Solar cell and photovoltaic module

Abstract

The invention relates to the technical field of solar cells, in particular to a solar cell and a photovoltaic module. In the embodiment of the invention, the resistivity of the substrate is adjusted by configuring the doping elements in the substrate to comprise the antimony element and the phosphorus element. The resistivity of the unit part of the substrate is configured to have the positive correlation change trend with the first thickness of the doped semiconductor layer in the unit area region of the first surface of the substrate, so that the resistivity of the position, corresponding to the thicker part in the doped semiconductor layer, in the substrate is larger, and the thickness of the doped semiconductor layer is increased. And the sheet resistance of the thicker part in the doped semiconductor layer is smaller, so that the overall sheet resistance of the part, corresponding to the doped semiconductor layer, of the substrate can be distributed more uniformly. Therefore, under the condition that the resistivity of the substrate is changed along with the sheet resistance of the doped semiconductor layer, the series resistance at different areas of the solar cell can be uniformly distributed, so that the conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to solar cells and photovoltaic modules. Background Art

[0002] Solar cells are devices that convert sunlight into electrical energy. Solar cells use the photovoltaic principle to generate carriers, and then use electrodes to extract the carriers, which is conducive to the effective use of electrical energy. However, the conversion efficiency of current solar cells needs to be further improved. Summary of the invention

[0003] Based on this, it is necessary to provide a solar cell and a photovoltaic module, which are at least beneficial to improving the conversion efficiency of the solar cell.

[0004] According to one aspect of the present application, an embodiment of the present application provides a solar cell, including:

[0005] A substrate having a first surface and a second surface disposed opposite to each other along a first direction; the doping elements in the substrate include antimony and phosphorus; and

[0006] The passivation contact layer includes a tunneling layer disposed on the first surface, and a doped semiconductor layer disposed on a surface of the tunneling layer that is away from the substrate; the doping element of the doped semiconductor layer includes phosphorus, and the thickness of the doped semiconductor layer is unevenly distributed along a direction perpendicular to the first direction;

[0007] The substrate has a unit portion corresponding to a unit area of ​​the first surface, and the average thickness of the portion of the doped semiconductor layer located in the unit area is a first thickness; the resistivity of the unit portion of the substrate is positively correlated with the first thickness of the doped semiconductor layer corresponding to the unit portion of the substrate;

[0008] The portion of the substrate extending from the first surface toward the second surface at a first depth is defined as the first portion, and the portion of the substrate other than the first portion is defined as the second portion. The doping concentration of phosphorus in the first portion is greater than the doping concentration of phosphorus in the second portion. The first depth h1 satisfies: h1≤300nm.

[0009] In one embodiment, the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate in the same unit portion shows a negative correlation with the resistivity of the unit portion.

[0010] In one embodiment, the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate in the same unit portion decreases continuously as the resistivity of the unit portion increases.

[0011] In one embodiment, the ratio of the doping concentration of the antimony element to the doping concentration of the phosphorus element in the substrate is 1 to 3.

[0012] In one embodiment, the doping concentration of antimony element is 1.549×10 15 cm -3 to 4.271×10 16 cm -3 ; and / or

[0013] The doping concentration of phosphorus in the substrate is 1.804×10 15 cm -3 to 4.798×10 16 cm -3 .

[0014] In one embodiment, the resistivity of a unit portion of the substrate increases continuously as the first thickness of the doped semiconductor layer increases.

[0015] In one embodiment, the first thickness of the doped semiconductor layer per unit area has a positive correlation with the distribution distance;

[0016] The distribution distance is the distance between the unit area region and the center of the first surface.

[0017] In one of the embodiments, the first thickness of the doped semiconductor layer within a unit area continuously increases with the increase of the distribution distance.

[0018] In one embodiment, an intersection line between a surface of the doped semiconductor layer facing away from the substrate and the reference plane is a first intersection line, and the first intersection line is symmetrically arranged about a central axis of the first surface;

[0019] The reference plane is a plane parallel to the first direction, and the central axis is located on the reference plane.

[0020] According to another aspect of the present application, an embodiment of the present application provides a photovoltaic assembly, including:

[0021] Battery string;

[0022] An encapsulation layer, used to cover the surface of the battery string; and

[0023] A cover plate, which is used to cover the surface of the packaging layer away from the battery string;

[0024] The battery string is formed by electrically connecting a plurality of solar cells in any of the above embodiments.

[0025] In the above solar cell and photovoltaic module, the solar cell at least includes a substrate and a passivation contact layer, the passivation contact layer includes a tunneling layer and a doped semiconductor layer, and the substrate includes a first part close to the doped semiconductor layer and a second part other than the first part. On the one hand, the thickness of the doped semiconductor layer is unevenly distributed, so that the square resistance of the doped semiconductor layer is also unevenly distributed; on the other hand, since the doping element of the doped semiconductor layer includes phosphorus, the doping concentration of the phosphorus element in the first part of the substrate is greater than the doping concentration of the phosphorus element in the second part of the substrate. Therefore, by configuring the doping elements in the substrate to include antimony elements and phosphorus elements, the resistivity of the substrate can be adjusted by means of the effects of both antimony elements and phosphorus elements. By configuring the size of the resistivity of a unit part of the substrate to be positively correlated with the first thickness of the doped semiconductor layer per unit area on the first surface of the substrate, the resistivity of the position corresponding to the thicker part of the doped semiconductor layer in the substrate is larger, and the square resistance of the thicker part of the doped semiconductor layer is smaller, so that the overall square resistance of the part corresponding to the substrate and the doped semiconductor layer can be distributed more evenly. In this way, when the resistivity of the substrate changes with the sheet resistance of the doped semiconductor layer, the series resistances at different regions of the solar cell can be distributed more evenly, thereby improving the conversion efficiency of the solar cell.

[0026] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the embodiments below. The accompanying drawings are only for the purpose of illustrating the embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0028] Figure 1 A schematic cross-sectional view of a solar cell provided in some embodiments of the present application;

[0029] Figure 2 A schematic diagram of a unit area of ​​a first surface in some embodiments of the present application;

[0030] Figure 3 Schematic diagram of a unit portion of a substrate in some embodiments of the present application;

[0031] Figure 4 A schematic cross-sectional view of a doped semiconductor layer in some embodiments of the present application;

[0032] Figure 5 Schematic cross-sectional view of a doped semiconductor layer in some other embodiments of the present application;

[0033] Figure 6 A SEM image of a portion of the structure of a solar cell provided in some embodiments of the present application;

[0034] Figure 7 A SEM image of another part of the structure of a solar cell provided in some embodiments of the present application;

[0035] Figure 8 A schematic diagram of a test point on a doped semiconductor layer in some embodiments of the present application;

[0036] Fig. 9 A schematic diagram of the structure of a photovoltaic module provided in some embodiments of the present application.

[0037] Description of reference numerals:

[0038] Solar cell 100;

[0039] Substrate 110, first surface m1, unit area z, second surface m2, first portion 111, second portion 112, first depth h1, unit portion u;

[0040] Passivation contact layer 120, tunneling layer 121, doped semiconductor layer 122, first thickness d1;

[0041] A first passivation layer 130;

[0042] A first electrode E1;

[0043] doping layer 140;

[0044] A second passivation layer 150;

[0045] A second electrode E2;

[0046] Reference surface E, first intersection line J, central axis L;

[0047] Test points p1, p2, p3, p4, p5;

[0048] Photovoltaic module 1, battery string 1a, encapsulation layer 1b, cover plate 1c, conductive tape 1d.

[0049] First Direction F 1 , the second direction F 2 , the third party to F 3 . DETAILED DESCRIPTION

[0050] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0051] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0052] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0053] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited. It is worth noting that in the following description and the attached claims, "electrical connection" between one feature and another feature not only includes one feature directly contacting another feature to form an electric energy transmission or current transmission channel, but also includes an intermediate feature between one feature and another feature, and the one feature, the other feature and the intermediate feature between them form an electric energy transmission channel or a current transmission channel to achieve electric energy transmission or transmission. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0055] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0056] Figure 1 A schematic cross-sectional structure diagram of a solar cell 100 provided in some embodiments of the present application is shown; Figure 2 A schematic diagram showing a unit area z of the first surface m1 in some embodiments of the present application; Figure 3 Schematic diagrams of unit parts u of the substrate 110 in some embodiments of the present application are shown; for ease of explanation, only the contents related to the embodiments of the present application are shown. 1 is the thickness direction of the substrate 110, and the second direction F 2 and third parties to F 3 The first direction F may be the length direction and the width direction of the substrate 110, respectively. 1 , the second direction F 2 and third parties to F 3 It should be noted that the size of the substrate 110 along the length direction may be greater than or equal to the size along the width direction, and no specific limitation is made here.

[0057] Please refer to Figures 1 to 3 An embodiment of the present application provides a solar cell 100 , including a substrate 110 and a passivation contact layer 120 .

[0058] The substrate 110 is used to receive incident light and generate photogenerated carriers. For example, the substrate 110 may be a silicon substrate. In the embodiment of the present application, the substrate 110 is an N-type substrate. For example, the substrate 110 may be an N-type single crystal silicon wafer. The substrate 110 has a first direction F 1The first surface m1 and the second surface m2 are arranged opposite to each other. Both the first surface m1 and the second surface m2 can be used to receive incident light. In the embodiment of the present application, the first surface m1 is the backlight surface, and the second surface m2 is the light-receiving surface. It can be understood that the light-receiving surface and the backlight surface are relative, and the light-receiving surface is specifically the surface on which the sunlight is mainly irradiated in the solar cell 100 or on the substrate 110 in the photovoltaic module. With the development of solar cell technology, the backlight surface will also receive energy from sunlight, mainly from reflected light or scattered light in the surrounding environment. The second surface m2 is usually provided with a velvet structure, which can increase the light absorption area, increase the photocurrent, and help improve the efficiency of the solar cell 100.

[0059] The passivation contact layer 120 is mainly used to passivate the first surface m1 of the substrate 110, which can reduce the recombination of carriers on the surface of the substrate 110, thereby increasing the open circuit voltage of the solar cell 100 and improving the photoelectric conversion efficiency of the solar cell 100. Specifically, the passivation contact layer 120 includes a tunneling layer 121 disposed on the first surface m1, and a doped semiconductor layer 122 disposed on a side surface of the tunneling layer 121 away from the substrate 110.

[0060] The tunneling layer 121 is used to achieve the interface passivation of the first surface m1 of the substrate 110, and has the effect of chemical passivation. Specifically, by saturating the dangling bonds of the first surface m1, the interface trapped state density of the first surface m1 is reduced, thereby reducing the recombination center of the first surface m1 to reduce the carrier recombination rate. Among them, the material of the tunneling layer 121 can be a dielectric material, such as at least one of silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide. In an embodiment of the present application, the tunneling layer 121 can be formed by low pressure chemical vapor deposition (LPCVD). Of course, the tunneling layer 121 can also be produced by other processes such as thermal oxidation process, plasma oxidation process or nitric acid oxidation process, and no specific limitation is made here.

[0061] The doping element type of the doped semiconductor layer 122 is the same as the doping element type of the substrate 110. In the case where the substrate 110 is an N-type substrate 110, the doped semiconductor layer 122 is an N-type doped semiconductor layer 122. Exemplarily, the doped semiconductor layer 122 can be one of an N-type amorphous silicon layer, an N-type microcrystalline silicon layer, an N-type polycrystalline silicon layer, or an N-type nanocrystalline silicon layer. It can be flexibly set according to the specific usage, and the embodiment of the present application does not impose specific restrictions on this. In the embodiment of the present application, the doped semiconductor layer 122 is an N-type doped polycrystalline silicon layer, and the doping element of the doped semiconductor layer 122 includes phosphorus.

[0062] The inventors of the present application have noticed that due to the limitation of the manufacturing process of the doped semiconductor layer 122, the thickness of the doped semiconductor layer 122 increases along the direction perpendicular to the first direction F. 1 The direction of the doped semiconductor layer 122 is unevenly distributed, which will cause the square resistance of the doped semiconductor layer 122 to be unevenly distributed. Further, since the doping element of the doped semiconductor layer 122 includes phosphorus, during the process of manufacturing the doped semiconductor layer 122, part of the doped phosphorus element will also enter a part of the substrate 110 close to the doped semiconductor layer 122, thereby affecting the square resistance of the substrate 110. Specifically, in conjunction with reference to Figure 1 , a portion of the substrate 110 extending from the first surface m1 toward the second surface m2 at a first depth h1 is defined as a first portion 111 , and a portion of the substrate 110 other than the first portion 111 is defined as a second portion 112 . Figure 1 The first portion 111 and the second portion 112 are distinguished by a dotted line. The doping concentration of the phosphorus element in the first portion 111 is greater than the doping concentration of the phosphorus element in the second portion 112. The first depth h1 satisfies: h1≤300nm. The first depth h1 can be 300nm, 260nm, 240nm, 200nm, 180nm, 150nm, 130nm, 90nm, 50nm or 30nm.

[0063] Based on this, the inventors of the present application have found through research that since the substrate 110 is usually made by cutting a crystal rod prepared by the Czochralski method, and different elements have different segregation coefficients and volatility characteristics, their distribution in the crystal will be different. Therefore, by co-doping different elements in the crystal, this difference can be used to compensate for each other's influence on the resistivity, thereby achieving uniformity and flattening of the resistivity of the entire crystal. For example, co-doping with phosphorus and antimony elements in N-type single crystal silicon can effectively improve the resistivity distribution characteristics of the crystal.

[0064] After in-depth research, the inventors of the present application configured the doping elements in the substrate 110 as two doping elements in combination with the doping type of the substrate 110 and the doping type of the doped semiconductor layer 122. Specifically, the doping elements in the substrate 110 include antimony and phosphorus. In the case where the doping elements in the substrate 110 include antimony and phosphorus, that is, in the process of preparing the crystal rod, the two doping elements of antimony and phosphorus are doped into the silicon crystal. Since phosphorus (P) and antimony (Sb) both belong to group V elements, their outermost electronic structures have one more electron than the stable group IV silicon atoms. When these group V elements are doped into silicon crystals, they replace some silicon atoms and introduce additional free electrons into the crystal lattice.

[0065] Specifically, phosphorus atoms have five valence electrons, four of which form covalent bonds with adjacent silicon atoms, while the fifth valence electron becomes a free electron that can move in the crystal lattice, thereby increasing the conductivity of the semiconductor. Antimony atoms also have excess valence electrons that can contribute to the free electron concentration in the semiconductor material. By co-doping phosphorus and antimony, the distribution of phosphorus can be controlled, thereby leveling the resistivity of the entire crystal.

[0066] In this way, the doping elements in the substrate 110 can be configured as phosphorus and antimony, and the thickness of the doped semiconductor layer 122 can be adjusted along the first direction F perpendicular to the first direction F. 1 The resistivity of the substrate 110 is regulated so that the series resistance at different regions of the solar cell 100 can be more evenly distributed.

[0067] Specifically, with reference to Figure 2 and Figure 3 The substrate 110 has a unit portion u corresponding to the unit area z of the first surface m1, and the average thickness of the portion of the doped semiconductor layer 122 located in the unit area z is the first thickness d1. The resistivity of the unit portion u of the substrate 110 is positively correlated with the first thickness d1 of the doped semiconductor layer 122 corresponding to the unit portion u of the substrate 110.

[0068] Among them, "unit area" refers to the first surface m1 of the substrate 110 and is related to the area of ​​the first surface m1. "Unit area region z" is an area selected from the first surface m1. The size and shape of the selected unit area region z depend on the size definition of different unit areas. After the unit area size is defined, the size of the unit area region z has a relative size and shape relative to the first surface m1. For example, the size of the unit area region z can be 1cm2 (square centimeter), 1mm2 (square millimeter), 1000mm2 (square millimeter), 1100 mm2 (square millimeter), etc. The size of the unit area can be determined according to the size and use requirements of the first surface m1, and the embodiment of the present application does not specifically limit this. Similarly, the division of the unit area region z can be customized according to actual conditions. For example, the first surface m1 can be divided into N×M square areas of equal area, each area is a unit area region z, where N and M are preset positive integers, and the selection of N and M is determined by the area size of the first surface m1. Of course, the shape of each unit area region z is not limited to a square. It can be understood that each unit area region z has the same shape and the same size.

[0069] Exemplary, with reference to Figure 2 , Figure 2 The second direction F 2 and third parties to F 3 In the case where the unit area z of the first surface m1 is divided, the unit area z is arranged in a square shape, and the plurality of unit area z are arranged along the second direction F 2 and third parties to F 3 Arranged in an array, along the second direction F 2 Two adjacent unit area regions z are adjacent to each other, along the third direction F 3 Two adjacent unit area regions z are adjacent. Where N is 29 and M is 16.

[0070] Of course, in some other embodiments, the shape of the unit area z may also be a rectangle or other shapes. The unit area z divided on the first surface m1 may include an incomplete unit area z. For example, after the unit area z is divided according to the use requirements, the remaining area is not enough to divide a complete unit area z. The remaining area can be converted according to the use requirements. Figure 2 In the illustrated cases, the first surface m1 is divided into a plurality of complete unit area regions z. The configuration can be made according to the specific usage, and no specific limitation is made here.

[0071] The “unit portion u” is a portion of the substrate 110 that corresponds to the unit area z of the first surface m1 as a whole. Figure 2 and Figure 3 For example, the unit part u is also like the unit area z, along the second direction F 2 and third parties to F 3 Accordingly, each portion of the doped semiconductor layer 122 also corresponds to each unit portion u of the substrate 110, which will not be described in detail here. Figure 3 From the perspective of 2 The unit part u of the arrangement. Figure 2 and Figure 3 The divided structures are indicated by dotted lines.

[0072] The "positive correlation change trend" refers to the relationship between "the magnitude of the resistivity of the unit portion u of the substrate 110" and "the first thickness d1 of the doped semiconductor layer 122 corresponding to the unit portion u of the substrate 110". When the first thickness d1 of the doped semiconductor layer 122 corresponding to the unit portion u of the substrate 110 increases, the resistivity of the unit portion u of the substrate 110 also tends to increase. When the first thickness d1 of the doped semiconductor layer 122 corresponding to the unit portion u of the substrate 110 decreases, the resistivity of the unit portion u of the substrate 110 also tends to decrease. In other words, the increase or decrease of the first thickness d1 of the doped semiconductor layer 122 corresponding to the unit portion u of the substrate 110 does not necessarily lead to an increase or decrease in the resistivity of the unit portion u of the substrate 110, as long as the "magnitude of the resistivity of the unit portion u of the substrate 110" and "the first thickness d1 of the doped semiconductor layer 122 corresponding to the unit portion u of the substrate 110" are roughly positively correlated.

[0073] Thus, by configuring the doping elements in the substrate 110 to include antimony and phosphorus, the resistivity of the substrate 110 can be adjusted by means of the effects of both antimony and phosphorus. By configuring the resistivity of the unit portion u of the substrate 110 to be positively correlated with the first thickness d1 of the unit area z of the doped semiconductor layer 122 on the first surface m1 of the substrate 110, the resistivity of the position corresponding to the thicker portion of the doped semiconductor layer 122 in the substrate 110 is larger, and the square resistance of the thicker portion of the doped semiconductor layer 122 is smaller, so that the overall square resistance of the portion of the substrate 110 corresponding to the doped semiconductor layer 122 can be distributed more evenly. In this way, when the resistivity of the substrate 110 changes with the square resistance of the doped semiconductor layer 122, the series resistance at different regions of the solar cell 100 can be distributed more evenly, thereby improving the conversion efficiency of the solar cell 100.

[0074] In some embodiments, please refer to Figures 1 to 3 The sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u shows a negative correlation with the resistivity of the unit part u. The phosphorus element in the substrate 110 includes the phosphorus element doped in the substrate 110 itself and the phosphorus element doped when the doped semiconductor layer 122 is manufactured.

[0075] The "negative correlation change trend" refers to the relationship between "the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u" and "the size of the resistivity of the unit part u". When the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u increases, the resistivity of the unit part u of the substrate 110 tends to decrease. When the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u decreases, the resistivity of the unit part u of the substrate 110 tends to increase. In other words, an increase or decrease in the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u does not necessarily lead to a decrease or increase in the resistivity of the unit part u of the substrate 110, as long as the "sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u" and "the size of the resistivity of the unit part u" are roughly negatively correlated.

[0076] In this way, by controlling the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u, the resistivity of the unit part u can be controlled accordingly, so that the resistivity of each unit part u of the substrate 110 can change in a positive correlation with the first thickness d1 mentioned above, thereby achieving the control of the series resistance at different regions of the solar cell 100.

[0077] In some embodiments, please refer to Figures 1 to 3 The sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u continuously decreases as the resistivity of the unit part u increases. That is, as the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u increases, the resistivity of the corresponding unit part u decreases.

[0078] Thus, by further controlling the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in each unit portion u, the resistivity of each unit portion u can be further controlled accordingly, thereby making the series resistance in each region of the solar cell 100 more uniform.

[0079] Of course, in some other embodiments, the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u may be reduced in stages as the resistivity of the unit part u increases. That is, as the sum of the doping concentrations of the antimony element and the phosphorus element in the substrate 110 in the same unit part u increases, the resistivity of the unit part u may be unchanged at first, then decreased, and then unchanged again; or, it may be decreased at first, then unchanged, and then decreased, etc. It can be set according to specific usage requirements and is not specifically limited here.

[0080] In some embodiments, the ratio of the doping concentration of the antimony element to the doping concentration of the phosphorus element in the substrate 110 is 1 to 3. Exemplarily, the ratio may be 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8 or 3.

[0081] The inventors of the present application have further studied and found that both the directional solidification method of polycrystalline silicon and the Czochralski method of single crystal silicon belong to liquid phase growth methods. The solubility of doping elements in the melt and the solid is different. Generally speaking, the solubility of doping elements in liquid is greater than that in solid. This difference will produce a segregation phenomenon. That is, as the crystal grows, the concentration of doping elements in the melt continues to accumulate, and the concentration of doping elements in the later grown crystals gradually increases compared to the earlier grown crystals, which is reflected in the gradual decrease in resistivity.

[0082] Since the segregation coefficient of phosphorus is about 0.35 and the segregation coefficient of antimony is about 0.023, the inventors of the present application noticed that phosphorus mainly participates in the regulation of resistivity by segregation, while antimony participates in the regulation of resistivity by segregation and evaporation at the same time. Based on this, by configuring the doping concentration of antimony to be greater than or equal to the doping concentration of phosphorus, antimony can be greatly utilized to cooperate with phosphorus to regulate resistivity, so that in the entire process of crystal pulling, antimony and phosphorus can cooperate to participate in the regulation of resistivity, thereby facilitating the regulation of the resistivity of each unit part u of the substrate 110. In this process, the inventors of the present application further studied and found that based on the process of phosphorus participating in the regulation of resistivity and the process of antimony participating in the regulation of resistivity, when the ratio of the doping concentration of antimony in the solar cell 100 to the doping concentration of phosphorus in the substrate 110 is 1 to 3, the resistivity of the substrate 110 can be more accurately regulated.

[0083] In this way, by controlling the ratio of the doping concentration of the antimony element to the doping concentration of the phosphorus element in the substrate 110 , it is convenient to more accurately control the resistivity of the substrate 110 , thereby obtaining the desired resistivity distribution of the substrate 110 .

[0084] In some embodiments, the doping concentration of antimony element is 1.549×10 15 cm -3 to 4.271×10 16 cm -3 ; and / or, the doping concentration of phosphorus in the substrate 110 is 1.804×10 15 cm -3 to 4.798×10 16 cm -3 .

[0085] For example, the doping concentration of antimony element may be 1.549×10 15 cm-3 , 5×10 15 cm -3 , 10×10 15 cm -3 , 15×10 15 cm -3 , 20×10 15 cm -3 , 25×10 15 cm -3 ,30×10 15 cm -3 , 40×10 15 cm -3 or 4.271×10 16 cm -3 The doping concentration of phosphorus in the substrate 110 may be 1.804×10 15 cm -3 , 2×10 15 cm -3 , 5×10 15 cm -3 , 10×10 15 cm -3 , 18×10 15 cm -3 , 20×10 15 cm -3 , 25×10 15 cm -3 ,30×10 15 cm -3 ,35×10 15 cm -3 or 4.798×10 16 cm -3 The selection can be made according to the specific use case and is not specifically limited here. Further, the ratio of the doping concentration of the antimony element to the doping concentration of the phosphorus element in the substrate 110 can be 1 to 3 as shown in some of the above embodiments.

[0086] In this way, by controlling the doping concentration of the antimony element and the doping concentration of the phosphorus element in the substrate 110, not only can the resistivity be adjusted to be within a certain range, but the substrate 110 can also have a certain conductivity, stability and reliability. In the case where the doping concentration of the antimony element and the doping concentration of the phosphorus element in the substrate 110 both meet the above corresponding doping concentration ranges, the resistivity, conductivity, stability and reliability of the substrate 110 can be coordinated by means of the doping concentration of the antimony element and the phosphorus element in the substrate 110.

[0087] In some embodiments, please refer to Figures 1 to 3The resistivity of the unit portion u of the substrate 110 increases continuously with the increase of the first thickness d1 of the doped semiconductor layer 122. That is, with the increase of the first thickness d1 of the doped semiconductor layer 122, the resistivity of the corresponding unit portion u increases.

[0088] In this way, by configuring the resistivity of the unit portion u of the substrate 110 to change continuously following the first thickness d1 of the doped semiconductor layer 122 , the series resistance of each region of the solar cell 100 can be further made uniform as a whole.

[0089] Of course, in some other embodiments, the resistivity of the unit portion u of the substrate 110 increases in stages as the first thickness d1 of the doped semiconductor layer 122 increases. This can be set according to specific usage conditions and is not specifically limited here.

[0090] Figure 4 A schematic cross-sectional view of the doped semiconductor layer 122 in some embodiments of the present application is shown; for ease of explanation, only the contents related to the embodiments of the present application are shown.

[0091] In some embodiments, please refer to Figure 4 The first thickness d1 of the doped semiconductor layer 122 within the unit area z has a positive correlation with the distribution distance. The distribution distance is the distance between the unit area z and the center of the first surface m1.

[0092] The "distribution distance" can be regarded as the distance between the center of the unit area region z and the center of the first surface m1. The "positive correlation change trend" refers to the relationship between the "size of the first thickness d1 of the doped semiconductor layer 122 within the unit area region z" and the "distribution distance". When the distribution distance increases, the size of the first thickness d1 of the doped semiconductor layer 122 within the unit area region z also tends to increase. When the distribution distance decreases, the size of the first thickness d1 of the doped semiconductor layer 122 within the unit area region z also tends to decrease. In other words, an increase or decrease in the distribution distance does not necessarily lead to an increase or decrease in the first thickness d1 of the doped semiconductor layer 122, as long as the "size of the first thickness d1 of the doped semiconductor layer 122 within the unit area region z" and the "distribution distance" are roughly positively correlated.

[0093] In this way, a structure is formed in which the first thickness d1 of the edge region of the doped semiconductor layer 122 is substantially greater than the first thickness d1 of the edge region of the doped semiconductor layer 122. Under such a structure of the doped semiconductor layer 122, the structure of the doped semiconductor layer 122 has a certain regularity, so that it is convenient to adjust the resistivity of each unit portion u of the substrate 110 in combination with the regularity of the thickness of the doped semiconductor layer 122.

[0094] In some embodiments, please refer to Figure 4 The first thickness d1 of the doped semiconductor layer 122 within the unit area z increases continuously with the increase of the distribution distance. At this time, the resistivity of the unit part u closer to the center of the substrate 110 is smaller, and the resistivity of the unit part u farther from the center is larger.

[0095] In this way, the thickness of the doped semiconductor layer 122 closer to its center is smaller, and the thickness of the part closer to its edge is larger, thereby forming a structure in which the thickness of the doped semiconductor layer 122 changes continuously, and the thickness of the doped semiconductor layer 122 is more regular, which further facilitates the control of the resistivity of each unit part u of the substrate 110 according to this regularity.

[0096] Of course, in some other embodiments, the first thickness d1 of the doped semiconductor layer 122 in the unit area z increases in stages as the distribution distance increases. The relevant understanding of this staged change can be understood by referring to the relevant situations illustrated in some of the aforementioned embodiments, and will not be repeated here. The doped semiconductor layer 122 can be set according to actual usage conditions, and no specific limitation is made here.

[0097] Figure 5 Schematic cross-sectional views of the doped semiconductor layer 122 in other embodiments of the present application are shown; for ease of explanation, only the contents related to the embodiments of the present application are shown.

[0098] In some embodiments, please refer to Figure 4 , and combined with reference Figure 5 The intersection line between the surface of the doped semiconductor layer 122 facing away from the substrate 110 and the reference plane E is a first intersection line J. The first intersection line J is symmetrically arranged about the central axis L of the first surface m1. The reference plane E is parallel to the first direction F 1 plane, and the central axis L is located on the reference plane E.

[0099] For example, Figure 4 As shown, it is shown that the first intersection line J is arranged in an arc shape, the lowest point of the first intersection line J is located at the central axis, and the first intersection line J smoothly transitions at the lowest point of the first intersection line J; Figure 5 As shown, it is illustrated that the first intersection line J is substantially arranged in a V-shape, and the lowest point of the first intersection line J is located at the central axis.

[0100] Understandably, Figure 4 In the illustrated case, the variation of the first thickness d1 of the doped semiconductor layer 122 can be smoother and more continuous than that of Figure 5 The situation shown is more conducive to regulating the resistivity of the substrate 110 by using phosphorus and antimony elements.

[0101] In this way, when the structure of the doped semiconductor layer 122 is more regular, it is not only beneficial to manufacture the doped semiconductor layer 122 , but also beneficial to control the resistivity of the substrate 110 .

[0102] Regarding the manufacturing process of the doped semiconductor layer 122, the inventor of the present application has noticed that in the manufacturing process of TOPCon (Tunnel Oxide Passivated Contact) cells, a double insertion process is usually used to form the doped semiconductor layer 122 on the substrate 110 to achieve the purpose of improving the process capacity. In this process, the doped semiconductor layer 122 is formed as follows: Figure 6 and Figure 7 As shown, Figure 6 It is shown that the thickness of a point in the middle region of the doped semiconductor layer 122 is approximately 154 nm. Figure 7 The thickness of the doped semiconductor layer 122 at two locations in the edge region is shown to be 160 nm and 167 nm, respectively. The location with a thickness of 160 nm is closer to the middle region of the doped semiconductor layer 122 than the location with a thickness of 167 nm. Overall, the cross section of the doped semiconductor layer 122 is substantially as follows: Figure 4 In this way, not only can the double insertion process be used to improve production capacity, but also the more regular structure of doped semiconductors formed by the double insertion process can be combined to correspondingly adjust the resistivity of the substrate 110. Of course, the solar cell 100 can also be other types of cells, which are not specifically limited here.

[0103] In some embodiments, please refer to Figure 1 The solar cell 100 further includes a first passivation layer 130 . The first passivation layer 130 is disposed on a surface of the doped conductive layer that is away from the tunneling layer 121 .

[0104] The first passivation layer 130 mainly plays a role in surface passivation and anti-reflection in the solar cell 100, and can chemically passivate the dangling bonds on the surface of the substrate 110 and achieve an anti-reflection effect. The first passivation layer 130 can adopt a single-layer structure or a multi-layer structure, and the material of the first passivation layer 130 can be at least one of aluminum oxide, silicon oxide, silicon nitride, or silicon oxynitride.

[0105] In some embodiments, please refer to Figure 1The solar cell 100 further includes a first electrode E1 disposed on a side of the doped semiconductor layer 122 away from the tunneling layer 121. The first electrode E1 is in ohmic contact with the doped semiconductor layer 122. In the embodiment of the present application, the material of the first electrode E1 includes, but is not limited to, one or more of aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), silver (Ag), copper (Cu) and tin (Sn). The first electrode E1 may be formed by one of screen printing, laser transfer and electroplating. In the embodiment of the present application, the first electrode E1 may be understood as a metal grid line, and the width and thickness of the metal grid line are not limited.

[0106] In some embodiments, please refer to Figure 1 The solar cell 100 further includes a doping layer 140 disposed on the second surface m2 of the substrate 110 , and a second passivation layer 150 disposed on a surface of the doping layer 140 that is away from the substrate 110 .

[0107] The doping layer 140 is made of a semiconductor material having a different conductivity type from the substrate 110. When the substrate 110 is an N-type substrate 110, the doping element type of the doping layer 140 is a P-type. The doping layer 140 can be disposed on the second surface m2 of the substrate 110, or can be formed by diffusion on the second surface m2 of the substrate 110 toward the first surface m1, for example.

[0108] The second passivation layer 150 mainly plays a role in surface passivation and anti-reflection in the solar cell 100, and can chemically passivate the dangling bonds on the surface of the substrate 110 and achieve an anti-reflection effect. The second passivation layer 150 can adopt a single-layer structure or a multi-layer structure, and the material of the second passivation layer 150 can be at least one of aluminum oxide, silicon oxide, silicon nitride, or silicon oxynitride.

[0109] In some embodiments, please refer to Figure 1 The solar cell 100 further includes a second electrode E2 disposed on a side of the doped layer 140 away from the substrate 110. The second electrode E2 is in ohmic contact with the doped layer 140. In the embodiment of the present application, the material of the second electrode E2 includes, but is not limited to, one or more of aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), silver (Ag), copper (Cu) and tin (Sn). The second electrode E2 may be formed by one of screen printing, laser transfer and electroplating. In the embodiment of the present application, the second electrode E2 may be understood as a metal grid line, and the width and thickness of the metal grid line are not limited.

[0110] The following is an exemplary description of the manufacturing process of the substrate 110 of the solar cell 100 provided in the embodiment of the present application in combination with the contents illustrated in some of the above embodiments, but is not limited thereto.

[0111] First, electronic grade polysilicon is used as raw material, phosphorus and antimony are used as main dopants; secondly, single crystal silicon wafers are prepared by Czochralski method, phosphorus and antimony are introduced into silicon crystal by solid diffusion; finally, the prepared crystal rod is cut to obtain the required substrate 110. During the growth of silicon crystal, at least one lead-out process, equal diameter growth process and re-feeding process are carried out in sequence. The process of preparing single crystal silicon rod by Czochralski method includes silicon material melting, seeding, shouldering, shoulder rotation, equal diameter growth, re-feeding and other processes. The above-mentioned lead-out process may include seeding, shouldering and shoulder rotation.

[0112] It should be noted that the various process parameters in the CZ process (for example, crucible rotation, crystal rotation, argon flow rate, pressure, power, temperature, liquid mouth distance, maximum value of liquid level control, etc.) can be controlled according to the required resistivity distribution of the substrate 110, and no specific restrictions are imposed herein.

[0113] For example, Figure 4 Taking the doped semiconductor layer 122 as an example, the resistivity of the unit part u closer to the center of the substrate 110 needs to be smaller, and the resistivity of the unit part u farther away from the center needs to be larger. At this time, taking the control of the thermal field temperature as an example, the radial temperature gradient of the crystal rod can be changed by changing the axial temperature gradient of the crystal rod, thereby changing the radial resistivity distribution of the crystal rod, and then controlling the resistivity of the middle area and the edge area of ​​the substrate 110. In this process, since phosphorus and antimony are used as doping elements, it is more conducive to controlling the desired resistivity distribution by changing the radial temperature gradient of the crystal rod by changing the axial temperature gradient of the crystal rod.

[0114] The solar cell 100 provided in the embodiment of the present application is exemplarily described below in combination with the contents illustrated in some of the above embodiments, but is not limited thereto.

[0115] Please refer to Figure 1 The substrate 110 of the solar cell 100 is manufactured by the manufacturing process of the substrate 110 shown above, and the doped semiconductor layer 122 is manufactured by the double insertion process to form a Figure 4The structure of the doped semiconductor layer 122 is shown. In the solar cell, the substrate 110 is an N-type single crystal silicon wafer with a thickness of 100 μm to 180 μm, the doping elements include antimony and phosphorus, the first depth h1 is 30 nm to 300 nm, in the embodiment of the present application, the thickness of the substrate 110 is 120 μm, and the first depth h1 is 130 nm; the material of the tunneling layer 121 is silicon oxide with a thickness of 1 nm to 2 nm, in the embodiment of the present application, the thickness of the tunneling layer 121 is 1.5 nm; the material of the doped semiconductor layer 122 is phosphorus-doped polycrystalline silicon with a thickness of 20 nm to 300nm, in the embodiment of the present application, the target thickness of the doped semiconductor layer 122 is 150nm; the material of the first passivation layer 130 is silicon nitride, and the thickness is 65nm to 85nm, in the embodiment of the present application, the thickness of the first passivation layer 130 is 75nm; the material of the doping layer 140 is boron-doped silicon, and the thickness is 0.1μm to 2μm, in the embodiment of the present application, the thickness of the doping layer 140 is 1μm; the material of the second passivation layer 150 is silicon nitride, and the thickness is 65nm to 85nm, in the embodiment of the present application, the thickness of the second passivation layer 150 is 75nm; The first electrode E1 is made of silver, with a width of 1μm to 100μm, and the spacing between two adjacent first electrodes E1 is 0.5mm to 1.5mm. In the embodiment of the present application, the width of the first electrode E1 is 25μm, and the spacing between two adjacent first electrodes E1 is 1mm; the second electrode E2 is made of silver, with a width of 1μm to 100μm, and the spacing between two adjacent second electrodes E2 is 0.5mm to 1.5mm. In the embodiment of the present application, the width of the second electrode E2 is 25μm, and the spacing between two adjacent second electrodes E2 is 1mm.

[0116] In Example 1, the ratio of the doping concentration of the antimony element in the substrate 110 to the doping concentration of the phosphorus element in the substrate 110 is 1, and the doping concentration of the antimony element is 2.52×10 15 cm -3 to 1.43×10 16 cm -3 The doping concentration of phosphorus in the substrate is 2.52×10 15 cm -3 to 1.43×10 16 cm -3 .

[0117] In Example 2, the ratio of the doping concentration of the antimony element in the substrate 110 to the doping concentration of the phosphorus element in the substrate 110 is 2, and the doping concentration of the antimony element is 3.364×10 15 cm -3 to 1.913×10 16 cm -3The doping concentration of phosphorus in the substrate is 1.682×10 15 cm -3 to 9.563×10 15 cm -3 .

[0118] In Example 3, the ratio of the doping concentration of the antimony element in the substrate 110 to the doping concentration of the phosphorus element in the substrate 110 is 3, and the doping concentration of the antimony element is 3.786×10 15 cm -3 to 2.152×10 16 cm -3 The doping concentration of phosphorus in the substrate is 1.262×10 15 cm -3 to 7.173×10 15 cm -3 .

[0119] In comparative example 1, the substrate 110 is doped with only antimony element, and the doping concentration of antimony element is 5.05×10 15 cm -3 to 2.87×10 16 cm -3 .

[0120] In comparative example 2, the substrate 110 is doped with only phosphorus, and the doping concentration of phosphorus is 5.05×10 15 cm -3 to 2.87×10 16 cm -3 .

[0121] Based on the solar cells manufactured in the above embodiments and comparative examples, the resistivity of the substrate 110, the first thickness d1 of the doped semiconductor layer 122, the square resistance of the doped semiconductor layer 122 and the series resistance of the solar cell 100 were tested using relevant equipment, and the power was tested using a digital source meter under AM1.5G simulated sunlight at 25 degrees Celsius. The test results are shown in Tables 1 to 6. Figure 8 , test point 3' is the lowest point of the first intersection line J (i.e., test point p3), test point 1' and test point 5' are two edge points of the first intersection line J (i.e., test point p1 and test point p5), and test point 2' and test point 4' (i.e., test point p2 and test point p4) are the middle points between the two edge points of the first intersection line J and the lowest point of the first intersection line J. It can be understood that test point 1, test point 1' and test point 1'' are located in the first direction F 1 The above are one-to-one correspondence, and the other test points can be understood in this way and will not be elaborated on.

[0122] Table 1

[0123]

[0124] Table 2

[0125]

[0126] Table 3

[0127]

[0128] Table 4

[0129]

[0130] Table 5

[0131]

[0132] It can be seen from Table 1 that, compared with Comparative Examples 1 and 2, the resistivity of the substrate in Examples 1 to 3 shows a trend of being low in the middle and high at the edges. It can be seen from the examples and comparative examples in Table 2 that, based on the target thickness of 150nm, the thickness of the prepared doped semiconductor layer varies unevenly, and the specific variation trend generally shows a trend of being thin in the middle and thick at the edges. From the square resistance test after the preparation of the doped semiconductor layer, it can be seen from Table 3 that the square resistance values ​​of Examples 1 to 3 are more uniform than those of Comparative Examples 1 and 2. The prepared solar cells were tested for series resistance, and it can be seen from Table 4 that the series resistance of Examples 1 to 3 is more uniform and smaller than that of Comparative Examples 1 to 2. From the electrical parameter test of the solar cell, it can be seen from Table 5 that, based on the experimental data of Comparative Example 2 as the benchmark value, the filling factor of Examples 1 to 3 is higher than that of Comparative Examples 1 and 2, and the improvement of the battery efficiency of Examples 1 to 3 is higher than that of Comparative Examples 1 and 2. Therefore, the solar cell provided in the embodiment of the present application has more advantages.

[0133] It should be noted that those skilled in the art can obtain the substrate 110 by peeling off the different layer structures in the solar cell 100. The doping concentration of the antimony element and the doping concentration of the phosphorus element in the substrate 110 can be detected by any method known to those skilled in the art, and those skilled in the art can select based on the needs, for example, by SIMS, ICP-MS, GDMS and other methods, and specifically by ICP-MS method. Those skilled in the art can understand that the doping concentration of the antimony element and the doping concentration of the phosphorus element can refer to the doping concentration of the antimony element and the doping concentration of the phosphorus element at any site on the surface of the substrate 110 (the first surface m1 or the second surface m2), in the substrate 110 or in the middle of the substrate 110, and of course, it can also be the doping concentration of the antimony element at multiple locations (for example, the concentration at the midpoint, the edge, etc.) and the doping concentration of the phosphorus element, or the average value of the antimony element concentration on the entire substrate 110. Those skilled in the art can select the above-mentioned arbitrary sites for detection based on the actual situation based on the detection conditions and the instruments used, or can calculate the average value of the multiple sites after detecting multiple sites as the doping concentration of the antimony element and the doping concentration of the phosphorus element in the substrate 110.

[0134] The resistivity of the substrate 110 can be detected by any method known to those skilled in the art, and those skilled in the art can make a choice based on the needs, for example, it can be tested by a four-probe tester, or it can be tested by a non-contact eddy current method and other methods (such as from a terahertz offline two-dimensional imaging device), and in a specific way, it can be tested by a four-probe tester. Those skilled in the art can understand that the resistivity of the substrate 110 can refer to the resistivity detection data of any point on the surface of the substrate 110 (the first surface m1 or the second surface m2) or in the middle of the substrate 110, and of course it can also be the average value of the resistivity detection data of multiple positions or the average value of the resistivity on the entire substrate 110. Those skilled in the art can select the above-mentioned arbitrary points for detection based on the actual situation based on the detection conditions and the instruments used, or can calculate the average value of multiple points after detecting multiple points as the resistivity of the substrate 110.

[0135] The selection of the unit area z of the first surface m1 of the substrate 110 can be selected according to the actual use situation. Taking the test of the resistivity of the substrate 110 as an example, the resistivity of the corresponding unit part u in the substrate 110 can select multiple sites of the unit part u to calculate the average value, and the average value is used to characterize the resistivity of the unit part u. The multiple sites can be randomly selected on the unit part u, for example, 2 sites, 3 sites, 4 sites, 5 sites, 6 sites, 7 sites, 8 sites, 9 sites, 10 sites or more for detection and calculation. In the embodiment of the present application, only one site on the corresponding unit part u is selected as a test point, and the one site is used to characterize the resistivity of the corresponding unit part u. Of course, multiple sites on the corresponding unit part u of the substrate 110 can also be selected for detection and calculation. It can be understood that the first thickness d1, square resistance, etc. of the doped semiconductor layer 122 can also be considered with reference to the resistivity-related detection and calculation method mentioned above, which will not be repeated here.

[0136] Fig. 9 A schematic structural diagram of a photovoltaic assembly 1 provided in some embodiments of the present application is shown; for ease of explanation, only contents related to the embodiments of the present application are shown.

[0137] Based on the same invention concept, please refer to Fig. 9 , an embodiment of the present application provides a photovoltaic module 1, including a cell string 1a, an encapsulation layer 1b and a cover plate 1c. The encapsulation layer 1b is used to cover the surface of the cell string 1a. The cover plate 1c is used to cover the surface of the encapsulation layer 1b away from the cell string 1a. Among them, the cell string 1a is formed by electrically connecting a plurality of solar cells 100 in any of the above embodiments. Furthermore, the solar cells 100 are electrically connected in the form of a whole piece or multiple pieces to form a plurality of cell strings 1a, and the plurality of cell strings 1a are electrically connected in series and / or in parallel.

[0138] In some embodiments, the plurality of cell strings 1 a may be electrically connected via conductive tapes 1 d. The encapsulation layer 1 b covers the front and back sides of the solar cell 100 .

[0139] In some embodiments, the encapsulation layer 1 b may be an organic encapsulation film such as an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film or a polyethylene terephthalate (PET) film.

[0140] In some embodiments, the cover plate 1c may be a cover plate 1c with a light-transmitting function such as a glass cover plate 1c or a plastic cover plate 1c.

[0141] In some embodiments, the surface of the cover plate 1c facing the encapsulation layer 1b may be a concave-convex surface, thereby increasing the utilization rate of the incident light.

[0142] The photovoltaic module 1 also has the advantages of the above solar cell 100 , which will not be described in detail here.

[0143] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A solar cell, characterized in that: include: A substrate having a first surface and a second surface arranged opposite to each other along a first direction; the doping elements in the substrate include antimony and phosphorus; and a passivation contact layer, comprising a tunneling layer disposed on the first surface, and a doped semiconductor layer disposed on a surface of the tunneling layer that is away from the substrate; the doping element of the doped semiconductor layer comprises phosphorus, and the thickness of the doped semiconductor layer is unevenly distributed along a direction perpendicular to the first direction; The substrate has a unit portion corresponding to a unit area of ​​the first surface, and the average thickness of the portion of the doped semiconductor layer located in the unit area is a first thickness; the resistivity of the unit portion of the substrate is positively correlated with the first thickness of the doped semiconductor layer corresponding to the unit portion of the substrate; A portion of the substrate extending from the first surface toward the second surface at a first depth is defined as a first portion, and a portion of the substrate other than the first portion is defined as a second portion, wherein a doping concentration of phosphorus in the first portion is greater than a doping concentration of phosphorus in the second portion; and the first depth h1 satisfies: h1≤300nm.

2. The solar cell according to claim 1, characterized in that The sum of the doping concentrations of the antimony element and the phosphorus element in the substrate in the same unit portion shows a negative correlation with the resistivity of the unit portion.

3. The solar cell according to claim 2, characterized in that: The sum of the doping concentrations of the antimony element and the phosphorus element in the substrate in the same unit portion decreases continuously as the resistivity of the unit portion increases.

4. The solar cell according to any one of claims 1 to 3, characterized in that: The ratio of the doping concentration of the antimony element to the doping concentration of the phosphorus element in the substrate is 1 to 3.

5. The solar cell according to any one of claims 1 to 3, characterized in that: The doping concentration of the antimony element is 1.549×10 15 cm -3 to 4.271×10 16 cm -3 ; and / or The doping concentration of phosphorus in the substrate is 1.804×10 15 cm -3 to 4.798×10 16 cm -3 .

6. The solar cell according to any one of claims 1 to 3, characterized in that: The resistivity of a unit portion of the substrate increases continuously with the increase of the first thickness of the doped semiconductor layer.

7. The solar cell according to any one of claims 1 to 3, characterized in that: The first thickness of the doped semiconductor layer within the unit area has a positive correlation with the distribution distance; The distribution distance is the distance between the unit area and the center of the first surface.

8. The solar cell according to claim 7, characterized in that: The first thickness of the doped semiconductor layer within the unit area continuously increases with the increase of the distribution distance.

9. The solar cell according to any one of claims 1 to 3, characterized in that: An intersection line between a surface of the doped semiconductor layer facing away from the substrate and the reference plane is a first intersection line, and the first intersection line is symmetrically arranged about a central axis of the first surface; The reference plane is a plane parallel to the first direction, and the central axis is located on the reference plane.

10. A photovoltaic module, characterized in that: include: Battery string; An encapsulation layer, used to cover the surface of the battery string; and A cover plate, the cover plate is used to cover the surface of the packaging layer away from the battery string; Wherein, the battery string is formed by electrically connecting a plurality of solar cells as described in any one of claims 1 to 9.

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