Solar cell, method of manufacturing solar cell, and photovoltaic module

Abstract

A solar cell, a method for manufacturing a solar cell, and a photovoltaic module are provided. [Solution] The solar cell includes a substrate having opposing first and second surfaces, a plurality of first doping portions 103 located in corresponding first regions 1, a plurality of second doping portions 104 located in corresponding second regions, a plurality of first electrodes located in the corresponding first doping portions, and a plurality of third doping portions 106 located on the upper surfaces of the corresponding first doping portions, the first surface having first and second regions arranged alternately in a first direction, the second doping portions are spaced apart from the first doping portions, the second doping portions and the first doping portions have different types of doping elements, and the first doping portions have a third doping portion located on at least one side of the first electrode in the first direction and spaced apart from the adjacent first electrode, where the third doping portion and the first doping portion have different types of doping elements.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present application relate to the field of photovoltaics, and in particular to solar cells, methods of 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 shape on the backlight surface of the battery, with the PN junction and electrodes located on the back surface of the battery. 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, making it possible to obtain 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 manufacturing method for 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 doping portions located in corresponding first regions 1, a plurality of second doping portions located in corresponding second regions, a plurality of first electrodes located in corresponding first doping portions and in electrical contact with the corresponding first doping portions, and a plurality of third doping portions located on a portion of an upper surface of the corresponding first doping portions, the first surface having first and second regions arranged alternately in a first direction, the second doping portions being spaced apart from the first doping portions, and the type of doping element in the second doping portions being different from the type of doping element in the first doping portions, the first doping portions including the third doping portions located on at least one side of the first electrode in the first direction, the third doping portions being spaced apart from the adjacent first electrode, and the type of doping element in the third doping portions being different from the type of doping element in the first doping portions.

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

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

[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 a 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 present between the first doped portion and the second doped portion adjacent to each other, and a portion of the first surface is exposed through the gap.

[0010] In some embodiments, 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.

[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 a distance between the first surface corresponding to the first region and the second surface is a first height, a 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 a portion of adjacent first doped portions and second doped portions.

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

[0013] In some embodiments, the material of the insulating layer comprises a silica glass material doped with a first doping element, the type of the first doping element being 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 and the material of the second doped portion are the same.

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

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

[0019] According to some embodiments of the present application, in another aspect of the embodiments of the present application, a photovoltaic module is further provided, the photovoltaic module including a cell string formed by connecting a plurality of solar cells provided in any of the above embodiments or solar cells manufactured by the manufacturing method for a solar cell 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 remote from the cell string. Effect of the Invention

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

[0021] In the technical proposal of the solar cell provided in the embodiment of the present application, the adjacent first doping portion is spaced from the second doping portion, so that the leakage problem occurring between the first doping portion and the second doping portion can be avoided. In addition, a third doping portion is provided on a part of the upper surface of the first doping portion, and the type of doping element in the third doping portion is different from the type of doping element in the first doping portion, so that the third doping portion, which is different from the type of doping element in the first doping portion, absorbs impurities in the first doping portion, and can improve the photoelectric conversion efficiency of the solar cell. In addition, since the third doping portion is spaced from the first electrode, it contributes to increasing the process window for manufacturing the first electrode, reducing the process difficulty, and avoiding the influence on the normal transport of carriers caused by the contact between the third doping portion and the first electrode. Furthermore, the third doping section may be a protective layer for the first doping section, and in the process of manufacturing the solar cell, the third doping section can 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 description of the drawings]

[0022] One or more embodiments are illustratively described in the figures in the corresponding 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 that need to be used in the embodiments are briefly introduced below, but obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative labor. [Figure 1] FIG. 1 is a diagram showing the structure of a first type of solar cell provided in the present application. [Diagram 2] FIG. 2 is a diagram showing the structure of a second type of solar cell provided in one embodiment of the present application. [Diagram 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. [Diagram 5] FIG. 5 is a diagram showing the structure of a fourth type of solar cell provided in one embodiment of the present application. [Figure 6] FIG. 6 is a diagram showing the structure of a fifth type of solar cell provided in one embodiment of the present application. [Figure 7] FIG. 7 is a diagram showing 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 the 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 showing a structure corresponding to the step of forming a second doped portion and a third doped portion in the method for manufacturing a solar cell provided in another embodiment of the present application. [Figure 14] FIG. 14 is a diagram showing a structure corresponding to the step of forming a second doped portion and a third doped portion in the 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 solar cell manufacturing method 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 solar cell manufacturing method provided in another embodiment of the present application. [Figure 17] 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. [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 a second doped portion and a third doped portion in another solar cell manufacturing method 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 PREFERRED EMBODIMENTS

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

[0024] In the solar cell provided in the embodiment of the present application, the adjacent first doping portion is spaced from the second doping portion, so that the leakage problem occurring between the first doping portion and the second doping portion can be avoided. In addition, a third doping portion is provided on a part of the upper surface of the first doping portion, and since the type of doping element in the third doping portion is different from the type of doping element in the first doping portion, the third doping portion absorbs impurities in the first doping portion, and the photoelectric conversion efficiency of the solar cell can be improved. In addition, since the third doping portion is spaced from the first electrode, it contributes to increasing the process window for manufacturing the first electrode, reducing the process difficulty, and avoiding the influence on the normal transport of carriers caused by the contact between the third doping portion and the first electrode. In addition, 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 can 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.

[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 in order to allow the reader to better understand the present application, the technical solution 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 an embodiment of the present application.

[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 electrically contacting the corresponding first doped portions 103, and a plurality of third doped portions 106 located on a part of an upper surface of the corresponding first doped portions 103, and the first surfaces 101 of the first regions 1 and the second regions 2 are alternately arranged in a first direction X. The first doped portion has a third doping portion 106 located on at least one side of the first electrode in a first direction, the third doping portion 106 being spaced apart from the adjacent first electrode 105, and the type of the doping element in the third doping portion 106 being different from the type of the doping element in the first doping portion 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 spaced apart contribute to avoiding a leakage problem occurring 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 in the first doping portion 103, and contributes to improving the photoelectric conversion efficiency of the solar cell, and the third doping portion is spaced apart from the first electrode, which increases the process window for manufacturing the first electrode, reduces the process difficulty, and helps to avoid an impact on normal transport of carriers caused by contact between the third doping portion and the first electrode. Furthermore, the third doping portion 106 can be a protective layer for the first doping portion 103, and in the subsequent process treatment of the first doping layer, the third doping portion 106 can reduce the possibility of damage to the first doping layer or reduce 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 placed away 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 is composed of a single element, and may be, for example, silicon or germanium. Here, the elemental semiconductor material may be in a monocrystalline state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state having both a monocrystalline state and an amorphous state is called a microcrystalline state), and for example, silicon may be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. The material of the substrate 100 may be silicon, and the material of the substrate 100 may include at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0032] In some embodiments, the material of the 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, 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, etc.

[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. In the N-type semiconductor substrate, an N-type doping element is doped, which may be any of the group V elements, such as phosphorus (P), bismuth (Bi), antimony (Sb) or arsenic (As). In the P-type semiconductor substrate 100, a P-type doping element is doped, which may be any of the 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 regular pyramidal textures and irregular black silicon textures. The slopes of the textured structure may increase the internal reflection of incident light, improve the absorption utilization of the substrate 100 for the incident light, and thus 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 textured structure of the surface with a polishing solution or laser etching. After polishing, the flatness of the back surface is increased, the reflection of long wavelength light is increased, secondary absorption of incident light is promoted, and Isc is increased. At the same time, the specific surface area of ​​the back surface is reduced, which can reduce the back surface recombination and improve the passivation effect of the back surface.

[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 a corresponding first region, and the second doped portion located on a surface of the dielectric layer away from the substrate corresponding to a corresponding second region.

[0039] For example, the dielectric layer may be a tunnel layer. The tunnel layer may cause an asymmetric offset in the bands of the first surface, so that the potential barrier for the majority carriers in the carriers is lower than the potential barrier for the minority carriers in the carriers. This allows the majority carriers to easily pass through the tunnel layer and undergo quantum tunneling to be transported to the first doping section or the second doping section, but the minority carriers have difficulty passing through the tunnel layer, so that selective transport of carriers can be realized. In addition, the tunnel layer exerts a chemical passivation effect on 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, a first doped portion may be in direct contact with a first surface corresponding to a corresponding first region, and a second doped portion may be in direct contact with a first surface corresponding to a corresponding second region, without providing a dielectric layer.

[0042] FIG. 2 is a diagram showing 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, the conductivity type of the doping element in the front surface field 107 is the same as that of the doping element in the substrate 100, and the concentration of the doping element in the front surface field is higher than that of the doping element in the substrate 100. This can utilize the field passivation effect to reduce the concentration of surface minority carriers, reduce the surface recombination velocity, reduce the series resistance, and improve the electron transport ability.

[0044] 2, in some embodiments, the solar cell includes a first passivation layer 108 located on a surface away from the substrate 100 of the front field, 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 an 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 a second direction Y, and the second direction Y and the first direction X intersect with each other.

[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 penetrates the second passivation layer 112 and is in electrical contact with the first doped portion 103, and the second electrode 109 penetrates the second passivation layer 112 and is in electrical contact with the second doped portion 104.

[0050] In some embodiments, the type of doping element in the first doping 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 doping portion 103 is greater than the concentration of the doping element in the substrate 100, and the first doping portion 103 forms a high-low junction with the substrate 100. A built-in electric field is formed in the high-low junction, in which the first doping portion 103 points toward the inside of the substrate 100, and the built-in electric field causes minority carriers to drift and escape from the interface, reducing the recombination rate of carriers at the interface of the substrate 100, enhancing the open circuit voltage, short circuit current and backing factor of the solar cell, and improving the photoelectric conversion efficiency of the back contact cell. The type of doping element in the second doping portion 104 may be opposite to the type of doping element in the substrate 100. Thus, the second doping portion 104 and the substrate 100 form a PN junction. The type of doping element in the third doping portion 106 is opposite to the type of doping element in the first doping portion 103.

[0051] For example, when 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, in the manufacturing process of a solar cell, due to limitations of the process environment and process equipment, metal impurities are easily introduced into the solar cell, and the metal impurities affect the photoelectric conversion efficiency of the solar cell. Therefore, in order to optimize the photoelectric conversion efficiency of the solar cell, it is necessary to remove the metal impurities in the solar cell. In some embodiments, the doping element in the third doping portion 106 is phosphorus, and the phosphorus-doped third doping portion 106 has a high solubility in the metal impurities, and provides the first doping portion 103 with the impurity absorption effect of phosphorus, which can reduce the content of the metal impurities in the first doping portion 103 and increase the photoelectric conversion efficiency of the solar cell.

[0052] For example, when 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 set to boron, and the boron-doped third doping portion 106 provides an impurity absorption effect for the first doping portion 103, so as to reduce the content of metal impurities in the first doping portion 103, and improve the photoelectric conversion efficiency of the solar cell.

[0053] In some embodiments, the type of doping element in the first doping portion 103 may be opposite to the type of doping element in the substrate 100. In this case, the first doping portion 103 and the substrate 100 form a PN junction. The type of doping element in the second doping portion 104 may be the same as the type of doping element in the substrate 100, and the concentration of the doping element in the second doping portion 104 may be higher than the concentration of the doping element in the substrate 100, and the type of the doping element in the third doping portion 106 may be opposite to the type of the doping element in the first doping 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. In this way, the third doping portion 106 and the second doping portion 104 can be manufactured in the same process step to simplify the process. For example, after forming the first doping portion 103, an initial first doping layer is formed covering the first surface 101 corresponding to the plurality of first doping portions 103 and the second region 2, a part of the initial first doping layer in the first doping portion 103 is removed to expose a part of the surface of the first doping portion 103, and the initial first doping layer located in the first doping portion 103 is the third doping portion 106, and then a first electrode 105 is formed on the upper surface of the first doping portion 103 exposed from the third doping portion 106, and the initial first doping layer located in the second region 2 is 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 be a passivation layer and can achieve a passivation effect on 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 together with 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 third doping portion 106 having a smaller thickness 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 section 106 may be 10 nm to 100 nm. For example, the thickness of the third doped section may be 10 nm, 18 nm, 34 nm, 61 nm, 76.5 nm, 88 nm, 95 nm, or 100 nm. This makes it possible to prevent the content of the doping element in the third doped section 106 from being too high, and to reduce the amount of the doping element diffusing from the third doped section 106 to the first doped section 103, while ensuring excellent impurity absorption ability of the third doped section.

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

[0063] In some embodiments, the third doped portion 106 may be located on one side of the first electrode 105 in the first direction in the first doped portion 103. Here, the ratio of the width of the third doped portion 106 to the width of the first doped portion 103 in the first direction is 0.05 to 0.5. For example, the ratio may be 0.05, 0.14, 0.27, 0.35, 0.48, or 0.5. Within this ratio range, it is ensured that the area of ​​the upper surface of the first doped portion 103 that is not covered by the third doped portion 106 is large, a large area is reserved for the first electrode 105, and the first electrode 105 and the third doped portion 106 on the first doped portion 103 can be spaced apart.

[0064] Here, the width of the first doping portion 103 in the first direction may be 150 μm to 1700 μm, for example, the width may be 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, the width may be 7.5 μm, 75 μm, 188 μm, 385 μm, 593 μm, 735 μm, 858 μm, or 935 μm.

[0066] In some embodiments, the first doping portion 103 may have the third doping portion located on both sides facing each other in the first direction of the first electrode 105. As a result, the area of ​​the upper surface of the first doping portion 103 covered by the third doping portion 106 is larger than when the third doping portion 106 is located on one side of the first electrode 105 in the first direction of the first doping portion 103, and the impurity absorption effect of the third doping portion 106 on the third doping portion 106 can be enhanced, which contributes to improving the photoelectric conversion efficiency of the solar cell. In addition, from the viewpoint of the manufacturing process, the third doping portion 106 can be formed by patterning the initial first doping layer covering the upper surface of the first doping portion 103. By arranging the third doping portion 106 in the first doping portion 103 so that it is located on both opposing sides in the first direction of the first electrode 105, 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, in the first direction, the distance between adjacent third doping portions 106 in each first doping portion 103 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, and may be, for example, 0.23, 16, 36, 42, 57, or 68. Within this range, the distance between the first electrode 105 and the adjacent third doping portion 106 is ensured to be large, the area of ​​the upper surface of the first doping portion 103 covered by the third doping portion 106 is ensured to be large, and a good impurity absorption effect of the third doping portion 106 on the first doping portion 103 is realized. In addition, from the viewpoint of the manufacturing process, the third doping portion 106 can be formed by patterning the initial first doping layer covering the upper surface of the first doping portion 103. Within this ratio range, it can ensure that the area of ​​the film opening region of the initial first doping layer is not too large or too small, and the time of the manufacturing process of the solar cell can be controlled to improve the 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] As shown in FIG. 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 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. The adverse effects may include, for example, causing a change in the conductivity type of the first doping portion 103. This may cause the solar cell to not operate normally.

[0070] Here, the material of the insulating layer 111 may include 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 in the first doping portion 103. Thus, 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, first, an intrinsic semiconductor layer and a doping source layer doped with the first doping element are 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 is the first doping portion 103, and the remaining doping source layer is the insulating layer 111. Thus, there is no need to form the insulating layer 111 in an extra step, and the manufacturing steps of the solar cell can be simplified, and 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 (HfO2), gallium oxide (Ga2O3), 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 doping portion 106 from the corresponding first doping portion 103, and the insulating layer 111 can also play a passivation effect, which contributes to improving the photoelectric conversion efficiency of the solar cell.

[0072] A gap 110 may be provided between the adjacent first doping portion 103 and the second doping portion 104, and a part of the first surface 101 is exposed through the gap 110. That is, the gap 110 separates the adjacent first doping portion 103 and the second doping portion 104. This makes it possible to avoid leakage current caused by a tunnel junction being formed between the first doping portion 103 and the second doping portion 104, and ensure 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 from the gap 110 may have a textured structure. This increases the internal reflection of the incident light on the first surface 101 exposed from the gap 110, improves the absorption utilization rate of the incident light on the substrate 100, and thereby increases the photoelectric conversion efficiency of the solar cell. In some embodiments, the first surface 101 exposed from the gap 110 may be a polished surface. This improves the flatness of the first surface 101, enhances the reflection of long wavelength light, promotes secondary absorption of the incident light, and improves Isc. The relatively flat first surface 101 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 showing the structure of a fourth type of solar cell provided in one embodiment of the present application.

[0077] As shown in FIG. 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 adjacent first doping portions 103 and second doping portions 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 and the second surface 102 corresponding to the first region 1 is a first height, the distance between the first surface 101 and the second surface 102 corresponding to the second region 2 is a second height, the first height is greater than the second height, and there may be a gap 110 between adjacent first doped portions 103 and second doped portions 104.

[0079] FIG. 6 is a diagram showing 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 is greater than the second height, and there are gaps 110 between some adjacent first doping portions 103 and second doping portions 104. As a result, compared to the case where gaps 110 are provided between all adjacent first doping portions 103 and second doping portions 104, the dimension of the multiple gaps 110 in the direction parallel to the first surface 101 can be reduced, and the dimension of the first doping portion 103 and the second doping portion 104 in the first direction can be increased within a limited dimensional range.

[0081] Here, adjacent first doped portions and second doped portions are considered as one unit, 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 showing the structure of a sixth type of solar cell provided in one embodiment of the present application.

[0083] 7, in some embodiments, the gap 110 may not be provided between the adjacent first doping portion 103 and the second doping portion 104, and since the first height is greater than the second height, the adjacent first doping portion 103 and the second doping portion 104 are separated in the thickness direction of the substrate 100 by a height difference. This contributes to increasing the density of the first doping portion and the second doping portion 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, but for the same or corresponding parts as the previous embodiment, the corresponding description of the previous embodiment can be referred to. Hereinafter, the description will not be repeated.

[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, the first surface 101 including first regions 1 and second regions 2 arranged alternately 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, that is, the first and second regions are arranged with a gap therebetween 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, a first surface corresponding to a first region may be flush with a first surface corresponding to a second region, and a gap 110 is provided between adjacent first and second regions.

[0090] The material of the substrate 100 can be referred to in the above embodiment, and will not be described here repeatedly. 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 the group V elements, such as phosphorus, bismuth, antimony, or arsenic. The P-type doping element may be any of the 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 provide a textured structure on the second surface 102. In some embodiments, the textured structure can be fabricated by a solution texturing process. The textured structure can increase the number of light refractions on the surface of the solar cell, which can contribute to the absorption of light by the solar cell, and can achieve the highest solar energy utilization rate of the solar cell. For example, if the substrate 100 is single crystal silicon, the surface of the substrate 100 can be textured by a mixture of an alkaline solution and an alcohol solution. If the substrate 100 is polysilicon, the surface of the substrate 100 can be textured by an acid solution. In some embodiments, the textured structure can be fabricated by 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 surface field 107 may be formed on the second surface 102 of the substrate 100. The concentration of the doping element in the front surface 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 capability.

[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 side 102 of the substrate 100. The process of 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 the 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, 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, the second direction intersecting with the first direction X, and the second direction being parallel to the upper surface of the first doped portion 103. In the next step, a first electrode is formed on the upper surface of the first doped portion, and the orthogonal projection of the first electrode on the upper surface of the corresponding first doped portion is located within the metal region. That is, the metal region is a portion where the upper surface of the first doped portion contacts the first electrode in correspondence with the first electrode. In the first direction X, the width of the metal region may be larger 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] FIG. 9 is a diagram showing a structure corresponding to a step of providing an initial substrate in a method for manufacturing a solar cell provided in another embodiment of the present application, and FIG. 10 is a diagram showing a structure corresponding to a 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 a third region 3 and a fourth region 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 part of the initial substrate 200 having a thickness corresponding to the fourth region 4, and making the remaining initial substrate 200 into the substrate 100, the remaining initial second doping layer 204 located in the third region 3 into the first doping portion 103, and the doping source layer located in the third region 3 into the insulating layer 111.

[0101] In this way, by removing a portion of the initial substrate 200 having a thickness corresponding to the fourth region 4, a second doped portion is 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, and leakage current due to a tunnel junction formed between the first doped portion 103 and the second doped portion can be avoided. This allows the high photoelectric conversion efficiency of the solar cell to be maintained, and the first surface 101 corresponding to the first region 1 is flush with the first surface 101 corresponding to the second region 2. Furthermore, an extra insulating layer formation step is not required, simplifying the manufacturing process of the solar cell.

[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 a part of the initial substrate 200 having a thickness corresponding to the fourth region 4 is removed, after which the initial substrate 200 is defined as the substrate 100, the third region 3 is defined as 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 is defined as the first surface 101 corresponding to the second region 2. Here, a front field 107 and a first passivation layer 108 may be formed on the fourth surface before manufacturing the first doped portion.

[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. Correspondingly, the insulating layer 111 is a silica glass material layer doped with an N-type doping element or a P-type doping element, and then, in the step of forming a third doping portion on the upper surface of the first doping portion 103, the insulating layer 111 plays a role of blocking, preventing the excess doping element in the third doping portion from diffusing into the first doping portion 103, and ensuring good performance of the first doping portion 103. For example, if the first doping portion 103 is doped with boron, which is a P-type doping element, the doping source layer is a borosilicate glass layer, and accordingly, the insulating layer is a borosilicate glass layer. Also, 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 spacing 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 spacing region. In the driving step, a portion of the initial substrate corresponding to the spacing region is transformed 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 spacing 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] As shown in FIG. 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 the adjacent first region and the second region. As shown in FIG. 16-FIG. 17, the step of forming the first doping 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 doping layer 204; removing the initial second doping layer 204 in the second region 2 and the gap 110, removing the doping source layer, and making the remaining initial second doping layer 204 located in the first region 1 the first doping 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 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 subsequently formed 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-mentioned 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, the doping source layer can be removed before forming the second doped portion and the third doped portion, that is, the doping source layer 203 on the upper surface of the first doped portion 103 is not left as an insulating layer, and an insulating layer is formed on the upper surface of the first doped portion 103. The material of the insulating layer may 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 these materials can separate the third doped portion 106 to be formed later from the corresponding first doped portion 103, and the insulating layer 111 can exert a passivation effect, which contributes to improving the photoelectric conversion efficiency of the solar cell.

[0111] FIG. 12 is a diagram showing a structure corresponding to a 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 FIG. 18 is a diagram showing a structure corresponding to a 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, the initial first doping layer 207 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 the adjacent first region 1 and second region 2, and the adjacent first region 1 and second region 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, the remaining initial first doped layer 207 located in the second region 2 and the first doped portion 103 are separated along the thickness direction of the substrate 100 after the initial first doped layer 207 is patterned by a laser process in a later step. 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 the 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. There may also be gaps between some adjacent first and second regions, and the initial first doping layer is also located in the gaps 110. In a later step, a laser process needs to remove the initial first doping layer 207 located in the gaps.

[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, at least a part of the initial first doping layer 207 in the metal region is removed by the laser process 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 the entire initial first doping layer 207 in the first doping portion 103, the area of ​​the film opening region of the initial first doping layer 207 is reduced, contributing to reduction in process costs and improvement in process efficiency, and the third doping portion 106 and the first doping portion 103 are formed in the same process step, eliminating the need to form the third doping portion 106 in an extra step, contributing to reduction in process costs.

[0119] In some embodiments, there are gaps 110 between at least some of the adjacent first and second regions 1 and 2, and the initial first doped layer covers the first surface 101 exposed through the gaps 110. The step of removing the initial first doped layer in at least the metal region with a laser process also removes the initial first doped 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 part 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, in the step of forming the first doped portion 103, the doping source layer 203 located in the first region 1 is left, 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 remove the doping source layer in the first region 1. Thus, there is no need to remove the insulating layer 111 in the laser process 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, and the third doped portion provides an impurity absorption effect for the first doped portion 103 and can reduce the content of metal impurities in the first doped portion 103, which contributes 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 by the laser process, the remaining initial first doping layer located in the first doping portion 103 can be subjected to a first process to convert the initial first doping layer 207 into the third doping portion 106. For example, the material of the third doping portion 106 can be silicon oxide, the material of the initial first doping layer 207 can be amorphous silicon or polysilicon, and the first process is a thermal oxidation process 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 can be silicon nitride, the material of the initial first doping layer 207 can be amorphous silicon or polysilicon, and the first process is a nitridation process 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 can absorb impurities from the first doped portion 103 as well as passivate the substrate 100 .

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

[0126] FIG. 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 FIG. 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, a plurality of first electrodes 105 are formed, the first electrodes 105 are located on corresponding metal regions and are in electrical contact with the first doped portions 103, and the first electrodes 105 are spaced apart from the third doped 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 above-mentioned laser process, the initial first doped layer 207 may be formed, and then the second passivation layer 112 covering the initial first doped layer 207 may be formed. In the laser process, a part of the initial first doped layer 207 in the metal region may be removed, and the second passivation layer 112 in the metal region may be removed to expose the upper surface of the first doped portion 103 corresponding to the metal region. This eliminates the need to perform laser slotting or sintering slotting on the second passivation layer 112 in the first doped portion 103 in an extra step, and the formation of the third doped portion 106 and the exposure of the upper surface of the first doped portion 103 corresponding to the metal region may be achieved directly by the laser process step alone, which reduces the process cost and contributes to reducing the process steps.

[0131] Accordingly, according to some embodiments of the present application, in another aspect of the embodiments of the present application, a photovoltaic module is further provided. 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 manufactured by the solar cell provided in the above embodiment or the manufacturing method of the solar cell provided in the above embodiment, 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 form of a plurality of divisions to form a plurality of cell strings, and the plurality of cell strings are electrically connected in a series and / or parallel manner.

[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 different polarities, a conduction band connects two adjacent solar cells on the same side.

[0133] In some embodiments, there is no space 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 or back surface of the solar cell, and the second encapsulation layer covers the other of the front or back surface of the solar cell. Specifically, at least one of the first encapsulation layer or 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, and after the lamination process, when the photovoltaic module is formed, the concept of the first sealing layer and the second sealing layer no longer exists; 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 cover plate with a light-transmitting function, such as a glass cover plate, a plastic cover plate, etc. Specifically, the surface of the cover plate 302 facing the sealing layer 301 may be an uneven surface, which can improve the utilization rate of the incident light. The cover plate 302 includes 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 for implementing the present application, but various changes in form and details are possible in practice without departing from the scope of the present application. Since any person 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 facing 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 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 region and the second region 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; 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; Here, a type of a doping element in the third doping portion is different from a type of a doping element in the first doping portion; a gap is provided 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; A solar cell characterized by:

2. The first doped portion is located on only 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 first 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. In the first direction, a distance between adjacent third doped portions in each of the first doped portions is a first width, and a ratio of the first width to a 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. 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 1 .

7. 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 1 .

8. 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 .

9. 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 doping portion; The solar cell according to claim 8 .

10. 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 .

11. A method for producing the solar cell according to any one of claims 1 to 10, comprising the steps of: providing a substrate having opposing first and second surfaces, the first surface including alternating first and second regions in a first direction; forming a plurality of first doped portions, the first doped portions being located in corresponding first regions, and upper surfaces of the first doped portions including metal regions; 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 at least a portion of the initial first doping layer in 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 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 the first electrodes being located on a corresponding one of the metal regions and in electrical contact with the first doped portion, the first electrodes being spaced apart from the third doped portion; a gap is provided 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; A method for producing a solar cell comprising the steps of:

12. 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 at least in the metal region by a laser process, the initial first doping layer in the gap is also removed. The method for producing a solar cell according to claim 11 .

13. A cell string formed by connecting a plurality of solar cells according to any one of claims 1 to 10; a sealing layer for covering a surface of the cell string; a cover plate for covering a surface of the sealing layer remote from the cell string. A photovoltaic module comprising:

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