Solar cell, manufacturing method thereof and photovoltaic module

Abstract

The invention relates to a solar cell and a manufacturing method thereof, and a photovoltaic module, and the manufacturing method of the solar cell comprises the steps: providing a substrate, and forming a first anti-reflection layer on the surface of one side of the substrate; a fine grid layer is formed on the side, away from the substrate, of the first anti-reflection layer, the fine grid layer comprises a plurality of fine grids which are arranged at intervals, and the fine grids extend in the first direction; a second anti-reflection layer is formed on the surface of one side, far away from the substrate, of the fine grid layer and the first anti-reflection layer, and an opening is formed in the second anti-reflection layer; and a main grid is formed, the main grid is at least formed in the opening, and the main grid is connected with the fine grid. The absorption performance of the solar cell in a visible light area is improved, so that the photoelectric conversion efficiency of the solar cell is improved, and the performance of a photovoltaic module is improved.

Description

Technical Field

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

[0002] TOPCon (Tunnel Oxide Passivated Contact) cell technology is a solar cell technology based on the selective carrier principle using a tunneled oxide passivated contact. Typically, a TOPCon cell structure uses N-type silicon as a substrate. The front structure on one side of the substrate includes a boron-doped emitter, a passivation layer, and metal grid lines. The back structure on the other side of the substrate includes a tunneled oxide layer, a phosphorus-doped polycrystalline silicon layer, a back passivation layer, and metal grid lines. Summary of the Invention

[0003] Therefore, it is necessary to provide a solar cell and its manufacturing method, as well as a photovoltaic module, to improve the absorption performance of solar cells in the visible light region and increase the photoelectric conversion efficiency of solar cells.

[0004] In a first aspect, this application provides a method for manufacturing a solar cell, comprising:

[0005] A substrate is provided, and a first antireflective layer is formed on one side surface of the substrate;

[0006] A fine gate layer is formed on the side of the first antireflection layer away from the substrate. The fine gate layer includes a plurality of fine gates spaced apart from each other, and the fine gates extend along a first direction.

[0007] A second antireflection layer is formed on the surface of the fine gate layer and the first antireflection layer on the side away from the substrate, and an opening is formed in the second antireflection layer;

[0008] A main gate is formed, which is at least formed within the opening and is connected to the fine gate.

[0009] In one embodiment, the process of forming a second antireflection layer on the surface of the fine gate layer and the first antireflection layer on the side away from the substrate includes:

[0010] A mask layer is formed on the fine gate layer and the first antireflection layer;

[0011] A second antireflection layer is formed on the surface of the mask layer, the fine grid layer, and the first antireflection layer on the side away from the substrate;

[0012] Remove the mask layer to form the opening within the second antireflective layer.

[0013] In one embodiment, the first antireflection layer and the second antireflection layer are formed by vapor deposition.

[0014] In one embodiment, the fine grid layer and the main grid are formed by screen printing and screen sintering processes, respectively.

[0015] In one embodiment, the method of manufacturing the solar cell further includes:

[0016] After the fine grid layer is formed, the solar cell on which the fine grid layer is formed is subjected to a laser-enhanced contact optimization process;

[0017] After the main grid is formed, the solar cell with the main grid formed is subjected to a laser-enhanced contact optimization process.

[0018] Secondly, this application also provides a solar energy device, comprising:

[0019] Base;

[0020] The first antireflective layer is located on one side surface of the substrate;

[0021] A fine gate layer is located on the side of the first antireflection layer away from the substrate. The fine gate layer includes a plurality of fine gates spaced apart from each other, and the fine gates extend along a first direction.

[0022] The second antireflection layer is located on the side of the fine gate layer away from the substrate, and an opening is provided in the second antireflection layer;

[0023] The main gate is located at least within the opening and is connected to the fine gate.

[0024] In one embodiment, both the first antireflective layer and the second antireflective layer are made of magnesium fluoride.

[0025] In one embodiment, the thickness of the first antireflection layer is in the range of 40 nm to 60 nm; and / or,

[0026] The thickness of the second antireflection layer is in the range of 40nm to 60nm.

[0027] In one embodiment, the sum of the thicknesses of the first antireflection layer and the second antireflection layer is in the range of 90 nm to 110 nm.

[0028] Thirdly, this application also provides a solar cell manufactured using the solar cell manufacturing method described above.

[0029] Fourthly, this application also provides a photovoltaic module, including the solar cell described above.

[0030] In summary, this application provides a solar cell, a method for manufacturing the same, and a photovoltaic module. The method for manufacturing the solar cell includes: providing a substrate; forming a first anti-reflection layer on one side surface of the substrate; forming a fine grid layer on the side of the first anti-reflection layer away from the substrate, the fine grid layer comprising a plurality of spaced-apart fine grids extending along a first direction; forming a second anti-reflection layer on the surfaces of the fine grid layer and the first anti-reflection layer away from the substrate, with an opening formed within the second anti-reflection layer; and forming a main grid, the main grid being formed at least within the opening and connected to the fine grids. This application improves the absorption performance of the solar cell in the visible light region, thereby improving the photoelectric conversion efficiency of the solar cell, and thus contributing to improved performance of the photovoltaic module. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of a TOPCon battery in a related technology.

[0033] Figure 2 A flowchart illustrating a method for manufacturing a solar cell according to one embodiment of this application.

[0034] Figure 3 This is a schematic diagram of the structure corresponding to the step of providing a substrate and forming a first antireflection layer in the manufacturing method of a solar cell provided in one embodiment of this application.

[0035] Figure 4 This is a schematic diagram of the structure corresponding to the step of forming a fine grid layer in the manufacturing method of a solar cell provided in one embodiment of this application.

[0036] Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure along the AB direction.

[0037] Figure 6 This is a schematic diagram of the structure corresponding to the step of forming the second antireflection layer in the manufacturing method of a solar cell provided in one embodiment of this application.

[0038] Figure 7 for Figure 6 A schematic diagram of the cross-sectional structure along the AB direction.

[0039] Figure 8This is a schematic diagram of the structure corresponding to the step of forming the main grid in the manufacturing method of a solar cell provided in one embodiment of this application.

[0040] Figure 9 for Figure 8 A schematic diagram of the cross-sectional structure along the AB direction.

[0041] Figure 10 This is a cross-sectional structural diagram of a photovoltaic module provided in one embodiment of this application.

[0042] The reference numerals in the figures include: 100-silicon substrate; 110-boron-doped emitter; 120-alumina layer; 130-front passivation layer; 140-front metal gate line; 150-tunneling oxide layer; 160-phosphorus-doped polycrystalline silicon layer; 170-back passivation layer; 180-back metal gate line; 200-substrate; 201-substrate; 202-emitter; 203-first dielectric layer; 204-first passivation layer; 205-tunneling layer; 206-polycrystalline silicon layer; 207-second passivation layer; 208-back gate; 210-first antireflection layer; 220-fine gate layer; 230-second antireflection layer; 231-opening; 240-main gate; 300-photovoltaic module; 310-solar cell; 311-conductive strip; 320-encapsulating film; 330-cover plate. Detailed Implementation

[0043] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0045] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this application, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0046] Spatial relation terms such as “below,” “under,” “below,” “below,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, an element or feature described as “below,” “below,” or “below” other elements or features would be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.

[0047] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, in this specification, the term “and / or” includes any and all combinations of the associated listed items.

[0048] Figure 1 This is a schematic diagram of the structure of a TOPCon battery in a related technology. (See also...) Figure 1 The existing TOPCon cell includes a silicon substrate 100. On one side surface of the silicon substrate 100, a boron-doped emitter 110, an aluminum oxide layer 120, and a front passivation layer 130 are sequentially disposed along the direction away from the silicon substrate 100. The side of the boron-doped emitter 110 away from the silicon substrate 100 is connected to a front metal grid line 140, and the front metal grid line 140 penetrates the aluminum oxide layer 120 and the front passivation layer 130. On the other side surface of the silicon substrate 100 (i.e., the side surface away from the boron-doped emitter 110), a tunneling oxide layer 150, a phosphorus-doped polycrystalline silicon layer 160, and a back passivation layer 170 are sequentially disposed along the direction away from the silicon substrate 100. The side of the phosphorus-doped polycrystalline silicon layer 160 away from the silicon substrate 100 is connected to a back metal grid line 180, and the back metal grid line 180 penetrates the back passivation layer 170.

[0049] Generally, the various films in the front structure of a TOPCon cell (including the boron-doped emitter 110, aluminum oxide layer 120, front passivation layer 130, and front metal grid lines 140) still have certain shortcomings in their absorption and reflection performance of sunlight, hindering further improvement in the photoelectric conversion efficiency (especially short-circuit current) of the TOPCon cell. Sunlight refers to light with wavelengths between 300nm and 1100nm, especially visible light with wavelengths between 300nm and 800nm.

[0050] Based on this, this application provides a solar cell and a method for manufacturing the same, to improve the absorption performance of the solar cell in the visible light region, thereby improving the photoelectric conversion efficiency of the solar cell.

[0051] Firstly, Figure 2 A flowchart illustrating a method for manufacturing a solar cell according to one embodiment of this application. See also... Figure 2 One embodiment of this application provides a method for manufacturing a solar cell, including the following steps S01 to S04.

[0052] Step S01: Provide a substrate and form a first antireflective layer on one side surface of the substrate.

[0053] It should be noted that by forming a first antireflection layer on the substrate, the surface reflectivity of the solar cell can be reduced, thereby enhancing the light absorption of the solar cell in the visible light range.

[0054] Step S02: A fine gate layer is formed on the side of the first antireflection layer away from the substrate. The fine gate layer includes a plurality of fine gates spaced apart from each other and the fine gates extend along a first direction.

[0055] Step S03: A second antireflection layer is formed on the surface of the fine gate layer and the first antireflection layer away from the substrate, and an opening is formed in the second antireflection layer.

[0056] It should be noted that forming an opening within the second anti-reflection layer facilitates the formation of the main gate within the opening in subsequent steps, thereby helping to reduce the distance between the main gate and the substrate.

[0057] Step S04: Form a main gate, which is formed at least within the opening and is connected to the fine gate.

[0058] It should be noted that by forming the main gate within the opening, the distance between the main gate and the substrate is reduced, which helps to reduce the contact resistance of the main gate.

[0059] The solar cell manufacturing method described above reduces the surface reflectivity of the solar cell and enhances its light absorption in the visible light range by forming a first antireflection layer on the substrate. By forming an opening in the second antireflection layer and forming a main grid within the opening, the distance between the main grid and the substrate is reduced, which helps to reduce the contact resistance of the main grid. This, in turn, helps to improve the short-circuit current and fill factor of the solar cell, thereby improving the efficiency of the solar cell.

[0060] Figures 3 to 9 This is a schematic diagram of some steps in the manufacturing method of a solar cell provided in one embodiment of this application. The following is in conjunction with... Figures 3 to 9 The manufacturing method of the solar cell provided in this embodiment is described in detail.

[0061] First, refer to Figure 3 In one embodiment, step S01 specifically includes: providing a substrate 200, and forming a first antireflection layer 210 on one side surface of the substrate 200 to reduce the surface reflectivity of the solar cell and enhance the light absorption of the solar cell in the visible light range. Optionally, the first antireflection layer 210 is formed using a vapor deposition process.

[0062] In one embodiment, the substrate 200 includes a substrate 201. An emitter 202, a first dielectric layer 203, and a first passivation layer 204 are sequentially disposed on one side surface of the substrate 201 in a direction away from the substrate 201. A tunneling layer 205, a polysilicon layer 206, and a second passivation layer 207 are disposed on the side surface of the substrate 201 away from the emitter 202. The side of the polysilicon layer 206 away from the tunneling layer 205 is connected to a back gate 208. The back gate 208 penetrates the second passivation layer 207 and is connected to the polysilicon layer 206. A first antireflection layer 210 is formed on the side of the first passivation layer 204 away from the first dielectric layer 203.

[0063] In one embodiment, the substrate 201 is made of silicon (Si) and is doped with N. Optionally, the doping element of the N-type substrate 201 includes antimony (Sb). Optionally, the surface of the substrate 201 near the emitter 202 is provided with a textured structure composed of multiple microstructures to enhance light reflection of the solar cell, increase light scattering and coupling, thereby helping to improve the light absorption efficiency of the solar cell.

[0064] In one embodiment, the emitter 202 is doped with boron (B) to improve the fill factor and conversion efficiency of the solar cell. In one embodiment, the first dielectric layer 203 is made of aluminum oxide (Al2O3), the tunneling layer 205 is made of silicon oxide (SiO2), and the polycrystalline silicon layer 206 is doped with phosphorus (P). Optionally, the first antireflection layer 210 is made of magnesium fluoride (MgF2).

[0065] In one embodiment, the first passivation layer 204 can be a single layer of silicon nitride or a combination of silicon nitride and silicon oxide; the second passivation layer 207 can be a single layer of silicon nitride or a combination of silicon nitride and silicon oxide. Optionally, the materials and structures of the first passivation layer 204 and the second passivation layer 207 can be the same or different.

[0066] In one embodiment, when the first passivation layer 204 is a single layer of silicon nitride and the first antireflection layer 210 is a magnesium fluoride layer, the reflectivity of light in the 300nm~500nm wavelength band is low, and the absorption effect of solar light is stronger.

[0067] It should be noted that in other embodiments of this application, the specific structure of the substrate 200 can be adjusted according to actual needs, and the materials and other parameters of each film layer in the substrate 200 can be adjusted according to actual needs. This application does not impose any restrictions on this.

[0068] See Figure 4 and Figure 5 In one embodiment, step S02 includes forming a fine gate layer 220 on the side of the first antireflection layer 210 away from the substrate 200. The fine gate layer 220 includes a plurality of mutually spaced fine gates 221, and the fine gates 221 extend along a first direction (i.e., the X direction).

[0069] In one embodiment, the fine grid layer 220 is formed using screen printing and screen sintering processes. Optionally, a low-temperature paste can be used for screen printing, followed by low-temperature sintering to form the fine grid layer 220. Optionally, after forming the fine grid layer 220, a laser-enhanced contact optimization process is performed on the solar cell with the fine grid layer 220 to improve the contact quality between the fine grid 221 and the substrate 200, thereby helping to improve the conversion efficiency of the solar cell.

[0070] Then refer to Figure 6 and Figure 7 In one embodiment, step S03 includes forming a second antireflection layer 230 on the surface of the fine gate layer 220 and the first antireflection layer 210 away from the substrate 200, and forming an opening 231 in the second antireflection layer 230. Optionally, the size of the opening 231 is matched with the cross-sectional size of the main gate to be formed subsequently, which helps to reduce the distance between the subsequently formed main gate and the substrate.

[0071] Exemplarily, the process of forming a second antireflection layer 230 on the surface of the fine gate layer 220 and the first antireflection layer 210 away from the substrate 200 includes: first, forming a mask layer (not shown in the figure) on the fine gate layer 220 and the first antireflection layer 210; then, forming a second antireflection layer 230 on the surface of the mask layer, the fine gate layer 220 and the first antireflection layer 210 away from the substrate 200; subsequently, removing the mask layer and a portion of the second antireflection layer 230 located on the side of the mask layer away from the substrate 200 to form an opening 231 within the second antireflection layer 230. Optionally, the mask layer includes high-temperature adhesive tape. In other embodiments of this application, other methods may also be used to form the second antireflection layer 230 with the opening 231, which is common knowledge well known to those skilled in the art and will not be elaborated here.

[0072] In one embodiment, a second antireflection layer 230 is formed using a vapor deposition process to further reduce the contact resistance of the solar cell. Optionally, the material of the second antireflection layer 230 includes magnesium fluoride (MgF2).

[0073] See Figure 8 and Figure 9 In one embodiment, step S04 includes forming a main gate 240, which is at least formed within the opening 231 and connected to the fine gate 221. Optionally, the extension direction of the main gate 240 (i.e., Figure 9 The Y direction in the middle is perpendicular to the extension direction of the fine gate 221.

[0074] In one embodiment, the main grid 240 is formed using a screen printing and screen sintering process. Optionally, a low-temperature paste can be used for screen printing, followed by low-temperature sintering to form the main grid 240. Optionally, after forming the main grid 240, a laser-enhanced contact optimization process is performed on the solar cell with the main grid 240 to improve the contact quality between the main grid 240 and the substrate 200, thereby helping to further improve the conversion efficiency of the solar cell.

[0075] It should be noted that by forming an opening in the second anti-reflection layer and forming the main grid within the opening, the distance between the main grid and the substrate is reduced, which helps to reduce the contact resistance of the main grid, thereby helping to improve the short-circuit current and fill factor of the solar cell, and thus helping to improve the efficiency of the solar cell.

[0076] The following tests were conducted on solar cells fabricated using the solar cell manufacturing method described above. Group A represents solar cells commonly used in related technologies (e.g., ...). Figure 1 Group A represents the TOPCon cell shown in the table. Group B represents the cell structure corresponding to the case where a magnesium fluoride antireflection layer is added to the solar cell shown in Group A. Group C represents the solar cell prepared by the manufacturing method of the solar cell provided in this application. Table 1 is used to show the test results of the current-voltage (IV) efficiency test for the above three different cell structures.

[0077] Table 1. IV Efficiency Test Results of Different Solar Cells

[0078]

[0079] It should be noted that U in Table 1 oc I represents the open-circuit voltage of a solar cell, measured in volts (V). sc FF represents the short-circuit current of the solar cell, measured in milliamperes (mA). FF represents the fill factor of the solar cell, and η represents the power conversion efficiency (also known as Eta) of the solar cell.

[0080] Comparing groups A and C in Table 1, and comparing groups A and B, it can be seen that the short-circuit currents of the solar cells in groups B and C are both increased (by approximately 30mA to 40mA) compared to those in group A. This demonstrates that adding a magnesium fluoride layer to the solar cell (i.e., the first and second antireflection layers in group C, or the magnesium fluoride antireflection layer in group B) can effectively increase the short-circuit current I of the solar cell. sc (For example, the short-circuit current I of the solar cell) sc Increased to 13.976mA~13.980mA).

[0081] Furthermore, as shown in Table 1, compared with Group A and Group B, the fill factor of the solar cells provided by Group C was improved by 0.2% to 0.4%, and the energy conversion efficiency was improved by 0.2%. It is evident that the solar cells provided in this application, by setting a first anti-reflection layer and a second anti-reflection layer with openings, reduce the distance between the main grid and the substrate, thereby effectively reducing the contact resistance, improving the fill factor of the solar cell, and simultaneously improving the energy conversion efficiency of the solar cell.

[0082] In some embodiments of this application, further tests can be performed on certain parameters of the solar cells. For example, the plasma brightness and average series resistance of different solar cells can be found in Tables 2 and 3. Table 2 shows the changes in plasma brightness of the solar cells in groups B and C before and after the preparation of the antireflection layer (the material of the antireflection layer is magnesium fluoride), and Table 3 shows the average series resistance of the solar cells in groups B and C.

[0083] Table 2. Changes in plasma brightness before and after fabrication of antireflection layers for different solar cells.

[0084]

[0085] It should be noted that the first average brightness in Table 2 is the average brightness of different solar cells before the antireflection layer is prepared, the second average brightness is the average brightness of different solar cells after the antireflection layer is prepared, and the difference is the absolute value of the difference between the first average brightness and the second average brightness.

[0086] Table 3. Average series resistance of different solar cells

[0087]

[0088] As shown in Table 2, the average first brightness value of both groups B and C is greater than the average second brightness value. Furthermore, the average first brightness value, average second brightness value, and difference of group C are less than those of group B. As shown in Table 3, compared to the average series resistance (Rs) of group B, the average series resistance (Rs) of group C is reduced by 0.0002~0.0003. This indicates that the metal recombination of the solar cells corresponding to group C is significantly reduced.

[0089] Continue reading Figure 8 and Figure 9One embodiment of this application also provides a solar energy device, including a substrate 200, a first anti-reflection layer 210, a fine grid layer 220, a second anti-reflection layer 230, and a main grid 240; wherein, the first anti-reflection layer 210 is located on one side surface of the substrate 200; the fine grid layer 220 is located on the side of the first anti-reflection layer 210 away from the substrate 200, and the fine grid layer 220 includes a plurality of mutually spaced fine grids 221, and the fine grids 221 extend along a first direction (i.e., the X direction); the second anti-reflection layer 230 is located on the side of the fine grid layer 220 away from the substrate 200, and an opening 231 is provided in the second anti-reflection layer 230; the main grid 240 is located at least in the opening 231, and the main grid 240 is connected to the fine grids 221.

[0090] As described above, the solar cell reduces the surface reflectivity of the solar cell by setting a first antireflection layer on the substrate, thereby enhancing the light absorption of the solar cell in the visible light range. By setting an opening in the second antireflection layer and setting the main grid in the opening, the distance between the main grid and the substrate is reduced, which helps to reduce the contact resistance of the main grid, thereby helping to improve the short-circuit current and fill factor of the solar cell, and thus helping to improve the efficiency of the solar cell.

[0091] Continue reading Figure 8 and Figure 9 In one embodiment, the substrate 200 includes a substrate 201. An emitter 202, a first dielectric layer 203, and a first passivation layer 204 are sequentially disposed on one side surface of the substrate 201 in a direction away from the substrate 201. A tunneling layer 205, a polysilicon layer 206, and a second passivation layer 207 are disposed on the side surface of the substrate 201 away from the emitter 202. The side of the polysilicon layer 206 away from the tunneling layer 205 is connected to the back gate 208. The back gate 208 penetrates the second passivation layer 207 and is connected to the polysilicon layer 206. A first antireflection layer 210 is formed on the side of the first passivation layer 204 away from the first dielectric layer 203.

[0092] In one embodiment, the substrate 201 is made of silicon (Si) and is doped with N. Optionally, the doping element of the N-type substrate 201 includes antimony (Sb). Optionally, the surface of the substrate 201 near the emitter 202 is provided with a textured structure composed of multiple microstructures to enhance light reflection of the solar cell, increase light scattering and coupling, thereby helping to improve the light absorption efficiency of the solar cell.

[0093] In one embodiment, the emitter 202 is doped with boron (B) to improve the fill factor and conversion efficiency of the solar cell. In one embodiment, the first dielectric layer 203 is made of aluminum oxide (Al2O3), the tunneling layer 205 is made of silicon oxide (SiO2), and the polycrystalline silicon layer 206 is doped with phosphorus (P).

[0094] In one embodiment, the first passivation layer 204 can be a single layer of silicon nitride or a combination of silicon nitride and silicon oxide; the second passivation layer 207 can be a single layer of silicon nitride or a combination of silicon nitride and silicon oxide. Optionally, the materials and structures of the first passivation layer 204 and the second passivation layer 207 can be the same or different.

[0095] In one embodiment, the first antireflective layer 210 is made of magnesium fluoride (MgF2), and its thickness is in the range of 40 nm to 60 nm. For example, the thickness of the first antireflective layer 210 can be 40 nm, 45 nm, 53 nm, or 60 nm. In one embodiment, the second antireflective layer 230 is made of magnesium fluoride (MgF2), and its thickness is in the range of 40 nm to 60 nm. For example, the thickness of the second antireflective layer 230 can be 40 nm, 43 nm, 56 nm, or 60 nm. Optionally, the sum of the thicknesses of the first antireflective layer 210 and the second antireflective layer 230 is in the range of 90 nm to 110 nm. For example, the sum of the thicknesses of the first antireflective layer 210 and the second antireflective layer 230 can be 90 nm, 98 nm, 105 nm, or 110 nm.

[0096] In one embodiment, when the first passivation layer 204 is a single layer of silicon nitride and the first antireflection layer 210 is a magnesium fluoride layer, the reflectivity of light in the 300nm~500nm wavelength band is low, and the absorption effect of solar light is stronger.

[0097] In one embodiment, the solar cell is manufactured using the solar cell manufacturing method described above. In other embodiments of this application, the solar cell described above can be manufactured using other conventional solar cell manufacturing methods, or other semiconductor structures with the same or similar structures can be manufactured using the solar cell manufacturing method described above; this application does not impose any limitations on this.

[0098] Figure 10 This is a schematic cross-sectional view of a photovoltaic module provided in one embodiment of this application. (See also...) Figure 10 One embodiment of this application provides a photovoltaic module 300 including a battery string, an encapsulating film 320 covering the surface of the battery string, and a cover plate 330 located on the side of the encapsulating film 320 away from the battery string; wherein, the battery string includes a plurality of solar cells 310, and the plurality of solar cells 310 are electrically connected to each other through conductive strips 311. Optionally, the solar cells 310 are the solar cells described above in this application (see...). Figure 8 and Figure 9 ), or it can be the manufacturing method of the solar cell as described above (see Figure 2The solar cells manufactured by this process help improve the absorption performance of the photovoltaic module 300 in the visible light region, thereby improving the photoelectric conversion efficiency of the photovoltaic module 300.

[0099] In one embodiment, the conductive strip 311 is electrically connected to the electrodes of the solar cell 310 by welding to ensure the normal operation of the photovoltaic module 300.

[0100] In one embodiment, the encapsulating film 320 can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyethylene terephthalate (PET) film. In other embodiments of this application, the specific materials and related parameters of the encapsulating film 320 can be adjusted according to actual needs, and this application does not impose any limitations on this.

[0101] In one embodiment, the cover plate 330 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Optionally, the surface of the cover plate 330 facing the encapsulating film 320 can be an uneven surface or a textured surface containing multiple raised structures to increase the utilization rate of incident light.

[0102] In summary, this application provides a solar cell, a method for manufacturing the same, and a photovoltaic module. The method for manufacturing the solar cell includes: providing a substrate; forming a first anti-reflection layer on one side surface of the substrate; forming a fine grid layer on the side of the first anti-reflection layer away from the substrate, the fine grid layer comprising a plurality of spaced-apart fine grids extending along a first direction; forming a second anti-reflection layer on the surfaces of the fine grid layer and the first anti-reflection layer away from the substrate, with an opening formed within the second anti-reflection layer; and forming a main grid, the main grid being formed at least within the opening and connected to the fine grids. This application improves the absorption performance of the solar cell in the visible light region, thereby improving the photoelectric conversion efficiency of the solar cell, and thus contributing to improved performance of the photovoltaic module.

[0103] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0104] 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 of 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.

[0105] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for manufacturing a solar cell, characterized in that, include: A substrate is provided, and a first antireflective layer is formed on one side surface of the substrate; A fine gate layer is formed on the side of the first antireflection layer away from the substrate. The fine gate layer includes a plurality of fine gates spaced apart from each other, and the fine gates extend along a first direction. A second antireflection layer is formed on the surface of the fine gate layer and the first antireflection layer on the side away from the substrate, and an opening is formed in the second antireflection layer; A main gate is formed, which is at least formed within the opening and is connected to the fine gate.

2. The method for manufacturing a solar cell according to claim 1, characterized in that, The process of forming a second antireflection layer on the surface of the fine gate layer and the first antireflection layer away from the substrate includes: A mask layer is formed on the fine gate layer and the first antireflection layer; A second antireflection layer is formed on the surface of the mask layer, the fine grid layer, and the first antireflection layer on the side away from the substrate; Remove the mask layer to form the opening within the second antireflective layer.

3. The method for manufacturing a solar cell according to claim 1, characterized in that, The first antireflection layer and the second antireflection layer are formed by vapor deposition.

4. The method for manufacturing a solar cell according to claim 1, characterized in that, The fine grid layer and the main grid are formed by screen printing and screen sintering processes, respectively.

5. The method for manufacturing a solar cell according to any one of claims 1 to 4, characterized in that, The method for manufacturing the solar cell further includes: After the fine grid layer is formed, the solar cell on which the fine grid layer is formed is subjected to a laser-enhanced contact optimization process; After the main grid is formed, the solar cell with the main grid formed is subjected to a laser-enhanced contact optimization process.

6. A solar cell, characterized in that, include: Base; The first antireflective layer is located on one side surface of the substrate; A fine gate layer is located on the side of the first antireflection layer away from the substrate. The fine gate layer includes a plurality of fine gates spaced apart from each other, and the fine gates extend along a first direction. The second antireflection layer is located on the side of the fine gate layer away from the substrate, and an opening is provided in the second antireflection layer; The main gate is located at least within the opening and is connected to the fine gate.

7. The solar cell according to claim 6, characterized in that, Both the first and second antireflective layers are made of magnesium fluoride.

8. The solar cell according to claim 6 or 7, characterized in that, The thickness of the first antireflection layer is in the range of 40nm to 60nm; and / or, The thickness of the second antireflection layer is in the range of 40nm to 60nm.

9. The solar cell according to claim 6 or 7, characterized in that, The combined thickness of the first antireflection layer and the second antireflection layer is in the range of 90nm to 110nm.

10. A solar cell, characterized in that, It is manufactured using the method for manufacturing a solar cell as described in any one of claims 1 to 5.

11. A photovoltaic module, characterized in that, Includes the solar cell as described in any one of claims 6 to 10.

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