boron conductive layer) covering the textured structure 20 on a portion of the first surface F and the first side surface C1.

[0274] Step SK': Refer to Figure 22 A tunneling material layer, a polysilicon doped material layer, and a silicon oxide material layer (not shown) are sequentially formed on each surface of substrate 101. The silicon oxide material layers on the first side surface and each side surface of substrate 101 are then etched away. The tunneling material layer and polysilicon doped material layer on the first side surface and each side surface of substrate 101 are also etched away. This leaves only the tunneling material layer, polysilicon doped layer, and oxide material layer on the second surface S. Of course, the oxide material layer (e.g., a silicon oxide layer) can serve as a mask in subsequent processes and can be removed by etching or other processes. In this way, a structure like... Figure 22 The passivation contact layer 50 shown is disposed on the second surface S.

[0275] Step SL′: Refer to Figure 23 A first passivation film layer 40 is formed on the doped conductive layer 30; wherein the first passivation film layer 40 covers the entire area of ​​the first surface F and the first side surface C1 to cover the doped conductive material layer 30.

[0276] Step SM′: Refer to Figure 24A second passivation film layer 60 is formed on the passivation contact layer 50 to form a solar cell substrate 103; wherein the second passivation film layer 60 covers the entire area of ​​the second side S and the first side C1 to cover the passivation contact layer 50 and completely cover the portion of the first passivation film layer 40 located on the first side C1.

[0277] Step SN′: Refer to Figure 25 Electrodes 70 are fabricated on the first passivation film layer 40 and the second passivation film layer 60 of the solar cell substrate 103, respectively.

[0278] Step SO': Refer to Figure 26 Laser cutting is performed along the thickness direction H of the solar cell substrate 103 to form at least two solar cells 100. The solar cell 100 formed in steps SJ′-SO′ is denoted as solar cell A2.

[0279] Solar cells A2 and B1 were tested for cell performance, and the results are recorded in Table 2. Where Uoc is the open-circuit voltage; FF is the fill factor; Eta is the conversion efficiency; Isc is the short-circuit current; and IRev2 is the reverse current.

[0280] Table 2: Performance test results of solar cells A2 and B1

[0281] Group Isc_A Uoc_mV FF_% Eta_% IRev2_A A2 15.57 714.4 83.00 24.18 0.05 B1 15.56 713.3 82.98 24.12 0.08

[0282] The experimental results above show that the open-circuit voltage of solar cell 100 increased by 1.1mV, the fill factor increased by about 0.02%, and the conversion efficiency increased by 0.06%. Under the 12V bias test, the leakage current decreased from 0.08A to 0.05A. Therefore, the leakage current of solar cell 100 was effectively reduced, and the solar cell A2 made by the method of this embodiment has a high efficiency.

[0283] Example 5

[0284] With the rapid development of photovoltaic technology and the expansion of its application scope, the market demand for high-efficiency photovoltaic modules is increasing daily. Generally, photovoltaic modules are encapsulated using a full-cell design. However, as the output current continues to increase, internal losses have a significant impact. To reduce internal losses and improve the output power of photovoltaic modules, module encapsulation has gradually evolved to the current half-cell or multi-cell technology. This technology typically uses laser cutting to cut standard-sized cells into half-cells or multiple cells. However, laser cutting technology results in high recombination rates on the cut sides of the half-cells, with numerous dangling bonds and defect states on the surface, becoming effective recombination centers for charge carriers. Furthermore, leakage current is easily generated on the cut sides, thus reducing the efficiency of the solar cell.

[0285] In this embodiment, by placing the cutting step in the middle of the solar cell fabrication process, after depositing the passivation contact material, the cut surface is passivated during the subsequent deposition of the first passivation film layer and the second passivation film layer, thus avoiding recombination problems on the cut surface and improving the efficiency of the solar cell 100.

[0286] Figure 28 This is a schematic flowchart illustrating the method for manufacturing a solar cell according to Embodiment 5 of this application. Figure 29 This is a schematic diagram of the substrate structure in the method for manufacturing a solar cell provided in Embodiment 5 of this application. Figure 30 This is a schematic diagram of the structure of the substrate in the method for fabricating a solar cell provided in Embodiment 5 of this application. Figure 31 This is a schematic diagram illustrating the formation of the first passivation film layer in the method for fabricating a solar cell according to Embodiment 5 of this application. Figure 32 This is a schematic diagram illustrating the formation of the second passivation film layer in the method for fabricating a solar cell according to Embodiment 5 of this application. Figure 33 This is a schematic diagram of the solar cell formed in the method for manufacturing the solar cell provided in Embodiment 5 of this application.

[0287] This embodiment provides a method for manufacturing a solar cell, which is used to produce the solar cell 100 in any of the above embodiments. The structure, function, and working principle of the solar cell 100 have been described in detail in Embodiment 1, and will not be repeated here.

[0288] Reference Figures 28-33 The method for manufacturing a solar cell provided in this embodiment includes:

[0289] S100, a substrate 101' is provided; the substrate 101' includes a base 10 and a doped conductive material layer 30'; the base 10 includes a first surface F and a second surface S disposed opposite to each other, and a plurality of first side surfaces C1 adjacent to the first surface F and the second surface S; a portion of the first surface F and the first side surfaces C1 of the base 10 have a textured structure 20; the doped conductive material layer 30' is disposed on a portion of the first surface F and the first side surfaces C1 to cover the textured structure 20.

[0290] S200, a passivation contact material layer is formed on each surface of the substrate 101'.

[0291] S300, the substrate 101' forming the passivation contact material layer is cut along the thickness direction H of the substrate to form at least two sub-substrates 102, and the doped conductive material layer 30' forms the doped conductive layer 30.

[0292] S400, etching away the passivation contact material layer (not shown) on the surface of the first side and each side of the sub-substrate 102 to form a passivation contact layer 50 on the sub-substrate 102, the first side being one side of the first surface F of the substrate 10.

[0293] S500, a first passivation film layer 40 is formed on the doped conductive layer 30; wherein the first passivation film layer 40 covers at least a portion of the first surface F and the first side surface C1, so as to at least cover the doped conductive layer 30; the first passivation film layer 40 also covers at least a portion of the cut edge side surface C2, wherein the cut edge side surface C2 is the side surface cut in the sub-substrate 102 (that is, the cut edge side surface C2 in the substrate 10).

[0294] By giving a textured structure 20 to a portion of the first surface F and the first side surface C1 of the substrate 10, a doped conductive material layer 30' is disposed on a portion of the first surface F and the first side surface C1 to cover the textured structure 20. Since the textured structure 20 is present on a portion of the first side surface C1, and the doped conductive material layer 30' is provided on the textured structure 20, the doped conductive material layer 30' in the first side surface C1 of the solar cell 100 formed after cutting helps to reduce recombination at the interface of the solar cell 100 corresponding to the first side surface C1, achieving a better passivation effect on the edge surface of the solar cell 100 corresponding to the first side surface C1. Furthermore, in the solar cell 100 formed after cutting, the textured structure 20 provided on the first side surface C1 increases the light absorption area of ​​the solar cell 100, improves the photocurrent of the solar cell 100, and helps to improve the efficiency of the solar cell 100.

[0295] On the other hand, a first passivation film layer 40 is formed on the doped conductive layer 30. The first passivation film layer 40 covers at least a portion of the cut edge side surface C2. Thus, the first passivation film layer 40 can protect at least a portion of the cut surface of the solar cell 100 corresponding to the cut edge side surface C2, and passivate the at least portion of the cut surface of the solar cell 100 corresponding to the cut edge side surface C2. This alleviates the recombination that occurs on the cut surface of the solar cell 100 corresponding to the cut edge side surface C2. In addition, the first passivation film layer 40 is an insulating film layer, which can also better prevent leakage on the side of the solar cell 100 corresponding to the cut edge side surface C2. This improves the cell conversion efficiency and increases the power output of the solar cell 100.

[0296] Furthermore, the first passivation film layer 40 also covers at least a portion of the first surface F and the first side surface C1 to at least cover the doped conductive layer 30. In the solar cell 100 formed after cutting, a portion of the first side surface in the original substrate 101' forms the first side surface C1 in the solar cell 100, while another portion of the first side surface is cut into multiple parts, and each small part of the first side surface also forms another portion of the first side surface C1 in the solar cell 100. Thus, by covering at least a portion of the first surface F and the first side surface C1 with the first passivation film layer 40, the first passivation film layer 40 can protect at least a portion of the first side surface C1 generated after cutting. This not only increases the passivation effect of at least a portion of the first side surface C1 and alleviates recombination on the edge surface of the solar cell 100 corresponding to the first side surface C1, but also, as the first passivation film layer 40 is an insulating film layer, it can better prevent leakage on the side surface of the solar cell 100 corresponding to the first side surface C1, thereby further improving the cell conversion efficiency and increasing the power output of the solar cell 100.

[0297] In this embodiment of the application, it can be understood that, due to the cutting step S300, the substrate 10 in the substrate 101' is cut into at least two parts. In other words, the substrate 101' is cut in step S300, and the solar cell 100 is formed only after subsequent manufacturing steps. Therefore, the size of the substrate 10 in the substrate 101' is larger than the size of the substrate 10 in the solar cell 100. Apart from the size and area, the first surface F and the second surface S included in the substrate 10 in the substrate 101' are the same as the first surface F and the second surface S included in the substrate 10 in the finally formed solar cell 100. This will not be repeated here.

[0298] It is understandable that after the substrate 101' is cut into the sub-substrate 102, part of the first side surface C1 of the substrate 10 is cut into multiple parts, and on the substrate 10 of the sub-substrate 102 (i.e., the solar cell 100), a new cut surface formed by the cutting, i.e. the cut edge side surface C2, will be generated.

[0299] Reference Figure 29 In substrate 101', multiple first side surfaces C1 of substrate 10 can be interconnected and collectively surround the first surface F, with each first side surface C1 connected between the first surface F and the second surface S. Furthermore, portions of the first surface F and the first side surfaces C1 of substrate 10 have a textured surface structure 20. Similar to the aforementioned, the textured surface structure 20 on the first surface F and the first side surfaces C1 of substrate 10 can be a continuous structure or a discontinuous structure. Thus, when it is a continuous structure, the entire textured surface structure 20 forms a cover-like element that fits onto the first surface F of substrate 10.

[0300] In this embodiment, the doped conductive material layer 30' is formed after the cutting step S300. Therefore, the material, film structure, and setting range of the doped conductive material layer 30' are the same as those of the doped conductive layer 30 in Embodiment 1, Embodiment 2, and Embodiment 3, and will not be described again here.

[0301] A doped conductive material layer 30' is disposed on a portion of the surface of the first surface F and the first side surface C1 to cover the textured structure 20. Therefore, a portion of the doped conductive material layer 30' is disposed on the first surface F, and another portion is disposed on a portion of the surface of the first side surface C1, with its disposed area covering the textured structure 20. In some embodiments, the disposed area of ​​the doped conductive material layer 30' may also be larger than that of the textured structure 20. In the embodiments of this application, the example is taken where the disposed area of ​​the doped conductive material layer 30' is equivalent to that of the textured structure 20, that is, the doped conductive material layer 30' exactly completely covers the textured structure 20.

[0302] Similar to the above, since a passivation contact material layer (not shown) is formed after steps S300 and S400, the material of the passivation contact material layer is the same as that of the passivation contact layer 50 in Embodiments 1, 2, and 3. Exemplarily, the passivation contact material layer may include a tunneling material layer and a polysilicon doped material layer (not shown) sequentially stacked on the second surface S. The material and structure of the tunneling material layer are the same as those of the tunneling oxide layer 51, and the material and structure of the polysilicon doped material layer are the same as those of the polysilicon doped conductive layer 52, and will not be described again here.

[0303] In this embodiment of the application, in step S500, a first passivation film layer 40 is formed on the doped conductive layer 30. The first passivation film layer 40 has been described in detail in embodiments one, two and three, and will not be repeated here.

[0304] In this embodiment, in step S100, refer to Figure 29 The substrate 101' includes:

[0305] At least the first surface F and the first side surface C1 of the substrate 10 are texturized and doped with elements; the substrate 10 is etched to expose the second surface S of the substrate 10 and the first target region C11 on each of the first side surfaces C1.

[0306] The first target region C11 is the region on each first side surface C1 of the base 10 that is adjacent to and connected to the second surface S.

[0307] In the above steps, the texturing process forms a textured surface on each surface of the substrate 10. Then, dopant diffusion is performed on the substrate 10. Since the diffusion process deposits some dopant onto the first side surface C1 and the second side surface S of the substrate 10, a single-sided etching process is used to etch the first side surface C1 and the second side surface S of the substrate 10, exposing the first target area C11 on the second side surface S and each of the first side surfaces C1, thus preventing leakage. At this point, a textured structure 20 and a doped conductive material layer 30' are formed on a portion of the surfaces of the first side surface F and the first side surface C1.

[0308] In specific implementation, the step of etching the substrate 10 to expose the second surface S and the first target region C11 on each of the first side surfaces C1 of the substrate 10 includes:

[0309] Step D”: Etch the substrate 10 after texturing and doping element diffusion to expose the texturized structure on the second surface S and the first target area C11 on each of the first side surfaces C1. In practice, a chain etching machine can be used for etching. Of course, during the etching process, the liquid level of the chain etching machine needs to be controlled to prevent the etching solution from adhering to the texturized structure 20 and the doped conductive material layer 30' on the first surface F of the substrate 10, thus preserving the irregular morphology.

[0310] Step E”: The exposed textured structure is etched away to expose the second surface S of the substrate 10 and the first target area C11 on each of the first side surfaces C1. In practice, a trough etching machine can be used for etching. It can be understood that etching away the textured structure 20 on the surface of the substrate 10 is equivalent to etching and polishing the textured structure 20 in the first target area C11 and the second surface S of the substrate 10 into a non-textured morphology.

[0311] In this embodiment of the application, step S200, which involves forming a passivation contact material layer on each surface of the substrate 101', includes:

[0312] A tunneling material layer, a polysilicon doped material layer, and an oxide material layer (mask layer) are sequentially stacked on each surface of the substrate 101'.

[0313] In step S400, the step of etching away the passivation contact material layer on the surface of the first side and each side of the sub-substrate 102 to form a passivation contact layer 50 on the sub-substrate 102 includes:

[0314] Etching removes the oxide material layer on the surface of the first side of the sub-substrate 102 and on each side of the sub-substrate 102;

[0315] The surface of the first side of the sub-substrate 102 and the polysilicon doped material layer and tunneling material layer on each side of the sub-substrate 102 are etched away; and the cut edge side C2 cut on the sub-substrate 102 is etched and polished.

[0316] In this way, the laser-damaged layer at position C2 on the side of the cut edge generated by cutting can be etched and polished, reducing recombination at the interface of C2 on the side of the cut edge. For example, the oxide material layer is removed by etching using a chain machine, and the polysilicon doped material layer and tunneling material layer are removed by etching using a tank machine.

[0317] Furthermore, after the step of etching away the polysilicon doped material and tunneling material layer on the surface of the first side of the sub-substrate 102 and on each side of the sub-substrate 102, the method further includes:

[0318] The oxide material layer on the surface of the second side of the sub-substrate 102 is removed by etching; wherein the second side is one side of the second surface S of the substrate 10, thereby forming a passivation contact layer 50 on the sub-substrate 102.

[0319] In this embodiment of the application, step S300, which involves cutting the substrate 101 with the passivation contact material layer formed along the thickness direction H of the substrate to form at least two sub-substrates 102, includes:

[0320] The substrate 101, which forms the passivation contact material layer, is laser-cut along the thickness direction H of the substrate to form two sub-substrates 102 of the same size.

[0321] In other words, two sub-substrates 102 of the same size can be cut out. It can be understood that the substrate 10, textured structure 20, and doped conductive layer 30 in the sub-substrates 102 are the same as those in the solar cells 100 of Embodiments 1, 2, and 3.

[0322] In the embodiments of this application, reference is made to Figure 32 In step S500, after forming the first passivation film layer 40 on the doped conductive layer 30, the following steps are also included:

[0323] A second passivation film layer 60 is formed on the passivation contact layer 50; wherein the second passivation film layer 60 covers at least a portion of the second surface S, at least a portion of the first side surface C1, and at least a portion of the cut edge side surface C2, so as to cover at least a portion of the passivation contact layer 50 and the first passivation film layer 40.

[0324] In this way, the first passivation film layer 40 and the second passivation film layer 60 together protect the first side surface C1 and the cut edge side surface C2. This not only increases the passivation effect of the edge surfaces of the solar cell 100 corresponding to the first side surface C1 and the cut edge side surface C2, thus mitigating recombination on the side surface of the solar cell 100, but also, since the first passivation film layer 40 and the second passivation film layer 60 are insulating films, they can also better prevent leakage on the side surface of the solar cell 100. Therefore, while improving the cell conversion efficiency, the power output of the solar cell 100 is also increased.

[0325] In the embodiments of this application, reference is made to Figure 33 After the step of forming the second passivation film layer 60 on the passivation contact layer 50, the method further includes:

[0326] Electrodes 70 are fabricated on the first passivation film layer 40 and the second passivation film layer 60 to form a solar cell 100.

[0327] like Figure 33 As shown, the electrode 70 located on the first surface F side of the substrate 10 is connected to the doped conductive layer 30, and the electrode 70 located on the second surface S side of the substrate 10 penetrates the second passivation film layer 60 and is connected to the passivation contact layer 50.

[0328] The following is a specific example illustrating the method for manufacturing a solar cell according to an embodiment:

[0329] Step SJ”: Refer to Figure 29 Texturing and boron diffusion are performed on each surface of the substrate 10 in the substrate 101'; and etching is performed on the substrate 10 to expose the second surface S and the first target area C11 on each first side surface C1 of the substrate 10, thereby forming a textured structure 20 on a portion of the first surface F and the first side surface C1 of the substrate 10, and forming a doped conductive material layer 30' (boron conductive material layer) covering the textured structure 20 on a portion of the first surface F and the first side surface C1.

[0330] Step SK”: Form a tunneling material layer, a polysilicon doped material layer and an oxide material layer on each surface of the substrate 101'.

[0331] Step SL: Refer to Figure 30The substrate 101', which forms the passivation contact material layer, is cut along the thickness direction H of the substrate to form at least two sub-substrates 102, so that the doped conductive material layer 30' forms the doped conductive layer 30. The oxide material layer on the first side surface and each side surface of the sub-substrates 102 is etched away; the polysilicon doped material and tunneling material layer on the first side surface and each side surface of the sub-substrates 102 are also etched away; and the cut edge side surface C2 on the sub-substrates 102 is etched and polished, thus retaining only the tunneling material layer, polysilicon doped material layer, and oxide material layer on the second surface S of the substrate 10. Of course, the oxide material layer here (e.g., a silicon oxide layer) can serve as a mask in subsequent processes and can be removed by etching or other processes. In this way, the passivation contact layer 50 can be formed on the sub-substrates 102.

[0332] Step SM: Refer to Figure 31 A first passivation film layer 40 is formed on the doped conductive layer 30; wherein the first passivation film layer 40 covers at least a portion of the surface of the first side of the sub-substrate 102 (the first surface F of the substrate 10) and the first side surface C1, so as to at least cover the doped conductive layer 30; the first passivation film layer 40 also covers at least a portion of the cut edge side surface C2.

[0333] Step SN: Refer to Figure 32 A second passivation film layer 60 is formed on the passivation contact layer 50; wherein the second passivation film layer 60 covers at least the surface of the second side of the sub-substrate 102, at least a portion of the first side surface C1, and at least a portion of the cut edge side surface C2, so as to cover at least a portion of the passivation contact layer 50 and the first passivation film layer 40, wherein the second side is one side of the second surface S of the substrate 10.

[0334] Step SO”: Refer to Figure 33 Electrodes 70 are fabricated on the first passivation film layer 40 and the second passivation film layer 60, respectively.

[0335] The solar cell 100 produced by steps SJ”-SSO” is denoted as solar cell A3.

[0336] Solar cells A3, B1, and B2 were tested for cell performance, and the results are recorded in Table 3. Where Uoc is the open-circuit voltage; FF is the fill factor; Eta is the conversion efficiency; Isc is the short-circuit current; and IRev2 is the reverse current.

[0337] Table 3: Performance test results of solar cells A3 and B1, B2

[0338] Group Isc_A Uoc_mV FF_% Eta_% IRev2_A A3 7.77 713.9 82.94 24.10 0.07 B1 15.56 713.3 82.98 24.12 0.08 B2 7.76 712.2 82.21 23.80 0.09

[0339] The experimental results above show that the efficiency of the solar cell A3 (after dicing) prepared by the method in Example 5 is basically the same as that of the whole solar cell B1 (undicated) in the comparative example. However, compared with the diced solar cell B2 in the comparative example, the open-circuit voltage of the cell increases by 1.7mV, the fill factor increases by about 0.73%, the cell conversion efficiency increases by about 0.3%, and the reverse current decreases from 0.09A to 0.07A. Therefore, it can be concluded that the solar cell A3 prepared by the method of this example has a higher efficiency.

[0340] Example 6

[0341] Figure 34 This is a schematic diagram of the structure of the photovoltaic module provided in Embodiment Six of this application. Figure 35 This is a structural schematic diagram of the manufacturing process of the photovoltaic module provided in Embodiment Six of this application.

[0342] Reference Figure 34 This embodiment provides a photovoltaic module 200, including at least one battery string 210. The battery string 210 includes at least two solar cells 100 as described in any one of Embodiment 1, Embodiment 2, and Embodiment 3. The solar cells 100 can be connected together by string welding.

[0343] Furthermore, referring to Figure 35 The solar cell substrate 103 formed in step S40 of embodiment 4 can be cut in half or into three parts to obtain solar cell 100. Then, multiple solar cells 100 can be connected together by wire bonding to form photovoltaic module 200.

[0344] For example, multiple solar cells 100 can be wired together in series using solder strips, thereby collecting the electrical energy generated by each individual solar cell 100 for subsequent transmission. Of course, the solar cells 100 can be arranged at intervals or stacked together in a shingled manner.

[0345] For example, the photovoltaic module 200 also includes an encapsulation layer and a cover plate (not shown). The encapsulation layer covers the surface of the cell string 210, and the cover plate covers the surface of the encapsulation layer away from the cell string 210. The solar cells 100 are electrically connected in a single piece or in multiple segments to form multiple cell strings 210, which are electrically connected in series and / or parallel. Specifically, in some embodiments, the multiple cell strings 210 can be electrically connected to each other via conductive links. The encapsulation layer covers the surface of the solar cell 100. For example, the encapsulation layer can be an organic encapsulation film such as an ethylene-vinyl acetate copolymer film, a polyethylene octene co-elastomer film, or a polyethylene terephthalate film. The cover plate can be a light-transmitting cover plate such as a glass cover plate or a plastic cover plate.

[0346] Example 7

[0347] This embodiment provides a photovoltaic system (not shown), including the photovoltaic module 200 of Embodiment Six.

[0348] 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 areas that require solar energy to generate electricity. Taking a photovoltaic power generation system grid as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be an array combination of multiple photovoltaic modules 200; for example, multiple photovoltaic modules 200 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 power grid before being connected to the mains power grid to achieve solar power supply.

[0349] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0350] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method of fabricating a solar cell, characterized by, include: Provide substrate; The substrate includes a substrate and a layer of doped conductive material; The substrate includes a first surface and a second surface disposed opposite to each other, and a plurality of first side surfaces adjacent to the first surface and the second surface; a portion of the first surface and the first side surfaces of the substrate have a textured structure; the doped conductive material layer is disposed on a portion of the first surface and the first side surfaces to cover the textured structure; A passivation contact material layer is formed on each surface of the substrate; The substrate forming the passivation contact material layer is cut along the thickness direction of the substrate to form at least two sub-substrates, so that the doped conductive material layer forms a doped conductive layer; Etching removes the passivation contact material layer on the surface of the first side and each side of the sub-substrate to form a passivation contact layer on the sub-substrate, wherein the first side is one side of the first surface of the substrate; A first passivation film is formed on the doped conductive layer; wherein the first passivation film covers at least a portion of the first surface and the first side surface to at least cover the doped conductive layer; the first passivation film also covers at least a portion of the cut edge side surface, wherein the cut edge side surface is the side surface cut out in the sub-substrate.

2. The method of producing a solar cell according to claim 1, wherein The provided substrate includes: At least the first surface and the first side surface of the substrate are texturized and doped with element diffusion. The substrate is etched to expose the second surface of the substrate and the first target area on each of the first side surfaces; The first target area is the area on each first side of the substrate that is adjacent to and connected to the second surface.

3. The method of producing a solar cell according to claim 2, wherein The step of etching the substrate to expose the second surface of the substrate and the first target regions on each of the first side surfaces includes: The substrate after texturing and doping element diffusion is etched to expose the texturing structure on the second surface and each of the first target regions. The exposed textured structure is etched away to expose the second surface of the substrate and the first target area on each of the first side surfaces.

4. The method for manufacturing a solar cell according to claim 1, characterized in that, The step of forming a passivation contact material layer on each surface of the substrate includes: A tunneling material layer, a polysilicon doped material layer, and an oxide material layer are sequentially stacked on each surface of the substrate.

5. The method for manufacturing a solar cell according to claim 4, characterized in that, The step of etching away the passivation contact material layer on the first side surface and each side surface of the sub-substrate to form a passivation contact layer on the sub-substrate includes: The oxide material layer on the surface of the first side of the sub-substrate and on each side of the sub-substrate is removed by etching. The polysilicon doped material and tunneling material layer on the surface of the first side of the sub-substrate and on each side of the sub-substrate are etched away; and the cut edge side of the sub-substrate is etched and polished.

6. The method for manufacturing a solar cell according to claim 5, characterized in that, The oxide material layer is removed by etching using a chain machine; The polycrystalline silicon doped material and tunneling material layer are removed by a tank mill.

7. The method for manufacturing a solar cell according to claim 5, characterized in that, The step of etching away the polysilicon doped material and tunneling material layer on the surface of the first side of the sub-substrate and on each side of the sub-substrate further includes: The oxide material layer on the surface of the second side of the sub-substrate is etched away; wherein the second side is one side of the second surface of the substrate.

8. The method for manufacturing a solar cell according to claim 1, characterized in that, After forming the first passivation film layer on the doped conductive layer, the method further includes: A second passivation film layer is formed on the passivation contact layer; wherein the second passivation film layer covers at least a portion of the second surface, at least a portion of the first side surface, and at least a portion of the cut edge side surface, to cover at least a portion of the passivation contact layer and the first passivation film layer.

9. The method for manufacturing a solar cell according to claim 8, characterized in that, The step of forming a second passivation film layer on the passivation contact layer further includes: Electrodes are fabricated on the first passivation film layer and the second passivation film layer respectively to form a solar cell.

10. The method for manufacturing a solar cell according to claim 1, characterized in that, The step of cutting the substrate forming the passivated contact material layer along the thickness direction of the substrate to form at least two sub-substrates includes: The substrate forming the passivation contact material layer is laser-cut along the thickness direction of the substrate to form two sub-substrates of the same size.

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