Solar cell, manufacturing method for the same, and photovoltaic module

Abstract

To provide a solar cell, a manufacturing method for the same, and a photovoltaic module.SOLUTION: A solar cell includes: a substrate having opposing first and second surfaces; a plurality of first doping parts 103 located in a corresponding first region; a plurality of second doping parts 104 located in a corresponding second region; a plurality of first electrodes located in the corresponding first doping parts; and a plurality of third doping parts 106 located on the upper surface of the corresponding first doping parts. The first surface includes first and second regions alternately arranged in a first direction. The second doping parts are spaced apart from the first doping parts. The second doping parts and the first doping parts contain different types of doping elements. In the first doping parts, the third doping parts are located on at least one side of the first electrodes in the first direction and are spaced apart from adjacent first electrodes. Here, the third doping parts and the first doping parts contain different types of doping elements.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present application relate to the field of photovoltaics, and more particularly to solar cells, methods for manufacturing solar cells, and photovoltaic modules. [Background technology]

[0002] An IBC cell (interdigitated back contact) is a back-contact solar cell structure in which positive and negative metal electrodes are arranged in a comb-like pattern on the backlight surface of the cell, with the PN junction and electrodes located on the back surface of the cell. In other words, the PN junction and metal electrodes of an IBC cell are both on the back surface of the cell, and there is no shielding of the metal electrodes on the front surface, allowing for high short-circuit current and conversion efficiency. However, there is currently a need to further improve the structure of IBC cells in order to improve their photoelectric conversion performance. Summary of the Invention [Problem to be solved by the invention]

[0003] In the embodiments of the present application, a solar cell, a method for manufacturing a solar cell, and a photovoltaic module are provided that are advantageous in improving at least the photoelectric conversion efficiency of the solar cell. [Means for solving the problem]

[0004] According to some embodiments of the present application, in one aspect of the embodiments of the present application, a solar cell is provided, the solar cell including: a substrate having opposing first and second surfaces; a plurality of first doped portions located in corresponding first regions; a plurality of second doped portions located in corresponding second regions; a plurality of first electrodes located in the corresponding first doped portions and in electrical contact with the corresponding first doped portions; and a plurality of third doped portions located on a portion of an upper surface of the corresponding first doped portion, wherein the first surface has first and second regions arranged alternately in a first direction, the second doped portions are spaced apart from the first doped portions, and the type of doping element in the second doped portions is different from the type of doping element in the first doped portions, and the third doped portion is located on at least one side of the first electrode in the first direction, and the third doped portion is spaced apart from the adjacent first electrode, wherein the type of doping element in the third doped portion is different from the type of doping element in the first doped portion.

[0005] In some embodiments, the third doped portion is located on one side of the first electrode in the first direction, and the ratio of the width of the third doped portion to the width of the first doped portion in the first direction is 0.05 to 0.5.

[0006] In some embodiments, the third doped portion is located on both sides of the first doped portion that are opposite to each other in the first direction of the first electrode.

[0007] In some embodiments, the distance between adjacent third doped portions in each of the first doped portions in the first direction is a first width, and the ratio of the first width to the width of the third doped portion in the first direction is 0.23 to 68.

[0008] In some embodiments, the thickness of the third doped portion is equal to the thickness of the second doped portion.

[0009] In some embodiments, a gap is formed between the first doped portion and the second doped portion adjacent to each other, and a part of the first surface is exposed through the gap.

[0010] In some embodiments, in the thickness direction of the substrate, the first surface corresponding to the first region is flush with the first surface corresponding to the second region, or in the thickness direction of the substrate, the first surface corresponding to the first region is not flush with the first surface corresponding to the second region, and a distance between the first surface corresponding to the first region and the second surface is a first height, and a distance between the first surface corresponding to the second region and the second surface is a second height, and the first height is greater than the second height.

[0011] In some embodiments, in the thickness direction of the substrate, the first surface corresponding to the first region is not flush with the first surface corresponding to the second region, and the distance between the first surface corresponding to the first region and the second surface is a first height, the distance between the first surface corresponding to the second region and the second surface is a second height, the first height is greater than the second height, and there is a gap between at least some of the adjacent first doped portions and second doped portions.

[0012] In some embodiments, the solar cell further includes an insulating layer located between the third doped portion and the first doped portion.

[0013] In some embodiments, the material of the insulating layer includes a silica glass material doped with a first doping element, and the type of the first doping element is the same as the type of the doping element doped into the first doped portion.

[0014] In some embodiments, the material of the third doped portion is the same as the material of the second doped portion.

[0015] According to some embodiments of the present application, in another aspect of the embodiments of the present application, there is provided a method for manufacturing a solar cell, the method for manufacturing a solar cell including: providing a substrate, the substrate having a first surface and a second surface opposite to each other, the first surface including first regions and second regions alternately arranged in a first direction; forming a plurality of first doped portions, the first doped portions being located in the corresponding first regions, upper surfaces of the first doped portions including metal regions; and forming an initial first doped layer, the initial first doped layer covering the first surface corresponding to the plurality of first doped portions and the plurality of second regions, and a type of doping element in the initial first doped layer being the first doped layer. the type of doping element in the first doped portion is different from the type of doping element in the first doped portion; removing at least a portion of the initial first doped layer in the metal region by a laser process to expose the metal region, the remaining portion of the initial first doped layer located in the second region being a second doped portion, the second doped portion being spaced apart from the first doped portion, and the remaining portion of the initial first doped layer located in the first doped portion being a third doped portion; and forming a plurality of first electrodes, the first electrodes being located in corresponding metal regions and in electrical contact with the first doped portion, and the first electrodes being spaced apart from the third doped portion.

[0016] In some embodiments, the step of forming the first doping portion includes: forming an initial substrate, the initial substrate having a third surface and a fourth surface opposite to each other, the third surface including third regions and fourth regions alternately arranged in the first direction; forming a doping source layer covering each of the third regions and each of the fourth regions, with a target doping element in the doping source layer; performing a driving step to drive the target doping element in the doping source layer into the initial substrate to form the initial second doping layer; removing the doping source layer and the initial second doping layer in the fourth region, removing a portion of the initial substrate with a thickness corresponding to the fourth region, using the remaining initial substrate as the substrate, the remaining initial second doping layer located in the third region as the first doping portion, and the doping source layer located in the third region as an insulating layer; and in the step of forming the initial first doping layer, the initial first doping layer covers the insulating layer in the first doping portion.

[0017] In some embodiments, the step of removing a portion of the initial first doping layer in at least the metal region using a laser process also removes the doping source layer in the metal region, and the doping source layer in the region of the third region excluding the metal region becomes the insulating layer.

[0018] In some embodiments, there is a gap between at least some of the adjacent first and second regions, and in the step of forming the initial first doping layer, the initial first doping layer is also located in the gap, and in the step of removing the initial first doping layer in at least the metal region by a laser process, the initial first doping layer in the gap is also removed.

[0019] According to some embodiments of the present application, in another aspect of the embodiments of the present application, there is further provided a photovoltaic module, which includes a cell string formed by connecting a plurality of solar cells provided in any of the above embodiments or solar cells manufactured by the solar cell manufacturing method provided in any of the above embodiments, an encapsulation layer for covering a surface of the cell string, and a cover plate for covering a surface of the encapsulation layer away from the cell string. [Effects of the Invention]

[0020] The technical solution according to the embodiments of the present disclosure has at least the following advantages:

[0021] In the solar cell technical proposals provided in the embodiments of the present application, adjacent first doping portions are spaced apart from the second doping portions, thereby avoiding leakage problems between the first and second doping portions. Furthermore, a third doping portion is provided on a portion of the top surface of the first doping portion. The type of doping element in the third doping portion is different from that in the first doping portion. The third doping portion, which has a different doping element type from that in the first doping portion, absorbs impurities from the first doping portion, thereby improving the photoelectric conversion efficiency of the solar cell. Furthermore, the third doping portion is spaced apart from the first electrode, which increases the process window for fabricating the first electrode, reduces process difficulty, and helps prevent contact between the third doping portion and the first electrode from affecting normal carrier transport. Furthermore, the third doping portion may be a protective layer for the first doping portion, and in the process of manufacturing the solar cell, the third doping portion may reduce the possibility of damaging the first doping layer or reduce the impurities introduced into the first doping layer, thereby improving the yield and quality of the solar cell. [Brief explanation of the drawings]

[0022] One or more embodiments are illustratively described in corresponding figures in the accompanying drawings, but these illustrative descriptions are not intended to limit the embodiments, and unless otherwise specified, the figures in the accompanying drawings are not limited to scale. In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without any creative effort. [Figure 1] FIG. 1 is a diagram showing the structure of a first type of solar cell provided in the present application examples. [Figure 2] FIG. 2 is a diagram illustrating the structure of a second type of solar cell provided in one embodiment of the present application. [Figure 3] FIG. 3 is a diagram showing a third type of structure of a solar cell provided in one embodiment of the present application. [Figure 4] FIG. 4 is a local top view of the solar cell shown in FIG. [Figure 5] FIG. 5 is a diagram illustrating the structure of a fourth type of solar cell provided in one embodiment of the present application. [Figure 6] FIG. 6 is a diagram illustrating the structure of a fifth type of solar cell provided in one embodiment of the present application. [Figure 7] FIG. 7 is a diagram illustrating the structure of a sixth type of solar cell provided in one embodiment of the present application. [Figure 8] FIG. 8 is a diagram showing a structure corresponding to the step of providing a substrate in the method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 9] FIG. 9 is a diagram showing a structure corresponding to the step of providing an initial substrate in the method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 10] FIG. 10 is a diagram showing a structure corresponding to the step of forming a doping source layer in the method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 11]FIG. 11 is a diagram showing a structure corresponding to the step of providing a substrate in a method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 12] FIG. 12 is a diagram showing a structure corresponding to the step of forming an initial first doping layer in the method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 13] FIG. 13 is a diagram illustrating a structure corresponding to the step of forming a second doped portion and a third doped portion in a method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 14] FIG. 14 is a diagram illustrating a structure corresponding to the step of forming a second doping portion and a third doping portion in a method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 15] FIG. 15 is a diagram showing a structure corresponding to a step of providing a substrate in another method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 16] FIG. 16 is a diagram showing a structure corresponding to a step of forming an intrinsic semiconductor layer in another method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 17] FIG. 17 is a diagram showing a structure corresponding to the step of providing a substrate in another method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 18] FIG. 18 is a diagram showing a structure corresponding to a step of forming an initial first doping layer in another solar cell manufacturing method provided in another embodiment of the present application. [Figure 19] FIG. 19 is a diagram showing a structure corresponding to the step of forming a second doped portion and a third doped portion in another method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 20] FIG. 20 is a diagram showing a structure corresponding to the step of forming the second doped portion and the third doped portion in another method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 21] FIG. 20 is a diagram showing the structure of a photovoltaic module provided in another embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0023] As can be seen from the background art, there is a need to further improve the photoelectric conversion efficiency of current IBC cells.

[0024] In the solar cell provided in the embodiments of the present application, adjacent first doping portions are spaced apart from the second doping portions, thereby avoiding leakage current problems between the first and second doping portions. Furthermore, a third doping portion is provided on a portion of the top surface of the first doping portion. Because the doping element type in the third doping portion is different from that in the first doping portion, the third doping portion absorbs impurities from the first doping portion, thereby improving the photoelectric conversion efficiency of the solar cell. Furthermore, because the third doping portion is spaced apart from the first electrode, this contributes to increasing the process window for fabricating the first electrode, reducing process difficulty, and preventing interference with normal carrier transport due to contact between the third doping portion and the first electrode. Furthermore, the third doping portion may serve as a protective layer for the first doping portion. During the solar cell manufacturing process, the third doping portion reduces the possibility of damaging the first doping layer or reducing impurities introduced into the first doping layer, thereby improving the yield and quality of the solar cell.

[0025] Hereinafter, each embodiment of the present application will be described in detail in conjunction with the drawings. However, as will be understood by those skilled in the art, although many technical details are proposed in the embodiments of the present application to help readers better understand the present application, the technical solutions claimed for protection in the embodiments of the present application can be realized without these technical details and various changes and modifications based on the following embodiments.

[0026] FIG. 1 is a diagram showing the structure of a first type of solar cell provided in the present example.

[0027] As shown in FIG. 1 , the solar cell includes a substrate 100 having a first surface 101 and a second surface 102 facing each other, a plurality of first doped portions 103 located in corresponding first regions 1, a plurality of second doped portions 104 located in corresponding second regions 2, a plurality of first electrodes 105 located in the corresponding first doped portions 103 and in electrical contact with the corresponding first doped portions 103, and a plurality of third doped portions 106 located on a part of the upper surface of the corresponding first doped portion 103, and the first surface 101 is arranged alternately in a first direction X in the first regions 1 and the second regions 2. The first doped region 105 includes a region 2, in which the second doped region 104 is spaced apart from the first doped region 103, and the type of doping element in the second doped region 104 is different from the type of doping element in the first doped region 103, and the first doped region 105 includes a third doped region 106 located on at least one side of the first electrode in a first direction, and the third doped region 106 is spaced apart from the adjacent first electrode 105, and the type of doping element in the third doped region 106 is different from the type of doping element in the first doped region 103.

[0028] In the solar cell provided in the embodiment of the present application, the first doping portion 103 and the second doping portion 104, which are spaced apart, contribute to preventing leakage problems that may occur between the first doping portion 103 and the second doping portion 104. The third doping portion 106, which has a doping type different from that of the first doping portion 103, absorbs impurities into the first doping portion 103, thereby improving the photoelectric conversion efficiency of the solar cell. The spacing between the third doping portion and the first electrode increases the process window for fabricating the first electrode, reducing process difficulty and helping to prevent interference with normal carrier transport due to contact between the third doping portion and the first electrode. Furthermore, the third doping portion 106 can serve as a protective layer for the first doping portion 103. During subsequent processing of the first doping portion, the third doping portion 106 reduces the possibility of damage to the first doping layer or reduces impurities introduced into the first doping layer, thereby improving the yield and quality of the solar cell. For example, a cleaning process is often used in the manufacturing process of a solar cell, and the presence of the third doping portion 106 can reduce the possibility of damage to the first doping layer during the cleaning process.

[0029] The upper surface of the first doped portion 103 is a surface that is set apart from the first surface 101 of the first doped portion 103 .

[0030] The substrate 100 is used to receive incident light and generate photo-generated carriers. In some embodiments, the substrate 100 may be a semiconductor substrate 100, such as silicon, germanium, silicon germanium, or silicon on insulator.

[0031] In some embodiments, the material of the substrate 100 may be an elemental semiconductor material. Specifically, the elemental semiconductor material may be composed of a single element, such as silicon or germanium. Here, the elemental semiconductor material may be in a single crystalline state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state having both a single crystalline state and an amorphous state is called a microcrystalline state). For example, silicon may be at least one of single crystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. The material of the substrate 100 may be silicon, or may include at least one of single crystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0032] In some embodiments, the material of substrate 100 may be a compound semiconductor material. Common compound semiconductor materials may be materials such as silicon germanium, silicon carbide, gallium arsenide, indium gallium, perovskites, cadmium telluride, copper indium selenide, or may be silicon carbide, organic materials, or multi-component compounds. Multi-component compounds may include, but are not limited to, materials such as perovskites, gallium arsenide, cadmium telluride, copper indium selenide, and the like.

[0033] The substrate 100 may be a sapphire substrate, a silicon-on-insulator substrate, or a germanium-on-insulator substrate.

[0034] In some embodiments, the substrate 100 may be an N-type semiconductor substrate or a P-type semiconductor substrate. The N-type semiconductor substrate is doped with an N-type doping element, which may be any of Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). The P-type semiconductor substrate 100 is doped with a P-type doping element, which may be any of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0035] The solar cell provided in the embodiments of the present application may be an IBC cell. In some embodiments, the solar cell is a single-sided cell, in which the second surface 102 of the substrate 100 is used as a light-receiving surface to receive incident light, and the first surface 101 of the substrate 100 is used as a backlight surface. In some embodiments, the solar cell provided in the embodiments of the present application may be a double-sided solar cell. That is, both the first surface 101 and the second surface 102 of the substrate 100 can be used as a light-receiving surface, and both the first surface 101 and the second surface 102 are used to receive incident light.

[0036] In some embodiments, the second surface 102 of the substrate 100 may have a textured structure, which may include a regularly shaped pyramidal texture and an irregularly shaped black silicon. The slopes of the textured structure may increase the internal reflection of incident light, improve the absorption efficiency of the substrate 100 for the incident light, and ultimately increase the cell efficiency of the solar cell.

[0037] In some embodiments, the first surface 101 of the substrate 100 may be a polished surface, which refers to a flat surface formed by removing the surface texture using a polishing solution or laser etching. After polishing, the back surface becomes more flat, which increases the reflectivity of long-wavelength light, promotes secondary absorption of incident light, and increases Isc. Furthermore, the specific surface area of the back surface is reduced, which reduces back surface recombination and improves back surface passivation.

[0038] In some embodiments, the solar cell may further include a dielectric layer (not shown) located on the first surface of the substrate, with the first doped portion located on a surface of the dielectric layer away from the substrate corresponding to the corresponding first region, and the second doped portion located on a surface of the dielectric layer away from the substrate corresponding to the corresponding second region.

[0039] For example, the dielectric layer may be a tunnel layer. The tunnel layer may create an asymmetric offset in the band of the first plane, so that the potential barrier for majority carriers in the carriers is lower than the potential barrier for minority carriers in the carriers. This allows majority carriers to easily pass through the tunnel layer and undergo quantum tunneling, allowing them to be transported to the first doped portion or the second doped portion, while minority carriers have difficulty passing through the tunnel layer, allowing for selective carrier transport. The tunnel layer also provides a chemical passivation effect for the substrate.

[0040] The material of the tunnel layer may include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or magnesium fluoride.

[0041] In some embodiments, the first doping portion may be in direct contact with the first surface corresponding to the corresponding first region, and the second doping portion may be in direct contact with the first surface corresponding to the corresponding second region, without providing a dielectric layer.

[0042] FIG. 2 is a diagram illustrating the structure of a second type of solar cell provided in one embodiment of the present application.

[0043] 2, in some embodiments, a front surface field (FSF) 107 is provided on the second surface 102 of the substrate 100, and the conductivity type of the doping elements in the front surface field 107 is the same as that of the doping elements in the substrate 100, and the concentration of the doping elements in the front surface field 107 is higher than that of the doping elements in the substrate 100. This reduces the concentration of surface minority carriers by utilizing the field passivation effect, thereby reducing the surface recombination rate, lowering the series resistance, and improving the electron transport capacity.

[0044] 2, in some embodiments, the solar cell includes a first passivation layer 108 located on a surface of the front field away from the substrate 100, and the first passivation layer performs a passivation function for the second surface 102 of the substrate 100. The first passivation layer 108 may have a single layer structure or a multilayer structure, and the material of the first passivation layer 108 may be one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0045] The material of the first electrode 105 may include one or more of aluminum, silver, gold, nickel, molybdenum, or copper.

[0046] FIG. 3 is a diagram showing a third type of structure of a solar cell provided in one embodiment of the present application, and FIG. 4 is a local top view of the solar cell shown in FIG.

[0047] 3 and 4, in some embodiments, the solar cell further includes a plurality of second electrodes 109 located on and in electrical contact with the corresponding second doped portions 104. The material of the second electrodes 109 may include one or more of aluminum, silver, gold, nickel, molybdenum, or copper.

[0048] The first electrode 105 and the second electrode 109 both extend along the second direction Y, and the second direction Y and the first direction X intersect.

[0049] As shown in FIG. 2, the solar cell may further include a second passivation layer 112, which covers the upper surface of the third doped portion 106, the upper surface of the second doped portion 104, and the upper surface of the first doped portion 103 that is not covered by the third doped portion 106, the first electrode 105 passes through the second passivation layer 112 to be in electrical contact with the first doped portion 103, and the second electrode 109 passes through the second passivation layer 112 to be in electrical contact with the second doped portion 104.

[0050] In some embodiments, the type of doping element in the first doped portion 103 may be the same as the type of doping element in the substrate 100, and the concentration of the doping element in the first doped portion 103 may be greater than the concentration of the doping element in the substrate 100, forming a high-low junction with the substrate 100. A built-in electric field is formed at the high-low junction, pointing the first doped portion 103 toward the inside of the substrate 100. The built-in electric field induces minority carrier drift and escapes from the interface, reducing the carrier recombination rate at the interface of the substrate 100. This improves the open-circuit voltage, short-circuit current, and backing factor of the solar cell and the photoelectric conversion efficiency of the back-contact cell. The type of doping element in the second doped portion 104 may be opposite to the type of doping element in the substrate 100, thereby forming a PN junction between the second doped portion 104 and the substrate 100. The type of doping element in the third doped portion 106 is opposite to the type of doping element in the first doped portion 103.

[0051] For example, if the doping element in the substrate 100 is a P-type doping element, the doping element in the first doping portion 103 may be a P-type doping element, and the second doping portion 104 and the third doping portion 106 are both doped with an N-type doping element. As can be understood, during the manufacturing process of a solar cell, metal impurities are easily introduced into the solar cell due to limitations in the process environment and process equipment, which can affect the photoelectric conversion efficiency of the solar cell. Therefore, to optimize the photoelectric conversion efficiency of the solar cell, it is necessary to remove the metal impurities from the solar cell. In some embodiments, the doping element in the third doping portion 106 is phosphorus. The phosphorus-doped third doping portion 106 has high solubility in the metal impurities, which provides the first doping portion 103 with a phosphorus impurity absorption effect, thereby reducing the content of metal impurities in the first doping portion 103 and improving the photoelectric conversion efficiency of the solar cell.

[0052] For example, if the doping element in the substrate 100 is an N-type doping element, the doping element in the first doping portion 103 is an N-type doping element, and the second doping portion 104 and the third doping portion 106 are both doped with a P-type doping element. In some embodiments, the doping element in the third doping portion 106 is boron, and the boron-doped third doping portion 106 provides impurity absorption to the first doping portion 103, reducing the content of metal impurities in the first doping portion 103 and improving the photoelectric conversion efficiency of the solar cell.

[0053] In some embodiments, the type of doping element in the first doped portion 103 may be opposite to the type of doping element in the substrate 100. In this case, the first doped portion 103 and the substrate 100 form a PN junction. The type of doping element in the second doped portion 104 may be the same as the type of doping element in the substrate 100, the concentration of the doping element in the second doped portion 104 may be higher than the concentration of the doping element in the substrate 100, and the type of doping element in the third doped portion 106 may be opposite to the type of doping element in the first doped portion 103.

[0054] In some embodiments, the third doped portion 106 may be doped with an N-type doping element or a P-type doping element, and may also be doped with hydrogen. The hydrogen in the third doped portion 106 can saturate the dangling bonds in the first doped portion 103 and passivate the first doped portion 103, reducing carrier recombination at the interface between the first doped portion 103 and the third doped portion 106, and contributing to improving the photoelectric conversion efficiency of the solar cell.

[0055] The material of the first doped portion 103 may include amorphous silicon, polycrystalline silicon, silicon carbide, gallium arsenide (GaAs), etc. The material of the second doped portion 104 may include amorphous silicon, polycrystalline silicon, silicon carbide, gallium arsenide (GaAs), etc.

[0056] The material of the third doped portion 106 may include amorphous silicon, polycrystalline silicon, silicon carbide, gallium arsenide (GaAs), and the like.

[0057] In some embodiments, the material of the third doping portion 106 and the material of the second doping portion 104 may be the same. This allows the third doping portion 106 and the second doping portion 104 to be manufactured in the same process step to simplify the manufacturing process. For example, after forming the first doping portion 103, an initial first doping layer is formed to cover the first surface 101 corresponding to the plurality of first doping portions 103 and the second region 2. Part of the initial first doping layer in the first doping portion 103 is removed to expose part of the surface of the first doping portion 103. The initial first doping layer located in the first doping portion 103 is designated as the third doping portion 106. Then, a first electrode 105 is formed on the upper surface of the first doping portion 103 exposed by the third doping portion 106. The initial first doping layer located in the second region 2 is designated as the second doping portion 104.

[0058] In some embodiments, the material of the third doping portion 106 may include silicon oxide or silicon nitride, so that the third doping portion 106 can serve as a passivation layer and can provide a passivation effect to the substrate 100 together with the second passivation layer 112.

[0059] In some embodiments, the third doped portion 106 may be fabricated from the same initial first doped layer as the second doped portion 104, such as by a patterning process, where the thickness of the third doped portion may be equal to the thickness of the second doped portion 104.

[0060] In some embodiments, the thickness of the third doping portion 106 may be smaller than the thickness of the first doping portion 103. In this way, the third doping portion 106 can provide an impurity absorption function for the first doping portion 103, while the thinner third doping portion 106 has a lower content of doping elements, which reduces the amount of doping elements diffusing from the third doping portion 106 to the first doping portion 103 and helps prevent the doping elements in the third doping portion 106 from diffusing into the first doping portion 103 and affecting the performance of the first doping portion 103.

[0061] The thickness of the third doped portion 106 may be 10 nm to 100 nm. For example, the thickness of the third doped portion 106 may be 10 nm, 18 nm, 34 nm, 61 nm, 76.5 nm, 88 nm, 95 nm, or 100 nm. This ensures excellent impurity absorption capability of the third doped portion, while preventing the third doped portion 106 from containing too much doping element and reducing the amount of doping element diffusing from the third doped portion 106 to the first doped portion 103.

[0062] The thickness of the first doped portion may be 50 nm to 140 nm, for example, 50 nm, 67 nm, 72 nm, 85 nm, 104 nm, 124 nm, 137 nm, or 140 nm.

[0063] In some embodiments, the third doping portion 106 may be located on one side of the first electrode 105 in the first direction of the first doping portion 103. Here, the ratio of the width of the third doping portion 106 to the width of the first doping portion 103 in the first direction is 0.05 to 0.5. For example, this ratio may be 0.05, 0.14, 0.27, 0.35, 0.48, or 0.5. This ratio range ensures that the area of the top surface of the first doping portion 103 that is not covered by the third doping portion 106 is large, a large area is reserved for the first electrode 105, and a sufficient distance can be maintained between the first electrode 105 and the third doping portion 106 on the first doping portion 103.

[0064] Here, the width of the first doping portion 103 in the first direction may be 150 μm to 1700 μm, for example, 150 μm, 437 μm, 798 μm, 926 μm, 1185 μm, 1372 μm, 1521 μm, or 1700 μm.

[0065] In the first direction, the width of the third doping portion 106 may be 7.5 μm to 935 μm, for example, 7.5 μm, 75 μm, 188 μm, 385 μm, 593 μm, 735 μm, 858 μm, or 935 μm.

[0066] In some embodiments, the first doped portion 103 may have the third doped portion located on both opposing sides in the first direction of the first electrode 105. This increases the area of the top surface of the first doped portion 103 covered by the third doped portion 106 compared to when the third doped portion 106 is located on one side of the first electrode 105 in the first direction, thereby enhancing the impurity absorption effect of the third doped portion 106 and contributing to improving the photoelectric conversion efficiency of the solar cell. In addition, from the perspective of the manufacturing process, the third doped portion 106 may be formed by patterning an initial first doped layer covering the top surface of the first doped portion 103. By arranging the third doping portion 106 in the first doping portion 103 so that it is located on opposite sides of the first electrode 105 in the first direction, the area of the film opening region of the initial first doping layer can be reduced, and damage to the bottom surface of the initial first doping layer of the first doping portion 103 can be reduced during the patterning process of the initial first doping layer, thereby contributing to improving the performance of the solar cell.

[0067] Here, the distance between adjacent third doping portions 106 in each first doping portion 103 in the first direction is a first width, and the ratio of the first width to the width of the third doping portion 106 in the first direction is 0.23 to 68, for example, this ratio may be 0.23, 16, 36, 42, 57, or 68. Within this range, a large distance between the first electrode 105 and the adjacent third doping portion 106 is ensured, and the area of the upper surface of the first doping portion 103 covered by the third doping portion 106 is ensured, thereby achieving a good impurity absorption effect of the third doping portion 106 on the first doping portion 103. Furthermore, from the perspective of the manufacturing process, the third doping portion 106 can be formed by patterning an initial first doping layer covering the upper surface of the first doping portion 103. Within this range, the area of the film opening region of the initial first doping layer can be ensured to be neither too large nor too small, and the time required for the solar cell manufacturing process can be controlled to improve manufacturing efficiency.

[0068] The first width may be 135 μm to 510 μm. For example, the first width may be 135 μm, 142 μm, 272 μm, 351 μm, 378 μm, 425 μm, 491 μm, or 510 μm. In the first direction X, the width of the third doping portion 106 may be 7.5 μm to 595 μm. For example, the width may be 7.5 μm, 57 μm, 182 μm, 236 μm, 374 μm, 461 μm, 523 μm, or 595 μm.

[0069] 3, the solar cell may further include an insulating layer 111 located between the third doping portion 106 and the first doping portion 103. The insulating layer 111 separates the third doping portion 106 from the first doping portion 103, thereby preventing the doping element in the third doping portion 106 from entering the first doping portion 103 and thereby preventing the doping element in the third doping portion 106 from entering the first doping portion 103 and causing adverse effects on the first doping portion 103. An adverse effect may be, for example, a change in the conductivity type of the first doping portion 103, which may result in the solar cell not operating normally.

[0070] Here, the material of the insulating layer 111 may include a silica glass material doped with a first doping element, where the type of the first doping element is the same as the type of doping element doped into the first doping portion 103. As a result, the insulating layer can be formed in the process step of forming the first doping portion. For example, in the process step of forming the first doping portion 103, an intrinsic semiconductor layer and a doping source layer doped with the first doping element are first sequentially formed, and the first doping element in the doping source layer is driven into the intrinsic semiconductor layer through a driving step, so that the intrinsic semiconductor layer doped with the first doping element becomes the first doping portion 103, and the remaining doping source layer becomes the insulating layer 111. As a result, an extra step of forming the insulating layer 111 is not required, simplifying the manufacturing steps of the solar cell. Furthermore, in the step of forming the third doping portion 106, the insulating layer 111 can prevent the doping element in the third doping portion 106 from diffusing into the first doping portion 103.

[0071] In some embodiments, the material of the insulating layer 111 may include at least one of silicon oxide, silicon oxynitride, aluminum oxide, titanium oxide, hafnium oxide (HfO), gallium oxide (GaO), silicon nitride, silicon carbonitride, aluminum nitride, titanium nitride, titanium carbonitride (TiCN), or silicon carbide (SiC). The insulating layer 111 made of these materials can separate the third doped portion 106 from the corresponding first doped portion 103, and the insulating layer 111 can also have a passivation effect, contributing to improving the photoelectric conversion efficiency of the solar cell.

[0072] A gap 110 may be formed between adjacent first doped portions 103 and second doped portions 104, with a portion of the first surface 101 exposed through the gap 110. In other words, the gap 110 separates the adjacent first doped portions 103 and second doped portions 104. This prevents current leakage due to the formation of a tunnel junction between the first doped portions 103 and the second doped portions 104, ensuring high photoelectric conversion efficiency of the solar cell. In some embodiments, the solar cell further includes a second passivation layer 112 covering the first surface 101 exposed through the gap 110.

[0073] In the first direction, the width of the gap 110 may be between 100 μm and 765 μm. For example, the width may be 100 μm, 165 μm, 310 μm, 455 μm, 582 μm, 637 μm, 705 μm, or 765 μm.

[0074] In some embodiments, the first surface 101 exposed through the gap 110 may have a textured structure. This increases the internal reflection of incident light at the first surface 101 exposed through the gap 110, improving the absorption utilization rate of the incident light in the substrate 100 and ultimately increasing the photoelectric conversion efficiency of the solar cell. In some embodiments, the first surface 101 exposed through the gap 110 may be a polished surface. This improves the flatness of the first surface 101, strengthening the reflection of long-wavelength light, promoting secondary absorption of the incident light, and improving Isc. The relatively flat first surface 101 also contributes to reducing defects in the second passivation layer formed on the first surface 101.

[0075] In some embodiments, the solar cell may include a dielectric layer located on the first surface. The dielectric layer may be located between the plurality of first doped portions and the first surface and between the plurality of second doped portions and the first surface, and may cover the first surface exposed through the gaps. Alternatively, the dielectric layer may be located only between the plurality of first doped portions and the first surface and between the plurality of second doped portions and the first surface.

[0076] FIG. 5 is a diagram illustrating the structure of a fourth type of solar cell provided in one embodiment of the present application.

[0077] As shown in Figure 5, in the thickness direction of the substrate 100, the first surface 101 corresponding to the first region 1 is flush with the first surface 101 corresponding to the second region 2, and there is a gap 110 between the adjacent first doping portion 103 and second doping portion 104.

[0078] As shown in FIG. 1, in the thickness direction of the substrate 100, the first surface 101 corresponding to the first region 1 may not be flush with the first surface 101 corresponding to the second region 2, and the distance between the first surface 101 corresponding to the first region 1 and the second surface 102 is a first height, the distance between the first surface 101 corresponding to the second region 2 and the second surface 102 is a second height, the first height is greater than the second height, and there may be a gap 110 between adjacent first doping portions 103 and second doping portions 104.

[0079] FIG. 6 is a diagram illustrating the structure of a fifth type of solar cell provided in one embodiment of the present application.

[0080] 6 , in the thickness direction of the substrate 100, the first surface 101 corresponding to the first region 1 and the first surface 101 corresponding to the second region 2 are not flush with each other, and the distance between the first surface 101 corresponding to the first region 1 and the second surface 102 is a first height, and the distance between the first surface 101 corresponding to the second region 2 and the second surface 102 is a second height, the first height being greater than the second height, and gaps 110 being present between some adjacent first doped portions 103 and second doped portions 104. This allows the size of the gaps 110 in the direction parallel to the first surface 101 to be reduced compared to a case in which gaps 110 are provided between all adjacent first doped portions 103 and second doped portions 104, and allows the size of the first doped portions 103 and second doped portions 104 in the first direction to be increased within a limited dimensional range.

[0081] Here, adjacent first doping portions and second doping portions are considered as one unit, and the number of gaps in the solar cell provided in the embodiments of the present application may be a first numerical value, and the ratio of the first numerical value to the number of units may be greater than 0 and less than 0.8.

[0082] FIG. 7 is a diagram illustrating the structure of a sixth type of solar cell provided in one embodiment of the present application.

[0083] 7, in some embodiments, there may be no gap 110 between adjacent first doped portions 103 and second doped portions 104, and since the first height is greater than the second height, the adjacent first doped portions 103 and second doped portions 104 are separated by a height difference in the thickness direction of the substrate 100. This contributes to increasing the density of the first doped portions and the second doped portions in the solar cell.

[0084] Therefore, in another embodiment of the present application, a method for manufacturing a solar cell is provided, and the solar cell provided in the above embodiment can be manufactured by the method for manufacturing a solar cell provided in another embodiment of the present application. Hereinafter, the method for manufacturing a solar cell provided in another embodiment of the present application will be described in detail with reference to the drawings. For parts that are the same as or corresponding to the previous embodiment, please refer to the corresponding description of the previous embodiment, and the description will not be repeated here.

[0085] Figures 8 to 14 are diagrams showing structures corresponding to each step of a method for manufacturing a solar cell provided in another embodiment of the present application, and Figures 15 to 20 are diagrams showing structures corresponding to each step of a method for manufacturing a solar cell provided in another embodiment of the present application.

[0086] Fig. 8 is a diagram showing a structure corresponding to a step of providing a substrate in a method for manufacturing a solar cell provided in another embodiment of the present application. Fig. 15 is a diagram showing a structure corresponding to a step of providing a substrate in another method for manufacturing a solar cell provided in another embodiment of the present application.

[0087] As shown in Fig. 8, a substrate 100 is provided, the substrate 100 having a first surface 101 and a second surface 102 facing each other, and the first surface 101 includes first regions 1 and second regions 2 alternately arranged in a first direction X. Fig. 8 shows an example in which a gap 110 is provided between adjacent first and second regions of the provided substrate, and the first surface corresponding to the first region is higher than the first surface corresponding to the second region, where the gap refers to a region separating the adjacent first and second regions, with a gap between the adjacent first and second regions in the first direction X.

[0088] In some embodiments, there may be no gap between adjacent first and second regions.

[0089] As shown in FIG. 15, in some embodiments, the first surface corresponding to the first region may be flush with the first surface corresponding to the second region, with a gap 110 provided between adjacent first and second regions.

[0090] The material of the substrate 100 can be referred to in the above examples, and will not be described again here. The substrate 100 may be doped with an N-type doping element or a P-type doping element. The N-type doping element may be any of Group V elements such as phosphorus, bismuth, antimony, or arsenic. The P-type doping element may be any of Group III elements such as boron, aluminum, gallium, or indium.

[0091] In some embodiments, the second surface 102 of the substrate 100 can be textured to impart a textured structure to the second surface 102. In some embodiments, the textured structure can be fabricated using a solution texturing method. The textured structure can increase the number of times light is refracted at the surface of the solar cell, contributing to the absorption of light by the solar cell and achieving maximum solar energy utilization by the solar cell. For example, if the substrate 100 is monocrystalline silicon, the surface of the substrate 100 can be textured using a mixed solution of an alkaline solution and an alcohol solution. If the substrate 100 is polysilicon, the surface of the substrate 100 can be textured using an acid solution. In some embodiments, the textured structure can be fabricated using a laser texturing process or a reactive ion etching (RIE) texturing process.

[0092] In some embodiments, the step of texturing the second side 102 of the substrate 100 may also include texturing the first side 101 of the substrate 100. In some embodiments, the first side 101 of the substrate 100 may be polished to provide a polished surface. The polished surface may help reduce defects in a film layer subsequently formed on the first side 101.

[0093] A front field 107 may be formed on the second surface 102 of the substrate 100. The concentration of the doping element in the front field is greater than the concentration of the doping element in the substrate 100, thereby utilizing the field passivation effect to reduce the concentration of surface minority carriers, reduce the surface recombination rate, reduce the series resistance, and increase the electron transport capacity.

[0094] In some embodiments, after forming the front field 107, a first passivation layer 108 can be formed on a surface of the front field away from the substrate 100. The first passivation layer provides a passivation effect to the second surface 102 of the substrate 100. Forming the first passivation layer may include an atomic layer deposition process or a PECVD process.

[0095] FIG. 11 is a diagram showing a structure corresponding to the step of providing a substrate in a method for manufacturing a solar cell provided in another embodiment of the present application.

[0096] As shown in FIG. 11, a plurality of first doped portions 103 are formed, and the first doped portions 103 are located in corresponding first regions 1, and the top surfaces of the first doped portions 103 include metal regions.

[0097] The metal region extends along a second direction, which intersects with the first direction X and is parallel to the top surface of the first doped portion 103. In the next step, a first electrode is formed on the top surface of the first doped portion, and the orthogonal projection of the first electrode on the top surface of the corresponding first doped portion is located within the metal region. In other words, the metal region is the portion where the top surface of the first doped portion contacts the first electrode. In the first direction X, the width of the metal region may be greater than the width of the first electrode.

[0098] The first doped portion 103 is doped with an N-type doping element or a P-type doping element. The type of the doping element in the first doped portion 103 may be the same as or different from the type of the doping element in the substrate 100.

[0099] Figure 9 is a diagram showing a structure corresponding to the step of providing an initial substrate in a method for manufacturing a solar cell provided in another embodiment of the present application, and Figure 10 is a diagram showing a structure corresponding to the step of forming a doping source layer in a method for manufacturing a solar cell provided in another embodiment of the present application.

[0100] As shown in FIGS. 9 to 11, the step of forming the first doping portion 103 includes forming an initial substrate 200, the initial substrate 200 having a third surface 201 and a fourth surface 202 facing each other, the third surface 201 including third regions 3 and fourth regions 4 alternately arranged in a first direction, forming a doping source layer 203 covering each of the third regions 3 and each of the fourth regions 4, and providing a target doping element in the doping source layer 203, and performing a driving step to disperse the target doping element in the doping source layer 203. The method includes driving a hot doping element into the initial substrate 200 to form an initial second doping layer 204; removing the doping source layer 203 and the initial second doping layer 204 in the fourth region; removing a portion of the initial substrate 200 corresponding to the fourth region 4; making the remaining initial substrate 200 the substrate 100; making the remaining initial second doping layer 204 located in the third region 3 the first doping portion 103; and making the doping source layer located in the third region 3 the insulating layer 111.

[0101] In this way, by removing a portion of the initial substrate 200 corresponding to the fourth region 4, a second doped portion can be formed in the second region 2 (i.e., the fourth region) in the next step, and a height difference can be formed between the first doped portion 103 and the second doped portion formed in a later step along the thickness direction of the substrate 100.The first doped portion 103 and the second doped portion are separated along the thickness direction of the substrate 100, which prevents leakage current due to a tunnel junction formed between the first doped portion 103 and the second doped portion, maintaining a high photoelectric conversion efficiency of the solar cell formed, and the first surface 101 corresponding to the first region 1 is flush with the first surface 101 corresponding to the second region 2.In addition, an extra insulating layer formation step is not required, simplifying the solar cell manufacturing process.

[0102] In the step of forming the first doped portion 103, the doping source layer 203 and the initial second doped layer 204 in the fourth region are removed, and after removing a portion of the initial substrate 200 with a thickness corresponding to the fourth region 4, the initial substrate 200 becomes the substrate 100, the third region 3 becomes the first region 1 of the substrate 100, and the surface of the initial substrate 200 adjacent to the initial second doped layer corresponding to the fourth region becomes the first surface 101 corresponding to the second region 2. Here, before manufacturing the first doped portion, a front field 107 and a first passivation layer 108 may be formed on the fourth surface.

[0103] Here, the target doping element may be an N-type doping element or a P-type doping element, and the doping source layer 203 may be a silica glass material layer doped with an N-type doping element or a P-type doping element. Accordingly, the insulating layer 111 is a silica glass material layer doped with an N-type doping element or a P-type doping element. In the subsequent step of forming a third doped portion on the upper surface of the first doped portion 103, the insulating layer 111 serves as a shield to prevent excess doping element in the third doped portion from diffusing into the first doped portion 103, thereby ensuring good performance of the first doped portion 103. For example, if the first doped portion 103 is doped with boron, a P-type doping element, the doping source layer is a borosilicate glass layer, and the insulating layer is a borosilicate glass layer accordingly. Furthermore, for example, when the first doped portion 103 is doped with boron, which is an N-type doping element, the doping source layer is a phosphosilicate glass layer, and accordingly, the insulating layer is a phosphosilicate glass layer.

[0104] In some embodiments, there is a gap region between adjacent fourth and third regions. In the step of forming the doping source layer 203, the doping source layer 203 is also located on the third surface corresponding to the gap region. In the driving step, a portion of the initial substrate corresponding to the gap region is converted into an initial second doped layer 204. In the step of forming the first doped portion 103, the doping source layer and the initial second doped layer corresponding to the gap region are removed.

[0105] FIG. 16 is a diagram showing a structure corresponding to a step of forming an intrinsic semiconductor layer in another solar cell manufacturing method provided in another embodiment of the present application, and FIG. 17 is a diagram showing a structure corresponding to a step of providing a substrate in another solar cell manufacturing method provided in another embodiment of the present application.

[0106] 15, in some embodiments, the first surface corresponding to the first region is flush with the first surface corresponding to the second region, and there is a gap 110 between adjacent first and second regions. As shown in FIGS. 16 and 17, the step of forming the first doped portion 103 includes forming an intrinsic semiconductor layer 206 in the substrate 100, the intrinsic semiconductor layer covering each first region 1, each second region 2, and the gap 110; forming a doping source layer 203 in the intrinsic semiconductor layer, the doping source layer 203 having a target doping element; performing a driving step to drive the target doping element in the doping source layer 203 into the intrinsic semiconductor layer 206 to form an initial second doped layer 204; removing the initial second doped layer 204 in the second region 2 and the gap 110; removing the doping source layer; and defining the remaining initial second doped layer 204 located in the first region 1 as the first doped portion 103.

[0107] In this way, in the step of forming the first doped portion 103, there is no need to remove a portion of the thickness of the substrate 100, the first surface 101 corresponding to the first region 1 is flush with the first surface 101 corresponding to the second region 2, and the bottom surface of the second doped portion formed thereafter in the second region 2 is flush with the bottom surface of the first doped portion 103. In order to separate the adjacent first doped portion 103 and second doped portion and avoid electrical leakage between the adjacent first doped portion 103 and second doped portion, it is necessary to remove a portion of the first doped portion 103 or a portion of the second doped portion in the laser process.

[0108] It should be noted that the above-described method for forming the first doped portion 103 is merely an example, and the embodiment of the present application does not particularly limit the method for forming the first doped portion 103.

[0109] In some embodiments, after forming the first doped portion 103, the doping source layer 203 can be removed before forming the second doped portion and the third doped portion, and the third doped portion formed thereafter directly contacts the upper surface of the corresponding first doped portion 103.

[0110] In some embodiments, after forming the first doped portion 103 and before forming the second and third doped portions, the doping source layer can be removed, i.e., the doping source layer 203 on the top surface of the first doped portion 103 is not left as an insulating layer, and an insulating layer is formed on the top surface of the first doped portion 103. The material of the insulating layer can include at least one of silicon oxide, silicon oxynitride, aluminum oxide, titanium oxide, hafnium oxide, gallium oxide, silicon nitride, silicon carbonitride, aluminum nitride, titanium nitride, titanium carbonitride, and silicon carbide. The insulating layer 111 made of such a material can separate the corresponding first doped portion 103 from the third doped portion 106 to be formed later, and the insulating layer 111 can also provide a passivation effect, contributing to improving the photoelectric conversion efficiency of the solar cell.

[0111] Figure 12 is a diagram showing a structure corresponding to the step of forming an initial first doping layer in a method for manufacturing a solar cell provided in another embodiment of the present application, and Figure 18 is a diagram showing a structure corresponding to the step of forming an initial first doping layer in another method for manufacturing a solar cell provided in another embodiment of the present application.

[0112] 12 and 18, an initial first doping layer 207 is formed, which covers the first surface 101 corresponding to the plurality of first doping portions 103 and the plurality of second regions 2, and the type of doping element in the initial first doping layer 207 is different from the type of doping element in the first doping portion 103. Here, the initial first doping layer 207 covers the insulating layer 111 in the first doping portion 103. The initial first doping layer is used to manufacture the second doping portion and the third doping portion after being patterned.

[0113] In some embodiments, when the first doped portion 103 is doped with a P-type doping element, the initial first doped layer 207 may be doped with an N-type doping element. In some embodiments, when the first doped portion 103 is doped with an N-type doping element, the initial first doped layer 207 may be doped with a P-type doping element.

[0114] 12 , in some embodiments, there may be a gap 110 between adjacent first and second regions 1 and 2. In the step of forming the initial first doping layer, the initial first doping layer is also located in the gap 110.

[0115] In some embodiments, there may be no gap between adjacent first regions 1 and second regions 2, and the adjacent first regions 1 and second regions 2 are connected. If the first surface 101 corresponding to the first region 1 is higher than the first surface 101 corresponding to the second region 2, after the initial first doped layer 207 is patterned by a laser process in a later step, the remaining initial first doped layer 207 located in the second region 2 and the first doped portion 103 will be separated along the thickness direction of the substrate 100. If the first surface 101 corresponding to the first region 1 is flush with the first surface 101 corresponding to the second region 2, it is necessary to remove the initial first doped layer 207 located on opposing sidewalls of the first doped portion 103 in the first direction by a laser process in a later step, to separate the first doped portion 103 from the initial first doped layer 207 in the adjacent second region 2.

[0116] In some embodiments, the first surface 101 corresponding to the first region 1 is higher than the first surface 101 corresponding to the second region 2. Also, gaps may be provided between some adjacent first and second regions, and the initial first doping layer 207 is also located in the gaps 110. In a later step, the initial first doping layer 207 located in the gaps needs to be removed by a laser process.

[0117] FIG. 13 is a diagram showing a structure corresponding to the step of forming a second doping portion and a third doping portion in a method for manufacturing a solar cell provided in another embodiment of the present application, and FIG. 19 is a diagram showing a structure corresponding to the step of forming a second doping portion and a third doping portion in another method for manufacturing a solar cell provided in another embodiment of the present application.

[0118] 13 and 19, a laser process is used to remove at least a portion of the initial first doping layer 207 in the metal region to expose the metal region, and the remaining initial first doping layer 207 located in the second region 2 is the second doping portion 104, and the remaining initial first doping layer located in the first doping portion 103 is the third doping portion 106. In this way, it is not necessary to remove all of the initial first doping layer 207 in the first doping portion 103, which reduces the area of the film opening region of the initial first doping layer 207, contributing to reduced process costs and improved process efficiency, and since the third doping portion 106 and the first doping portion 103 are formed in the same process step, there is no need to form the third doping portion 106 in an extra step, contributing to reduced process costs.

[0119] In some embodiments, there are gaps 110 between at least some adjacent first and second regions 1 and 2, and the initial first doping layer covers the first surface 101 exposed through the gaps 110. The step of removing the initial first doping layer in at least the metal region using a laser process also removes the initial first doping layer in the gaps.

[0120] In some embodiments, the step of removing the initial first doping layer in at least the metal region by the laser process removes not only the initial first doping layer in the gap, but also a portion of the initial first doping layer in the second region 2 adjacent to the first region 1, thereby increasing the process window of the laser process and reducing the difficulty of the process.

[0121] 11 , in the above embodiment, the doping source layer 203 located in the first region 1 is left in the step of forming the first doping portion 103, and this part of the doping source layer is made into the insulating layer 111. In the step of removing at least a part of the initial first doping layer in the metal region by the laser process, the doping source layer in the metal region can also be removed, and the doping source layer in the region excluding the metal region in the third region 3 (i.e., the first region 1) can be made into the insulating layer 111.

[0122] In some embodiments, the step of forming the first doped portion 103 may also involve removing the doping source layer in the first region 1. As a result, the insulating layer 111 does not need to be removed in the laser processing step, and the formed third doped portion is in direct contact with the first doped portion 103. The type of doping element in the third doped portion is different from the type of doping element in the first doped portion 103. The third doped portion provides impurity absorption to the first doped portion 103, which can reduce the content of metal impurities in the first doped portion 103 and contribute to improving the photoelectric conversion efficiency of the formed solar cell.

[0123] In some embodiments, after removing at least a portion of the initial first doping layer in the metal region using a laser process, the remaining initial first doping layer located in the first doping portion 103 may be subjected to a first treatment to convert the initial first doping layer 207 into the third doping portion 106. For example, the material of the third doping portion 106 may be silicon oxide, and the material of the initial first doping layer 207 may be amorphous silicon or polysilicon, and the first treatment is a thermal oxidation treatment to convert the initial first doping layer located in the first doping portion 103 into the third doping portion. Also, for example, the material of the third doping portion 106 may be silicon nitride, and the material of the initial first doping layer 207 may be amorphous silicon or polysilicon, and the first treatment is a nitridation treatment to convert the initial first doping layer located in the first doping portion 103 into the third doping portion.

[0124] The third doped portion 106 made of silicon oxide or silicon nitride not only absorbs impurities from the first doped portion 103 but also serves as a passivation for the substrate 100 .

[0125] In some embodiments, after the third doping portion 106 is formed, a texture forming process can be performed on the first surface exposed through the gap 110. Because the third doping portion is formed on the top surface of the first doping portion, the third doping portion can act as a protective layer to reduce corrosion of the first doping portion by the texture forming solution and ensure good performance of the first doping portion.

[0126] Figure 14 is a diagram showing a structure corresponding to the step of forming a second doping portion and a third doping portion in a method for manufacturing a solar cell provided in another embodiment of the present application, and Figure 20 is a diagram showing a structure corresponding to the step of forming a second doping portion and a third doping portion in another method for manufacturing a solar cell provided in another embodiment of the present application.

[0127] As shown in Figures 14 to 20, multiple first electrodes 105 are formed, and the first electrodes 105 are located in corresponding metal regions and are in electrical contact with the first doping portions 103, and the first electrodes 105 are spaced apart from the third doping portions 106.

[0128] In the step of forming the first electrodes, multiple second electrodes 109 can also be formed synchronously, and the second electrodes 109 are located at corresponding second doped portions 104 and are in electrical contact with the corresponding second doped portions 104.

[0129] Before forming the first electrode 105 and the second electrode, a second passivation layer 112 may be formed. The second passivation layer covers the upper surface of the third doped portion 106, the upper surface of the second doped portion 104, and the upper surface of the first doped portion 103 that is not covered by the third doped portion 106. The first electrode 105 penetrates the second passivation layer 112 to be in electrical contact with the first doped portion 103, and the second electrode 109 penetrates the second passivation layer 112 to be in electrical contact with the second doped portion 104.

[0130] In some embodiments, before performing the laser process, the initial first doped layer 207 may be formed, and then the second passivation layer 112 may be formed to cover the initial first doped layer 207. The laser process can remove a portion of the initial first doped layer 207 in the metal region and the second passivation layer 112 in the metal region, thereby exposing the top surface of the first doped portion 103 corresponding to the metal region. This eliminates the need for an additional step of laser slotting or sintering slotting the second passivation layer 112 in the first doped portion 103, and can directly form the third doped portion 106 and expose the top surface of the first doped portion 103 corresponding to the metal region through the laser process alone, thereby reducing process costs and process steps.

[0131] Accordingly, according to some embodiments of the present application, another aspect of the embodiments of the present application further provides a photovoltaic module. FIG. 21 is a diagram showing the structure of a photovoltaic module provided in another embodiment of the present application. As shown in FIG. 21 , the photovoltaic module includes a cell string formed by connecting a plurality of solar cells 300 provided in the above embodiments or manufactured by the manufacturing method of a solar cell provided in the above embodiments, an encapsulation layer 301 for covering the surface of the cell string, and a cover plate 302 for covering the surface of the encapsulation layer 301 away from the cell string. The solar cells 300 are electrically connected as a whole or in a divided form to form a plurality of cell strings, and the plurality of cell strings are electrically connected in series and / or parallel.

[0132] Specifically, in some embodiments, multiple cell strings may be electrically connected by a conduction band 303. The solar cell provided in the embodiments of the present application is an IBC cell, and includes a first electrode 105 and a second electrode 109 (see FIG. 2) located on the same side of the solar cell. When the first electrode and the second electrode have opposite polarities, a conduction band connects two adjacent solar cells on the same side.

[0133] In some embodiments, there is no spacing between the solar cells, i.e., the solar cells overlap each other.

[0134] In some embodiments, the encapsulation layer 301 includes a first encapsulation layer and a second encapsulation layer, where the first encapsulation layer covers one of the front and back surfaces of the solar cell, and the second encapsulation layer covers the other of the front and back surfaces of the solar cell. Specifically, at least one of the first encapsulation layer and the second encapsulation layer may be an organic encapsulation layer, such as a polyvinyl butyral (PVB) adhesive film, an ethylene vinyl acetate copolymer (EVA) adhesive film, a polyethylene-octene copolymer (POE) adhesive film, or a polyethylene terephthalate (PET) adhesive film.

[0135] Before the lamination process, there is a boundary between the first sealing layer and the second sealing layer, but after the lamination process, when the photovoltaic module is formed, the concepts of the first sealing layer and the second sealing layer no longer exist; in other words, the first sealing layer and the second sealing layer are integrated to form sealing layer 301.

[0136] In some embodiments, the cover plate 302 may be a light-transmitting cover plate, such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 302 facing the sealing layer 301 may be textured to improve the utilization rate of incident light. The cover plate 302 may include a first cover plate and a second cover plate, where the first cover plate faces the first sealing layer and the second cover plate faces the second sealing layer.

[0137] Those skilled in the art will understand that the above embodiments are specific examples of realizing the present application, but that various changes in form and details are possible in practice without departing from the scope of the present application. Since anyone skilled in the art can make changes and modifications without departing from the spirit and scope of the present application, the scope of protection of the present application should be based on the scope limited by the claims.

Claims

1. a substrate having a first surface and a second surface opposite to each other; a plurality of first doped portions located in corresponding first regions; a plurality of second doped portions located in corresponding second regions; a plurality of first electrodes located in the corresponding first doped portions and in electrical contact with the corresponding first doped portions; and a plurality of third doped portions located on a portion of an upper surface of the corresponding first doped portion; the first surface includes the first regions and the second regions that are alternately arranged in a first direction, the second doped portion is spaced apart from the first doped portion, and a type of doping element in the second doped portion is different from a type of doping element in the first doped portion; the third doped portion is located on at least one side of the first electrode in the first direction, and the third doped portion is spaced apart from the adjacent first electrode; wherein the type of the doping element in the third doping portion is different from the type of the doping element in the first doping portion; A solar cell characterized by:

2. the third doped portion is located on one side of the first electrode in the first direction, wherein a ratio of a width of the third doped portion to a width of the first doped portion in the first direction is 0.05 to 0.5; The solar cell according to claim 1 .

3. The third doped portion is located on both sides of the first electrode facing each other in a first direction. The solar cell according to claim 1 .

4. a distance between adjacent third doped portions in each of the first doped portions in the first direction is a first width, and a ratio of the first width to the width of the third doped portion in the first direction is 0.23 to 68; The solar cell according to claim 3 .

5. The thickness of the third doped portion is equal to the thickness of the second doped portion. The solar cell according to claim 1 .

6. a gap is formed between the first doped portion and the second doped portion adjacent to each other, and a part of the first surface is exposed through the gap; The solar cell according to claim 1 .

7. In a thickness direction of the substrate, the first surface corresponding to the first region is flush with the first surface corresponding to the second region, or In a thickness direction of the substrate, the first surface corresponding to the first region is not flush with the first surface corresponding to the second region, and a distance between the first surface corresponding to the first region and the second surface is a first height, and a distance between the first surface corresponding to the second region and the second surface is a second height, and the first height is greater than the second height. The solar cell according to claim 6 .

8. In a thickness direction of the substrate, the first surface corresponding to the first region is not flush with the first surface corresponding to the second region, and a distance between the first surface corresponding to the first region and the second surface is a first height, and a distance between the first surface corresponding to the second region and the second surface is a second height, and the first height is greater than the second height; wherein there is a gap between at least some of the first doped portions and the second doped portions adjacent to each other. The solar cell according to claim 1 .

9. The solar cell further includes an insulating layer located between the third doping portion and the first doping portion. The solar cell according to claim 1 .

10. the material of the insulating layer includes a silica glass material doped with a first doping element, and the type of the first doping element is the same as the type of the doping element doped into the first doped portion; The solar cell according to claim 9 .

11. The material of the third doped portion is the same as the material of the second doped portion. The solar cell according to claim 1 .

12. providing a substrate having opposing first and second surfaces, the first surface including first and second regions alternating in a first direction; forming a plurality of first doped portions, each of the first doped portions being located in a corresponding first region, and an upper surface of the first doped portion including a metal region; forming an initial first doping layer, the initial first doping layer covering a first surface corresponding to a plurality of the first doping portions and a plurality of the second regions, and a type of doping element in the initial first doping layer being different from a type of doping element in the first doping portions; removing a portion of the initial first doping layer in at least the metal region by a laser process to expose the metal region, and the remaining portion of the initial first doping layer located in the second region is a second doping portion, the second doping portion is spaced apart from the first doping portion, and the remaining portion of the initial first doping layer located in the first doping portion is a third doping portion; forming a plurality of first electrodes, each of which is located on a corresponding one of the metal regions and electrically contacts the first doped portion, and the first electrodes are spaced apart from the third doped portion; A method for manufacturing a solar cell comprising the steps of:

13. The step of forming the first doping portion includes: forming an initial substrate, the initial substrate having a third surface and a fourth surface facing each other, the third surface including third regions and fourth regions alternately disposed in the first direction; forming a doping source layer covering each of the third regions and each of the fourth regions, the doping source layer including a target doping element; performing a driving step to drive the target doping element in the doping source layer into the initial substrate to form the initial second doped layer; removing the doping source layer and the initial second doping layer in the fourth region, removing a part of the initial substrate having a thickness corresponding to the fourth region, and using the remaining initial substrate as the substrate; using the remaining initial second doping layer located in the third region as the first doping portion; and using the doping source layer located in the third region as an insulating layer, In the step of forming the initial first doped layer, the initial first doped layer covers the insulating layer in the first doped portion. The method for manufacturing a solar cell according to claim 12 .

14. In the step of removing a part of the initial first doping layer in at least the metal region by a laser process, the doping source layer in the metal region is also removed, and the doping source layer in the region excluding the metal region in the third region becomes the insulating layer. The method for manufacturing a solar cell according to claim 13 .

15. There is a gap between at least some of the adjacent first regions and second regions, In the step of forming the initial first doping layer, the initial first doping layer is also located in the gap; In the step of removing the initial first doping layer in at least the metal region by a laser process, the initial first doping layer in the gap is also removed. The method for manufacturing a solar cell according to claim 12 .

16. A cell string formed by connecting a plurality of solar cells according to any one of claims 1 to 11 or solar cells manufactured by the method for manufacturing a solar cell according to any one of claims 12 to 15; a sealing layer for covering a surface of the cell string; a cover plate for covering a surface of the sealing layer away from the cell string. A photovoltaic module characterized by:

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