Photovoltaic cell and preparation method thereof

Abstract

The invention relates to a photovoltaic cell and a preparation method thereof, the photovoltaic cell comprises a silicon substrate, the silicon substrate comprises a first surface and a second surface, the first surface comprises a plurality of first areas and a plurality of second areas, the first areas and the second areas are alternately arranged, the first areas are provided with emitters, and the second areas are provided with second emitters. The second surface comprises a plurality of third areas and a plurality of fourth areas, the third areas and the fourth areas are alternately arranged, and the third areas are provided with passivation contact structures so as to improve the passivation effect of the second surface. The first area and the third area are both of a first suede structure. The first electrode is arranged in the first area and is in electric contact with the emitting electrode, the second electrode is arranged in the third area and is in electric contact with the passivation contact structure, and the first suede structure can enhance the adhesive force of electrode slurry on the first surface and the second surface, so that the sections of the first electrode and the second electrode are closer to rectangles; therefore, the conductive effect of the first electrode and the second electrode is improved, and the power of the photovoltaic cell is further improved.

Description

Technical Field

[0001] This application relates to the technical field of solar power generation, and particularly to a photovoltaic cell and a method for manufacturing the same. Background Art

[0002] With the increasing shortage of conventional energy supply and the increasingly prominent environmental pollution problems in the world, humans have realized the crisis of energy and environment and began to seek renewable clean energy to replace conventional energy. Photovoltaic power generation has become an emerging industry that has attracted widespread attention and key development in various countries around the world due to its characteristics of cleanliness, safety, convenience, and high efficiency. Currently, affected by the low passivation effect of photovoltaic cells and the low conductivity effect of electrodes, the power generation efficiency of photovoltaic cells used for solar power generation is relatively low. Summary of the Invention

[0003] In view of this, embodiments of this application provide a photovoltaic cell and a method for manufacturing the same to solve the problem of relatively low power generation efficiency of photovoltaic cells.

[0004] In a first aspect, this application relates to a photovoltaic cell, which includes: A silicon substrate, which includes a first surface and a second surface; The first surface includes a plurality of first regions and a plurality of second regions, the first regions and the second regions are arranged alternately, and a plurality of emitters are arranged in the first regions; The second surface includes a plurality of third regions and a plurality of fourth regions, the third regions and the fourth regions are arranged alternately, and a passivated contact structure is arranged in the third regions; A first electrode, which is arranged in the first region and is electrically connected to the emitter; A second electrode, which is arranged in the third region and is electrically connected to the passivated contact structure; Wherein, both the first region and the third region are of a first textured structure.

[0005] In a possible embodiment, the widths of both the first region and the third region are 10 μm to 200 μm.

[0006] In a possible embodiment, the fourth region is any one of the first textured structure, the second textured structure, and the polished structure.

[0007] In a possible embodiment, the first textured structure includes a plurality of first pyramid structures, and the second textured structure includes a plurality of second pyramid structures; the side walls of the first pyramid structures and the side walls of the second pyramid structures both have wrinkles.

[0008] In a possible embodiment, the tip angle of the first pyramid structure is from 10° to 70°; the tip angle of the second pyramid structure is from 10° to 90°; and the tip angle of the second pyramid structure is greater than that of the first pyramid structure.

[0009] In a possible embodiment, the tip and edges of the second pyramid structure are both arc surface structures, and the angle of the arc surface is from 10° to 150°.

[0010] In a possible embodiment, the reflectivity of the first matte surface structure is from 0.1% to 8%, and the reflectivity of the second matte surface structure is from 4% to 14%; and the reflectivity of the second matte surface structure is greater than that of the first matte surface structure.

[0011] In a second aspect, the present application also relates to a method for manufacturing a photovoltaic cell for manufacturing the photovoltaic cell according to any one of the above, and the manufacturing method includes: Preparing a silicon substrate; Preparing a first matte surface structure on both the first surface and the second surface of the silicon substrate; Preparing a first doping layer on the first surface to form an emitter; Removing the first doping layer on the second surface; Preparing a second doping layer on the second surface to form a passivated contact structure on the second surface; Performing laser grooving in the second region and the fourth region to form grooves; Preparing a matte surface structure or a polished structure in the grooves; Successively preparing a passivation layer and an antireflection layer on the first surface and the second surface; Preparing electrodes at the emitter and the passivated contact structure.

[0012] In a possible embodiment, when preparing a matte surface structure or polishing in the grooves, the manufacturing method includes: Preparing a second matte surface structure in the grooves on both the first surface and the second surface.

[0013] In a possible embodiment, when preparing a matte surface structure or polishing in the grooves, the manufacturing method includes: Preparing a second matte surface in the grooves on the first surface; Preparing a first matte surface in the grooves on the second surface.

[0014] The present application relates to a photovoltaic cell and a method for manufacturing the same. The photovoltaic cell includes a silicon substrate, which has a first surface and a second surface. The first surface includes a plurality of first regions and a plurality of second regions, which are arranged alternately. An emitter is disposed on the first region. The second surface includes a plurality of third regions and a plurality of fourth regions, which are arranged alternately. A passivated contact structure is disposed on the third region to improve the passivation effect of the second surface. Both the first region and the third region have a first textured structure. A first electrode is disposed on the first region and is in electrical contact with the emitter. A second electrode is disposed on the third region and is in electrical contact with the passivated contact structure. The first textured structure can enhance the adhesion of the electrode paste on the first surface and the second surface, and can make the cross-sections of the first electrode and the second electrode more approximate to a rectangle, so as to improve the electrical conductivity of the first electrode and the second electrode, and further improve the power of the photovoltaic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 FIG. 9 is a schematic structural diagram of an embodiment of the photovoltaic cell provided by an embodiment of the present application; Figure 2 FIG. 12 is a schematic structural diagram of another embodiment of the photovoltaic cell provided by an embodiment of the present application; Figure 3 FIG. 15 is a schematic structural diagram of another embodiment of the photovoltaic cell provided by an embodiment of the present application; Figure 4 FIG. 18 is a schematic structural diagram of another embodiment of the photovoltaic cell provided by an embodiment of the present application; Figure 5 FIG. 21 is a schematic structural diagram of the first pyramid structure provided by an embodiment of the present application; Figure 6 FIG. 24 is a schematic structural diagram of the second pyramid structure provided by an embodiment of the present application; Figure 7 FIG. 27 is a flowchart of a method for manufacturing an embodiment of the photovoltaic cell provided by an embodiment of the present application; Figure 8 FIG. 30 is a flowchart of a method for manufacturing another embodiment of the photovoltaic cell provided by an embodiment of the present application; Figure 9 FIG. 33 is a flowchart of a method for manufacturing another embodiment of the photovoltaic cell provided by an embodiment of the present application; Figure 10Flow chart of the preparation method of another embodiment of the photovoltaic cell provided by the embodiment of the present application.

[0017] Reference numerals: 1 - Silicon substrate; 11 - First surface; 111 - First region; 112 - Second region; 113 - Emitter; 12 - Second surface; 121 - Third region; 122 - Fourth region; 123 - Passivated contact structure; 13 - First texturing structure; 14 - Second texturing structure; 2 - Passivation layer; 3 - Antireflection layer; 4 - First electrode; 5 - Second electrode. Detailed implementation manners

[0018] In order to better understand the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0019] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0020] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0021] It should be understood that the term " / and" used herein is only a description of the associated relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0022] Such as Figures 1 to 3As shown in the figure, an embodiment of the present application provides a photovoltaic cell, including a silicon substrate 1. The silicon substrate 1 includes a first surface 11. The first surface 11 includes a plurality of first regions 111 and a plurality of second regions 112, and the first regions 111 and the second regions 112 are alternately arranged. An emitter 113 is provided in the first region 111. A first electrode 4 is disposed in the first region 111 and is in electrical contact with the emitter 113. The emitter 113 can generate photo - carriers, and the photo - generated carriers are collected into the external circuit of the photovoltaic cell through the first electrode 4, thereby generating an electric current.

[0023] The silicon substrate 1 further includes a second surface 12. The second surface 12 includes a plurality of third regions 121 and a plurality of fourth regions 122, and the third regions 121 and the fourth regions 122 are alternately arranged. A passivated contact structure 123 is provided in the third region 121. The passivated contact structure 123 can first deposit an amorphous silicon layer or a microcrystalline silicon layer on the second surface, and then perform diffusion doping on the surface of the amorphous silicon layer or the microcrystalline silicon layer to form a poly layer. The doping concentration of the poly layer is between 1E19 cm -3 to 1E21 cm -3 Among them, the most preferred is 1E20 cm -3 to 5E20 cm -3 And the doping concentration of the poly layer is greater than the doping concentration in the silicon substrate 1 to form a high - low junction structure on the second surface, improving the passivation effect of the second surface 12. A second electrode 5 is disposed in the third region 121 and is in electrical contact with the passivated contact structure 123. The current generated in the photovoltaic cell can be transmitted to the external circuit through the second electrode 5.

[0024] Both the first region 111 and the third region 121 are of a first textured structure 13.

[0025] The first electrode 4 and the second electrode 5 can be disposed in the first region 111 and the third region 121 by screen - printing with electrode paste. The first textured structure 13 can enhance the adhesion of the electrode paste in the first region 111 and the third region 121, and can make the cross - section of the first electrode 4 and the second electrode 5 more approximate to a rectangle, so as to improve the conductive effect of the first electrode 4 and the second electrode 5, and further improve the power of the photovoltaic cell.

[0026] The present application does not limit the structure of the cell. The types of cells include but are not limited to tunnel oxide passivated contact (TOPCon) cells.

[0027] For a TOPCon cell, along its thickness direction, the TOPCon cell sequentially includes a metallic silver electrode, a front surface silicon nitride passivation layer, a boron-doped emitter, an N-type substrate silicon layer, a diffusion doping layer, an ultra-thin silicon oxide, doped polysilicon, silicon nitride, and a metallic silver electrode. The back surface of the cell is composed of an ultra-thin silicon oxide layer (1 nm - 2 nm) and a phosphorus-doped polysilicon layer, and the two together form a passivated contact structure. This structure can block the recombination of minority carriers (holes), improving the open-circuit voltage and short-circuit current of the cell. The ultra-thin oxide layer allows majority carriers (electrons) to tunnel into the polysilicon layer while blocking the recombination of minority carriers (holes). The good passivation effect of the ultra-thin silicon oxide and the heavily doped silicon thin film causes the energy band on the silicon wafer surface to bend, thus forming a field passivation effect, greatly increasing the probability of electron tunneling, reducing the contact resistance, improving the open-circuit voltage and short-circuit current of the cell, and thereby enhancing the conversion efficiency of the cell.

[0028] As Figures 1 to 4 shown, both the first surface 11 and the second surface 12 are provided with a first textured structure 13 and / or a second textured structure 14. The first textured structure 13 includes a plurality of first pyramid structures, and the second textured structure 14 includes a plurality of second pyramid structures.

[0029] As Figure 5 shown, in a possible embodiment, the base size of the first pyramid structure is 0.1 μm to 5 μm, and the tip angle is 10° to 70°.

[0030] The base size of the first pyramid structure can be 0.1 μm, 3 μm, 5 μm, etc. Compared with the pyramid structures in the related art, the base size of the first pyramid structure is smaller, and the number of first pyramid structures per unit area is larger. The tip angle can be 10°, 40°, 70°, etc. At the same time, there are a plurality of pits on the side wall of the first pyramid structure, forming wrinkles. The bottom wall of the pits on the side wall of the first pyramid structure can extend away from the silicon substrate, making the wrinkles into a barb structure, which can improve the adhesion ability of the electrode paste on the first textured structure 13. It can also enable light to refract multiple times within the first textured structure 13, reducing the reflectivity of the first textured structure 13 to 0.1% to 8%, improving the light absorption effect of the photovoltaic cell.

[0031] The smaller base of the first pyramid structure makes the density of the first pyramid structures in the first textured structure 13 per unit area higher. At the same time, the side wall of the first pyramid structure has wrinkles, which is more convenient for the adhesion of the electrode paste, and its adhesion can be increased by 10% to 50%. After the paste is cured to form the first electrode 4 and the second electrode 5, the strength of the first electrode 4 and the second electrode 5 is increased.

[0032] The density of the first pyramid structure per unit area of the first suede structure 13 is relatively high. After the electrode paste is coated on the first suede surface, affected by the surface tension of the electrode paste, the cross-section of the solidified electrode paste approaches a rectangle, increasing the cross-sectional area of the electrode to improve the conductivity of the first electrode 4 and the second electrode 5.

[0033] In a possible embodiment, the widths of both the first region 111 and the third region 121 are from 10 μm to 200 μm. In the same photovoltaic cell, the widths of the first region 111 and the third region 121 can be the same or different, which is not limited herein.

[0034] The emitter 113 is disposed in the first region 111, and the passivated contact structure 123 is disposed in the third region 121. If the widths of the first region 111 and the third region 121 are less than 10 μm, the generated photo-generated carriers are insufficient, resulting in a small current generated by the photovoltaic cell. The reflectivity of the first suede structure 13 is relatively low, which may cause excessive recombination at the position where the first suede structure 13 is provided, resulting in a reduction in the efficiency of the photovoltaic cell. The first suede structure 13 is provided in both the first region 111 and the third region 121. If the widths of the first region 111 and the third region 121 are greater than 200 μm, it will cause excessive recombination in the photovoltaic cell, resulting in a reduction in the efficiency of the photovoltaic cell. The first electrode 4 is disposed in the first region 111, and the second electrode 5 is disposed in the third region 121. The first suede structure 13 can improve the adhesion of the first electrode 4 and the second electrode 5, and can also improve the conductivity efficiency of the first electrode 4 and the second electrode 5, improving the efficiency of the photovoltaic cell. The widths of the first region 111 and the third region 121 can be 10 μm, 100 μm, 200 μm, etc. Considering the influence of the first suede structure 13 on the efficiency of the photovoltaic cell, the first suede structure 13 can improve the efficiency of the photovoltaic cell.

[0035] As Figure 6 shown, in a possible embodiment, the base size of the second pyramid structure is from 0.1 μm to 5 μm, the apex angle is from 10° to 90°, and the apex angle of the second pyramid structure is greater than the apex angle of the first pyramid.

[0036] The base size of the second pyramid structure can be 0.1 μm, 3 μm, 5 μm, etc. Compared with the pyramid structure in the related art, the base size of the second pyramid structure is smaller, and the number of second pyramid structures per unit area of the second suede structure 14 is larger, facilitating the adhesion of the electrode paste.

[0037] The angles of the pyramid tips can be 10°, 50°, 90°, etc. At the same time, the side walls of the second pyramid structure have wrinkles (not shown in the figure). The wrinkles on the side walls of the second pyramid are light-trapping structure wrinkles, enabling light to be reflected multiple times within the second textured surface structure 14, reducing the reflectivity of the second textured surface structure 14, making the reflectivity of the second textured surface structure 14 range from 4% to 14%, and improving the light absorption effect of the photovoltaic cell. As Figure 6 shown, in a possible embodiment, both the tips and edges of the second pyramid structure are arc-shaped structures. The arc angles of the pyramid tips and the arc angles of the pyramid edges are both 10° to 150°.

[0038] Both the tips and edges of the second pyramid structure are arc-shaped structures. At the same time, the angle between two opposite side walls of the second pyramid structure is greater than the angle between two opposite side walls of the first pyramid, making the reflectivity of the second textured surface structure 14 less than that of the textured surface structure in the related art and greater than that of the first textured surface structure 13. Thus, the second textured surface structure 14 has a better light absorption effect, and at the same time has a smaller impact on the excessive recombination of carriers in the photovoltaic cell, which is beneficial to improving the power generation efficiency of the photovoltaic cell.

[0039] As Figures 1 to 3 shown, in the photovoltaic cell, the fourth region 122 is any one of the first textured surface structure 13, the second textured surface structure 14, and the polished structure.

[0040] As Figure 1 shown, in a possible embodiment, in the first surface 11 of the photovoltaic cell, the first region 111 is the first textured surface structure 13, and the second region 112 is the second textured surface structure 14; in the second surface 12, the third region 121 is the first textured surface structure 13, and the fourth region 122 is the second textured surface structure 14.

[0041] The first electrode 4 is disposed in the first region 111. The first textured surface structure 13 can improve the adhesion of the electrode paste and the conductivity efficiency of the first electrode 4 after curing, so as to improve the power generation efficiency of the photovoltaic cell. The second textured surface can improve the light absorption effect of the first surface 11 and at the same time reduce the carrier recombination on the first surface 11, so as to improve the power generation efficiency of the photovoltaic cell. The second electrode 5 is disposed in the third region 121. The first textured surface structure 13 can improve the adhesion of the electrode paste and the conductivity efficiency of the second electrode 5 after curing, so as to improve the power generation efficiency of the photovoltaic cell. The second textured surface can improve the light absorption effect of the second surface 12, increase the bifaciality of the photovoltaic cell, and can also reduce the carrier recombination on the second surface 12, so as to improve the power generation efficiency of the photovoltaic cell. At the same time, it can also improve the open-circuit voltage and fill factor of the photovoltaic cell.

[0042] As Figure 2As shown, in a possible embodiment, the first region 111 in the first surface 11 of the photovoltaic cell is a first textured structure 13, and the second region 112 is a second textured structure 14; the third region 121 in the second surface 12 is a first textured structure 13, and the fourth region 122 is also a first textured structure 13.

[0043] The first electrode 4 is disposed in the first region 111. The first textured structure 13 can improve the adhesion of the electrode paste and the conduction efficiency of the first electrode 4 after curing, so as to improve the power generation efficiency of the photovoltaic cell. The second textured surface can improve the light absorption effect of the first surface 11 and at the same time reduce the carrier recombination of the first surface 11, so as to improve the power generation efficiency of the photovoltaic cell. The second electrode 5 is disposed in the third region 121. The first textured structure 13 can improve the adhesion of the electrode paste and the conduction efficiency of the second electrode 5 after curing, and at the same time can also improve the open voltage and fill factor of the photovoltaic cell, so as to improve the power generation efficiency of the photovoltaic cell. The second surface 12 of the photovoltaic cell has a passivation film layer with good passivation effect. Therefore, the textured structure of the second surface 12 has little influence on the passivation effect of the second surface 12. The reflectivity of the first textured structure 13 is less than that of the second textured structure 14. The fourth region 122 is also a first textured structure 13, which can improve the light absorption efficiency of the second surface 12 and further improve the bifaciality of the photovoltaic module.

[0044] As Figure 3 shown, in a possible embodiment, the first region 111 in the first surface 11 of the photovoltaic cell is a first textured structure 13, and the second region 112 is a second textured structure 14; the third region 121 in the second surface 12 is a first textured structure 13, and the fourth region 122 is a polished structure.

[0045] The first electrode 4 is disposed in the first region 111 on the first surface 11. The first textured structure 13 can improve the adhesion of the electrode paste and the conduction efficiency of the first electrode 4 after curing, and at the same time can also improve the open voltage and fill factor of the photovoltaic cell, so as to improve the power generation efficiency of the photovoltaic cell. The second textured surface can improve the light absorption effect of the first surface 11 and at the same time reduce the carrier recombination of the first surface 11, so as to improve the power generation efficiency of the photovoltaic cell. The second electrode 5 is disposed in the third region 121 on the second surface 12. The first textured structure 13 can improve the adhesion of the electrode paste and the conduction efficiency of the second electrode 5 after curing, so as to improve the power generation efficiency of the photovoltaic cell. In the second surface 12, the fourth region 122 is a polished structure, which can improve the passivation effect of the second surface 12.

[0046] As Figure 4As shown, in a possible embodiment, the first region 111 in the first surface 11 of the photovoltaic cell is the second textured structure 14, and the second region 112 is also the second textured structure 14; the third region 121 in the second surface 12 is the first textured structure 13, and the fourth region 122 is also the first textured structure 13.

[0047] Both the first region 111 and the second region 112 in the first surface 11 are the second textured structure 14. While improving the light absorption effect of the first surface 11, it can also reduce the possibility of excessive recombination in the emitter 113 region. The reflectivity of the first textured structure 13 is less than that of the second textured structure 14. Both the third region 121 and the fourth region 122 in the second surface 12 are the first textured structure 13, which can improve the bifaciality of the photovoltaic cell.

[0048] The embodiment of the present application also provides a preparation method of a photovoltaic cell for preparing the above photovoltaic cell. As Figures 7 to 9 shown, the preparation method of the photovoltaic cell includes: Prepare the silicon substrate 1; Prepare the first textured structure 13 on both the first surface 11 and the second surface 12 of the silicon substrate 1; Prepare the first doping layer on the first surface 11 to form the emitter 113; Remove the first doping layer on the second surface 12; Prepare the second doping layer on the second surface 12 to form the passivated contact structure 123 on the second surface 12; Perform laser grooving on the second region 112 and the fourth region 122 to remove the first doping layer in the second region 112 and the second doping layer in the fourth region 122 to form grooves; Prepare a textured structure or a polished structure in the grooves; Prepare the passivation layer 2 and the antireflection layer 3 on the first surface 11 and the second surface 12 in sequence; Prepare the first electrode 4 in the first region 111 and the second electrode 5 in the third region 121.

[0049] Taking the N-type silicon base as an example, the first doping layer can be prepared on the first surface 11 through boron diffusion. At this time, the first doping layer will also be formed on the second surface 12. Before removing the second doping layer on the second surface 12, the first doping layer on the second surface 12 can be etched by chain pickling with an acidic solution such as hydrofluoric acid to etch away the first doping layer on the second surface 12, exposing the silicon substrate 1 on the second surface 12, and enabling the second surface 12 to still have the first textured structure 13.

[0050] When preparing the second doping layer on the second surface 12, the amorphous silicon layer can be deposited on the second surface 12 by LPCVD, and then the amorphous silicon layer can be converted into the second doping layer through phosphorus diffusion.

[0051] The first doping layer and the second doping layer can be removed by laser. The depth of laser etching can be 10 μm to 200 μm, exposing the silicon substrate 1 in the second region 112 and the silicon substrate 1 in the fourth region 122, facilitating secondary texturing on the exposed silicon substrate 1. The intensity of the middle region and the edge region of the laser is different, and the intensity of the edge region is smaller. Therefore, the grooving effect is different, making the side wall of the groove a ramp-like structure, which can increase the light-receiving area in the groove, thereby improving the light absorption efficiency of the photovoltaic cell. A textured structure or a polished structure is prepared in the groove to improve the performance of the photovoltaic cell and its power generation efficiency.

[0052] In a possible embodiment, when the passivation layer 2 and the antireflection layer 3 are sequentially prepared on the first surface 11 and the second surface 12, the passivation layer 2 can be deposited on the first surface 11 and the second surface 12 by ALD process. The passivation layer 2 can be an alumina layer to improve the passivation effect of the photovoltaic cell. Then, the antireflection layer 3 is deposited on the first surface 11 and the second surface 12 by PECVD. The antireflection layer 3 can be a silicon nitride layer to reduce the reflectivity of the first surface 11 and the second surface 12 of the photovoltaic cell, thereby improving the light absorption effect of the photovoltaic module.

[0053] When preparing the first electrode 4 and the second electrode 5, the electrode paste can be disposed in the first region 111 or the third region 121 by screen printing.

[0054] As Figure 1 and Figure 7 shown, when in the first surface 11 of the photovoltaic cell, the first region 111 is the first textured structure 13 and the second region 112 is the second textured structure 14; in the second surface 12, the third region 121 is the first textured structure 13 and the fourth region 122 is the second textured structure 14, the preparation method for preparing a textured structure or polishing in the groove includes: Preparing the second textured structure 14 in the grooves on both the first surface 11 and the second surface 12.

[0055] After laser grooving, the photovoltaic cell is placed in a texturing solvent, and the texturing solvent will etch the exposed silicon substrate 1 at the bottom of the groove to form the second textured structure 14 in the groove. It can be adjusted by adjusting the content of each substance in the texturing solution to etch out the second pyramid structure. The shape of the pyramid structure after texturing can be adjusted by adding additives to the texturing solvent. The tips and edges of the second pyramid structure in the second textured structure 14 are both arc-shaped surfaces. Additives such as high-temperature rounding, ozone in-situ rounding, and rounding additives can be added to the texturing solution.

[0056] As Figure 2 and Figure 8As shown, when the first region 111 in the first surface 11 of the photovoltaic cell is the first texture structure 13, the second region 112 is the second texture structure 14; the third region 121 in the second surface 12 is the first texture structure 13, and the fourth region 122 is also the first texture structure 13, when preparing a texture structure or polishing in the grooves, the preparation method includes: Prepare a second texture in the grooves of the first surface 11; Prepare a first texture in the grooves of the second surface 12.

[0057] By means of chain texturing, the texturing solution for etching the inner wall of the grooves on the first surface 11 is different from the texturing solution for etching the inner wall of the grooves on the second surface 12, facilitating the formation of a second texture in the grooves of the first surface 11 and a first texture in the grooves of the second surface 12.

[0058] Such as Figure 3 and Figure 9 As shown, when the first region 111 in the first surface 11 of the photovoltaic cell is the first texture structure 13, the second region 112 is the second texture structure 14; the third region 121 in the second surface 12 is the first texture structure 13, and the fourth region 122 is a polishing structure, when preparing a texture structure or polishing in the grooves, the preparation method includes: Prepare a second texture in the grooves of the first surface 11; Prepare a polishing structure in the grooves of the second surface 12.

[0059] Prepare a second texture in the grooves of the first surface 11 by means of chain texturing, reducing the possibility of the texturing solution affecting the inner wall of the grooves on the second surface 12. Prepare a polishing structure in the grooves of the second surface 12 by means of chain processing, making the surface structure in the grooves of the first surface 11 different from the surface structure in the grooves of the second surface 12.

[0060] Such as Figure 4 and Figure 10 As shown, when the first region 111 in the first surface 11 of the photovoltaic cell is the second texture structure 14, the second region 112 is also the second texture structure 14; the third region 121 in the second surface 12 is the first texture structure 13, and the fourth region 122 is also the first texture structure 13, the preparation method of the photovoltaic cell includes: Prepare a silicon substrate 1; Prepare a second texture structure 14 on both the first surface 11 and the second surface 12 of the silicon substrate 1; Prepare a first doping layer on the first surface 11 to form an emitter 113; Remove the first doping layer on the second surface 12; Prepare a first texture structure 13 on the second surface 12; A second doped layer is prepared on the second surface 12 to form a passivated contact structure 123 on the second surface 12; Laser grooving is performed in the second region 112 and the fourth region 122 to remove the first doped layer in the second region 112 and the second doped layer in the fourth region 122, so that the emitters 113 on the first surface 11 are arranged at intervals, and the passivated contact structures 123 on the second surface 12 are also arranged at intervals, and grooves are formed between adjacent emitters 113 and between adjacent passivated contact structures 123; A second textured structure 14 is prepared in the grooves on the first surface 11, and a first textured structure 13 is prepared in the grooves on the second surface 12; A passivation layer 2 and an antireflection layer 3 are sequentially prepared on the first surface 11 and the second surface 12; A first electrode 4 is prepared in the first region 111, and a second electrode 5 is prepared in the third region 121.

[0061] After removing the first doped layer on the second surface 12, a first textured structure 13 is prepared on the second surface 12, so that the third region 121 of the second surface 12 is the first textured structure 13, which is beneficial to improving the bifaciality of the photovoltaic cell.

[0062] This application relates to a photovoltaic cell and a method for manufacturing the photovoltaic cell. The photovoltaic cell includes a silicon substrate 1. The silicon substrate 1 includes a first surface 11 and a second surface 12. The first surface 11 includes a plurality of first regions 111 and a plurality of second regions 112. The first regions 111 and the second regions 112 are alternately arranged. The first regions 111 are provided with emitters 113. The second surface 12 includes a plurality of third regions 121 and a plurality of fourth regions 122. The third regions 121 and the fourth regions 122 are alternately arranged. The third regions 121 are provided with passivated contact structures 123 to improve the passivation effect of the second surface 12. Both the first regions 111 and the third regions 121 are the first textured structures 13. The first electrode 4 is disposed in the first region 111 and is in electrical contact with the emitter 113. The second electrode 5 is disposed in the third region 121 and is in electrical contact with the passivated contact structure 123. The first textured structure 13 can enhance the adhesion of the electrode paste on the first surface 11 and the second surface 12, and can make the cross-sections of the first electrode 4 and the second electrode 5 more approximate to rectangles, so as to improve the conductive effect of the first electrode 4 and the second electrode 5, and further improve the power of the photovoltaic cell.

Claims

1. A photovoltaic cell, characterized in that: The photovoltaic cell comprises: A silicon substrate, the silicon substrate comprising a first surface and a second surface; The first surface includes a plurality of first regions and a plurality of second regions, the first regions and the second regions are arranged alternately, and the first regions are provided with a plurality of emitters; The second surface includes a plurality of third regions and a plurality of fourth regions, the third regions and the fourth regions are arranged alternately, and the third regions are provided with a passivation contact structure; a first electrode, the first electrode being disposed in the first region and electrically connected to the emitter; a second electrode, the second electrode being disposed in the third region and electrically connected to the passivation contact structure; Wherein, the first region and the third region are both first suede structures.

2. The photovoltaic cell according to claim 1, characterized in that: The width of the first region and the width of the third region are both 10 μm to 200 μm.

3. The photovoltaic cell according to claim 1, characterized in that: The fourth region is any one of the first suede structure, the second suede structure, and the polished structure.

4. The photovoltaic cell according to claim 3, characterized in that: The first suede structure includes a plurality of first pyramid structures, and the second suede structure includes a plurality of second pyramid structures; the side walls of the first pyramid structures and the side walls of the second pyramid structures both have wrinkles.

5. The photovoltaic cell according to claim 4, characterized in that: The spire angle of the first pyramid structure is 10° to 70°; the spire angle of the second pyramid structure is 10° to 90°; and the spire angle of the second pyramid structure is greater than the spire angle of the first pyramid structure.

6. The photovoltaic cell according to claim 4, characterized in that: The top and the edges of the second pyramid structure are both curved structures, and the angle of the curved surface is 10° to 150°.

7. The photovoltaic cell according to any one of claims 3 to 6, characterized in that: The reflectivity of the first velvet structure is 0.1% to 8%, and the reflectivity of the second velvet structure is 4% to 14%; and the reflectivity of the second velvet structure is greater than the reflectivity of the first velvet structure.

8. A method for preparing a photovoltaic cell, for preparing the photovoltaic cell according to any one of claims 1 to 7, characterized in that: The preparation method comprises: preparing a silicon substrate; A first velvet structure is prepared on both the first surface and the second surface of the silicon substrate; Preparing a first doping layer on the first surface to form an emitter; removing the first doping layer on the second surface; Prepare a second doping layer on the second surface to form a passivation contact structure on the second surface; Performing laser grooving in the second region and the fourth region to form grooves; Preparing a velvet structure or a polished structure in the groove; Sequentially prepare a passivation layer and an anti-reflection layer on the first surface and the second surface; Electrodes are prepared at the emitter and at the passivation contact structure.

9. The method for preparing a photovoltaic cell according to claim 8, characterized in that: When a suede structure or polishing is prepared in a groove, the preparation method comprises: A second velvet structure is prepared in the grooves of the first surface and in the grooves of the second surface.

10. The method for preparing a photovoltaic cell according to claim 8, characterized in that: When a suede structure or polishing is prepared in a groove, the preparation method comprises: preparing a second suede surface in the groove of the first surface; A first velvet surface is prepared in the grooves of the second surface.

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