Photovoltaic cell and preparation method thereof

Abstract

The invention relates to a photovoltaic cell piece and a preparation method, the preparation method comprises the steps that a laminated structure is formed on a silicon substrate, the laminated structure comprises a first tunneling layer, a second tunneling layer, a first doping layer, a third tunneling layer and a second doping layer which are arranged in a laminated mode, the first tunneling layer is adjacent to the silicon substrate, and the second tunneling layer is adjacent to the third tunneling layer; a mask layer is formed on the side, away from the third tunneling layer, of the second doping layer, the part, located in the non-metallization area, of the mask layer is removed through laser to form a patterned mask layer, and at least part, located in the non-metallization area, of the laminated structure is removed through laser to form a patterned laminated structure, and removing the patterned mask layer by using an acid solution, and depositing a passivation layer on the patterned laminated structure to form a metal electrode in ohmic contact with a doping layer included in the patterned laminated structure. The photovoltaic cell prepared according to the preparation method provided by the invention can have relatively high photoelectric conversion efficiency and fill factor.

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic cells, and particularly to a photovoltaic cell and a preparation method thereof. Background Art

[0002] Photovoltaic cells are used to convert light energy into electrical energy, and the photoelectric conversion efficiency of photovoltaic cells is affected by the thickness dimension of the tunneling oxide passivation contact structure. In the related art, when the tunneling oxide passivation contact structure is relatively thin, the tunneling oxide passivation contact structure is easily burned through by the metal electrode, and there are relatively many recombination centers at the interface between the silicon substrate and the tunneling oxide passivation contact structure. The recombination rate of electrons and holes is relatively high, resulting in a relatively low photoelectric conversion efficiency. Summary of the Invention

[0003] In view of this, this application provides a photovoltaic cell and a preparation method thereof, which can improve the problem of relatively low photoelectric conversion efficiency.

[0004] In a first aspect, the present application provides a method for preparing a photovoltaic cell. The preparation method includes: forming a stacked structure on a silicon substrate, the stacked structure including a first tunneling layer, a second tunneling layer, a first doping layer, a third tunneling layer, and a second doping layer that are stacked, the first tunneling layer being adjacent to the silicon substrate; forming a mask layer on a side of the second doping layer facing away from the third tunneling layer; using a laser to remove a part of the mask layer located in a non-metallization area to form a patterned mask layer; using a laser to remove at least a part of the structure of the stacked structure located in the non-metallization area to form a patterned stacked structure; using an acid solution to remove the patterned mask layer; depositing a passivation layer on the patterned stacked structure; and forming a metal electrode that makes an ohmic contact with the doping layer included in the patterned stacked structure. On the one hand, during the process of forming the metal electrode, the patterned stacked structure can reduce the possibility that the uncured material (such as fluid materials like paste and ink) used to form the metal electrode extends to the interface between the patterned stacked structure and the silicon substrate, so as to reduce the number of defects that can be generated at the interface between the patterned stacked structure and the silicon substrate, reduce the number of recombination centers that can be generated, and thus reduce the recombination rate of electrons and holes in the photovoltaic cell to be prepared. On the other hand, since at least a part of the structure of the stacked structure located in the non-metallization area is removed during the preparation process, the subsequent formed patterned stacked structure can be not located in the non-metallization area but in the area to be metallized, or the thickness of the part of the patterned stacked structure located in the non-metallization area is smaller than the thickness of the part of the patterned stacked structure located in the area to be metallized. Therefore, in the photovoltaic cell to be prepared subsequently, the degree of parasitic absorption (light absorption that does not generate electron-hole pairs) of the light on the backlight side by the patterned stacked structure is relatively small, the amount of light on the backlight side that can enter the silicon substrate is relatively large, and the number of photo-generated electrons and photo-generated holes generated in the silicon substrate is relatively large. Therefore, the photovoltaic cell prepared according to the preparation method of the present application can have a high photoelectric conversion efficiency (measuring the ability of the cell to convert light energy into electrical energy).

[0005] Optionally, the method for forming a mask layer on a side of the second doping layer facing away from the third tunneling layer includes: forming the mask layer by plasma enhanced chemical vapor deposition.

[0006] Optionally, the method for using a laser to remove at least a part of the structure of the stacked structure located in the non-metallization area includes: using a laser to remove the part of the second doping layer located in the non-metallization area to form a patterned stacked structure including a patterned second doping layer.

[0007] Optionally, the method of the present application further includes: after forming the patterned stacked structure including the patterned second doping layer, removing the patterned mask layer with an acid solution, and removing the part of the third tunneling layer located in the non-metallized area with the acid solution, so as to form a patterned stacked structure further including the patterned third tunneling layer.

[0008] Optionally, the method of removing at least part of the structure located in the non-metallized area in the stacked structure by using a laser includes: successively removing the part of the second doping layer located in the non-metallized area, the part of the third tunneling layer located in the non-metallized area, and the part of the first doping layer located in the non-metallized area with the laser, so as to form a patterned stacked structure including the patterned second doping layer, the patterned third tunneling layer, and the patterned first doping layer; or, successively removing the part of the second doping layer located in the non-metallized area, the part of the third tunneling layer located in the non-metallized area, the part of the first doping layer located in the non-metallized area, and the part of the second tunneling layer located in the non-metallized area with the laser, so as to form a patterned stacked structure including the patterned second doping layer, the patterned third tunneling layer, the patterned first doping layer, and the patterned second tunneling layer.

[0009] Optionally, the method of the present application further includes: after forming the patterned stacked structure including the patterned second doping layer, the patterned third tunneling layer, and the patterned first doping layer, removing the patterned mask layer with an acid solution, and removing the part of the second tunneling layer located in the non-metallized area and the part of the first tunneling layer located in the non-metallized area with the acid solution, so as to form a patterned stacked structure further including the patterned second tunneling layer and the patterned first tunneling layer; or, after forming the patterned stacked structure including the patterned second doping layer, the patterned third tunneling layer, the patterned first doping layer, and the patterned second tunneling layer, removing the patterned mask layer with an acid solution, and removing the part of the first tunneling layer located in the non-metallized area with the acid solution, so as to form a patterned stacked structure further including the patterned first tunneling layer.

[0010] Optionally, the method of the present application further includes: texturing the surface of the silicon substrate before forming the stacked structure on the silicon substrate; before forming the patterned mask layer and before removing the patterned mask layer with an acid solution, removing all the structures located in the non-metallized area in the stacked structure with a laser, so as to form the patterned mask layer and expose the part of the textured surface of the silicon substrate located in the non-metallized area, and polishing the part of the textured surface of the silicon substrate located in the non-metallized area with an alkaline solution.

[0011] Optionally, before forming the stacked structure on the light-receiving side of the silicon substrate, forming an emitter layer on the light-receiving side of the silicon substrate, and forming a silicon glass layer on the side of the emitter layer facing away from the silicon substrate; and / or, after forming the stacked structure on the silicon substrate and before forming the patterned mask layer on the stacked structure, depositing mask layers on both the light-receiving side and the light-emitting side of the silicon substrate.

[0012] Optionally, the method for depositing a passivation layer on a patterned stack structure includes: depositing an aluminum oxide passivation layer on the patterned stack structure, and depositing a silicon nitride passivation layer on the aluminum oxide passivation layer.

[0013] In a second aspect, the present application provides a photovoltaic cell, which is prepared by the preparation method of the photovoltaic cell described above. Correspondingly, the photovoltaic cell has relatively high photoelectric conversion efficiency and fill factor.

[0014] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used 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 It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 2 It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 3 It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 4 It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 4a It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 5 It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 5a It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 6 It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 6a It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 7 It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 7a It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 7b It is a schematic structural diagram of a substrate in an embodiment of a preparation method; Figure 7c Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 7d Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 8 Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 8a Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 8b Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 9 Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 9a Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 9b Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 9c Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 10 Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 11 Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 11a Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 11b Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 11c Schematic structural diagram of the substrate in an embodiment of a preparation method; Figure 12 Schematic structural diagram of a photovoltaic cell in an embodiment; Figure 12a Schematic structural diagram of a photovoltaic cell in an embodiment; Figure 12b Schematic structural diagram of a photovoltaic cell in an embodiment; Figure 12c Schematic structural diagram of a photovoltaic cell in an embodiment; Figure 13 Partial structural schematic diagram of the first doping layer, the third tunneling layer, the second doping layer, the alumina passivation layer and the silicon nitride passivation layer.

[0017] Reference numerals: 10 - Substrate, 10a - Non - metallized region, 10b - Region to be metallized, 101 - Light - receiving side, 102 - Back - light side, 1 - Silicon substrate, 11 - Matt surface, 12 - Polished surface, 2 - Stacked structure, 2a - Patterned stacked structure, 21 - First tunneling layer, 21a - Patterned first tunneling layer, 22 - Second tunneling layer, 22a - Patterned second tunneling layer, 23 - First doping layer, 23a - Patterned first doping layer, 24 - Third tunneling layer, 24a - Patterned third tunneling layer, 25 - Second doping layer, 25a - Patterned second doping layer, 20 - Bypass plating layer, 3 - Mask layer, 3a - Patterned mask layer, 5a - Negative metal electrode, 5b - Positive metal electrode, 6 - Emitter layer, 60 - Bypass diffusion layer, 7 - Aluminum oxide passivation layer, 8 - Silicon nitride passivation layer. Detailed implementation manners

[0018] To better understand the technical solutions of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be clear that the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of this application. The terms used in the embodiments of this application are only for the purpose of describing specific embodiments, and are not intended to limit this application. The singular forms "a", "the" and "that" used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should be understood that the term " / " used herein generally represents an "or" relationship between the associated objects before and after.

[0019] In the accompanying drawings of this article, direction X is perpendicular to direction Y. Direction Y can represent the thickness direction of the photovoltaic cell, or direction Y can represent the thickness direction of the substrate. The substrate refers to the structure in any state before being prepared into a photovoltaic cell that can be put into use. Both the photovoltaic cell and the substrate can be preset with a light - receiving side and a back - light side, so as to Figure 1 Taking the substrate 10 shown as an example, the light - receiving side 101 is the side that will be directly irradiated by sunlight in the photovoltaic cell to be formed subsequently, and the back - light side 102 is the side that will not be directly irradiated by sunlight in the photovoltaic cell to be formed subsequently. The direction from the light - receiving side 101 to the back - light side 102 can represent direction Y. Taking Figure 1Taking the substrate 10 shown as an example, the substrate 10 may be preset with non-metallized regions 10a and regions to be metallized 10b that are alternately distributed in the direction X. The range of the projection of the metal electrode to be formed subsequently in the direction Y is within the region to be metallized 10b. The range of the projection of the metal electrode in the direction Y may be less than or equal to the range of the region to be metallized 10b, and the non-metallized region 10a does not overlap with the range of the projection of the metal electrode to be formed subsequently in the direction Y.

[0020] In a first aspect, the present application provides a preparation method for some photovoltaic cell wafers. The preparation method includes: on the basis of a substrate including a silicon substrate, forming a stacked structure on the silicon substrate. The stacked structure includes a first tunneling layer, a second tunneling layer, a first doping layer, a third tunneling layer, and a second doping layer that are stacked. The first tunneling layer is adjacent to the silicon substrate. A mask layer is formed on the side of the second doping layer facing away from the third tunneling layer. The portion of the mask layer located within the non-metallized region is removed by laser to form a patterned mask layer. At least a portion of the structure of the stacked structure located within the non-metallized region is removed by laser to form a patterned stacked structure. The patterned mask layer is removed by an acid solution. A passivation layer is deposited on the patterned stacked structure, and a metal electrode that forms an ohmic contact with the doping layer included in the patterned stacked structure is formed. On the one hand, during the process of forming the metal electrode, the patterned stacked structure can reduce the possibility that the uncured materials (such as fluids like slurries, inks, etc.) used to form the metal electrode extend to the interface between the patterned stacked structure and the silicon substrate, so as to reduce the number of defects that can be generated at the interface between the patterned stacked structure and the silicon substrate, reduce the number of recombination centers that can be generated, and thus reduce the recombination rate of electrons and holes in the photovoltaic cell wafer to be prepared. On the other hand, since at least a portion of the structure of the stacked structure located within the non-metallized region is removed during the preparation process, the subsequent formed patterned stacked structure can be not located within the non-metallized region but within the region to be metallized, or the thickness of the portion of the patterned stacked structure located within the non-metallized region is smaller than the thickness of the portion of the patterned stacked structure located within the region to be metallized. Therefore, in the photovoltaic cell wafer to be prepared subsequently, the degree of parasitic absorption (light absorption that does not generate electron-hole pairs) of the light on the backlight side by the patterned stacked structure is relatively small, the amount of light on the backlight side that can enter the silicon substrate is relatively large, and the number of photo-generated electrons and photo-generated holes generated in the silicon substrate is relatively large. Therefore, the photovoltaic cell wafer prepared according to some embodiments of the preparation method of the present application can have a relatively high photoelectric conversion efficiency (measuring the ability of the battery to convert light energy into electrical energy) and fill factor (characterizing the degree to which the output characteristics of the battery approach the ideal value).

[0021] Optionally, the method of using a laser to remove at least a part of the structure located in the non-metallized area in the stacked structure may include: using a laser to remove the part of the second doping layer located in the non-metallized area to form a patterned stacked structure including a patterned second doping layer. In this setting, the thickness of the part of the patterned stacked structure located in the non-metallized area can be made relatively small. In the subsequent photovoltaic cell to be fabricated, the degree of parasitic absorption that the patterned stacked structure can generate for the light located on the backlight side is relatively small.

[0022] Optionally, after forming the patterned stacked structure including the patterned second doping layer, use an acid solution to remove the patterned mask layer, and use an acid solution to remove the part of the third tunneling layer located in the non-metallized area to form a patterned stacked structure further including a patterned third tunneling layer. In this setting, on the one hand, the thickness of the part of the patterned stacked structure located in the non-metallized area can be made smaller. In the subsequent photovoltaic cell to be fabricated, the degree of parasitic absorption that the patterned stacked structure can generate for the light located on the backlight side is smaller. On the other hand, when pickling and removing the part of the third tunneling layer located in the non-metallized area, the patterned mask layer can be used to protect the patterned second doping layer, that is to say, the patterned mask layer is sacrificed to protect the patterned second doping layer.

[0023] Optionally, the method of using a laser to remove at least a part of the structure located in the non-metallized area in the stacked structure may include: using a laser to successively remove the part of the second doping layer located in the non-metallized area, the part of the third tunneling layer in the non-metallized area, and the part of the first doping layer located in the non-metallized area to form a patterned stacked structure including a patterned second doping layer, a patterned third tunneling layer, and a patterned first doping layer. In this setting, the thickness of the part of the patterned stacked structure located in the non-metallized area can be made relatively small, or, subsequently, the patterned stacked structure can be made to be not in the non-metallized area but in the area to be metallized. In the subsequent photovoltaic cell to be fabricated, the degree of parasitic absorption that the patterned stacked structure can generate for the light located on the backlight side is relatively small.

[0024] Optionally, after forming the patterned stacked structure including the patterned second doped layer, the patterned third tunneling layer, and the patterned first doped layer, the patterned mask layer is removed using an acid solution, and the portions of the second tunneling layer and the first tunneling layer located in the non-metallization region are removed using the acid solution to form a patterned stacked structure further including the patterned second tunneling layer and the patterned first tunneling layer. In this setting, on the one hand, the patterned stacked structure can be made to be located not in the non-metallization region but in the region to be metallized. In the photovoltaic cell to be prepared subsequently, the degree of parasitic absorption that the patterned stacked structure can generate for the light on the backlight side is smaller. On the other hand, when pickling and removing the portions of the second tunneling layer and the first tunneling layer located in the non-metallization region, the patterned mask layer can be used to protect the patterned second doped layer, that is to say, the patterned mask layer is sacrificed to protect the patterned second doped layer.

[0025] Optionally, the method of using a laser to remove at least part of the structure located in the non-metallization region in the stacked structure may include: using the laser to sequentially remove the portion of the second doped layer located in the non-metallization region, the portion of the third tunneling layer located in the non-metallization region, the portion of the first doped layer located in the non-metallization region, and the portion of the second tunneling layer located in the non-metallization region to form a patterned stacked structure including the patterned second doped layer, the patterned third tunneling layer, the patterned first doped layer, and the patterned second tunneling layer. In this setting, the thickness of the portion of the patterned stacked structure located in the non-metallization region can be made relatively small, or alternatively, the patterned stacked structure can be made to be located not in the non-metallization region but in the region to be metallized subsequently. In the photovoltaic cell to be prepared subsequently, the degree of parasitic absorption that the patterned stacked structure can generate for the light on the backlight side is relatively small.

[0026] Optionally, after forming the patterned stacked structure including the patterned second doped layer, the patterned third tunneling layer, the patterned first doped layer, and the patterned second tunneling layer, the patterned mask layer is removed using an acid solution, and the portion of the first tunneling layer located in the non-metallization region is removed using the acid solution to form a patterned stacked structure further including the patterned first tunneling layer. In this setting, on the one hand, the patterned stacked structure can be made to be located not in the non-metallization region but in the region to be metallized. In the photovoltaic cell to be prepared subsequently, the degree of parasitic absorption that the patterned stacked structure can generate for the light on the backlight side is smaller. On the other hand, when pickling and removing the portion of the first tunneling layer located in the non-metallization region, the patterned mask layer can be used to protect the patterned second doped layer, that is to say, the patterned mask layer is sacrificed to protect the patterned second doped layer.

[0027] Optionally, before forming the stacked structure, the surface of the silicon substrate is textured. Subsequently, the formed stacked structure will also have a textured surface, and each layer structure within the stacked structure will also have a textured surface. After forming the patterned mask layer and before removing the patterned mask layer using an acid solution, all structures within the non-metallized region of the stacked structure are removed using a laser to form a patterned mask layer within the region to be metallized and a patterned stacked structure within the region to be metallized, and a portion of the textured surface of the silicon substrate near the backlight side within the non-metallized region is exposed. The portion of the textured surface of the silicon substrate near the backlight side within the non-metallized region is polished using an alkaline solution to remove the damage to the exposed surface of the silicon substrate within the non-metallized region, thereby reducing defects and accordingly reducing the number of recombination centers. After polishing, a polished surface within the non-metallized region is also formed. Additionally, each layer structure within the patterned stacked structure within the region to be metallized still has a uniform textured surface, which can improve the bonding force between the doped layer (such as at least one of the patterned first doped layer and the patterned second doped layer) within the patterned stacked structure and the metal electrode, and reduce the contact resistance between the doped layer within the patterned stacked structure and the metal electrode during the subsequent formation of the metal electrode. If the process of forming the metal electrode uses an electroplated copper process, the bonding force between the doped layer with a textured surface within the patterned stacked structure and the metal electrode is greater, and the contact resistance between the doped layer with a textured surface within the patterned stacked structure and the metal electrode is smaller. Therefore, the photovoltaic cell prepared according to some embodiments of the preparation method of the present application can have a relatively high photoelectric conversion efficiency (measuring the ability of the battery to convert light energy into electrical energy) and fill factor (characterizing the degree to which the battery output characteristics approach the ideal value).

[0028] Optionally, before forming the stacked structure on the backlight side of the silicon substrate, an emitter layer is formed on the light-receiving side of the silicon substrate, and a silicon glass layer is formed on the side of the emitter layer facing away from the silicon substrate. The silicon glass layer can be used to protect the emitter layer from being easily corroded by corrosive alkaline or acid solutions during subsequent wet processing.

[0029] Among them, the method of forming the silicon glass layer can include: introducing oxygen during the process of forming the emitter layer using a diffusion process to form the silicon glass layer, and / or introducing oxygen after forming the emitter layer using a diffusion process to form the silicon glass layer. Correspondingly, the silicon glass layer can be borosilicate glass or phosphosilicate glass.

[0030] Optionally, after forming the stacked structure on the silicon substrate and before forming the patterned mask layer on the stacked structure, a mask layer is deposited on both the light-receiving side and the backlight side of the silicon substrate. The mask layer on the backlight side is subsequently used to be selectively removed by a laser to become a patterned mask layer, and the mask layer on the light-receiving side can protect the emitter layer from being easily corroded by corrosive alkaline or acid solutions during subsequent wet processing.

[0031] In some embodiments, the preparation method may include the following: Providing or forming a substrate 10 as Figure 1 shown, where the substrate 10 includes a silicon substrate 1. Herein, the silicon substrate 1 may also be referred to as a silicon wafer. The silicon substrate 1 may include an N-type substrate, that is, the silicon substrate 1 may be doped with at least one N-type element (elements in Group V of the periodic table of chemical elements), such as N-type elements like phosphorus, arsenic, antimony, etc.

[0032] Cleaning the silicon substrate 1 as Figure 1 shown with an alkaline solution containing a texturing additive to remove mechanical damage on the surface of the silicon substrate 1 and form a textured surface 11 (with multiple micron-sized grooves and protrusions) on both side surfaces of the silicon substrate 1 as Figure 2 shown.

[0033] Forming an emitter layer 6 as Figure 3 shown on the textured surface 11 of the silicon substrate 1 near the light-receiving side by a diffusion process. The emitter layer 6 may also be referred to as a diffusion layer. The emitter layer 6 may include P-type elements, that is, the emitter layer 6 may be doped with at least one P-type element (elements in Group III of the periodic table of chemical elements), such as P-type elements like boron, aluminum, gallium, etc.

[0034] Polishing the textured surface of the silicon substrate 1 near the backlight side as Figure 3 shown with an alkaline solution containing a polishing additive and removing the bypass diffusion layer 60 (an additional structure formed when forming the emitter layer 6) to form a polished surface 12 of the silicon substrate 1 near the backlight side as Figure 4 shown.

[0035] Please refer to Figure 5 shown to form a stacked structure 2 on the polished surface of the silicon substrate 1 near the backlight side. The stacked structure 2 may include a first tunneling layer 21, a second tunneling layer 22, a first doped layer 23, a third tunneling layer 24, and a second doped layer 25 that are stacked. The first tunneling layer 21 is adjacent to the silicon substrate 1. The first tunneling layer 21, the second tunneling layer 22, a first dielectric layer (the structure before forming the first doped layer by the diffusion process), the third tunneling layer 24, and a second dielectric layer (the structure before forming the second doped layer by the diffusion process) may be sequentially deposited by Low Pressure Chemical Vapor Deposition (LPCVD). Then, impurities containing N-type elements are diffused into the first dielectric layer and the second dielectric layer by a diffusion process to transform the first dielectric layer into the first doped layer 23 and the second dielectric layer into the second doped layer 25.

[0036] The processes for depositing the first tunneling layer 21, depositing the second tunneling layer 22, depositing the first dielectric layer, depositing the third tunneling layer 24, and depositing the second dielectric layer are not limited to low-pressure chemical vapor deposition. Plasma Enhanced Chemical Vapor Deposition (PECVD) or Atmospheric Pressure Chemical Vapor Deposition (APCVD) can also be selected.

[0037] Please refer to Figure 5 As shown, the deposited first tunneling layer 21 may include silicon oxide (SIO), silicon nitride (‌Si 3 N 4 ‌), silicon oxynitride (SiON), or silicon oxycarbide (SiOC). The thickness dimension (dimension along the Y direction) of the first tunneling layer 21 can be in the range of 0.5 nm to 1.5 nm. Specifically, the thickness dimension of the first tunneling layer 21 can be 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, or 1.5 nm.

[0038] Please refer to Figure 5 As shown, the deposited second tunneling layer 22 may include silicon oxide, silicon nitride, silicon oxynitride, or silicon oxycarbide. The thickness dimension (dimension along the Y direction) of the second tunneling layer 22 can be in the range of 0.1 nm to 3 nm. Specifically, the thickness dimension of the second tunneling layer 22 can be 0.1 nm, 0.2 nm, 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, 1.8 nm, 1.9 nm, 2 nm, 2.1 nm, 2.2 nm, 2.3 nm, 2.4 nm, 2.5 nm, 2.6 nm, 2.7 nm, 2.8 nm, 2.9 nm, or 3 nm.

[0039] Please refer to Figure 5 As shown, the deposited first doping layer 23 may include at least one of amorphous silicon, polycrystalline silicon, and microcrystalline silicon. At least one N-type element (the fifth main group element in the periodic table of chemical elements), such as N-type elements like phosphorus, arsenic, and antimony, can be doped in the first doping layer 23. Accordingly, the concentration of the N-type element doped in the first doping layer 23 needs to be greater than the concentration of the N-type element doped in the silicon substrate 1. Therefore, the first doping layer 23 is a heavily doped region relative to the silicon substrate 1.

[0040] Please refer toFigure 5 As shown, the deposited and formed third tunneling layer 24 may include silicon oxide, silicon nitride, silicon oxynitride, or silicon carbonitride. The thickness dimension (dimension along the Y direction) of the third tunneling layer 24 may be in the range of 0.8 nm to 2 nm, and the thickness dimension of the third tunneling layer 24 may specifically be 0.8 nm, 0.9 nm, 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, 1.8 nm, 1.9 nm, or 2 nm.

[0041] Please refer to Figure 5 As shown, the deposited and formed second doped layer 25 may include at least one of amorphous silicon, polycrystalline silicon, and microcrystalline silicon. At least one N-type element (the elements in the fifth main group of the periodic table of chemical elements), such as N-type elements like phosphorus element, arsenic element, antimony element, etc., may be doped in the second doped layer 25. Correspondingly, the concentration of the N-type element doped in the second doped layer 25 is greater than the concentration of the N-type element doped in the first doped layer 23. Therefore, the second doped layer 25 is a heavily doped region relative to the first doped layer 23.

[0042] The first tunneling layer 21, the second tunneling layer 22, and the first doped layer 23 may serve as a tunneling oxide passivated contact structure (Tunnel Oxide Passivated Contact, TOPCon) in the photovoltaic cell to be prepared subsequently, and the tunneling oxide passivated contact structure may also be simply referred to as a tunneling passivated contact structure. The tunneling oxide passivated contact structure is used to provide field passivation, chemical passivation, and selective carrier passing effects. The third tunneling layer 24 and the second doped layer 25 may also serve as a tunneling oxide passivated contact structure in the photovoltaic cell to be prepared subsequently. It can also be said that Figure 5 the stacked structure 2 shown may serve as a stacked tunneling oxide passivated contact structure or a double tunneling oxide passivated contact structure in the photovoltaic cell to be prepared subsequently.

[0043] After forming the stacked structure 2 as Figure 5 shown, a mask layer 3 as Figure 6 shown is formed on the side of the second doped layer 25 facing away from the third tunneling layer 24.

[0044] The mask layer 3 may be formed by plasma-enhanced chemical vapor deposition, or alternatively, the mask layer 3 may be formed by atomic layer deposition (ALD), or the mask layer 3 may be formed by photoresist.

[0045] The subsequent content of this article mainly describes by taking "forming the mask layer by plasma-enhanced chemical vapor deposition" as an example. Correspondingly, the material of the mask layer 3 may include silicon oxide or silicon oxynitride.

[0046] In the formation of Figure 6 After forming the mask layer 3 as shown, the portion of the mask layer 3 located in the non-metallized area 10a is removed by laser to form a Figure 7 The patterned mask layer 3a is shown.

[0047] In the formation of Figure 6 After the mask layer 3 is formed, a portion of the second doping layer 25 located in the non-metallized area 10a is removed by laser to form a Figure 7 The patterned second doping layer 25a shown in FIG. Figure 7 The patterned stacked structure 2a shown includes a patterned second doping layer 25a.

[0048] Optionally, the patterned mask layer 3a may be completely formed first, and then the patterned second doping layer 25a may be formed. Alternatively, a portion of the patterned mask layer 3a may be formed first, and then a portion of the patterned second doping layer 25a may be formed, and then another portion of the patterned mask layer 3a may be formed, and then another portion of the patterned second doping layer 25a may be formed, that is, the patterned mask layer 3a may be formed by alternately removing the patterned mask layer 3a. Figure 7 The patterned mask layer 3a and the patterned second doping layer 25a are shown.

[0049] In the formation of Figure 7 After the structure shown in FIG. 1 is formed, the patterned mask layer 3a is removed by acid, and the portion of the third tunneling layer 24 located in the non-metallized area 10a is removed by acid to form a structure shown in FIG. Figure 8 The patterned third tunneling layer 24a is shown. It can also be said that the formation of Figure 7 The patterned stacked structure 2a shown further includes a patterned third tunneling layer 24a.

[0050] Optionally, see Figure 7 As shown, the winding coating 20 (a byproduct formed when forming the stacked structure 2) can be modified by laser, and the energy of the laser can make the internal structure of the winding coating 20 loose. After the winding coating 20 is modified, when the patterned mask layer 3a is removed by acid, and when the portion of the third tunneling layer 24 located in the non-metallized area 10a is removed by acid, the acid can easily remove the modified winding coating 20. After removing the winding coating 20, the acid can also remove the silicon glass layer (a byproduct formed when forming the emitter layer 6, and the silicon glass layer is located on the side of the emitter layer away from the silicon substrate) to form a structure as shown in FIG. Figure 8 The structure shown.

[0051] Optionally, see Figure 7As shown, the plating layer 20 can first be removed using an alkaline solution, and then the patterned mask layer 3a can be removed using an acidic solution. The portion of the third tunneling layer 24 within the non-metallized region 10a can be removed using an acidic solution, and the silicon glass layer can be removed using an acidic solution to form a structure as shown in Figure 8 shown.

[0052] Whether using a combination including laser modification and acidic solution removal, or a combination including alkaline solution removal and acidic solution removal, during the process of transitioning from the structure shown in Figure 7 to the structure shown in Figure 8 shown, the patterned third doping layer 25a can be well protected by the patterned mask layer 3a, so that the structure of the patterned third doping layer 25a is not easily damaged by the corrosive acidic solution and the corrosive alkaline solution.

[0053] Please refer to Figure 9 shown, an alumina passivation layer 7 is deposited on the patterned stacked structure 2a including the patterned third tunneling layer 24a and the patterned second doping layer 25a. Correspondingly, the alumina passivation layer 7 can also be deposited on the emitter layer 6.

[0054] Optionally, the process of depositing the alumina passivation layer 7 can include atomic layer deposition or plasma enhanced chemical vapor deposition.

[0055] After forming the alumina passivation layer 7, the portion of the alumina passivation layer 7 deposited on the patterned stacked structure 2a within the to-be-metallized region 10b as shown in Figure 9 shown is selectively removed using a laser to form a structure as shown in Figure 10 shown. In this setting, when forming the metal electrode subsequently, the possibility of aluminum-containing impurities entering the interior of the patterned second doping layer 25a can be reduced, so as to reduce the possibility of generating more recombination centers within the patterned second doping layer 25a, thereby reducing the recombination rate of electrons and holes in the photovoltaic cell to be fabricated.

[0056] After forming the structure as shown in Figure 10 shown, a silicon nitride passivation layer 8 as shown in Figure 11 shown is deposited on both sides. Optionally, the process of depositing the silicon nitride passivation layer 8 can include low-pressure chemical vapor deposition, plasma enhanced chemical vapor deposition, or physical vapor deposition (PVD).

[0057] After forming the structure as shown in Figure 11 shown, please refer to Figure 12 shown, a negative metal electrode 5a that forms an ohmic contact with the patterned third doping layer 25a is formed. Correspondingly, a positive metal electrode 5b that forms an ohmic contact with the emitter layer 6 is formed.

[0058] Optionally (not shown in the figures), since the number of negative metal electrodes may include multiple ones, some of the negative metal electrodes may also extend into the first doped layer, that is, some of the negative metal electrodes may also have an ohmic contact with the first doped layer.

[0059] Optionally, after forming the structure as Figure 8 shown, please refer to Figure 9a shown, an alumina passivation layer 7 is deposited on the emitter layer 6, and the alumina passivation layer is not deposited on the patterned stacked structure 2a. After forming the structure as Figure 9a shown, a silicon nitride passivation layer 8 is deposited on both sides as Figure 11a shown. After forming the structure as Figure 11a shown, please refer to Figure 12a shown, a negative metal electrode 5a that forms an ohmic contact with the patterned third doped layer 25a is formed, and correspondingly, a positive metal electrode 5b that forms an ohmic contact with the emitter layer 6 is formed.

[0060] Optionally, after forming the structure as Figure 6 shown, a part of the mask layer 3 located within the non-metallized region 10a can be removed by using a laser to form a patterned mask layer 3a as Figure 7a shown. After forming the structure as Figure 6 shown, a part of the second doped layer 25 located within the non-metallized region 10a can also be removed by using a laser, a part of the third tunneling layer 24 located within the non-metallized region 10a can be removed, and a part of the first doped layer 23 located within the non-metallized region 10a can be removed to form a patterned second doped layer 25a, a patterned third tunneling layer 24a, and a patterned first doped layer 23a as Figure 7a shown. It can also be said that a patterned stacked structure 2a including the patterned second doped layer 25a, the patterned third tunneling layer 24a, and the patterned first doped layer 23a is formed as Figure 7a shown.

[0061] After forming the structure as Figure 7a shown, the patterned mask layer 3a is removed by using an acid solution, a part of the second tunneling layer 22 located within the non-metallized region 10a is removed by using an acid solution, and a part of the first tunneling layer 21 located within the non-metallized region 10a is removed by using an acid solution. To form a patterned second tunneling layer 22a and a patterned first tunneling layer 21a as Figure 8a shown. It can also be said that a patterned stacked structure 2a further including the patterned second tunneling layer 22a and the patterned first tunneling layer 21a is formed as Figure 8a shown. Regarding the removal method of the plating layer 20 and the silicon glass layer in Figure 7a , reference can be made to the content described above, and details are not repeated here.

[0062] Optionally, after forming the structure as shown in Figure 6 , the part of the mask layer 3 within the non-metallization region 10a can be removed by laser to form a patterned mask layer 3a as shown in Figure 7b . After forming the structure as shown in Figure 6 , the part of the second doping layer 25 within the non-metallization region 10a can also be removed by laser, the part of the third tunneling layer 24 within the non-metallization region 10a can be removed, the part of the first doping layer 23 within the non-metallization region 10a can be removed, and the part of the second tunneling layer 22 within the non-metallization region 10a can be removed to form a patterned second doping layer 25a, a patterned third tunneling layer 24a, a patterned first doping layer 23a, and a patterned second tunneling layer 22a as shown in Figure 7b . It can also be said that a patterned stacked structure 2a including the patterned second doping layer 25a, the patterned third tunneling layer 24a, the patterned first doping layer 23a, and the patterned second tunneling layer 22a is formed as shown in Figure 7b .

[0063] After forming the structure as shown in Figure 7b , the patterned mask layer 3a is removed by acid solution, and the part of the first tunneling layer 21 within the non-metallization region 10a is removed by acid solution. To form a patterned first tunneling layer 21a as shown in Figure 8a . It can also be said that a patterned stacked structure 2a further including the patterned first tunneling layer 21a is formed as shown in Figure 8a . Regarding the removal method of the plating layer 20 and the silicon glass layer in Figure 7b , reference can be made to the content described above, and details are not repeated here.

[0064] After forming the structure as shown in Figure 8a , please refer to Figure 9b , an alumina passivation layer 7 can be deposited on the emitter layer 6. After forming the structure as shown in Figure 9b , a silicon nitride passivation layer 8 is deposited on both sides as shown in Figure 11b . After forming the structure as shown in Figure 11b , please refer to Figure 12b , a negative metal electrode 5a that forms an ohmic contact with the patterned third doping layer 25a and a positive metal electrode 5b that forms an ohmic contact with the emitter layer 6 are formed.

[0065] Optionally, after forming the structure as shown in Figure 8aAfter the structure shown, an alumina passivation layer can also be deposited on both sides, that is, an alumina passivation layer deposited on the patterned stack structure and an alumina passivation layer deposited on the emitter layer are formed. Then, the part of the alumina passivation layer deposited on the patterned stack structure located in the area to be metallized is removed by laser. Next, a silicon nitride passivation layer is deposited on both sides, and then a negative metal electrode in ohmic contact with the second doped layer and a positive metal electrode in ohmic contact with the emitter layer are formed.

[0066] In some embodiments, the preparation method may further include the following: On the basis of the structure as Figure 3 shown, the etch stop layer 60 is removed by an alkaline solution containing a texturing additive, and a textured surface 11 as Figure 4a shown is formed on the surface of the silicon substrate 1 near the backlight side.

[0067] On the textured surface 11 near the backlight side as Figure 4 shown, a stack structure 2 as Figure 5a shown is formed. Among them, since the stack structure 2 is formed on the textured surface 11, correspondingly, the stack structure 2 and each layer structure in the stack structure 2 have a textured surface. Regarding the process of forming the stack structure 2 and the materials and dimensions of each layer structure in the stack structure 2, they have all been described above and will not be elaborated here.

[0068] After the structure as Figure 5a shown is formed, a mask layer 3 as Figure 6a shown is formed on the side of the second doped layer 25 facing away from the third tunneling layer 24. Regarding the process and materials for forming the mask layer 3, they have been described above and will not be elaborated here.

[0069] After the structure as Figure 6a shown is formed, the part of the mask layer 3 located in the non-metallization area 10a is removed by laser to form a patterned mask layer 3a as Figure 7c shown. The part of the stack structure 2 located in the non-metallization area 10a can also be removed by laser to form a patterned stack structure 2a as Figure 7c shown. Correspondingly, the patterned stack structure 2a includes a patterned first tunneling layer 21a, a patterned second tunneling layer 22a, a patterned first doped layer 23a, a patterned third tunneling layer 24a, and a patterned second doped layer 25a. In Figure 7c , the part of the textured surface 11 of the silicon substrate 1 near the backlight side located in the non-metallization area 10a is exposed.

[0070] After the structure as Figure 7c shown is formed, the part of the textured surface 11 of the silicon substrate 1 near the backlight side located in the non-metallization area 10a is polished by an alkaline solution containing a polishing additive to form a surface as Figure 7dThe polished surface 12 of the silicon substrate 1 shown, which is close to the backlight side and located within the non-metallized region 10a. During the polishing process, the patterned mask layer 3a can better protect the patterned stack structure 2a, thereby reducing the likelihood of the patterned stack structure 2a being damaged by the corrosive alkaline solution.

[0071] After forming the structure as Figure 7d shown, the patterned mask layer 3a is removed using an acid solution to form the structure as Figure 8b shown. The acid solution can also neutralize the previous alkaline solution to reduce the pollution level of the generated waste liquid.

[0072] Regarding Figure 7d the removal method of the wrap-around plating layer 20 and the removal method of the silicon glass layer in

[0073] After forming the structure as Figure 8b shown, please refer to Figure 9c shown, an alumina passivation layer 7 can be deposited on the emitter layer 6. After forming the structure as Figure 9c shown, a silicon nitride passivation layer 8 as Figure 11c shown is deposited on both sides. After forming the structure as Figure 11c shown, please refer to Figure 12c shown, a negative metal electrode 5a that forms an ohmic contact with the patterned third doping layer 25a and a positive metal electrode 5b that forms an ohmic contact with the emitter layer 6 are formed.

[0074] Optionally, after forming the structure as Figure 8b shown, an alumina passivation layer can also be deposited on both sides, that is, an alumina passivation layer deposited on the patterned stack structure and an alumina passivation layer deposited on the emitter layer are formed. Then, the part of the alumina passivation layer deposited on the patterned stack structure that is located within the to-be-metallized region is removed using a laser. Next, a silicon nitride passivation layer is deposited on both sides, and then a negative metal electrode that forms an ohmic contact with the second doping layer and a positive metal electrode that forms an ohmic contact with the emitter layer are formed.

[0075] Optionally, when forming the mask layer 3 on the side of the second doping layer 25 of the stack structure 2 that faces away from the third tunneling layer 24, a mask layer can also be deposited on the side of the emitter layer 6 that faces away from the silicon substrate 1, that is, a mask layer can be deposited on both sides using plasma-enhanced chemical vapor deposition. The mask layer close to the emitter layer 6 can reduce the likelihood of the emitter layer 6 being damaged by the corrosive alkaline solution and acid solution.

[0076] According to the above description, some relatively specific embodiments regarding the preparation method are sorted out in this article: In the first embodiment, the structural change of the substrate can be caused by Figure 1 , Figure 2 , Figure 3 ,Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 transition to Figure 12 . The specific methods have been described above and will not be elaborated here. In the second embodiment, the structural change of the substrate can be caused by Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9a , Figure 11a transition to Figure 12a . The specific methods have been described above and will not be elaborated here. In the third embodiment, the structural change of the substrate can be caused by Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7a , Figure 8a , Figure 9b , Figure 11b transition to Figure 12b . The specific methods have been described above and will not be elaborated here. In the fourth embodiment, the structural change of the substrate can be caused by Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7b , Figure 8a , Figure 9b , Figure 11b transition to Figure 12b . The specific methods have been described above and will not be elaborated here. In the fifth embodiment, the structural change of the substrate can be caused by Figure 1 , Figure 2 , Figure 3 , Figure 4a , Figure 5a , Figure 6a , Figure 7c , Figure 7d , Figure 8b , Figure 9c , Figure 11c transition to Figure 12c . The specific methods have been described above and will not be elaborated here.

[0077] Optionally, the method for forming a metal electrode may include paste printing and sintering. Paste printing may include screen printing or stencil printing, both of which involve printing a metal-containing paste onto a substrate and forming the printed paste on the substrate into a line shape. After printing, the paste is dried and then sintered to form a metal electrode that makes an ohmic contact with the doped layer. Among them, the paste may include a silver-containing paste or a silver-aluminum-containing paste. If it is used to form a negative metal electrode, a silver-containing paste can be used; if it is used to form a positive metal electrode, a silver-aluminum-containing paste can be used. The paste may also include other additives such as frit, solvent, modifier, non-volatile polymer or resin.

[0078] In other embodiments, the method for forming a metal electrode that makes an ohmic contact with the doped layer may also include laser transfer, electroplating, inkjet or sputtering.

[0079] Before or after forming the metal electrode, the substrate may be annealed to eliminate the internal stress of the substrate and improve the crystallization rate of each doped layer or each patterned doped layer in the substrate, that is, within the doped layer or within the patterned doped layer, the volume ratio of polysilicon to amorphous silicon is relatively large and the conductivity is relatively high.

[0080] In a second aspect, the present application provides some embodiments of a photovoltaic cell, and the photovoltaic cell is prepared by the preparation method described above. Accordingly, the photovoltaic cell has a relatively high photoelectric conversion efficiency and fill factor.

[0081] Optionally, the structure of the photovoltaic cell may be as Figure 12 shown, as Figure 12a shown, as Figure 12b shown or as Figure 12c shown. The functions, materials and dimensions of the structure of the photovoltaic cell have been described above and will not be elaborated here.

[0082] In some embodiments, such as Figure 12 , Figure 12a , Figure 12b and Figure 12c shown, the photovoltaic cell can be referred to as a tunnel oxide passivated contact solar cell (TOPCon Solar Cell). Under the condition that the silicon substrate 1 contains N-type elements, such as Figure 12 , Figure 12a , Figure 12b and Figure 12c shown, the photovoltaic cell can be referred to as an N-type TOPCon photovoltaic cell.

[0083] Optionally, in such as Figure 12In the photovoltaic cell shown, the structure of the aluminum oxide passivation layer 7 on the backlight side can be as Figure 13 shown. With this structure, since the aluminum oxide passivation layer 7 contains aluminum, which is a P-type element, an internal built-in electric field E can be established between the aluminum oxide passivation layer 7 and the first doped layer 23 (containing N-type elements). 1 An internal built-in electric field E can also be established between the aluminum oxide passivation layer 7 and the patterned second doped layer 25a (containing N-type elements). 2 . The internal built-in electric field E 1 can prevent the electrons collected by the first doped layer 23 from moving towards the interface between the first doped layer 23 and the aluminum oxide passivation layer 7, thereby reducing the recombination rate of the electrons collected by the first doped layer 23. The internal built-in electric field E 2 can prevent the electrons collected by the patterned second doped layer 25a from moving towards the interface between the patterned second doped layer 25a and the aluminum oxide passivation layer 7, thereby reducing the recombination rate of the electrons collected by the patterned second doped layer 25a. Therefore, under the field passivation effect of the internal built-in electric field E 1 and the field passivation effect of the internal built-in electric field E 2 , a relatively large number of electrons collected by the patterned stacked structure can migrate towards the negative metal electrode 5a, enabling the negative metal electrode 5a to output an electron current well. Therefore, the photovoltaic cells of some embodiments of the present application have relatively high photoelectric conversion efficiency and fill factor.

[0084] In Figure 13 , "+" represents positive charge, "-" represents negative charge, and the direction from positive charge to negative charge is the direction of the internal built-in electric field.

[0085] In this article, "doped with N-type elements" mainly means that the chemical elements of the doped impurities include N-type elements. Similarly, in this article, "doped with P-type elements" mainly means that the chemical elements of the doped impurities include P-type elements.

[0086] In a third aspect, the present application provides some embodiments of a photovoltaic module, which includes a laminate and a frame, and the frame is installed at the edge of the laminate. The laminate includes a photovoltaic glass, a first encapsulation film, a battery string, a second encapsulation film, and a backsheet stacked together. Alternatively, the laminate includes a first photovoltaic glass, a first encapsulation film, a battery string, a second encapsulation film, and a second photovoltaic glass stacked together. Among them, the battery string can be formed by electrically connecting a plurality of photovoltaic cells described above. The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a photovoltaic cell, characterized in that: The preparation method comprises: forming a stacked structure on a silicon substrate, the stacked structure comprising a first tunneling layer, a second tunneling layer, a first doping layer, a third tunneling layer and a second doping layer which are stacked, wherein the first tunneling layer is adjacent to the silicon substrate; forming a mask layer on a side of the second doped layer away from the third tunneling layer; Using laser to remove the portion of the mask layer located in the non-metallized area to form a patterned mask layer; Using laser to remove at least a portion of the structure of the stacked structure located in the non-metallized area to form a patterned stacked structure; removing the patterned mask layer by using an acid solution; Depositing a passivation layer on the patterned stacked structure; A metal electrode is formed in ohmic contact with the doped layer included in the patterned stacked structure.

2. The method for preparing a photovoltaic cell according to claim 1, characterized in that: The method of forming a mask layer on a side of the second doping layer away from the third tunneling layer comprises: The mask layer is formed by plasma enhanced chemical vapor deposition.

3. The method for preparing a photovoltaic cell according to claim 1, characterized in that: The method of removing at least a portion of the structure located in the non-metallized area of ​​the stacked structure by using a laser comprises: The laser is used to remove the portion of the second doping layer located in the non-metallized area to form a patterned stacked structure including a patterned second doping layer.

4. The method for preparing a photovoltaic cell according to claim 3, characterized in that: The method further comprises: After forming the patterned stacked structure including the patterned second doping layer, the patterned mask layer is removed by the acid solution, and the portion of the third tunneling layer located in the non-metallized area is removed by the acid solution to form a patterned stacked structure also including the patterned third tunneling layer.

5. The method for preparing a photovoltaic cell according to claim 1, characterized in that: The method of removing at least a portion of the structure located in the non-metallized area of ​​the stacked structure by using a laser comprises: Using laser to sequentially remove the portion of the second doped layer located in the non-metallized area, the portion of the third tunneling layer located in the non-metallized area, and the portion of the first doped layer located in the non-metallized area, so as to form a patterned stacked structure including a patterned second doped layer, a patterned third tunneling layer, and a patterned first doped layer; Alternatively, a portion of the second doped layer located in the non-metallized area, a portion of the third tunneling layer located in the non-metallized area, a portion of the first doped layer located in the non-metallized area, and a portion of the second tunneling layer located in the non-metallized area are removed in sequence by laser to form a patterned stacked structure comprising a patterned second doped layer, a patterned third tunneling layer, a patterned first doped layer, and a patterned second tunneling layer.

6. The method for preparing a photovoltaic cell according to claim 5, characterized in that: The method further comprises: After forming the patterned stacked structure including the patterned second doping layer, the patterned third tunneling layer and the patterned first doping layer, removing the patterned mask layer by using the acid solution, and removing the portion of the second tunneling layer located in the non-metallized area and the portion of the first tunneling layer located in the non-metallized area by using the acid solution, so as to form a patterned stacked structure further including the patterned second tunneling layer and the patterned first tunneling layer; Alternatively, after forming the patterned stacked structure including the patterned second doping layer, the patterned third tunneling layer, the patterned first doping layer and the patterned second tunneling layer, the patterned mask layer is removed using the acid solution, and the portion of the first tunneling layer located in the non-metallized area is removed using the acid solution to form a patterned stacked structure also including the patterned first tunneling layer.

7. The method for preparing a photovoltaic cell according to claim 1, characterized in that: The method further comprises: Before forming the laminated structure on the silicon substrate, texturing the surface of the silicon substrate; After forming the patterned mask layer and before removing the patterned mask layer with acid solution, all structures in the stacked structure located in the non-metallized area are removed with laser to form the patterned mask layer and to expose the portion of the suede surface of the silicon substrate located in the non-metallized area, and the portion of the suede surface of the silicon substrate located in the non-metallized area is polished with alkaline solution.

8. The method for preparing a photovoltaic cell according to any one of claims 1 to 7, characterized in that: Before forming the stacked structure on the backlight side of the silicon substrate, an emitter layer is formed on the light-receiving side of the silicon substrate, and a silicon glass layer is formed on the side of the emitter layer away from the silicon substrate; And / or, after forming the stacked structure on the silicon substrate and before forming the patterned mask layer located on the stacked structure, a mask layer is deposited on both the light-receiving side and the backlight side of the silicon substrate.

9. The method for preparing a photovoltaic cell according to any one of claims 1 to 7, characterized in that: The method of depositing a passivation layer on the patterned stacked structure comprises: An aluminum oxide passivation layer is deposited on the patterned stacked structure, and a silicon nitride passivation layer is deposited on the aluminum oxide passivation layer.

10. A photovoltaic cell, characterized in that: The photovoltaic cell is prepared by the method for preparing a photovoltaic cell according to any one of claims 1 to 9.

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