Solar cell and manufacturing method therefor, photovoltaic module, and photovoltaic system

Abstract

The present application relates to a solar cell and a manufacturing method therefor, a photovoltaic module, and a photovoltaic system. The solar cell comprises: a substrate (110) comprising a first surface (S1) and a second surface (S2) arranged opposite to each other, wherein the first surface (S1) has a first region (A) and a second region (B) adjacent to each other in a first direction; a passivation contact layer (120) located in the first region (A) of the first surface (S1); a polysilicon layer (130) located on the surface of the side of at least part of the passivation contact layer (120) away from the substrate (110), wherein the passivation contact layer (120) comprises a first tunneling layer (121) and a first doped layer (122), and the first tunneling layer (121) and the first doped layer (122) are sequentially stacked on the first region (A) of the first surface (S1) of the substrate (110) in a direction moving away from the second surface (S2); and a first passivation layer (140) located on the surface of the side of the polysilicon layer (130) away from the passivation contact layer (120), and located on the second region (B) of the first surface (S1).

Description

Solar cell and manufacturing method thereof, photovoltaic module and photovoltaic system

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 2024103251946, filed on March 21, 2024, entitled “Solar cells and methods for manufacturing the same, photovoltaic modules and photovoltaic systems,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the technical field of solar cells, and in particular to a solar cell and a manufacturing method thereof, a photovoltaic module and a photovoltaic system. Background Art

[0004] With the rapid development of photovoltaic technology, the conversion efficiency of crystalline silicon solar cells has increased year by year. Back-contact (BC) cell technology is considered the future development direction of crystalline silicon solar cells. Currently, the main types of BC cells include TBC, HPBC, and HBC. BC cells move the PN junction and metal contact to the back of the cell, eliminating the front electrode from blocking sunlight. This allows the cell to absorb sunlight over a larger area, thereby improving conversion efficiency and generating more power.

[0005] In the related art, during the manufacturing process of BC cells, laser damage is caused to the doped polysilicon in the passivation contact structure during the laser patterning process, thereby reducing the efficiency of the solar cell.

[0006] Summary of the Invention

[0007] According to various embodiments of the present application, a solar cell and a method for manufacturing the same, a photovoltaic module, and a photovoltaic system are provided.

[0008] A first aspect of an embodiment of the present application provides a solar cell, comprising:

[0009] The substrate comprises a first surface and a second surface disposed opposite to each other; wherein the first surface has a first area and a second area adjacent to each other in a first direction;

[0010] a passivation contact layer located in the first region of the first surface; the passivation contact layer comprising a first tunneling layer and a first doping layer, the first tunneling layer and the first doping layer being stacked in sequence on the first region of the first surface of the substrate in a direction away from the second surface;

[0011] a polysilicon layer located on a surface of at least a portion of the passivation contact layer away from the substrate; and

[0012] A first passivation layer is located on a surface of the polysilicon layer away from the passivation contact layer and on the second region of the first surface.

[0013] A second aspect of the embodiments of the present application provides a method for manufacturing a solar cell, comprising:

[0014] A substrate is provided; wherein the substrate includes a base and a passivation contact layer; wherein the base includes a first surface and a second surface disposed opposite to each other, the first surface including a first region and a second region adjacent to each other in a first direction; the passivation contact layer is located in the first region of the first surface; the passivation contact layer includes a first tunneling layer and a first doping layer, the first tunneling layer and the first doping layer being stacked in sequence in the first region of the first surface of the base in a direction away from the second surface;

[0015] forming a polysilicon layer on at least a portion of a surface of the passivation contact layer away from the substrate; and

[0016] A first passivation layer is formed on a surface of the polysilicon layer away from the passivation contact layer and on a second region of the first surface of the substrate.

[0017] A third aspect of an embodiment of the present application provides a photovoltaic module, comprising at least one cell string, the cell string comprising at least two of the aforementioned solar cells, or the cell string comprising at least two solar cells manufactured by the aforementioned solar cell manufacturing method.

[0018] A fourth aspect of an embodiment of the present application provides a photovoltaic system, comprising the above-mentioned photovoltaic assembly.

[0019] The beneficial effects of the above-mentioned solar cell and its manufacturing method, photovoltaic module and photovoltaic system are as follows:

[0020] The solar cell provided in the embodiment of the present application includes a substrate, a passivation contact layer, a polycrystalline silicon layer and a first passivation layer, wherein the polycrystalline silicon layer is arranged between the passivation contact layer and the first passivation layer. In this way, in the subsequent laser process, the laser can directly act on the polycrystalline silicon layer, which can reduce the loss introduced by the doped polycrystalline silicon in the passivation contact layer, and can also avoid laser damage to the passivation contact layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0021] The details of one or more embodiments of the present disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without any creative work.

[0023] FIG1 is a schematic diagram of the structure of a solar cell provided in Example 1 of the present application;

[0024] FIG2 is a top view of the solar cell structure provided in an embodiment of the present application;

[0025] FIG3 is a second schematic diagram of a solar cell provided in an embodiment of the present application;

[0026] FIG4 is a third schematic diagram of a solar cell provided in an embodiment of the present application;

[0027] FIG5 is a fourth schematic diagram of a solar cell provided in an embodiment of the present application;

[0028] FIG6 is a fifth schematic diagram of a solar cell provided in an embodiment of the present application;

[0029] FIG7 is a sixth schematic diagram of a solar cell provided in an embodiment of the present application;

[0030] FIG8 is a seventh schematic diagram of a solar cell provided in an embodiment of the present application;

[0031] FIG9 is an eighth schematic diagram of a solar cell provided in an embodiment of the present application;

[0032] FIG10 is a ninth schematic diagram of a solar cell provided in an embodiment of the present application;

[0033] FIG11 is a tenth schematic diagram of a solar cell provided in an embodiment of the present application;

[0034] FIG12 is an eleventh schematic diagram of a solar cell provided in an embodiment of the present application;

[0035] FIG13 is a twelfth schematic diagram of a solar cell provided in an embodiment of the present application;

[0036] FIG14 is a schematic flow chart of a method for manufacturing a solar cell according to an embodiment of the present application;

[0037] FIG15 is a schematic cross-sectional view of a solar cell in a method for manufacturing a solar cell according to an embodiment of the present application;

[0038] FIG16 is a schematic structural diagram of a transparent conductive layer formed in a method for manufacturing a solar cell provided in an embodiment of the present application;

[0039] FIG17 is a schematic diagram of forming an electrode opening in a method for manufacturing a solar cell according to an embodiment of the present application;

[0040] FIG18 is a schematic diagram of forming a transparent conductive layer in a method for manufacturing a solar cell according to another embodiment of the present application;

[0041] FIG19 is a schematic diagram of forming a second tunneling layer in the method for manufacturing a solar cell provided in an embodiment of the present application;

[0042] FIG20 is a schematic structural diagram of forming a first diffusion layer in the method for manufacturing a solar cell provided in an embodiment of the present application;

[0043] FIG21 is a schematic structural diagram of forming an insulating layer in the method for manufacturing a solar cell provided in an embodiment of the present application;

[0044] FIG22 is a schematic diagram of forming a second diffusion region, a second passivation layer, and an anti-reflection layer on a substrate in a method for manufacturing a solar cell provided in an embodiment of the present application;

[0045] FIG23 is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of the present application.

[0046] Explanation of the accompanying drawings: 110-substrate; S1-first surface; S2-second surface; A-first region; B-second region; 112-first diffusion layer; 120-passivation contact layer; 121-first tunneling layer; 122-first doped layer; 1221-intrinsic portion; 1222-doped diffusion portion; 123-second tunneling layer; 130-polysilicon layer; 140-first passivation layer; 150-second doped layer; 160-transparent conductive layer; 170-first electrode; 180-second electrode; 190-insulating layer; 101-second diffusion region, 102-second passivation layer; 103-anti-reflection layer; 104-isolation trench; 200-photovoltaic module; 210-cell string. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0049] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0051] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0052] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0053] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0054] The solar cell and its manufacturing method, photovoltaic module and photovoltaic system according to the embodiment of the present application are described below with reference to the accompanying drawings.

[0055] FIG1 is a schematic diagram of the structure of a solar cell provided in an embodiment of the present application. Referring to FIG1 , an embodiment of the present application provides a solar cell. In this embodiment of the present application, for ease of explanation, a solar cell is described using a back-contact crystalline silicon heterojunction solar cell (HBC) as an example. The solar cell may include a substrate 110, a passivation contact layer 120, a polysilicon layer 130, and a first passivation layer 140.

[0056] The substrate 110 includes a first surface S1 and a second surface S2 arranged opposite to each other; wherein the first surface S1 has a first area A and a second area B adjacent to each other in the first direction D1. It can be understood that the substrate 110 has a first surface S1 (or backlight surface) and a second surface S2 (or light-receiving surface) opposite to each other in the second direction D2 (i.e., the thickness direction of the solar cell). The light-receiving surface and the backlight surface can also be understood as the outermost two surfaces of the solar cell facing the sunlight and facing away from the sunlight. In an embodiment of the present application, the first area A and the second area B may be arranged flush or not. Optionally, there is a step between the substrate 110 where the first area A is located and the substrate 110 where the second area B is located. The thickness of the substrate 110 where the first area A is located is greater than or equal to the thickness of the substrate 110 where the second area B is located.

[0057] Substrate 110 is used to receive incident light and generate photogenerated carriers. Substrate 110 includes, but is not limited to, a doped semiconductor substrate made of materials such as silicon or germanium, or a doped compound semiconductor substrate made of silicon carbide, silicon germanium, gallium arsenide, indium phosphide, zinc oxide, or gallium oxide. For example, in embodiments of the present application, substrate 110 may be made of doped single-crystalline silicon. Furthermore, substrate 110 may be doped with an N-type element, such as phosphorus, arsenic, or antimony. Substrate 110 may also be doped with a P-type element, such as boron and gallium. In embodiments of the present application, the first surface S1 and the second surface S2 of substrate 110 may vary in morphology depending on the topography of the battery film layers and other features. For example, the light-receiving surface may have a suede texture, while a portion of the backlight surface may have a flat surface, and another portion of the backlight surface may also have a suede texture.

[0058] The passivation contact layer 120 is located in the first region A of the first surface S1. It is understood that the passivation contact layer 120 is located in the first region A of the backlight side of the substrate 110. The passivation contact layer 120 can reduce carrier recombination on the surface of the substrate 110, thereby increasing the open-circuit voltage of the solar cell and improving the photovoltaic conversion efficiency of the solar cell. The passivation contact layer 120 may include a first tunneling layer 121 and a first doping layer 122, which are stacked sequentially on the first region A of the first surface S1 of the substrate 110, moving away from the second surface S2. The first tunneling layer 121 is used to achieve interfacial passivation on the first surface S1 of the substrate 110, providing a chemical passivation effect. By saturating the dangling bonds on the surface of the substrate 110, the density of interfacial defect states on the first surface S1 of the substrate 110 is reduced, thereby reducing the number of recombination centers on the first surface S1 of the substrate 110 and lowering the carrier recombination rate. The thickness of the first tunneling layer 121 is less than or equal to 3 nanometers. The first tunneling layer 121 may be made of a dielectric material, such as at least one of silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide, or titanium oxide. The dielectric material may contain the same doping element as the substrate 110 .

[0059] The thickness of the first doped layer 122 is greater than or equal to 20 nanometers and not greater than 600 nanometers. The material of the first doped layer 122 can be doped polysilicon, or doped polysilicon containing at least one of oxygen, carbon, and nitrogen. The doping type of the first doped layer 122 can be the same as the doping type of the substrate 110, or the opposite.

[0060] The polysilicon layer 130 is located on a surface of at least a portion of the passivation contact layer 120 that is away from the substrate 110. The first tunneling layer 121, the first doped layer 122, and the polysilicon layer 130 are sequentially stacked on the first surface S1 in a direction away from the second surface S2. The polysilicon layer 130 may be made of intrinsic polysilicon. Optionally, the doping element of the polysilicon layer 130 includes at least one of oxygen, carbon, and nitrogen. The thickness of the polysilicon layer 130 ranges from 3 nanometers to 150 nanometers.

[0061] In the embodiment of the present application, by forming a polysilicon layer 130 between the first doped layer 122 and the first passivation layer 140, the laser can act on the polysilicon layer 130 (e.g., intrinsic poly-Si) during the laser process, reducing the loss introduced by the poly-Si into the first doped layer 122 and improving the conversion efficiency of the battery. At the same time, by providing the polysilicon layer 130 (e.g., intrinsic poly-Si), uniform doping can be formed in the contact area of ​​the first doped layer 122, reducing the thickness requirement of the first doped layer 122, reducing the optical loss in the first doped layer, and improving the battery efficiency.

[0062] The first passivation layer 140 is located on the surface of the polysilicon layer 130 away from the passivation contact layer 120, and on the second region B of the first surface S1. The thickness of the first passivation layer 140 ranges from 3 to 15 nanometers. The material of the first passivation layer 140 can include intrinsic amorphous silicon, or the material of the first passivation layer can be doped with at least one of oxygen, carbon, and nitrogen, for example, amorphous silicon containing at least one of oxygen, carbon, and nitrogen.

[0063] The solar cell provided in the embodiment of the present application includes a substrate, a passivation contact layer, a polycrystalline silicon layer and a first passivation layer, wherein the polycrystalline silicon layer is arranged between the passivation contact layer and the first passivation layer. In this way, during the subsequent laser process, the laser can act on the polycrystalline silicon layer, which can reduce the loss introduced by the doped polycrystalline silicon in the passivation contact layer and can also avoid laser damage to the passivation contact layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0064] Figure 2 is a top view of the solar cell structure provided in an embodiment of the present application, and Figure 3 is a second schematic diagram of the solar cell provided in an embodiment of the present application. Referring to Figure 3, based on the above embodiment, the solar cell provided in this embodiment may further include a second doped layer 150, a transparent conductive layer 160, a first electrode 170, and a second electrode 180. The second doped layer 150 is located on the surface of the first passivation layer 140 away from the polysilicon layer 130. The material of the second doped layer 150 may include doped amorphous silicon or microcrystalline silicon, or doped amorphous silicon or microcrystalline silicon containing at least one of oxygen, carbon, and nitrogen. The doping type of the second doped layer 150 is opposite to that of the first doped layer 122. In this embodiment, the thickness of the second doped layer 150 ranges from 3 to 60 nanometers. In this embodiment of the present application, the first passivation layer 140 and the second doped layer 150 extend from the space where the first region A is located to the space where the second region B is located. It can be understood that the first passivation layer 140 covers the polysilicon layer 130 and the second region B of the second surface S2 of the substrate 110 , and the second doping layer 150 covers the side of the first passivation layer 140 away from the substrate 110 .

[0065] Transparent conductive layer 160 is located on the surface of second doped layer 150 away from second doped layer 150. Transparent conductive layer 160 has a thickness greater than or equal to 10 nanometers and less than or equal to 200 nanometers. The material of transparent conductive layer 160 can be one or more of zinc oxide (ZnO), indium oxide (InO), and tin oxide (SnO). The transparent conductive material can be doped with one or more of gallium (Ga), tin (Sn), molybdenum (Mo), cerium (Ce), fluorine (F), tungsten (W), and aluminum (Al).

[0066] The first electrode 170 is located in the first region and extends from the transparent conductive layer 160 through at least the polysilicon layer 130. A first end of the first electrode 170 is in electrical contact with the first doped layer 122, and a second end of the first electrode 170 is in contact with the transparent conductive layer 160 located in the first region A. It will be understood that the first electrode 170 may extend from the transparent conductive layer 160 through the polysilicon layer 130 to electrically contact the first doped layer 122 through the transparent conductive layer 160, or may extend from the transparent conductive layer 160 through the first doped layer 122 to directly contact the first doped layer 122.

[0067] The second electrode 180 is located in the second region, wherein the second electrode 180 is disposed in contact with the transparent conductive layer 160. It is understood that the projection of the second electrode 180 toward the substrate 110 is located in the second region B. The transparent conductive layer 160 is provided with an isolation trench 104, which is disposed between the first electrode 170 and the second electrode 180 and extends at least through the transparent conductive layer 160. Optionally, the isolation trench 104 may extend through the first passivation layer 140, the second doping layer 150, and the transparent conductive layer 160 to insulate the first electrode 170 from the second electrode 180. Furthermore, the isolation trench 104 is located in the first region. Optionally, the isolation trench 104 is located in the second region. Optionally, the isolation trench 104 is located at the boundary between the first and second regions.

[0068] In the embodiment of the present application, the materials of the first electrode 170 and the second electrode 180 include, but are not limited to, one or more of aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), silver (Ag), copper (Cu), and tin (Sn). The first electrode 170 and the second electrode 180 may be formed by screen printing, laser transfer, and electroplating. In the embodiment of the present application, the first electrode 170 and the second electrode 180 can be understood as metal gate lines, and the width and thickness of the metal gate lines are not limited.

[0069] The electrical contact between the first electrode 170 and the first doping layer 122 will be described below with reference to FIG. 3 to FIG. 6 .

[0070] Referring to FIG. 3 , a transparent conductive layer 160 may be located on the surface of the second doped layer 150 away from the first passivation layer 140. The transparent conductive layer 160 may include an integrally formed transparent conductive layer segment A and a transparent conductive layer segment B. The projection of the transparent conductive layer segment A toward the substrate 110 falls within the first region A of the first surface S1 of the substrate 110, while the projection of the transparent conductive layer segment B toward the substrate 110 falls within the second region B of the first surface S1 of the substrate 110. In FIG. 3 , the transparent conductive layer segment A is stacked on the second doped layer 150. A first electrode 170 extends from the transparent conductive layer 160 through the first doped layer 122, and the first electrode 170 is disposed in contact with the first doped layer 122. The first electrode 170 may extend through the interface between the first doped layer 122 and the polysilicon layer 130, thereby contacting the first doped layer 122. Alternatively, the first electrode 170 may extend through the interior of the first doped layer 122, thereby contacting the first doped layer 122. In this embodiment, an electrode opening may be formed in the transparent conductive layer 160, the second doped layer 150, and the first passivation layer 140, wherein the bottom of the electrode opening is at least partially the first doped layer 122, and the first electrode 170 is located in the electrode opening to electrically contact the first doped layer 122. The first electrode 170 may include a first electrode portion 171 and a second electrode portion 172, wherein the first electrode portion 171 is located in the electrode opening, and a first end of the first electrode portion 171 is in contact with the first doped layer 122. It can be understood that the first electrode portion 171 extends from the transparent conductive layer 160 through the first doped layer 122, the first end of the first electrode portion 171 is in contact with the first doped layer 122, the second end of the first electrode portion 171 is in contact with the second electrode portion 172, and the second electrode portion 172 is exposed in section A of the transparent conductive layer.

[0071] Optionally, referring to Figure 4, the first doped layer 122 includes an intrinsic portion 1221 and a doped diffusion portion 1222, wherein the intrinsic portion 1221 is located on the surface of the first tunneling layer 121 away from the substrate 110, and the polysilicon layer 130 is located on the surface of the intrinsic portion 1221 away from the first doped layer 122; the doped diffusion portion 1222 is located on a portion of the surface of the intrinsic portion 1221 away from the first tunneling layer 121, and diffuses to the polysilicon layer 130 along the direction of the substrate 110 pointing to the first passivation layer 140; the doped diffusion portion 1222 is in contact with the first electrode 170.

[0072] In one embodiment, the doped diffusion portion 1222 may penetrate the polysilicon layer 130. Alternatively, the doped diffusion portion 1222 may diffuse into the polysilicon layer 130 and not penetrate the polysilicon layer 130. The doped diffusion portion 1222 may be understood as a contact region that contacts the first electrode 170, where the doped polysilicon in the contact region is doped with a doping element that is the same as, or opposite to, the doping type of the substrate 110. The doped diffusion portion 1222 may be formed by heat generated during the laser process of forming electrode openings during the solar cell fabrication process, causing the doping elements of the first doped layer 122 to diffuse into the polysilicon layer 130, thereby forming a diffusion portion in the polysilicon layer 130.

[0073] In this embodiment, the first doped layer further includes a doped diffusion portion diffused into the polysilicon layer, wherein the doped diffusion portion is electrically connected to the first electrode. Thus, the doped diffusion portion can collect current and transmit the collected current to the first electrode via the doped diffusion portion, thereby reducing or eliminating the short-circuit effect between adjacent electrodes, thereby reducing electrical losses and improving the photovoltaic conversion efficiency of the solar cell. Furthermore, the polysilicon layer includes intrinsic polysilicon. The introduction of intrinsic polysilicon can form uniform doping in the doped diffusion portion of the first doped layer, reducing the thickness requirement of the first doped layer, thereby reducing optical losses in the first doped layer, and further improving the photovoltaic conversion efficiency of the cell.

[0074] Referring to Figures 5 and 6 , the transparent conductive layer 160 in the solar cell provided in this embodiment has a different structure than the transparent conductive layer 160 of the solar cell shown in Figures 3 and 4 . In this embodiment, electrode grooves are provided in the second doped layer 150 and the first passivation layer 140, and at least a portion of the bottom of the electrode grooves is the first doped layer 122. The transparent conductive layer 160 is located on the surface of the second doped layer 150 away from the first passivation layer 140, as well as on the bottom and walls of the electrode grooves. A portion of the first electrode 170 is located within the electrode grooves to electrically contact the first doped layer 122, while the remaining portion of the first electrode 170 is exposed outside the electrode grooves to electrically contact the transparent conductive layer 160 outside the electrode grooves. The first electrode portion 171 of the first electrode 170 is located within the electrode grooves and can be electrically connected to the first doped layer 122 via the transparent conductive layer 160 located at the bottom of the grooves. The second electrode portion 172 of the first electrode 170 is exposed outside the transparent conductive layer 160 to connect to an external power supply.

[0075] 5 and 6 , the transparent conductive layer 160 at the bottom of the electrode trench is entirely in contact with the first doped layer 122, so that the first electrode 170 built into the electrode trench can be in direct electrical contact with the first doped layer 122. In an embodiment of the present application, as shown in FIG5 , the contact surface between the transparent conductive layer 160 at the bottom of the electrode trench and the first doped layer 122 can be part of the contact surface between the first doped layer 122 and the polysilicon layer 130. Alternatively, as shown in FIG6 , the contact surface between the transparent conductive layer 160 at the bottom of the electrode trench and the first doped layer 122 extends into the interior of the first doped layer 122.

[0076] Referring to Figure 7 , the transparent conductive layer 160 at the bottom of the electrode trench can contact the doped diffusion portion diffused into the polysilicon layer 130, so that the first electrode 170 is electrically in contact with the doped diffusion portion of the first doped layer 122 through the transparent conductive layer 160. In the embodiment of the present application, the contact surface between the transparent conductive layer 160 at the bottom of the electrode trench and the first doped layer 122 can be determined based on the diffusion depth of the doped diffusion portion. For example, the contact surface between the transparent conductive layer 160 at the bottom of the electrode trench and the first doped layer 122 can be part of the contact surface between the second doped layer 150 and the polysilicon layer 130, or can extend into the interior of the polysilicon layer 130.

[0077] In an embodiment, the first electrode is electrically connected or in contact with the first doped layer via the transparent conductive layer, which can improve the electrical contact stability between the first doped layer and the first electrode, thereby improving the stability of the transmitted current and further improving the efficiency of the solar cell.

[0078] 8 to 11 , based on any of the foregoing embodiments, the solar cell may further include an insulating layer 190. The insulating layer 190 is located on the surface of the polysilicon layer 130 away from the passivation contact layer 120, and is located between the polysilicon layer 130 and the first passivation layer 140. The material of the insulating layer 190 may include at least one of a silicon oxide layer, a silicon nitride layer, and a silicon oxynitride layer. The material of the insulating layer 190 may also include the same doping element as the material of the first doping layer 122. In the embodiment of the present application, the thickness of the insulating layer 190 is greater than or equal to 1.5 nanometers. It should be noted that in the embodiment of the present application, the insulating layer 190 may be retained or removed, and may be set according to actual preparation requirements.

[0079] In this embodiment, if the insulating layer 190 is removed from the solar cell, it can reduce the electrical loss in the contact area between the first doped layer and the second doped layer. Alternatively, if the insulating layer 190 is retained in the solar cell, it can increase the protection of the polysilicon layer and the first doped layer.

[0080] Referring to Figure 12, based on the previous embodiment, the solar cell provided in this embodiment may further include a second tunneling layer 123. The second tunneling layer 123 is located on the surface of the first doped layer 122 on the side away from the first tunneling layer 121, and is located between the first doped layer 122 and the polysilicon layer 130. In this embodiment of the present application, the second tunneling layer 123 may be formed by natural oxidation of the first doped layer 122 during the preparation process. Alternatively, the second tunneling layer 123 may also be formed by chemical vapor deposition. The material of the second tunneling layer 123 may include at least one of silicon oxide, silicon oxynitride, aluminum oxide, or titanium oxide.

[0081] Optionally, a region of the polysilicon layer 130 near the second tunneling layer 123 is a lightly doped region, wherein the doping type of the lightly doped region is the same as the doping type of the first doped layer 122. Furthermore, within the polysilicon layer 130, the doping concentration of the lightly doped region decreases along the direction from the first tunneling layer 121 to the first passivation layer 140 until the doping concentration reaches zero.

[0082] In an embodiment of the present application, a second tunneling layer is provided between the first doped layer and the polysilicon layer, which can be naturally formed in the process flow. The second tunneling layer can reduce the diffusion of the doping elements in the first doped layer to the polysilicon layer under low temperature conditions, and at the same time can reduce the mutual transmission of current between the first doped layer and the polysilicon layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0083] 8 to 13 , the solar cell provided in the present embodiment may further include a first diffusion layer 112 . The first diffusion layer 112 is located in the first region A of the first surface S1 and between the substrate 110 and the first tunneling layer 121 .

[0084] Furthermore, the first diffusion layer 112 includes a crystalline silicon substrate, wherein the conductivity type of the doping element of the crystalline silicon substrate is the same as the conductivity type of the doping element in the first doping layer 122, and the doping concentration of the doping element in the crystalline silicon substrate is less than or equal to the doping concentration of the doping element in the first doping layer 122. The diffusion depth of the doping element in the first doped crystalline silicon is greater than or equal to 10 nanometers and less than or equal to 1500 nanometers.

[0085] In the embodiment of the present application, by providing the first diffusion layer 112 between the first doping layer 122 and the polysilicon layer 130 , the diffusion of the doping elements in the substrate can be improved.

[0086] Optionally, please continue to refer to FIG. 8 to FIG. 13 . The solar cell provided in the embodiment of the present application may further include a second diffusion region 101 , relative to any of the aforementioned embodiments.

[0087] Furthermore, the material of the second diffusion region 101 includes a second doped crystalline silicon, wherein the doping concentration of the second doped crystalline silicon is greater than the doping concentration of the doping element in the substrate 110. The diffusion depth of the doping element in the second doped crystalline silicon is greater than or equal to 10 nanometers and less than or equal to 1500 nanometers. The provision of the second diffusion region can improve the fill factor of the solar cell. Furthermore, the adjustment space for the size ratio of the first and second electrodes can be increased, which can reserve more space for laser patterning and reduce the requirements for the laser beam during the laser patterning process.

[0088] In one embodiment, referring to Figures 8-13 , the solar cell further includes a passivation anti-reflection layer located on the second surface of the substrate 110. The passivation anti-reflection layer includes a second passivation layer 102 and an anti-reflection layer 103 stacked on the second surface of the substrate 110. The second passivation layer 102 can have a single-layer or multi-layer structure, and the material of the second passivation layer 102 can be at least one of aluminum oxide, silicon oxide, silicon nitride, and silicon oxynitride. Alternatively, the material of the second passivation layer 102 can be intrinsic amorphous silicon, or amorphous silicon containing at least one of oxygen, carbon, and nitrogen. The thickness of the second passivation layer 102 can be greater than or equal to 1.5 nanometers. Alternatively, the second passivation layer 102 can be formed by chemical deposition. The second passivation layer 102 serves as a surface passivation in the solar cell, effectively chemically passivating dangling bonds on the surface of the substrate 110.

[0089] The anti-reflection layer 103 can have a single-layer or multi-layer structure. In a multi-layer anti-reflection layer 103, each layer can be made of materials such as silicon oxide, silicon nitride, or silicon oxynitride. The thickness of the anti-reflection layer 103 can be greater than or equal to 40 nanometers. The anti-reflection layer 103 is located on the backlight side of the solar cell and provides an anti-reflection effect on the back surface of the solar cell. Alternatively, in other embodiments, the anti-reflection layer 103 can be omitted.

[0090] FIG14 is a flow chart of a method for manufacturing a solar cell provided in Example 4 of the present application.

[0091] This embodiment provides a method for manufacturing a solar cell, which is used to manufacture the solar cell described in any of the above embodiments. The structure, function, and operating principle of the solar cell have been described in detail in the first embodiment and will not be repeated here. In one embodiment, Figure 15 is a flow chart of a method for manufacturing a solar cell in one embodiment. The method for manufacturing a solar cell includes steps 1410 to 1430.

[0092] Step 1410, provide a substrate.

[0093] Referring to Figure 15, the substrate includes a base 110 and a passivation contact layer. The base 110 includes a first surface S1 and a second surface S2 arranged opposite to each other, and the first surface S1 includes a first area A and a second area B adjacent to each other in a first direction. The base 110 includes but is not limited to a doped semiconductor substrate made of silicon or germanium, or a doped compound semiconductor substrate made of silicon carbide, silicon germanium, gallium arsenide, indium phosphide, zinc oxide or gallium oxide. Optionally, a part of the surface of the provided base 110 can also be subjected to a texturing treatment. For example, the base 110 is a doped single crystal silicon substrate. The anisotropic corrosion characteristics of the silicon substrate in a low concentration alkali solution form a pyramid velvet surface. Furthermore, dirt on the surface of the silicon substrate and the cutting damage layer can be removed, which can reduce the reflectivity and increase the absorption of sunlight by the silicon substrate.

[0094] In an embodiment of the present application, a passivation contact layer can be formed on the first surface S1 of the substrate 110 by plasma enhanced chemical vapor deposition (PECVD). It can be understood that the passivation contact layer is formed on the backlight surface of the substrate 110. Furthermore, the passivation contact layer may include a first tunneling layer 121 and a first doping layer 122, and the first tunneling layer 121 and the first doping layer 122 are deposited in sequence on the first surface S1 of the substrate 110 in a direction away from the second surface S2. The first tunneling layer 121 is used to achieve interface passivation of the first surface S1 of the substrate 110, and has the effect of chemical passivation. Among them, by saturating the dangling bonds on the surface of the substrate 110, the interface defect state density of the first surface S1 of the substrate 110 is reduced, thereby reducing the recombination center of the first surface S1 of the substrate 110 to reduce the carrier recombination rate.

[0095] Step 1420 , forming a polysilicon layer on a surface of the passivation contact layer away from the substrate.

[0096] Continuing with FIG. 15 , a polysilicon layer 130 can be formed on one side of the first doped layer 122 and the first tunneling layer 121 using PECVD. The first tunneling layer 121, the first doped layer 122, and the polysilicon layer 130 are sequentially deposited on the first surface S1 of the substrate 110 in a direction away from the second surface S2. It should be noted that the formation process of the polysilicon layer 130 is not limited to that described in the embodiment of the present application, and other processes may also be used.

[0097] Step 1430 : Form a first passivation layer on a surface of the polysilicon layer away from the passivation contact layer and on a second region of the first surface of the substrate.

[0098] 15 , the structure obtained in step 1420 may be subjected to backside patterning to remove a portion of the passivation contact layer 120 and the polysilicon layer 130 to expose the substrate 110 , thereby obtaining a second region on the first surface of the substrate.

[0099] A first passivation layer 140 is formed on the surface of the polysilicon layer 130 away from the passivation contact layer 120 (the first doping layer 122 away from the first tunneling layer 121) and the second area of ​​the first surface of the substrate. Optionally, the method for preparing a solar cell may further include cleaning the structure after the back surface patterning treatment. The first passivation layer 140 is formed after the cleaning treatment. In an embodiment of the present application, PECVD, plasma enhanced atomic layer deposition PEALD or atomic layer deposition ALD can be used to deposit relevant passivation materials, such as intrinsic amorphous silicon, or intrinsic amorphous silicon containing at least one of oxygen, carbon and nitrogen, on the surface of the polysilicon layer 130 away from the passivation contact layer 120 and the second area of ​​the first surface of the substrate to form the first passivation layer 140.

[0100] It is understandable that the structures, film materials, setting ranges, etc. of the substrate 110, the first tunneling layer 121 and the first doping layer 122, the polysilicon layer 130 and the first passivation layer 140 have been described in detail in the aforementioned embodiments and will not be repeated here.

[0101] The solar cell fabrication method provided in the embodiments of the present application forms a polysilicon layer on the surface of the passivation contact layer away from the substrate before forming the first passivation layer. This allows the laser to act on the polysilicon layer during the subsequent laser process, reducing losses introduced by the doped polysilicon in the passivation contact layer and preventing laser damage to the passivation contact layer, thereby improving the solar cell's photoelectric conversion efficiency. Furthermore, the solar cell fabrication method provided in the embodiments of the present application, without changing the basic HBC process, does not use a nitrogen source to form the polysilicon layer before forming the first passivation layer, further effectively improving the cell's photoelectric conversion efficiency.

[0102] In one embodiment, after the step of forming a first passivation layer on the surface of the polysilicon layer away from the passivation contact layer and the second area of ​​the first surface of the substrate, the solar cell preparation method further includes: forming a second doped layer on the surface of the first passivation layer away from the polysilicon layer; forming a transparent conductive layer and a first electrode on the surface of the second doped layer away from the first passivation layer; forming a second electrode on the surface of the transparent conductive layer away from the first passivation layer; wherein the second electrode is located in the second area.

[0103] Referring to FIG16 , based on the structure shown in FIG15 , a conductive doping material can be deposited on the surface of the first passivation layer 140 away from the polysilicon layer 130 using a method such as PECVD to form a second doped layer 150 on the first passivation layer. Furthermore, a conductive transparent material can be deposited on the surface of the first passivation layer 140 away from the polysilicon layer 130 using a method such as PECVD to form a transparent conductive layer 160 on the second doped layer 150. Referring to FIG3 , based on the resulting structure, an electrode opening or electrode groove is formed using a method such as laser patterning, and then filled with an electrode metal material to form a first electrode 170. The first electrode 170 extends from the transparent conductive layer 160 through at least the polysilicon layer 130. A first end of the first electrode 170 is in electrical contact with the first doped layer 122, and a second end of the first electrode 170 is in contact with the transparent conductive layer 160 located in the first region A. Exemplarily, the first electrode 170 is located in the first region and extends from the transparent conductive layer 160 at least through the polysilicon layer 130. At least a portion of the first electrode 170 is in contact with at least one of the first doped layer 122 and the polysilicon layer 130. The remaining portion of the first electrode 170 is in contact with the transparent conductive layer 160 located in the first region. The resulting structure can be referred to Figures 3-4.

[0104] In one embodiment, forming a transparent conductive layer and a first electrode on a surface of the second doped layer away from the first passivation layer includes the steps of: forming a transparent conductive layer on a surface of the second doped layer away from the first passivation layer; forming an electrode opening in the transparent conductive layer, the second doped layer, and the first passivation layer; and forming the first electrode in the electrode opening. The bottom of the electrode opening is at least partially formed by the first doped layer.

[0105] Referring to FIG17 , a conductive transparent material can be deposited on the surface of the first passivation layer 140 facing away from the polysilicon layer 130 using a method such as PECVD to form a transparent conductive layer 160 on the second doped layer 150 . Based on the resulting structure, an electrode opening C can be formed within the transparent conductive layer 160, the second doped layer 150, the first passivation layer 140, and a portion of the polysilicon layer 130, and a first electrode 170 can be formed within the electrode opening C. The resulting structure can be referenced to FIG3-4 . The electrode opening C can be formed using a laser patterning process. The electrode opening C can be opened to the polysilicon layer 130, and the first electrode 170 within the electrode opening C can be in electrical contact with the doped diffusion portion 1222 diffused into the polysilicon layer. Alternatively, the electrode opening C can be opened to the first doped layer 122, and the first electrode 170 within the electrode opening C can be in contact with the first doped layer 122.

[0106] Furthermore, before forming the first electrode 170, the transparent conductive layer 160, the second doped layer 150, and the first passivation layer 140 may be patterned to form the isolation trench 104. Furthermore, while forming the first electrode 170, the second electrode 180 may be formed on the transparent conductive layer. The first electrode 170 and the second electrode 180 are insulated by the isolation trench 104.

[0107] Alternatively, referring to FIG. 18 , in one embodiment, a transparent conductive layer and a first electrode are formed on a surface of the second doped layer facing away from the first passivation layer. This includes forming an electrode trench within the transparent conductive layer, the second doped layer, and the first passivation layer; forming a transparent conductive layer on a surface of the second doped layer facing away from the first passivation layer, as well as on the walls and bottom of the electrode trench; and forming the first electrode in the remaining area within the electrode trench. Unlike the previous embodiment, the transparent conductive layer 160 in this embodiment is formed after the electrode trench is formed. The electrode trench E can be formed using a laser patterning process, where the electrode trench E can be opened to the polysilicon layer 130 or the first doped layer 122. A conductive transparent material can be deposited on a surface of the second doped layer 150 facing away from the first passivation layer 140 using methods such as PECVD to form a transparent conductive layer on the second doped layer 150 and the walls and bottom of the electrode trench E. Based on this structure, a first electrode 170 is formed in the remaining area F within the electrode trench. The resulting structure can be seen in FIG. 5 to FIG. 7 .

[0108] In an embodiment, the first electrode is electrically connected or in contact with the first doped layer via the transparent conductive layer, which can improve the electrical contact stability between the first doped layer and the first electrode, thereby improving the stability of the transmitted current and further improving the efficiency of the solar cell.

[0109] In one embodiment, the solar cell manufacturing method further includes a step of performing a localized laser heat treatment on the polycrystalline silicon layer to diffuse the dopant elements of the first doping layer into the polycrystalline silicon layer, thereby forming a dopant diffusion portion in the polycrystalline silicon layer. Referring to Figures 4 and 7 , the first doping layer 122 includes an intrinsic portion 1221 and a dopant diffusion portion 1222, wherein the intrinsic portion 1221 is located on the surface of the first tunneling layer 121 away from the substrate 110. The heat treatment can be understood as the process of forming electrode openings or electrode grooves by laser patterning. The laser patterning process generates a large amount of heat, which acts on the polycrystalline silicon layer 130 and is transferred to the first doping layer 122, causing the dopant elements of the first doping layer 122 to diffuse into the polycrystalline silicon layer 130, thereby forming the dopant diffusion portion 1222 in the polycrystalline silicon layer 130. It should be noted that the heat treatment is not limited to the examples described in this application, and other processes can also be used to achieve the heat treatment to form the dopant diffusion portion 1222 in the polycrystalline silicon layer 130. In this way, the first electrode 170 may be formed to electrically contact the doped diffusion portion 1222 to transmit the current collected by the doped diffusion portion 1222 .

[0110] In this embodiment, during the formation of the first doped layer, the first doped layer can be diffused into the polysilicon layer to form a doped diffusion portion. The doped diffusion portion can be electrically connected to the first electrode. Thus, the doped diffusion portion can collect current, which can be transmitted to the first electrode via the doped diffusion portion. This can prevent a short circuit between the first doped layer and the second doped layer in the second region, thereby reducing electrical losses and improving the photovoltaic conversion efficiency of the solar cell. Furthermore, the polysilicon layer includes intrinsic polysilicon. The formation of intrinsic polysilicon allows the first doped layer to diffuse into the polysilicon layer, resulting in uniform doping in the doped diffusion portion. This reduces the thickness requirement for the first doped layer, reduces optical losses in the first doped layer, and further improves the photovoltaic conversion efficiency of the solar cell.

[0111] In one embodiment, before forming a polysilicon layer on at least a portion of the surface of the passivation contact layer facing away from the substrate, the solar cell fabrication method further includes forming a second tunneling layer on the surface of the first doped layer facing away from the substrate. Referring to FIG. 19 , before forming the polysilicon layer 130, the first doped layer 122 is exposed. Oxygen in the environment causes an oxidation reaction on the exposed surface of the first doped layer 122, forming the second tunneling layer 123.

[0112] In an embodiment of the present application, a second tunneling layer is formed on the surface of the first doped layer close to the polysilicon layer. In the solar cell, the second tunneling layer is located between the first doped layer and the polysilicon layer, and can be naturally formed under the process preparation environment. The second tunneling layer formed can reduce the diffusion of the doping elements in the first doped layer to the polysilicon layer under low temperature conditions, and at the same time can reduce the mutual transmission of current between the first doped layer and the polysilicon layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0113] In one embodiment, the step of providing a substrate includes providing a base, the base including a first surface and a second surface disposed opposite to each other, and the step of sequentially stacking a first diffusion layer, a first tunneling layer, and a first doping layer on the first surface of the base in a direction away from the second surface. Based on the aforementioned embodiment, the substrate in the embodiment of the present application further includes a first diffusion layer formed before the first tunneling layer is formed. Referring to FIG. 20 , in the embodiment of the present application, a method such as plasma-enhanced chemical vapor deposition (PECVD) can be used to deposit relevant diffusion materials on the first surface S1 of the base 110 to form the first diffusion layer 112. Furthermore, a first tunneling layer 121 and a first doping layer 122 are sequentially formed on the surface of the first diffusion layer 112 away from the base 110.

[0114] In the embodiment of the present application, by forming the first diffusion layer 112 between the first doping layer 122 and the polysilicon layer 130 , diffusion of the doping elements in the substrate and the doping elements in the first doping layer can be improved.

[0115] In one embodiment, after forming a first diffusion layer, a first tunneling layer, and a first doped layer in a stacked manner on the first surface of the substrate in a direction away from the second surface, the solar cell manufacturing method further includes the steps of forming an insulating layer on the surface of the first doped layer away from the first tunneling layer, and removing a portion of the first diffusion layer, the first tunneling layer, the first doped layer, and the insulating layer to expose the second region of the substrate. Referring to FIG. 21 , the insulating layer 190 and the polysilicon layer 130 can be manufactured using the same process equipment. For example, the insulating layer 190 can be formed on the side of the polysilicon layer 130 away from the second tunneling layer 123, and then patterned to remove a portion of the first diffusion layer 112, the first tunneling layer 121, the first doped layer 122, and the insulating layer 190 to expose the second region B of the substrate.

[0116] In the embodiment of the present application, the insulating layer 190 can be completely removed. If completely removed, the resulting solar cell has no insulating layer between the polysilicon layer 130 and the first passivation layer 140, which can reduce electrical losses in the contact area between the first doped layer and the second doped layer. Alternatively, the insulating layer 190 can be partially removed to retain the insulating layer 190 between the polysilicon layer 130 and the first passivation layer 140. This can increase protection for the polysilicon layer and the first doped layer, and can also reduce or eliminate the short-circuit effect between adjacent electrodes.

[0117] In one embodiment, the solar cell preparation method further includes the steps of sequentially forming a second diffusion region, a second passivation layer, and an anti-reflection layer on the second surface of the substrate. As shown in FIG22 , in the embodiment of the present application, the second diffusion region 101 can be formed simultaneously with the first diffusion layer 112, and the second diffusion region 101 is formed on the second surface S2 of the substrate 110. The formation principle of the second diffusion region 101 is the same as the formation principle of the first diffusion layer 112, and will not be repeated here. Furthermore, after the second diffusion region 101 is formed, a second passivation layer 102 and an anti-reflection layer 103 can be sequentially deposited on the side of the second diffusion region 101 away from the substrate. In the embodiment of the present application, by forming the second diffusion region, the fill factor of the solar cell can be improved; in addition, the adjustment space for the size ratio of the first electrode and the second electrode can be increased, and more space can be reserved for laser patterning, thereby reducing the requirements for the laser beam during the laser patterning process.

[0118] FIG23 is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of the present application. Referring to FIG23 , this embodiment provides a photovoltaic module 200 comprising at least one cell string 210 , each cell string 210 comprising at least two solar cells 100 according to any of the aforementioned embodiments, each solar cell 100 being connected together by serial welding.

[0119] For example, multiple solar cells can be connected in series by welding ribbons, so that the electricity generated by the individual solar cells can be collected for subsequent transmission. Of course, the solar cells can be arranged at intervals or stacked in a shingled form.

[0120] Exemplarily, the photovoltaic module 200 further includes an encapsulation layer and a cover plate (not shown), the encapsulation layer is used to cover the surface of the battery string 210, and the cover plate is used to cover the surface of the encapsulation layer away from the battery string 210. The solar cells are electrically connected in the form of a whole piece or multiple pieces to form a plurality of battery strings 210, and the plurality of battery strings 210 are electrically connected in series and / or in parallel. In some embodiments, the plurality of battery strings 210 can be electrically connected by a conductive tape. The encapsulation layer covers the surface of the solar cell. For example, the encapsulation layer can be an organic encapsulation film such as an ethylene-vinyl acetate copolymer film, a polyethylene octene co-elastomer film or a polyethylene terephthalate film. The cover plate can be a cover plate with a light-transmitting function such as a glass cover plate or a plastic cover plate.

[0121] This embodiment provides a photovoltaic system (not shown), including the aforementioned photovoltaic components. The photovoltaic system can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to convert it into the alternating current required by the mains power grid and then connected to the mains power network to achieve solar power supply.

[0122] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A solar cell, comprising: The substrate comprises a first surface and a second surface disposed opposite to each other; wherein the first surface has a first area and a second area adjacent to each other in a first direction; a passivation contact layer located in the first region of the first surface; the passivation contact layer comprising a first tunneling layer and a first doping layer, the first tunneling layer and the first doping layer being stacked in sequence on the first region of the first surface of the substrate in a direction away from the second surface; a polysilicon layer located on a surface of at least a portion of the passivation contact layer away from the substrate; and A first passivation layer is located on a surface of the polysilicon layer away from the passivation contact layer and on the second region of the first surface.

2. The solar cell according to claim 1, wherein The solar cell further comprises: The second doped layer is located on a surface of the first passivation layer away from the polysilicon layer.

3. The solar cell according to claim 2, wherein The solar cell further comprises: a transparent conductive layer, located on a surface of the second doped layer away from the first doped layer; a first electrode, located in the first region, extending from the transparent conductive layer at least through the polysilicon layer, at least a portion of the first electrode being in contact with at least one of the first doped layer and the polysilicon layer, and a remaining portion of the first electrode being in contact with the transparent conductive layer located in the first region; The second electrode is located in the second region and contacts the transparent conductive layer.

4. The solar cell according to claim 3, wherein The first doped layer includes an intrinsic portion and a doped diffusion portion. The doped diffusion portion is located on a portion of the surface of the first doped layer away from the first tunneling layer and penetrates the polysilicon layer along the direction from the substrate to the first passivation layer. The doped diffusion portion is in contact with the first electrode.

5. The solar cell according to claim 2, wherein An electrode groove is provided in the second doped layer and the first passivation layer of the first region, and the bottom of the electrode groove extends at least to the surface of the polysilicon layer away from the first doped layer; wherein the solar cell further comprises: a transparent conductive layer, located on a surface of the second doped layer away from the first passivation layer, and on the bottom and walls of the electrode grooves in the first region; a first electrode located in the first region, at least partially located in the electrode groove to electrically contact the transparent conductive layer at the bottom of the electrode groove, and the remaining portion of the first electrode exposed outside the electrode groove to electrically contact the transparent conductive layer outside the electrode groove; The second electrode is located in the second region and contacts the transparent conductive layer.

6. The solar cell according to claim 5, wherein The first doped layer includes an intrinsic portion and a doped diffusion portion. The doped diffusion portion is located on a portion of the surface of the first doped layer away from the first tunneling layer, and penetrates the polysilicon layer along the direction from the substrate to the first passivation layer; the doped diffusion portion is in contact with the transparent conductive layer at the bottom of the electrode groove.

7. The solar cell according to claim 3 or 5, wherein: The solar cell is further provided with an isolation groove, the isolation groove at least passing through the transparent conductive layer, and the isolation groove is located between the first electrode and the second electrode.

8. The solar cell according to claim 7, wherein The isolation trench is located in the first region.

9. The solar cell according to claim 7, wherein The isolation trench is located in the second region.

10. The solar cell according to claim 7, wherein The isolation trench is located across a boundary between the first region and the second region.

11. The solar cell according to claim 2, wherein The solar cell further comprises: The second tunneling layer is located on a surface of the first doping layer away from the first tunneling layer and is located between the first doping layer and the polysilicon layer.

12. The solar cell according to claim 11, wherein The region of the polysilicon layer close to the second tunneling layer is a lightly doped region, and the doping type of the lightly doped region is the same as the doping type of the first doping layer.

13. The solar cell according to claim 12, wherein: In the polysilicon layer, the doping concentration of the lightly doped region decreases gradually along the first tunneling layer toward the first passivation layer until the doping concentration reaches zero.

14. The solar cell according to claim 2, wherein The doping element of the first doping layer includes at least one element selected from the group consisting of oxygen, carbon and nitrogen.

15. The solar cell according to claim 2, wherein The doping element of the second doping layer includes at least one element selected from the group consisting of oxygen, carbon and nitrogen.

16. The solar cell according to claim 2, wherein The solar cell further comprises: The first diffusion layer is located in the first area of ​​the first surface and between the substrate and the first tunneling layer.

17. The solar cell according to claim 16, wherein The first diffusion layer includes a crystalline silicon substrate, wherein the doping conductivity type of the doping element of the crystalline silicon substrate is the same as the conductivity type of the doping element in the first doping layer, and the doping concentration of the doping element of the crystalline silicon substrate is less than or equal to the doping concentration of the doping element in the first doping layer.

18. The solar cell according to claim 1, wherein The solar cell further comprises: The insulating layer is located on a surface of the polysilicon layer away from the passivation contact layer and is located between the polysilicon layer and the first passivation layer.

19. The solar cell according to claim 1, wherein The material of the polysilicon layer is intrinsic polysilicon.

20. The solar cell according to claim 1, wherein The doping element of the polysilicon layer includes at least one element selected from the group consisting of oxygen, carbon and nitrogen.

21. The solar cell according to claim 1, wherein The thickness of the polysilicon layer is 3 nanometers to 150 nanometers.

22. The solar cell according to claim 1, wherein The solar cell further comprises: The second diffusion region is located on the second surface of the substrate.

23. The solar cell according to claim 20, wherein The second diffusion region comprises a crystalline silicon substrate, wherein the doping concentration of the second diffusion region is greater than the doping concentration of the doping element in the substrate.

24. The solar cell according to claim 1, wherein The solar cell further comprises: The passivation anti-reflection layer is located on the second surface of the substrate.

25. The solar cell according to claim 24, wherein The passivation anti-reflection layer includes: a second passivation layer stacked on the second surface of the substrate; wherein, The material of the second passivation layer includes one of intrinsic amorphous silicon, doped amorphous silicon, silicon oxide and aluminum oxide.

26. The solar cell according to claim 24, wherein The passivation anti-reflection layer comprises: a second passivation layer and an anti-reflection layer stacked on the second surface of the substrate; wherein, The material of the second passivation layer includes one of intrinsic amorphous silicon, doped amorphous silicon, silicon oxide and aluminum oxide; The anti-reflection layer is made of at least one of silicon nitride and silicon oxynitride.

27. The solar cell according to claim 1, wherein The material of the first passivation layer includes intrinsic amorphous silicon.

28. The solar cell according to claim 1, wherein The material of the first passivation layer is doped with at least one element selected from the group consisting of oxygen, carbon and nitrogen.

29. A method for manufacturing a solar cell, comprising: A substrate is provided; wherein the substrate includes a base and a passivation contact layer; wherein the base includes a first surface and a second surface disposed opposite to each other, the first surface including a first region and a second region adjacent to each other in a first direction; the passivation contact layer is located in the first region of the first surface; the passivation contact layer includes a first tunneling layer and a first doping layer, the first tunneling layer and the first doping layer being stacked in sequence in the first region of the first surface of the base in a direction away from the second surface; forming a polysilicon layer on at least a portion of a surface of the passivation contact layer away from the substrate; and A first passivation layer is formed on a surface of the polysilicon layer away from the passivation contact layer and on a second region of the first surface of the substrate.

30. The method for manufacturing a solar cell according to claim 29, wherein: After the step of forming a first passivation layer on the surface of the polysilicon layer away from the passivation contact layer and the second area of ​​the first surface of the substrate, the method further includes: forming a second doping layer on a surface of the first passivation layer away from the polysilicon layer; forming a transparent conductive layer and a first electrode on a surface of the second doped layer away from the first passivation layer; wherein the first electrode is located in the first region and extends from the transparent conductive layer at least through the polysilicon layer, at least a portion of the first electrode is in contact with at least one of the first doped layer and the polysilicon layer, and the remaining portion of the first electrode is in contact with the transparent conductive layer located in the first region; A second electrode is formed on a surface of the transparent conductive layer away from the first passivation layer; wherein the second electrode is located in the second region.

31. The method for manufacturing a solar cell according to claim 30, wherein: The step of forming a transparent conductive layer and a first electrode on a surface of the second doped layer away from the first passivation layer comprises: forming a transparent conductive layer on a surface of the second doped layer away from the first passivation layer; forming an electrode opening in the transparent conductive layer, the second doped layer, and the first passivation layer; wherein at least a portion of the bottom of the electrode opening is the first doped layer; The first electrode is formed in the electrode opening.

32. The method for manufacturing a solar cell according to claim 30, wherein: The step of forming a transparent conductive layer and a first electrode on a surface of the second doped layer away from the first passivation layer comprises: forming electrode grooves in the transparent conductive layer, the second doping layer, and the first passivation layer; A transparent conductive layer is formed on the surface of the second doped layer away from the first passivation layer, and on the groove wall and groove bottom of the electrode groove; wherein the groove bottom of the electrode groove is at least partially the first doped layer The first electrode is formed in the remaining area of ​​the electrode groove.

33. The method for manufacturing a solar cell according to claim 30, wherein: The method further comprises: The polysilicon layer is subjected to laser local heat treatment to diffuse the doping elements of the first doping layer into the polysilicon layer, thereby forming a doping diffusion portion in the polysilicon layer; wherein the first doping layer includes an intrinsic portion and the doping diffusion portion, and the intrinsic portion is located on the surface of the first tunneling layer away from the substrate.

34. The method for manufacturing a solar cell according to claim 30, wherein: Before the step of forming a polysilicon layer on at least a portion of the surface of the passivation contact layer away from the substrate, the method further comprises: A second tunneling layer is formed on a surface of the first doped layer away from the substrate.

35. The method for manufacturing a solar cell according to claim 29, wherein: The step of providing a substrate comprises: Providing a substrate, the substrate comprising a first surface and a second surface disposed opposite to each other; A first diffusion layer, a first tunneling layer and a first doping layer are sequentially stacked on the first surface of the substrate in a direction away from the second surface.

36. The method for manufacturing a solar cell according to claim 35, wherein: After forming a first diffusion layer, a first tunneling layer, and a first doping layer in sequence on the first surface of the substrate in a direction away from the second surface, the method further includes: forming an insulating layer on a surface of the first doped layer away from the first tunneling layer; Parts of the first diffusion layer, the first tunneling layer, the first doping layer, and the insulating layer are removed to expose the second region of the substrate.

37. The method for manufacturing a solar cell according to claim 29, wherein: The method further comprises: A second diffusion region, a second passivation layer and an emission reduction layer are sequentially formed on the second surface of the substrate.

38. A photovoltaic module comprising at least one cell string, wherein the cell string comprises at least two solar cells according to any one of claims 1 to 28.

39. A photovoltaic module comprising at least one cell string, wherein the cell string comprises at least two solar cells manufactured by the method for manufacturing a solar cell according to any one of claims 29 to 37.

40. A photovoltaic system comprising the photovoltaic module according to claim 38 or 39.

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