Solar battery and manufacturing method thereof

Abstract

To provide a solar battery and a manufacturing method of the solar battery.SOLUTION: A solar battery comprises a substrate, sheet-shaped antireflection layers, and a plurality of grid lines. The substrate has a first surface and comprises a plurality of gird line areas arranged at intervals. There is a texture structure over the entire first surface in each grid line area. The sheet-shaped antireflection layer is positioned on at least portion of the texture structure in each gird line area and exposes a portion of the surface of the texture structure. The gird lines correspond to the grid line areas by one-by-one basis. The gird line is provided on the corresponding grid area, and the grid line is in contact with both the surface of the texture structure in the grid line area and the surface of the sheet-shaped antireflection layer. The present invention is advantageous in increasing the coupling strength at least between the gird lines and the substrate and in lowering the probability of drop of the gird lines from the substrate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to the field of solar cells, and more particularly to solar cells and methods for manufacturing the same. [Background technology]

[0002] Fossil energy has the advantages of air pollution and limited reserves, while solar energy is clean, pollution-free, and abundant in resources. Therefore, solar energy is replacing fossil energy as the core clean energy. Solar cells have good photoelectric conversion efficiency, and solar cells have become the focus of the development of clean energy utilization.

[0003] When a solar cell is in operation, sunlight enters the cell through its surface, and the inside of the cell generates photo-generated carriers through the action of the light energy. The photo-generated carriers are collected and transported by grid lines installed on the surface of the solar cell, thereby realizing the conversion and utilization of solar energy into electrical energy. During the manufacturing process of solar cells, grid lines can be formed on the surface of the solar cell by an electroplating process, but conventional solar cells have the problem that the bonding strength between the grid lines and the battery cells is weak and they are prone to falling off. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present application provide a solar cell and a manufacturing method thereof that are advantageous in at least improving the bonding strength between the grid lines and the battery cell and reducing the probability of the grid lines falling off. [Means for solving the problem]

[0005] In an embodiment of the present application, a solar cell is provided, the solar cell including a substrate, a sheet-shaped anti-reflective layer, and a plurality of grid lines, the substrate having a first surface, the substrate including a plurality of grid line regions arranged at intervals, a textured structure across the entire first surface of the grid line regions, the sheet-shaped anti-reflective layer being positioned on the textured structure in at least a portion of each of the grid line regions, and the sheet-shaped anti-reflective layer exposing a portion of a surface of the textured structure, each of the grid lines corresponding to the grid line regions in a one-to-one correspondence, the grid lines being provided in the corresponding grid line regions, and the grid lines being in contact with the surface of the textured structure and the surface of the sheet-shaped anti-reflective layer in the grid line regions, respectively.

[0006] In some embodiments, the grid line region includes a first region, a second region, and a third region arranged in order in a direction perpendicular to an extension direction of the grid line region, and the sheet-shaped antireflection layer is located on at least a part of the texture structure in the first region and at least a part of the texture structure in the third region.

[0007] In some embodiments, the surface of the textured structure in the second region is free of the sheet-shaped anti-reflection layer, and the textured structure in the first region and the third region is pyramidal or pyramidal-like, and the textured structure in the second region is pine-cone shaped.

[0008] In some embodiments, in a direction perpendicular to the first surface, the ratio of the height of the texture structure in the second region protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface is 0.3 to 0.9.

[0009] In some embodiments, the sheet-like anti-reflective layer is also located on the textured structure in at least a portion of the second region.

[0010] In some embodiments, the maximum distance between any two points on the surface of the sheet-shaped antireflection layer is 0.3 μm to 6 μm.

[0011] In some embodiments, the maximum distance between any two points on the surface of the sheet-like antireflection layer is 2 μm to 6 μm, and the ratio of the height of the texture structure in the grid line region protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface in a direction perpendicular to the first surface is 0.4 to 0.9.

[0012] In some embodiments, the maximum distance between any two points on the surface of the sheet-shaped antireflection layer is 0.3 μm to 2 μm, and the ratio of the height of the texture structure in the grid line region protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface in a direction perpendicular to the first surface is 0.6 to 1.

[0013] In some embodiments, the distance between adjacent sheet-shaped antireflection layers is 20 nm to 5 μm.

[0014] In some embodiments, the surface of the sheet-shaped anti-reflection layer facing the textured structure includes an attached region in contact with the textured structure and a suspended region not in contact with the textured structure.

[0015] In some embodiments, the distance between the suspended region of the sheet-shaped antireflection layer and the textured structure is 50 nm to 1000 nm in a direction perpendicular to the surface of the sheet-shaped antireflection layer facing the textured structure.

[0016] In some embodiments, the ratio of the area of ​​the suspended region to the area of ​​the surface of the sheet-shaped anti-reflection layer facing the texture structure is 5% to 90%.

[0017] In some embodiments, in a direction perpendicular to the surface facing the texture structure of the sheet-like antireflection layer, the thickness of the sheet-like antireflection layer is 40 nm to 600 nm.

[0018] In some embodiments, the texture structure is composed of a plurality of pyramid-shaped protrusions, and the length of the hypotenuse of the pyramid is 400 nm to 5 μm.

[0019] Correspondingly, an embodiment of the present application further provides a method for manufacturing a solar cell. The method for manufacturing the solar cell includes providing a substrate, the substrate having a first surface, the substrate including a plurality of grid line regions arranged at intervals, the first surface of the grid line regions having a texture structure over the entire surface, and the texture structure having an antireflection layer covering the texture structure; processing the antireflection layer of each grid line region by a laser process to form a sheet-like antireflection layer in the grid line region, the sheet-like antireflection layer exposing a part of the surface of the texture structure of the grid line region; forming a plurality of grid lines corresponding one-to-one to the grid line regions in each grid line region, each grid line being in contact with the surface of the texture structure and the surface of the sheet-like antireflection layer in the corresponding grid line region.

[0020] In some embodiments, when the size of the central region of the laser spot in the laser process is d, the speed of the laser spot is v, and the laser frequency is f, 0.8d < v / f < 2d is satisfied.

[0021] In some embodiments, the process parameters of the laser process include that the ratio of the size of the central region of the laser spot to the size of the laser spot is 0.4 to 0.6 or 0 to 0.1.

[0022] In some embodiments, forming the sheet-shaped anti-reflection layer includes performing multiple laser treatments on the anti-reflection layer in the grid line regions using a laser having a ratio of the size of the central region of the laser spot to the size of the laser spot of 0 to 0.1.

[0023] In some embodiments, the method further includes, after forming the sheet-shaped anti-reflection layer, performing a deoxidation treatment on each of the grid line regions using slow-release hydrofluoric acid with a concentration of 0.3% to 20%.

[0024] In some embodiments, the deoxidation treatment lasts for a period of 20 seconds to 90 seconds. [Effects of the Invention]

[0025] The technical solution according to the embodiments of the present application has at least the following advantages:

[0026] In the solar cell according to the embodiment of the present application, a grid line region is provided with a textured structure over its entire surface, and since the textured structure covers the entire grid line region, the contact area between the grid line and the substrate is significantly increased during the process of forming the grid lines in the grid line region, thereby improving the bonding strength between the grid line and the substrate to a certain extent. At least a portion of the textured structure in the grid line region has a sheet-shaped anti-reflective layer, and the surface of the sheet-shaped anti-reflective layer facing the textured structure is in close contact with the textured structure, and there are a number of pores in the sheet-shaped anti-reflective layer exposing the surface of the textured structure. During the process of installing the grid lines, the grid lines respectively contact the exposed surface of the textured structure and the surface of the sheet-shaped anti-reflective layer. The sheet-shaped anti-reflective layer has a predetermined thickness, and the grid lines also contact the side surfaces of the sheet-shaped anti-reflective layer, thereby further increasing the contact area between the grid lines and the substrate, and the sheet-shaped anti-reflective layer still in close contact with the substrate, which further fixes the structure, significantly improving the bonding strength between the grid lines and the substrate, minimizing the probability of the grid lines falling off, and improving the reliability of the solar cell. [Brief explanation of the drawings]

[0027] One or more embodiments are illustratively illustrated in corresponding accompanying drawing figures; these illustrative illustrations are not intended to limit the embodiments, and unless otherwise specified, the accompanying drawing figures do not form a proportionality limit. [Figure 1] FIG. 1 is a top view of a solar cell according to an embodiment of the present application. [Figure 2] FIG. 2 is a cross-sectional view of a solar cell according to an embodiment of the present application. [Figure 3] FIG. 3 is a partial cross-sectional view of a solar cell according to an embodiment of the present application. [Figure 4] FIG. 4 is a partial top view of a grid line area according to one embodiment of the present application. [Figure 5] FIG. 5 is a diagram showing a configuration of a part of a texture structure according to an embodiment of the present invention. [Figure 6] FIG. 6 is a partial cross-sectional view of another solar cell according to an embodiment of the present application. [Figure 7] FIG. 7 is a partial cross-sectional view of a solar cell according to one embodiment of the present application. [Figure 8] FIG. 8 is a flowchart of a method for manufacturing a solar cell according to another embodiment of the present application. [Figure 9] FIG. 9 is a top view of a substrate provided according to one embodiment of the present application. [Figure 10] FIG. 10 is a cross-sectional view of a substrate according to one embodiment of the present application. [Figure 11] FIG. 11 is a cross-sectional view of a semi-finished solar cell according to one embodiment of the present application. [Figure 12] FIG. 12 is a diagram illustrating a laser spot according to one embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0028] As can be seen from the background art, in conventional solar cells, grid lines can be formed on the surface of the battery cells using electroplating, but the contact area and bonding strength between the grid lines and the battery cells are both low, making the grid lines prone to falling off. Currently, the commonly used method is to use electrochemical methods to improve the bonding strength between different plating layers, thereby maximizing the bonding strength of the grid lines between different plating layers and preventing the grid lines from falling off between different plating layers, thereby reducing the probability of the grid lines falling off. However, the bonding strength between the grid lines and the substrate has not yet been effectively improved.

[0029] In one embodiment of the present application, a solar cell is provided, in which a grid line region has a textured structure over the entire surface of the cell, and when grid lines are formed in the grid line region, the textured structure over the entire grid line region significantly increases the contact area between the grid lines and the substrate, and to a certain extent, improves the bonding strength between the grid lines and the substrate. At least a portion of the textured structure in the grid line region has a sheet-shaped anti-reflective layer, and the surface of the sheet-shaped anti-reflective layer facing the textured structure is in close contact with the textured structure, and there are a number of pores in the sheet-shaped anti-reflective layer exposing the surface of the textured structure. After the grid lines are formed, the grid lines respectively contact the exposed surface of the textured structure and the surface of the sheet-shaped anti-reflective layer. The sheet-shaped anti-reflective layer has a predetermined thickness, and the grid lines also contact the side surfaces of the sheet-shaped anti-reflective layer, thereby further increasing the contact area between the grid lines and the substrate, and the sheet-shaped anti-reflective layer still in close contact with the substrate, which further fixes the structure, significantly improving the bonding strength between the grid lines and the substrate, minimizing the probability of the grid lines falling off, and improving the reliability of the solar cell.

[0030] Hereinafter, each embodiment of the present application will be described in detail with reference to the accompanying drawings. However, as will be understood by those skilled in the art, although many technical details are proposed in each embodiment of the present application to help readers better understand the present application, the technical solution claimed for protection by the present application can be realized without these technical details and various changes and modifications based on the following embodiments.

[0031] One embodiment of the present application provides a solar cell. Referring to Figures 1 to 6, Figure 1 is a top view of the solar cell, Figure 2 is a cross-sectional view of the solar cell along the AA direction, Figure 3 is a cross-sectional view of a second region 122 of the grid line region 102 that does not have a sheet-like antireflection layer 110, Figure 4 is a partial top view of the grid line region 102, Figure 5 is a diagram showing the configuration of the texture structure of the second region 122, and Figure 6 is a cross-sectional view of the second region 122 of the grid line region 102 that has a sheet-like antireflection layer 110.

[0032] The solar cell includes a substrate 100, a sheet-like anti-reflective layer 110, and a plurality of grid lines 120, the substrate 100 having a first surface, the substrate 100 including a plurality of grid line regions 102 arranged at intervals, the grid line regions 102 having a textured structure over the entire first surface, the sheet-like anti-reflective layer 110 being located on the textured structure in at least a portion of each grid line region 102, and the sheet-like anti-reflective layer 110 exposing a portion of the surface of the textured structure, the grid lines 120 corresponding to the grid line regions 102 in a one-to-one correspondence, the grid lines 120 being provided in the corresponding grid line regions 102, and the grid lines 120 being in contact with the surface of the textured structure in the grid line regions 102 and the surface of the sheet-like anti-reflective layer 110, respectively.

[0033] In the process of manufacturing a solar cell, first, a plurality of spaced apart grid line regions 102 are identified, and the entire first surface of the grid line regions 102 is textured to greatly increase the surface area of ​​the grid line regions 102, thereby increasing the contact area between the grid lines 120 and the substrate 100 after the grid lines 120 are formed in the grid line regions 102 and improving to a certain extent the bonding strength between the grid lines 120 and the substrate 100. A sheet-type anti-reflective layer 110 is formed on a portion of the textured structure of the grid line regions 102, so that a portion of the surface of the textured structure is exposed by the sheet-type anti-reflective layer 110, and the grid lines 120 are in contact with the exposed surface of the textured structure and the surface of the sheet-type anti-reflective layer 110, respectively. The grid lines 120 also contact the side surfaces of the sheet-type anti-reflective layer 110, further improving the contact area and bonding strength between the grid lines 120 and the substrate 100. The sheet-type anti-reflective layer 110 in the textured structure remains in close contact with the substrate 100, and the sheet-type anti-reflective layer 110 functions to fix the structure, greatly improving the bonding strength between the grid lines 120 and the substrate 100, minimizing the probability of detachment between the grid lines 120 and the substrate 100, and improving the reliability of the solar cell.

[0034] In some embodiments, the substrate 100 may be a semiconductor substrate, such as silicon, germanium, germanium silicon, or silicon insulator. The material of the substrate 100 may be an elemental semiconductor material. Specifically, the elemental semiconductor material may be composed of a single element, such as silicon or germanium. The elemental semiconductor material may be in a single crystalline state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state in which both the single crystalline state and the amorphous state are simultaneously present is called a microcrystalline state). For example, silicon may be at least one of single crystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. The material of the substrate 100 may be silicon, and the material of the substrate 100 may be at least one of single crystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. The material of the substrate 100 may be a compound semiconductor material. For example, the material may be silicon germanium, silicon carbide, gallium arsenide, indium gallium, perovskite, cadmium telluride, copper indium selenide, etc. The material of the substrate 100 may be silicon carbide, an organic material, or a multi-component compound.

[0035] In some embodiments, the substrate 100 may be an N-type semiconductor substrate or a P-type semiconductor substrate. The N-type semiconductor substrate is doped with an N-type doping element, which may be any one of Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). The P-type semiconductor substrate is doped with a P-type doping element, which may be any one of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0036] In some embodiments, the grid line region 102 includes a first region 121, a second region 122, and a third region 123 arranged in order in a direction perpendicular to the extension direction of the grid line region 102. The sheet-shaped antireflection layer 110 is located on at least a part of the texture structure of the first region 121 and at least a part of the texture structure of the third region 123.

[0037] In the process of manufacturing a solar cell, when forming the grid lines 120, the texture structure of the corresponding first surface of the grid line region 102 can be first selectively etched. In a direction perpendicular to the extending direction of the grid line region 102, the grid line region 102 includes a first region 121, a second region 122, and a third region 123 arranged in order, and the sheet-like anti-reflection layer 110 located at least on at least a part of the texture structure of the first region 121 and at least a part of the texture structure of the third region 123 is formed by selective etching. At least a portion of the texture in the first region 121 has a sheet-type anti-reflective layer 110, and at least a portion of the texture structure in the third region 123 has a sheet-type anti-reflective layer 110. In the process of the grid lines 120 contacting the substrate 100, the contact area between the grid lines 120 and the substrate 100 in the first region 121 and the third region 123 includes the side area of ​​the sheet-type anti-reflective layer 110. This increases the contact area, thereby improving the bonding strength between the grid lines 120 and the substrate 100 and reducing the probability of the grid lines 120 and the substrate 100 falling off.

[0038] In the selective etching process, not only a portion of the textured structure in the grid line region 102 but also a portion of the textured structure in the first region 121 and the third region 123 can be etched, and in the first region 121 and the third region 123, some of the textured structures have an anti-reflection layer completely covering the surface of the textured structure, and some of the textured structures have a sheet-like anti-reflection layer 110. In addition, the selective etching method may be selective laser etching or selective chemical etching, and the embodiments of the present application do not limit the specific method of selective etching.

[0039] In some embodiments, there is no sheet-shaped anti-reflection layer 110 on the surface of the textured structure in the second region 122, and the textured structures in the first region 121 and the third region 123 are pyramidal or pyramidal-like, and the textured structure in the second region 122 is pine-cone shaped.

[0040] During the process of fabricating the textured structure, pyramidal or pyramidal-like protrusion structures can be formed as the textured structure on the first surface across the entire first surface of the substrate 100, effectively improving the light trapping ability of the light trapping structure. After selectively etching the first surface, the anti-reflection layer in at least a portion of the textured structure in the first region 121 and the third region 123 is removed, forming a sheet-shaped anti-reflection layer 110 including a portion of the surface of the textured structure. At the same time, the anti-reflection layer in the textured structure in the second region 122 is completely removed, and the textured structure in the second region 122 is partially etched, changing the textured structure in the second region 122 from a pyramidal or pyramidal-like shape to a pinecone shape. See FIG. 4 for a diagram illustrating the structure of a portion of the gridline region 102. See FIG. 5 for a diagram illustrating the structure of the pinecone-shaped textured structure.

[0041] At least a portion of the textured structure in the first region 121 and the third region 123 has the sheet-type anti-reflection layer 110, which effectively increases the contact area and bonding strength between the grid lines 120 and the substrate 100. The textured structure in the second region 122 does not have the sheet-type anti-reflection layer 110. When the grid lines 120 contact the substrate 100 in the second region 122, they directly contact the fully exposed textured structure. This reduces the contact resistance between the grid lines 120 and the substrate 100, reduces carrier collection losses in the grid lines 120, and improves the photoelectric conversion efficiency of the solar cell. Furthermore, after the pyramidal or near-pyramidal textured structure is transformed into a pinecone-shaped structure, the multiple protrusions of the pinecone-shaped textured structure further increase the contact area between the grid lines 120 and the substrate 100, improving contact strength and reducing the contact resistance between the grid lines 120 and the substrate 100.

[0042] Furthermore, after selectively etching the textured structure in the grid line region 102, the textured structure in the second region 122 may not have an anti-reflection layer at all, or may have an anti-reflection layer that completely covers the surface of the textured structure and some other parts without an anti-reflection layer. Forming a textured structure that has no anti-reflection layer in some parts and has an anti-reflection layer that completely covers the surface of the textured structure in other parts can reduce damage to the anti-reflection layer on the surface of the substrate 100 caused by the fabrication of the grid lines 120, thereby improving the photoelectric conversion efficiency of the solar cell.

[0043] In some embodiments, the ratio of the height of the texture structure in the second region 122 protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface in a direction perpendicular to the first surface is 0.3 to 0.9.

[0044] In a direction perpendicular to the first surface, the protruding height of the texture structure from the first surface refers to the distance between the first surface and the point on the texture structure farthest from the first surface. In the process of selectively removing the anti-reflection layer from the texture structure in the grid line region 102, ensuring that the texture structure in the second region 122 is free of the sheet-like anti-reflection layer 110 may damage the texture structure from which the anti-reflection layer is removed, and may further affect the ratio between the protruding height of the texture structure in the second region 122 from the first surface and the protruding height of the texture structure in the non-grid line region.

[0045] If the ratio between the height of the textured structure protruding from the first surface in the second region 122 and the height of the textured structure protruding from the first surface in the non-gridline region is too small, the damage to the textured structure in the second region 122 will be severe, resulting in excessive damage to the substrate 100 and excessive voltage loss in the solar cell. Furthermore, the damage to the textured structure will likely reduce the contact area between the grid lines 120 and the substrate 100, affecting the contact strength between the grid lines 120 and the substrate 100. If the ratio between the height of the textured structure protruding from the first surface in the second region 122 and the height of the textured structure protruding from the first surface in the non-gridline region is too large, the loss of the textured structure in the second region 122 will be small, and there will be remaining anti-reflection layer in the second region 122. This will increase the contact resistance when the grid lines 120 contact the substrate 100 in the second region 122, potentially reducing the carrier collection efficiency of the solar cell.

[0046] Therefore, the ratio of the height of the textured structure in the second region 122 protruding from the first surface to the height of the textured structure in the non-gridline region protruding from the first surface can be set to a range of 0.3 to 0.9, such as 0.35, 0.4, 0.45, 0.5, 0.6, 0.75, 0.8, or 0.85, thereby reducing damage to the substrate 100 during the manufacturing of the gridlines 120, preventing excessive voltage loss in the solar cell, and reducing the contact resistance between the gridlines 120 and the substrate 100, thereby improving the carrier collection ability and photoelectric conversion efficiency of the solar cell.

[0047] In the extension direction of the grid line region 102, some texture structures in the second region 122 may not have an antireflection layer at all, and some texture structures may have a sheet-like antireflection layer 110, and therefore the height of the texture structures in the second region 122 protruding from the first surface may be represented by the average height or maximum height of the texture structures in the second region 122 protruding from the first surface. Similarly, the height of the texture structures in the non-grid line region protruding from the first surface may also be represented by the average height or maximum height of the texture structures in the non-grid line region protruding from the first surface.

[0048] In some embodiments, the sheet-like anti-reflective layer 110 is also located on at least a portion of the textured structure of the second region 122 .

[0049] After selectively removing the anti-reflection layer in the textured structure of the grid line region 102, a structure can be formed in which the sheet-type anti-reflection layer 110 is present in at least a portion of the textured structure of the first region 121, the second region 122, and the third region 123. See FIG. 6 for a structural diagram in which the sheet-type anti-reflection layer 110 is present in at least a portion of the textured structure of each of the three divided regions of the grid line region 102.

[0050] When the sheet-type anti-reflective layer 110 is present in at least some of the textured structures of the three divided regions of the grid line region 102, the contact area between the grid lines 120 and the substrate 100 is significantly increased, and the sheet-type anti-reflective layer 110 in each divided region has a fixing function, which significantly increases the bonding strength between the grid lines 120 and the substrate 100 and minimizes damage to the anti-reflective layer in the textured structure and the textured structure itself, thereby reducing the open circuit loss of the solar cell and improving the photoelectric conversion efficiency.

[0051] In some embodiments, the maximum distance between any two points on the surface of the sheet-shaped anti-reflection layer 110 is between 0.3 μm and 6 μm.

[0052] If the dimensions of the sheet-type anti-reflective layer 110 formed after selectively etching the anti-reflective layer in the textured structure are too large, the selective etching process is likely to cause significant damage to the textured structure, resulting in large open circuit loss and damage to the anti-reflective layer, which will affect the photoelectric conversion efficiency of the solar cell. If the dimensions of the sheet-type anti-reflective layer 110 formed are too small, it will be difficult to ensure the bonding strength between the sheet-type anti-reflective layer 110 and the substrate 100 when manufacturing the grid lines 120, and the sheet-type anti-reflective layer 110 will be more likely to fall off, increasing the probability of the grid lines 120 falling off. Here, the dimensions of the sheet-type anti-reflective layer 110 refer to the maximum distance between any two points on the surface of the sheet-type anti-reflective layer 110.

[0053] Therefore, the dimensions of the sheet-type anti-reflection layer 110 formed after selective etching may be set in the range of 0.3 μm to 6 μm, for example, 0.35 μm, 0.4 μm, 0.5 μm, 0.75 μm, 1 μm, 1.25 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.75 μm, 4.5 μm, or 5.5 μm, etc. This reduces open circuit loss of the battery cell and damage to the anti-reflection layer, improves the photoelectric conversion efficiency of the solar cell, ensures a sufficiently high bonding strength between the sheet-type anti-reflection layer 110 and the substrate 100, and effectively increases the bonding strength between the grid lines 120 and the substrate 100, reducing the probability of the grid lines 120 falling off.

[0054] In some embodiments, the maximum distance between any two points on the surface of the sheet-like anti-reflection layer 110 is 2 μm to 6 μm, and the ratio of the height of the texture structure in the grid line region 102 protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface in a direction perpendicular to the first surface is 0.4 to 0.9.

[0055] The height of the textured structure protruding from the first surface in a direction perpendicular to the first surface refers to the distance between the first surface and the point on the textured structure farthest from the first surface. The dimensions of the sheet-shaped anti-reflective layer 110 in the grid line region 102 formed by the selective etching process are related to the height of the textured structure protruding from the first surface after etching. Generally, the larger the dimensions of the sheet-shaped anti-reflective layer 110, the greater the degree of etching of the anti-reflective layer by selective etching and the greater the damage to the textured structure. By adjusting the etching process, a sheet-shaped anti-reflective layer 110 with a dimension of 2 μm to 6 μm can be formed in the etched portion of the textured structure, for example, a sheet-shaped anti-reflective layer 110 with a dimension of 2.5 μm, 3 μm, 3.75 μm, 4.5 μm, 5.5 μm, or 5.8 μm can be formed. The ratio of the height of the texture structure in the grid line region 102 protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface is 0.4 to 0.9, for example, 0.45, 0.5, 0.55, 0.65, 0.75, or 0.8. Here, the dimension of the sheet-type antireflection layer 110 refers to the maximum distance between any two points on the surface of the sheet-type antireflection layer 110.

[0056] The height of the texture structure in the grid line region 102 protruding from the first surface is represented by the maximum height or average height of the texture structure protruding from the first surface of the portion of the texture structure to which the sheet-like antireflection layer 110 is attached, and the height of the texture structure in the non-grid line region protruding from the first surface can be represented by the corresponding maximum height or average height of the texture structure in the non-grid line region protruding from the first surface.

[0057] The dimensions of the sheet-type anti-reflective layer 110 in at least a portion of the textured structure in the grid line region 102 are controlled to be in the range of 2 μm to 6 μm, and the ratio of the height of the textured structure in the grid line region 102 protruding from the first surface to the height of the textured structure in the non-grid line region is controlled to be in the range of 0.4 to 0.9, thereby forming the sheet-type anti-reflective layer 110 in the grid line region 102 as a randomly distributed large block-shaped anti-reflective layer. The randomly distributed large block-shaped arrangement effectively increases the bonding strength between the sheet-type anti-reflective layer 110 and the substrate 100, and allows more of the textured structure to be exposed from the sheet-type anti-reflective layer 110, further increasing the contact area between the grid lines 120 and the substrate 100, reducing the contact resistance between the grid lines 120 and the substrate 100 and reducing carrier collection loss in the grid lines 120.

[0058] In some embodiments, the maximum distance between any two points on the surface of the sheet-shaped anti-reflection layer 110 is 0.3 μm to 2 μm, and the ratio of the height of the texture structure in the grid line region 102 protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface in a direction perpendicular to the first surface is 0.6 to 1.

[0059] After performing a selective etching process on the texture structure in the grid line region 102, a sheet-shaped antireflection layer 110 having a dimension in the range of 0.3 μm to 2 μm can be formed, for example, a sheet-shaped antireflection layer 110 having a dimension of 0.35 μm, 0.5 μm, 0.75 μm, 1 μm, 1.5 μm, or 1.75 μm can be formed. In addition, the ratio of the height of the texture structure in the grid line region 102 protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface in the direction perpendicular to the first surface is controlled to be in the range of 0.6 to 1, for example, 0.625, 0.65, 0.7, 0.75, 0.825, 0.875, or 0.95. Here, the dimension of the sheet-type anti-reflection layer 110 refers to the maximum distance between any two points on the surface of the sheet-type anti-reflection layer 110, and the height of the texture structure protruding from the first surface in the direction perpendicular to the first surface refers to the distance between the first surface and the point in the texture structure that is farthest from the first surface.

[0060] By controlling the dimensions of the sheet-type anti-reflective layer 110 and the ratio between the height of the textured structure in the grid line region 102 protruding from the first surface and the height of the textured structure in the non-grid line region within appropriate ranges, the sheet-type anti-reflective layer 110 in the textured structure becomes a uniform, small, block-shaped anti-reflective layer. Forming uniformly arranged, small, sheet-type anti-reflective layers 110 reduces the exposed textured structure, reduces damage to the anti-reflective layer and open circuit loss in the solar cell, and improves the photoelectric conversion efficiency of the solar cell. This also increases the sum of the side surface areas of the sheet-type anti-reflective layer 110, increases the contact area and strength between the grid lines 120 and the substrate 100, and reduces the probability of the grid lines 120 falling off.

[0061] Similarly, the height of the texture structure in the grid line region 102 protruding from the first surface can be represented by the maximum height or average height of the portion of the texture structure to which the sheet-like antireflection layer 110 is attached protruding from the first surface, and the height of the texture structure in the non-grid line region protruding from the first surface can be represented by the corresponding maximum height or average height of the texture structure in the non-grid line region protruding from the first surface.

[0062] In some embodiments, the spacing between adjacent sheet-shaped anti-reflection layers 110 is between 20 nm and 5 μm.

[0063] The spacing between adjacent sheet-shaped anti-reflection layers 110 refers to the minimum distance between any two points located on the surfaces of two adjacent sheet-shaped anti-reflection layers 110. The area of ​​the texture structure exposed from adjacent sheet-shaped anti-reflection layers 110 is related to the size of the spacing between adjacent sheet-shaped anti-reflection layers 110. When other conditions are met, the area of ​​the texture structure exposed between the sheet-shaped anti-reflection layers 110 is positively correlated to the spacing between adjacent sheet-shaped anti-reflection layers 110.

[0064] The spacing between adjacent sheet-shaped anti-reflective layers 110 is related to the degree of etching of the anti-reflective layer; the greater the degree of etching, the greater the spacing between adjacent sheet-shaped anti-reflective layers 110. If the spacing between adjacent sheet-shaped anti-reflective layers 110 is too large, the damage to both the textured structure and the anti-reflective layer will be significant, the textured structure will be poorly maintained, and the damage to the substrate 100 will be significant, which will likely lead to excessive open-circuit loss in the solar cell and affect the photoelectric conversion efficiency of the solar cell. If the spacing between adjacent sheet-shaped anti-reflective layers 110 is too small, the total area of ​​the exposed textured structure will be small, the contact resistance between the grid lines 120 and the substrate 100 will be high, and the carrier collection loss in the solar cell will be excessive.

[0065] Therefore, the spacing between adjacent sheet-shaped antireflection layers 110 can be set to 20 nm to 5 μm, for example, 25 nm, 35 nm, 50 nm, 75 nm, 100 nm, 150 nm, 200 nm, 275 nm, 350 nm, 500 nm, 750 nm, 1 μm, 1.25 μm, 1.5 μm, 2 μm, 2.5 μm, 3.5 μm, or 4.5 μm. Setting the spacing between adjacent sheet-shaped antireflection layers 110 within an appropriate range minimizes open circuit loss and damage to the antireflection layer in the solar cell, while also reducing contact resistance and carrier collection loss between the grid lines 120 and the substrate 100, thereby improving the photoelectric conversion efficiency of the solar cell.

[0066] 1 to 7, in some embodiments, the surface of the sheet-shaped anti-reflection layer 110 facing the textured structure includes an attached region 111 that contacts the textured structure and a suspended region 112 that does not contact the textured structure, of which FIG. 7 is a local enlarged view of region b in FIG. 2.

[0067] One of the main functions of the sheet-type anti-reflective layer 110 is to increase the bonding strength between the grid lines 120 and the substrate 100. When the surface of the sheet-type anti-reflective layer 110 facing the textured structure is completely in intimate contact with the textured structure, the main reason for increasing the bonding strength between the grid lines 120 and the substrate 100 is to increase the total contact area of ​​the grid lines 120 with the substrate. After the surface of the sheet-type anti-reflective layer 110 facing the textured structure is installed to include an attachment region 111 that contacts the textured structure and a suspension region 112 that does not contact the textured structure, the grid lines 120 include portions located between the suspension region 112 and the textured structure, and the sheet-type anti-reflective layer 110 can fix the grid lines 120 by the corresponding portions of the suspension region 112, thereby increasing the bonding strength between the grid lines 120 and the substrate 100 and minimizing the probability of the grid lines 120 falling off.

[0068] Furthermore, all of the sheet-shaped anti-reflection layers 110 in the textured structure may have an adhesive region 111 and a hanging region 112, or some of the sheet-shaped anti-reflection layers 110 may have an adhesive region 111 and a hanging region 112, and some of the sheet-shaped anti-reflection layers may not have an adhesive region 111 or a hanging region 112.

[0069] In some embodiments, the distance between the suspended region 112 of the sheet-shaped antireflection layer 110 and the texture structure in the direction perpendicular to the surface of the sheet-shaped antireflection layer 110 facing the texture structure is 50 nm to 1000 nm.

[0070] In a direction perpendicular to the surface of the sheet-type anti-reflective layer 110 facing the textured structure, the distance between the suspended region 112 of the sheet-type anti-reflective layer 110 and the textured structure is the minimum distance between any one point in the suspended region 112 and the textured structure. If the distance between the suspended region 112 and the textured structure is too small, the thickness of the portion of the grid lines 120 between the suspended region 112 and the textured structure will be too small. If the grid lines 120 are deformed or displaced by an external force, the portion between the suspended region 112 and the textured structure will be easily broken. Furthermore, the sheet-type anti-reflective layer 110 will not be able to properly fix the grid lines 120 with the corresponding portion of the suspended region 112, and the bonding strength between the grid lines 120 and the substrate 100 will be reduced. If the gap between the suspended region 112 and the textured structure is too large, the thickness of the portion of the grid line 120 between the suspended region 112 and the textured structure will be too large, which will make it easier for bubbles or gaps to appear during the formation process, increase the resistivity of the grid line 120 itself, and further increase the contact resistance between the grid line 120 and the substrate 100, reduce the carrier collection ability of the grid line 120, and severely damage the textured structure. This will result in a large open-circuit loss in the battery cell and adversely affect the photoelectric conversion performance.

[0071] Therefore, in the direction perpendicular to the surface facing the textured structure of the sheet-type anti-reflective layer 110, the distance between the suspended regions 112 of the sheet-type anti-reflective layer 110 and the textured structure can be set to a range of 50 nm to 1000 nm, such as 55 nm, 65 nm, 80 nm, 100 nm, 125 nm, 150 nm, 200 nm, 250 nm, 325 nm, 400 nm, 500 nm, 650 nm, 750 nm, 850 nm, or 975 nm. Setting the distance between the suspended regions 112 and the textured structure within an appropriate range can effectively improve the bonding strength between the grid lines 120 and the substrate 100, reduce the resistivity of the grid lines 120 and the open-circuit loss of the battery cell, and reduce the probability of the grid lines 120 falling off, while simultaneously improving the carrier collection ability of the grid lines 120 and the photoelectric conversion efficiency of the battery cell.

[0072] The intervals between the suspended regions 112 and the texture structures of different sheet-shaped anti-reflection layers 110 may be the same or different, and the present invention is not limited to this in the embodiments.

[0073] In some embodiments, the ratio of the area of ​​the suspended region 112 to the area of ​​the surface facing the textured structure of the sheet-shaped anti-reflection layer 110 is 5% to 90%.

[0074] The strength of the formed portion of the grid lines 120 between the suspended regions 112 and the spacing of the texture is not only related to the spacing between the suspended regions 112 and the textured structure, i.e., the thickness of the portion of the grid lines 120 between the suspended regions 112 and the textured structure, but also to the proportion of the area of ​​the suspended regions 112 to the surface area of ​​the sheet-like anti-reflective layer 110 facing the textured structure. If the proportion of the area of ​​the suspended regions 112 is too small, most of the area of ​​the sheet-like anti-reflective layer 110 will be in close contact with the textured structure, and the volume of the portion between the suspended regions 112 and the textured structure will be too small, which will limit the force that can be provided to prevent the grid lines 120 from falling off and will not effectively increase the bonding strength between the grid lines 120 and the substrate 100. If the proportion of the area taken up by the suspended region 112 is too large, the area of ​​the sheet-type anti-reflective layer 110 that does not contact the textured structure will be too large, and the bonding strength between the sheet-type anti-reflective layer 110 itself and the substrate 100 will be limited. In the process of providing the grid lines 120 with a force to prevent them from falling off or being displaced, the sheet-type anti-reflective layer 110 itself will easily fall off from the substrate 100, and similarly, the bonding strength between the grid lines 120 and the substrate 100 will not be effectively increased.

[0075] Therefore, the ratio of the area of ​​the suspended region 112 to the area of ​​the surface facing the textured structure of the sheet-shaped anti-reflective layer 110 can be set in the range of 5% to 90%, such as 6%, 7.5%, 9%, 10%, 12.5%, 15%, 20%, 25%, 35%, 50%, 60%, 75%, 80%, or 85%. By controlling the area ratio of the suspended region 112 within an appropriate range, the bonding strength between the sheet-shaped anti-reflective layer 110 and the substrate 100 can be sufficiently increased, reducing the probability of the sheet-shaped anti-reflective layer 110 falling off and improving the ability of the sheet-shaped anti-reflective layer 110 to prevent the grid lines 120 from falling off, thereby effectively increasing the bonding strength between the grid lines 120 and the substrate 100 and reducing the probability of the grid lines 120 falling off.

[0076] Furthermore, as the area proportion of the suspended regions 112 increases, the contact area of ​​the grid lines 120 with the surface of the textured structure also increases accordingly. Therefore, by controlling the area proportion of the suspended regions 112 within an appropriate range, not only can the bonding strength between the grid lines 120 and the substrate 100 be effectively increased, but also the contact area between the grid lines 120 and the substrate 100 can be increased, thereby reducing the contact resistance between the grid lines 120 and the substrate 100, improving the carrier collection ability of the grid lines 120, and reducing carrier collection loss.

[0077] In some embodiments, the thickness of the sheet-shaped anti-reflection layer 110 in the direction perpendicular to the surface toward the texture structure of the sheet-shaped anti-reflection layer 110 is 40 nm to 600 nm.

[0078] The thickness of the sheet-shaped anti-reflective layer 110 refers to the distance between the surface of the sheet-shaped anti-reflective layer 110 facing the textured structure and the surface of the sheet-shaped anti-reflective layer 110 facing away from the textured structure. If the thickness of the sheet-shaped anti-reflective layer 110 is too small, the anti-reflective ability of the sheet-shaped anti-reflective layer 110 is limited, and the lateral area of ​​the sheet-shaped anti-reflective layer 110 is also limited, making it impossible to effectively increase the contact area between the grid lines 120 and the substrate 100. If the thickness of the sheet-shaped anti-reflective layer 110 is too large, the manufacturing cost of the anti-reflective layer itself is too high, and the volume of raw material for the grid lines 120 needs to be greatly increased in order to bring the grid lines 120 into contact with the surface of the textured structure, which correspondingly increases the manufacturing cost of the grid lines 120.

[0079] Therefore, the thickness of the sheet-type anti-reflective layer 110 is set to a range of 40 nm to 600 nm in the direction perpendicular to the surface facing the texture structure of the sheet-type anti-reflective layer 110, for example, 45 nm, 50 nm, 60 nm, 75 nm, 90 nm, 100 nm, 125 nm, 150 nm, 180 nm, 200 nm, 225 nm, 275 nm, 350 nm, 400 nm, 475 nm, 550 nm, or 585 nm. Setting the thickness of the sheet-type anti-reflective layer 110 within an appropriate range effectively increases the contact area and contact strength between the grid lines 120 and the substrate 100, while also controlling the manufacturing costs of the anti-reflective layer and the grid lines 120 to a certain extent, thereby reducing the manufacturing costs of the grid lines 120 and the anti-reflective layer.

[0080] In addition, the thickness of the sheet-type anti-reflection layer 110 in the same texture structure may be the same or different, and the thickness of the sheet-type anti-reflection layer 110 in different texture structures may be the same or different, and this is not limited to the examples of the present application.

[0081] In some embodiments, the texture structure is composed of a plurality of pyramidal protrusions, and the length of the hypotenuse of the pyramid is 400 nm to 5 μm. The textured structure on the first surface formed by pyramidal protrusions can effectively improve the light trapping ability of the solar cell. The length of the hypotenuse of the pyramids can be set to a range of 400 nm to 5 μm, for example, 450 nm, 500 nm, 575 nm, 650 nm, 750 nm, 900 nm, 1000 nm, 1.2 μm, 1.25 μm, 1.5 μm, 2 μm, 2.75 μm, 3.5 μm, or 4.5 μm, thereby effectively increasing the surface area of ​​the textured structure, increasing the contact area and contact strength between the grid lines 120 and the substrate 100, and controlling the height of the textured structure protruding from the substrate 100. This increases the thickness of the grid lines 120 in the direction perpendicular to the first surface of the substrate 100, thereby reducing the carrier transport resistance of the grid lines 120.

[0082] Furthermore, the lengths of the hypotenuses of the pyramidal protrusions included in the texture structure of the same battery cell may be the same or different, and the lengths of the hypotenuses of the pyramidal protrusions included in the texture structure of different battery cells may similarly be the same or different.

[0083] In an embodiment of the present application, a solar cell is provided, in which a grid line region 102 having a textured structure is provided over the entire corresponding first surface, and grid lines 120 are formed in the grid line region 102. Since the entire corresponding first surface of the grid line region 102 has the textured structure, the contact area between the grid lines 120 and the substrate 100 is greatly increased, thereby increasing the bonding strength between the grid lines 120 and the substrate 100 to a certain extent. At least a portion of the textured structure in the grid line region 102 is provided with a sheet-type anti-reflective layer 110. The surface of the sheet-type anti-reflective layer 110 facing the textured structure is in intimate contact with the textured structure, and there are numerous gaps between the sheet-type anti-reflective layers 110, exposing the surface of the textured structure. After the grid lines 120 are formed, the grid lines 120 contact the exposed surface of the textured structure and the surface of the sheet-type anti-reflective layer 110, respectively. The sheet-type anti-reflective layer 110 has a predetermined thickness, and the grid lines 120 also contact the side surfaces of the sheet-type anti-reflective layer 110, further increasing the contact area between the grid lines 120 and the substrate 100. The intimate contact between the sheet-type anti-reflective layer 110 and the substrate 100 serves to secure the grid lines 120. This significantly increases the bonding strength between the grid lines 120 and the substrate 100, minimizing the likelihood of the grid lines 120 falling off, and improving the reliability of the solar cell.

[0084] In the embodiment of the present application, a method for manufacturing a solar cell is further provided, which is applied to a battery production device, and the manufacturing process of the solar cell can be seen in FIG.

[0085] 8 and 11, a substrate 100 is provided, the substrate 100 having a first surface, the substrate 100 including a plurality of grid line regions 102 arranged at intervals, a textured structure across the first surface of the grid line regions 102, and an anti-reflective layer covering the textured structure, where FIG. 9 is a top view of the first surface of the substrate 100, FIG. 10 is a cross-sectional view of the substrate 100 along B-B1, and FIG. 11 is a local cross-sectional view of the substrate 100 after selectively etching the anti-reflective layer in the grid line regions 102.

[0086] In the process of manufacturing a solar cell, first, a substrate 100 is provided in which the texture structure on the first surface and the anti-reflection layer covering the texture structure have been previously completed.

[0087] In some embodiments, the texture structure is composed of a plurality of pyramidal or pyramidal protrusions, which effectively improves the light absorption ability of the solar cell, and the pyramidal or pyramidal structure also has a certain absorption effect on the laser, which facilitates subsequent selective etching of the anti-reflection layer.

[0088] In some embodiments, the anti-reflective layer may be composed of a single layer of anti-reflective material, or may be composed of two or more layers of anti-reflective material that are stacked in sequence and made of different materials, including silicon dioxide, silicon nitride, titanium dioxide, and zirconium oxide.

[0089] The anti-reflection layer in each grid line area 102 is treated by a laser process to form a sheet-like anti-reflection layer 110 in the grid line area 102, and the sheet-like anti-reflection layer 110 exposes a portion of the surface of the texture structure in the grid line area 102.

[0090] In the process of manufacturing the battery cell, a first surface corresponding to the grid line region 102 needs to be etched by a selective etching process to expose the surface of the textured structure of the grid line region 102. When performing the selective etching, the anti-reflection layer in the grid line region 102 can be treated by a laser process, and at least a portion of the anti-reflection layer in the grid line region 102 can be removed by laser etching, and the remaining anti-reflection layer can be etched as a sheet-shaped anti-reflection layer 110, and there are gaps between the sheet-shaped anti-reflection layers 110 that expose at least a portion of the surface of the textured structure of the grid line region 102.

[0091] Furthermore, since the process of selectively etching the anti-reflection layer may cause some damage to the textured structure, the surface of the textured structure is made uneven, and a suspended region that does not contact the textured structure is formed on the surface facing the textured structure of the formed sheet-shaped anti-reflection layer 110. By adjusting the laser parameters or the number of repetitions of the laser treatment, it is possible to form a sheet-shaped anti-reflection layer 110 in which the area ratio of the suspended region exceeds 5%.

[0092] In some embodiments, the selective etching process utilized may be a chemical etching process.

[0093] 8 to 12, in some embodiments, the process parameters of the laser process include a ratio of the size of the central region of the laser spot, d, to the size of the laser spot, D, of 0.4 to 0.6 or 0 to 0.1, where FIG. 12 is a diagram showing a laser spot.

[0094] Theoretically, the size of the laser spot is D, and the size of the central region of the laser spot is d, where the size of the laser spot refers to the maximum distance D between the center of a spot and any one point on the edge of the sheet-like anti-reflective layer 110 to be formed, and the size of the central region of the laser spot refers to the distance d between the center of the spot and the nearest point on the sheet-like anti-reflective layer 110. Taking a circular spot as an example, the size of the laser spot refers to the maximum distance D between the center of the spot and any one point on the edge of the sheet-like anti-reflective layer 110, and the size of the central region of the laser spot refers to the minimum distance d between the center of the spot and any one point on the nearest point on the edge of the sheet-like anti-reflective layer 110.

[0095] In the process of selectively etching the anti-reflection layer in the gridline region 102 using a laser process, a laser model can be selected first. For example, a Gaussian spot laser device can be selected for the laser process. After selecting the laser device to be used, the laser spot movement speed, pulse count per process, and laser frequency are determined. Then, a test substrate is sampled at different power levels to find a laser power that satisfies a ratio of the size d of the central region of the laser spot to the size D of the laser spot of 0.4 to 0.6 or 0 to 0.1. The anti-reflection layer in the gridline region 102 of the substrate 100 is selectively etched using the determined laser power. The laser power is limited based on the ratio of the size d of the central region of the laser spot to the size D of the laser spot. This limits the laser power range so that the laser process is in a low power range, allowing the sheet-shaped anti-reflection layer 110 to be formed on at least a portion of the textured structure in the gridline region 102 while simultaneously reducing damage to the textured structure morphology during the laser process and reducing damage to the substrate 100 during mold opening.

[0096] The test substrate and substrate 100 have the same or almost the same material and structure, and the surface of the test substrate also has a textured structure made of the same material as substrate 100 and an anti-reflection layer covering the textured structure.

[0097] In some embodiments, forming the sheet-like anti-reflective layer 110 includes performing multiple laser treatments on the anti-reflective layer in the gridline region 102 using a laser having a ratio of the size d of the central region of the laser spot to the size D of the laser spot between 0 and 0.1.

[0098] In the process of selectively etching the anti-reflection layer in the grid line region 102 by selecting a laser having a ratio of the size d of the central region of the laser spot to the size D of the laser spot of 0 to 0.1, the power of the laser is very small, and after a single laser treatment is performed on the grid line region 102, most of the areas between the sheet-type anti-reflection layer 110 formed in at least a portion of the texture structure in the grid line region 102 remain continuous, with few gaps between the sheet-type anti-reflection layer 110. As a result, the total area of ​​the texture structure and the area of ​​the anti-reflection layer exposed on the substrate 100 increases only slightly, and the total exposed area of ​​the substrate 100 cannot be effectively increased.

[0099] Therefore, when a laser having a ratio of the size of the central region of the laser spot to the size of the laser spot of 0 to 0.1 is selected for selective etching, the grid line region 102 is repeatedly treated with low-power laser light in accordance with the pattern shape of the grid line region 102 using a laser with set parameters, for example, two, three, four, five, six, or seven times. A number of large, randomly distributed sheet-type anti-reflection layers 110 or uniformly arranged small, sheet-type anti-reflection layers 110 can be formed on the surface of the grid line region 102, and the area of ​​the textured structure exposed between the sheet-type anti-reflection layers 110 is sufficiently large, effectively increasing the total exposed area of ​​the substrate 100.

[0100] The grid line area 102 is repeatedly laser processed in small amounts, for example, laser processed 2 to 4 times. After that, the sheet-like antireflection layers 110 in at least a part of the texture structure of the grid line area 102 are uniformly arranged, a large number of gaps exist between the sheet-like antireflection layers 110, and the texture structure of the grid line area 102 is completely retained, effectively reducing the damage of the mold opening of the substrate 100.

[0101] In some embodiments, when the size of the central region of the laser spot in the laser process is d, the speed of the laser spot is v, and the laser frequency is f, 0.8d < v / f < 2d is satisfied.

[0102] Referring to the above content, the size of the central region of the laser spot refers to the distance d between the center of the spot and the sheet-like antireflection layer 110 closest to it. After completing the selection of the laser model, according to the predetermined laser power, the pulse count processed once, and the set laser frequency f, the speed v of the laser spot is adjusted, and sampling is performed step by step on the test substrate. Here, the materials and structures of the test substrate and the substrate 100 are the same or substantially the same, and on the surface of the test substrate, an antireflection layer covering the same texture structure and texture structure as the substrate 100 is fabricated. According to the results of the step-by-step sampling, the speed v of the laser spot in the laser etching process is determined, and the laser spot used in the laser process can satisfy 0.8d < v / f < 2d. Then, according to the determined speed v of the laser spot, the set laser power, the pulse count processed once, and the set laser frequency f, the first surface of the substrate 100 is selectively laser etched along the shape pattern of the predetermined grid line area 102.

[0103] When the size of the central region of the laser spot in the laser process is d, the speed of the laser spot is v, and the laser frequency is f, under the condition that 0.8d < v / f < 2d is satisfied, the antireflection layer in the texture structure and the collection function of the antireflection layer for the laser in the texture structure are used to open the mold of the antireflection layer, and a plurality of sheet-like antireflection layers 110 are formed on at least a part of the texture structure, improving the form retention effect of the texture structure in the grid line region 102, reducing the damage of the mold opening to the substrate 100, and increasing the total area of the texture structure and the antireflection layer exposed from the substrate 100.

[0104] Also, in the laser process, parameters such as the laser frequency f and / or the number of laser shots can be adjusted. After adjusting the laser frequency and / or the number of laser shots, the speed v of the laser spot is adjusted again, sampled on a test substrate, and a new speed v of the laser spot that satisfies the condition 0.8d < v / f < 2d is determined. Then, the antireflection layer in the grid line region 102 is selectively etched according to the updated laser process parameters.

[0105] In some embodiments, after forming the sheet-like antireflection layer 110, it further includes performing a deoxidation treatment on each grid line region 102 using a slow-release hydrofluoric acid with a concentration of 0.3% to 20%.

[0106] After laser treatment, an oxide layer is formed on the texture structure and / or the sheet-like antireflection layer 110 in the grid line region 102. Since the oxide layer affects the photoelectric conversion efficiency of the battery cell, after forming the sheet-like antireflection layer 110, each grid line region 102 can be deoxidized using a slow-release hydrofluoric acid with a concentration in the range of 0.3% to %20%. For example, each grid line region 102 is deoxidized using a slow-release hydrofluoric acid with a concentration of 0.5%, 1%, 2.5%, 5%, 8%, 12.5%, 15%, 18% or 19%. Thereby, the oxide layer formed by natural oxidation and / or laser oxidation on the surface of the substrate 100 can be removed, and the photoelectric conversion efficiency of the solar cell can be increased.

[0107] In some embodiments, the deoxidation treatment time is 20 seconds to 90 seconds. The thickness of the oxide layer on the surface of the substrate 100 varies depending on the selected concentration of sustained-release hydrofluoric acid and the laser power used in the laser treatment. If the deoxidation time is too long, the hydrofluoric acid may corrode the substrate 100 or the sheet-shaped anti-reflective layer 110, increasing damage to the substrate 100 during mold opening and impairing the shape and strength of the sheet-shaped anti-reflective layer 110. If the deoxidation time is too short, the oxide layer may not be completely removed.

[0108] Therefore, the deoxidation time can be controlled within a range of 20 seconds to 90 seconds, for example, set to 22 seconds, 25 seconds, 30 seconds, 37.5 seconds, 45 seconds, 55 seconds, 60 seconds, 75 seconds, or 85 seconds, etc. This effectively removes the oxide layer on the surface of the substrate 100 and reduces damage to the substrate 100 and the sheet-shaped anti-reflection coating 110.

[0109] 1, 2, and 8 to 11, a plurality of grid lines 120 corresponding one-to-one to the grid line regions 102 are formed in each grid line region 102, and each grid line 120 is in contact with the surface of the textured structure in the corresponding grid line region 102 and the surface of the sheet-like antireflection layer 110.

[0110] After the fabrication of the sheet-type anti-reflective layer 110 is completed, a plurality of grid lines 120 can be formed in the grid line regions 102 by vapor deposition, electroplating, or other methods depending on the positions of the grid line regions 102, so as to correspond one-to-one to the grid line regions 102. Each grid line 120 is in contact with the exposed surface of the textured structure in the corresponding grid line region 102 and the surface of the sheet-type anti-reflective layer 110. By forming the sheet-type anti-reflective layer 110 with the textured structure surface exposed in at least a portion of the grid line region 102, the remaining textured structure and the side surfaces of the sheet-type anti-reflective layer 110 can effectively increase the contact area between the grid lines 120 and the substrate 100. The sheet-type anti-reflective layer 110 can also fix the grid lines 120, effectively increasing the bonding strength between the grid lines 120 and the substrate 100, reducing the probability of the grid lines 120 falling off from the substrate 100, and improving the reliability of the solar cell.

[0111] In some embodiments, the grid lines 120 may be formed with multiple plating layers stacked in sequence. For example, a first plating layer having a thickness of 0.3 μm to 1 μm may be formed in the grid line region 102 by electroplating, chemical plating, or chemical vapor deposition. The first plating layer may completely cover the surface of the textured structure exposed between the sheet-shaped anti-reflective layers 110. The second and third plating layers are then sequentially grown by electroplating. The first plating layer may be grown with one to five sublayers depending on the actual situation, and the total thickness of the second and third plating layers is 4 μm or more. The total thickness of the second and third plating layers refers to the distance between the surface of the second plating layer facing the first plating layer and the surface of the third plating layer facing away from the first plating layer in a direction perpendicular to the surface away from the textured structure of the first plating layer.

[0112] Of course, this embodiment is an embodiment of a manufacturing method corresponding to the configuration embodiment of a solar cell, and the details of this embodiment are equally applicable to the configuration embodiment of a solar cell, and similarly, the details of the configuration embodiment of a solar cell are also applicable to this embodiment.

[0113] The present application has been disclosed as above in preferred embodiments, but is not intended to limit the claims, and any person skilled in the art may make some possible changes and modifications without departing from the concept and scope of the present application, provided that they do not deviate from the concept of the present application. Therefore, the scope of protection of the present application should be based on the scope limited by the claims of the present application.

Claims

1. a substrate, a plurality of sheet-like anti-reflective layers, and a plurality of grid lines; the substrate has a first surface, the substrate including a plurality of spaced apart grid line regions, the grid line regions having a textured structure across the first surface; the sheet-shaped anti-reflection layer is located on at least a portion of the texture structure in each of the grid line regions, and the sheet-shaped anti-reflection layer exposes a portion of the surface of the texture structure; Each of the grid lines corresponds to a grid line region in a one-to-one manner, the grid lines are provided in the corresponding grid line regions, and the grid lines are in contact with a surface of the textured structure and a surface of the sheet-shaped anti-reflection layer in the grid line regions, respectively. A solar cell characterized by:

2. the grid line region includes a first region, a second region, and a third region that are arranged in order in a direction perpendicular to an extension direction of the grid line region, The sheet-shaped antireflection layer is located on at least a part of the texture structure in the first region and at least a part of the texture structure in the third region. The solar cell according to claim 1 .

3. the sheet-shaped antireflection layer is not present on a surface of the texture structure in the second region, and the texture structure in the first region and the third region is a pyramidal or pyramidal structure, and the texture structure in the second region is a pinecone structure. The solar cell according to claim 2 .

4. a ratio of a height of the texture structure in the second region protruding from the first surface to a height of the texture structure in a non-grid line region protruding from the first surface in a direction perpendicular to the first surface is 0.3 to 0.9; The solar cell according to claim 2 .

5. The sheet-shaped anti-reflection layer is also located on at least a part of the texture structure in the second region. The solar cell according to claim 2 .

6. The maximum distance between any two points on the surface of the sheet-like anti-reflection layer is 0.3 μm to 6 μm. The solar cell according to claim 5 .

7. the maximum distance between any two points on the surface of the sheet-shaped antireflection layer is 2 μm to 6 μm, and in a direction perpendicular to the first surface, the ratio of the height of the texture structure in the grid line region protruding from the first surface to the height of the texture structure in the non-grid line region protruding from the first surface is 0.4 to 0.9; The solar cell according to claim 6 .

8. the maximum distance between any two points on the surface of the sheet-shaped antireflection layer is 0.3 μm to 2 μm, and in a direction perpendicular to the first surface, the ratio of a height of the texture structure in the grid line region protruding from the first surface to a height of the texture structure in the non-grid line region protruding from the first surface is 0.6 to 1; The solar cell according to claim 6 .

9. The distance between adjacent sheet-shaped antireflection layers is 20 nm to 5 μm. The solar cell according to claim 1 .

10. The surface of the sheet-shaped anti-reflection layer facing the texture structure includes an attached region in contact with the texture structure and a suspended region not in contact with the texture structure. The solar cell according to claim 1 .

11. a distance between the suspended region of the sheet-shaped antireflection layer and the texture structure is 50 nm to 1000 nm in a direction perpendicular to the surface of the sheet-shaped antireflection layer facing the texture structure; The solar cell according to claim 10 .

12. the ratio of the area of ​​the hanging region to the area of ​​the surface of the sheet-shaped anti-reflection layer facing the texture structure is 5% to 90%; The solar cell according to claim 10 .

13. The thickness of the sheet-shaped antireflection layer is 40 nm to 600 nm in a direction perpendicular to the surface of the sheet-shaped antireflection layer facing the texture structure. The solar cell according to any one of claims 1 to 12.

14. The texture structure is composed of a plurality of pyramid-shaped protrusions, and the length of the hypotenuse of the pyramid is 400 nm to 5 μm. The solar cell according to any one of claims 1 to 12.

15. providing a substrate having a first surface, the substrate including a plurality of spaced apart grid line regions, the grid line regions having a textured structure across the first surface, the textured structure having an anti-reflective layer covering the textured structure; treating the anti-reflective layer of each of the grid line regions by a laser process to form a plurality of sheet-shaped anti-reflective layers in the grid line regions, the sheet-shaped anti-reflective layers exposing a portion of the surface of the texture structure of the grid line regions; forming a plurality of grid lines in each of the grid line regions in a one-to-one correspondence with the grid line regions, and each of the grid lines is in contact with a surface of the textured structure and a surface of the sheet-shaped anti-reflection layer in the corresponding grid line region; A method for producing a solar cell comprising the steps of:

16. In the laser process, when the size of the central region of the laser spot is d, the speed of the laser spot is v, and the laser frequency is f, the relationship 0.8d<v / f<2d is satisfied. The method for producing a solar cell according to claim 15 .

17. The process parameters of the laser process include a ratio of the size of the central area of ​​the laser spot to the size of the laser spot of 0.4 to 0.6 or 0 to 0.1; The method for producing a solar cell according to claim 15 .

18. forming the sheet-shaped anti-reflection layer includes performing a laser treatment on the anti-reflection layer in the grid line region multiple times using a laser having a ratio of a size of a central region of the laser spot to a size of the laser spot of 0 to 0.1; The method for producing a solar cell according to claim 17 .

19. The method further includes performing a deoxidation treatment on each of the grid line regions using a sustained release hydrofluoric acid having a concentration of 0.3% to 20% after forming the sheet-shaped anti-reflection layer. The method for producing a solar cell according to claim 15 .

20. The time length of the deoxidation treatment is 20 s to 90 s. The method for producing a solar cell according to claim 19 .

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