Solar cells and their manufacturing methods, tandem cells, photovoltaic modules

Abstract

This disclosure relates to the photovoltaic field, providing a solar cell and its manufacturing method, a tandem cell, and a photovoltaic module. The solar cell includes: a substrate with a front and a back side, and a first and a second region; a tunneling layer covering the back side of the substrate; and a doped conductive layer covering the surface of the tunneling layer. The doped conductive layer, with its orthographic projection located within the first region, includes: a first doped sublayer and a second doped sublayer stacked together, the first doped sublayer covering the surface of the tunneling layer, and the second doped sublayer covering the surface of the first doped sublayer. The doping concentration of the first doped sublayer is less than that of the second doped sublayer. The material of the second doped sublayer is nanocrystalline silicon, or a portion of the material of the second doped sublayer is amorphous silicon, and the material of the first doped sublayer is polycrystalline silicon; a passivation layer; and a back electrode electrically connected to the second doped sublayer. This can improve the reliability of the solar cell.

Description

Technical Field

[0001] This disclosure relates to the photovoltaic field, and in particular to a solar cell and its manufacturing method, a tandem cell, and a photovoltaic module. Background Technology

[0002] Photovoltaic power generation refers to the conversion of solar energy into electrical energy through the photovoltaic effect of semiconductors. For example, TOPCON (Tunnel Oxide Passivated Contact) cells have received increasing attention due to their better photoelectric conversion performance.

[0003] TOPCON solar cells are a type of tunneling oxide passivated contact solar cell technology based on the principle of selective charge carriers. In TOPCON solar cells, selective transport of charge carriers is achieved by forming a passivated contact structure on the substrate surface.

[0004] Currently, high-temperature annealing is typically used to complete the doping process in forming the doped conductive layer. However, high-temperature annealing can cause thermal damage to the substrate, reducing the reliability of solar cells. Summary of the Invention

[0005] This disclosure provides a solar cell and its manufacturing method, a tandem cell, and a photovoltaic module, which can at least improve the reliability of the solar cell.

[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a solar cell, comprising: a substrate, the substrate including a front side and a back side opposite to each other, the substrate further having alternating first and second regions; a tunneling layer covering the back side of the substrate; a doped conductive layer covering the surface of the tunneling layer away from the front side, wherein the doped conductive layer, projected onto the surface of the substrate in the first region, comprises: a first doped sublayer and a second doped sublayer stacked thereon, the first doped sublayer covering the surface of the tunneling layer, the second doped sublayer covering the surface of the first doped sublayer, the doping concentration of the first doped sublayer being less than the doping concentration of the second doped sublayer, the material of the second doped sublayer being nanocrystalline silicon, or a portion of the material of the second doped sublayer being amorphous silicon, and the material of the first doped sublayer being polycrystalline silicon; a passivation layer covering the surface of the doped conductive layer; and a back electrode electrically connected to the second doped sublayer.

[0007] In some embodiments, the doped conductive layer located within the second region by orthogonal projection on the substrate surface includes: a first doped sublayer and a second doped sublayer stacked together.

[0008] In some embodiments, the thickness of the first doped sublayer is greater than or equal to the thickness of the second doped sublayer.

[0009] In some embodiments, the thickness of the first doped sublayer is 200 nm to 500 nm, and the thickness of the second doped sublayer is ≤ 200 nm.

[0010] In some embodiments, the doping concentration of the first doped sublayer is ≤1x10⁻⁶. 20 cm -3 The doping concentration of the second doped sublayer is ≥1x10⁻⁶. 21 cm -3 .

[0011] In some embodiments, the doped conductive layer further includes a transition layer, the transition layer being located between the first doped sublayer and the second doped sublayer, wherein the doping concentration of the transition layer is greater than the doping concentration of the first doped sublayer and the doping concentration of the transition layer is less than the doping concentration of the second doped sublayer.

[0012] In some embodiments, the width of each first region is 20 μm to 50 μm, and the width of each back electrode is 30 μm to 50 μm.

[0013] In some embodiments, the material of the second doped sublayer is nanocrystalline silicon, or the material of the second doped sublayer is partially amorphous silicon, and the material of the first doped sublayer is polycrystalline silicon.

[0014] According to some embodiments of this disclosure, another aspect of this disclosure provides a method for manufacturing a solar cell, comprising: providing a substrate, the substrate including a front side and a back side opposite to each other, the substrate further having alternating first regions and second regions; forming a tunneling layer, the tunneling layer covering the back side of the substrate; forming a doped conductive layer, the doped conductive layer covering the surface of the tunneling layer away from the front side, wherein the doped conductive layer, projected onto the surface of the substrate in the first region, comprises: a first doped sublayer and a second doped sublayer stacked thereon, the first doped sublayer covering the surface of the tunneling layer, the second doped sublayer covering the surface of the first doped sublayer, the doping concentration of the first doped sublayer being less than the doping concentration of the second doped sublayer, the material of the second doped sublayer being nanocrystalline silicon, or a portion of the material of the second doped sublayer being amorphous silicon, and the material of the first doped sublayer being polycrystalline silicon; forming a passivation layer, the passivation layer covering the surface of the doped conductive layer; and forming a back electrode, the back electrode being electrically connected to the second doped sublayer.

[0015] In some embodiments, the method of forming a doped conductive layer includes: forming a functional layer covering the surface of the tunneling layer; coating the surface of the functional layer with a dopant; and performing a laser doping process, wherein the laser doping process provides a laser to irradiate the functional layer orthogonally projected onto the first region, so that a portion of the thickness of the functional layer is converted into a molten state, wherein during the laser irradiation of the functional layer, dopant ions in the dopant diffuse into the functional layer, the molten functional layer is converted into a second doped sublayer, and the remaining functional layer is converted into the first doped sublayer.

[0016] In some embodiments, the laser doping process includes: a laser wavelength of 532 nm, a laser energy density of 0.5 J / cm² to 1.5 J / cm², and a scanning speed of 1 m / s to 5 m / s.

[0017] In some embodiments, the laser doping process further includes: detecting the doping depth of dopant ions within the functional layer; if the doping depth of the dopant ions is less than 200 nm, controlling the laser energy density of the laser doping process to be 1.2 J / cm²~1.5 J / cm²; if the doping depth of the dopant ions within the functional layer is 200 nm~350 nm, controlling the laser energy density of the laser doping process to be 0.8 J / cm²~1.2 J / cm²; if the doping depth of the dopant ions within the functional layer is greater than 350 nm, controlling the laser energy density of the laser doping process to be 0.5 J / cm²~0.8 J / cm².

[0018] In some embodiments, the passivation layer is formed in a low-temperature environment. During the formation of the passivation layer, dopant ions in the doped conductive layer diffuse toward the substrate. The low-temperature environment is an ambient temperature ≤ 400°C.

[0019] According to some embodiments of this disclosure, another aspect of this disclosure also provides a stacked battery, including: a bottom battery, a composite layer, and a perovskite top battery stacked sequentially along a preset direction; wherein the bottom battery is a solar cell as described above, or a solar cell formed by the method for manufacturing solar cells as described above.

[0020] According to some embodiments of this disclosure, another aspect of this disclosure provides a photovoltaic module, comprising: a battery string, the battery string comprising: a plurality of solar cells as described above, or a plurality of solar cells formed by the method described above for manufacturing solar cells, or a plurality of tandem cells as described above; a solder ribbon electrically connected to at least two solar cells to connect adjacent solar cells in series, or the solder ribbon electrically connected to at least two tandem cells to connect adjacent tandem cells in series; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film away from the battery string.

[0021] The technical solution provided by the embodiments of this disclosure has at least the following advantages: a first doped sublayer and a second doped sublayer are stacked in a first region of the doped conductive layer for electrical contact with the back electrode. The second doped sublayer near the back electrode has a higher doping concentration to reduce the contact resistance between the doped conductive layer and the back electrode. At the same time, the first doped sublayer near the substrate has a low doping concentration to reduce the parasitic absorption of the first doped sublayer and reduce the recombination of ions in the first doped sublayer.

[0022] On the other hand, during the formation of the doped conductive layer, the material of the second doped sublayer is set to be nanocrystalline silicon or amorphous silicon, so that the second doped sublayer can accommodate more doped ions during the formation of the second doped sublayer. Moreover, there is no large lattice difference between nanocrystalline silicon or amorphous silicon and polycrystalline silicon, which can also reduce the interface state at the contact interface between the first doped sublayer and the second doped sublayer. Attached Figure Description

[0023] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a solar cell provided in one embodiment of the present disclosure;

[0025] Figure 2 This is a schematic diagram of the structure of another solar cell provided in an embodiment of the present disclosure;

[0026] Figure 3 This is a schematic diagram of the structure of another solar cell provided in an embodiment of the present disclosure;

[0027] Figure 4 A flowchart illustrating a method for manufacturing a solar cell according to an embodiment of this disclosure;

[0028] Figure 5 This is a schematic diagram of a structure forming a functional layer according to an embodiment of the present disclosure;

[0029] Figure 6 This is a schematic diagram of a structure for forming a doped conductive layer according to an embodiment of the present disclosure;

[0030] Figure 7 This is a schematic diagram of a structure for forming a solar cell according to an embodiment of the present disclosure;

[0031] Figure 8 This is a schematic diagram of a stacked battery provided in one embodiment of the present disclosure.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100, Substrate; 110, Front side; 120, Back side; 112, First region; 122, Second region; 101, Tunneling layer; 102, Doped conductive layer; 132, First doped sublayer; 142, Second doped sublayer; 152, Transition layer; 162, Functional layer; 172, Doped layer; 103, Passivation layer; 104, Back electrode; 105, Emitter; 106, Second passivation layer; 107, Front electrode.

[0034] 200, Substrate; 210, Front side; 220, Back side; 212, First region; 222, Second region; 201, Tunneling layer; 202, Doped conductive layer; 232, First doped sublayer; 242, Second doped sublayer; 203, Passivation layer; 204, Back electrode; 205, Emitter; 206, Second passivation layer; 207, Front electrode.

[0035] 300, Substrate; 310, Front side; 320, Back side; 312, First region; 322, Second region; 301, Tunneling layer; 302, Doped conductive layer; 332, First doped sublayer; 342, Second doped sublayer; 352, Transition layer; 303, Passivation layer; 304, Back electrode; 305, Emitter; 306, Second passivation layer; 307, Front electrode.

[0036] 400, bottom cell; 401, composite layer; 402, perovskite top cell; 404, back electrode; 412, hole transport layer; 422, perovskite absorber layer; 432, electron transport layer; 442, electrode. Detailed Implementation

[0037] As is known from the background technology, high-temperature doping is usually used when forming a doped conductive layer. High temperature is used to diffuse charge carriers into the doped conductive layer. However, high temperature can cause problems such as substrate warping and tunneling layer cracking, which will reduce minority carrier lifetime.

[0038] In this embodiment, a first doped sublayer and a second doped sublayer are stacked in a first region of the doped conductive layer for electrical contact with the back electrode. The second doped sublayer closer to the back electrode has a higher doping concentration to reduce the contact resistance between the doped conductive layer and the back electrode. At the same time, the first doped sublayer closer to the substrate has a low doping concentration to reduce parasitic absorption of the first doped sublayer and reduce ion recombination of the first doped sublayer.

[0039] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0040] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0042] In the description of embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0043] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0044] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0045] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0046] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly" on the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Additionally, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0047] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0048] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0049] refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a solar cell provided in one embodiment of the present disclosure.

[0050] In some embodiments, a solar cell may include a substrate 100, which includes a front side 110 and a back side 120, and the substrate also has alternating first regions 112 and second regions 122.

[0051] The solar cell may also include a tunneling layer 101, which covers the back side 120 of the substrate 100.

[0052] The solar cell may further include: a doped conductive layer 102, which covers the surface of the tunneling layer 101 away from the front side 110. The doped conductive layer 102, which is projected onto the surface of the substrate 100 and located in the first region 112, includes: a first doped sublayer 132 and a second doped sublayer 142 stacked together. The first doped sublayer 132 covers the surface of the tunneling layer 101, and the second doped sublayer 142 covers the surface of the first doped sublayer 132. The doping concentration of the first doped sublayer 132 is less than that of the second doped sublayer 142. The material of the second doped sublayer 142 is nanocrystalline silicon, or part of the material of the second doped sublayer 142 is amorphous silicon, and the material of the first doped sublayer 132 is polycrystalline silicon.

[0053] The solar cell may also include a passivation layer 103, which covers the surface of the doped conductive layer 102.

[0054] The solar cell may also include a back electrode 104, which is electrically connected to the second doped sublayer 142.

[0055] In this embodiment, a first doped sublayer 132 and a second doped sublayer 142 are stacked in a first region 112 of the doped conductive layer 102 for electrical contact with the back electrode 104. The second doped sublayer 142 closer to the back electrode 104 has a higher doping concentration to reduce the contact resistance between the doped conductive layer 102 and the back electrode 104. At the same time, the first doped sublayer 132 closer to the substrate 100 has a lower doping concentration to reduce parasitic absorption and ion recombination in the first doped sublayer 132. On the other hand, during the formation of the doped conductive layer 102, the material of the second doped sublayer 142 is nanocrystalline silicon or amorphous silicon, which allows the second doped sublayer 142 to accommodate more doped ions during its formation. Moreover, there is no significant lattice difference between nanocrystalline silicon or amorphous silicon and polycrystalline silicon, which can also reduce the interface states at the contact interface between the first doped sublayer 132 and the second doped sublayer 142.

[0056] In some embodiments, the battery cell is a single-sided battery, in which case the front side 110 of the substrate 100 can serve as a light-receiving surface to receive incident light, and the back side 120 serves as a backlighting surface. In some embodiments, the battery cell is a double-sided battery, in which case both the front side 110 and the back side 120 of the substrate 100 can serve as light-receiving surfaces and can both be used to receive incident light. It is understood that the backlighting surface referred to in the embodiments of this disclosure can also receive incident light, but the degree of reception of incident light is weaker than that of the light-receiving surface, and therefore it is defined as a backlighting surface.

[0057] The tunneling layer 101 has a chemical passivation effect on the back side 120 of the substrate 100. Specifically, by saturating the dangling bonds of the back side 120 of the substrate 100, it reduces the defect state density of the back side 120 of the substrate 100 and reduces the recombination centers on the surface of the substrate 100 to reduce the carrier recombination rate.

[0058] In some embodiments, the material of the tunneling layer 101 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or magnesium fluoride.

[0059] In some embodiments, the average doping concentration of the doped conductive layer 102 projected onto the second region 122 is equal to the average doping concentration of the first doped sublayer 132. In other words, the doped conductive layer 102 projected onto the second region 122 is composed of the first doped sublayer 132, and the second doped sublayer 142 is located only in the first region 112. By setting the second doped sublayer 142 with a higher doping concentration only in the first region 112, the parasitic absorption capacity of the doped conductive layer 102 can be further reduced, and the tunneling of charge carriers can be supported while ensuring sufficient conductivity.

[0060] It should be noted that the doping concentration here can refer to the average doping concentration of the doped conductive layer 102 projected onto the second region 122 being exactly equal to the average doping concentration of the first doped sublayer 132, or it can refer to the average doping concentration of the doped conductive layer 102 projected onto the second region 122 being within a preset difference from the average doping concentration of the first doped sublayer 132.

[0061] In some embodiments, the doped conductive layer 102, projected onto the surface of the substrate 100 within the second region 122, comprises a first doped sublayer 132 and a second doped sublayer 142 stacked together. In other words, the entire doped conductive layer 102 is composed of the first doped sublayer 132 and the second doped sublayer 142. Thus, when the back electrode 104 is formed later, it is not necessary to align the back electrode 104 with the first region 112, thereby reducing the process difficulty of forming the back electrode 104. At the same time, due to the high doping concentration of the second doped sublayer 142, band bending is formed within the doped conductive layer 102, which can slow down the collection of charge carriers, thereby improving the photoelectric conversion efficiency of the solar cell.

[0062] In some embodiments, the thickness of the first doped sublayer 132 is greater than or equal to the thickness of the second doped sublayer 142. If the second doped sublayer 142 is too thick, the doped conductive layer 102 will have a high parasitic light absorption capacity. By setting the thickness of the first doped sublayer 132 to be greater than or equal to the thickness of the second doped sublayer 142, the parasitic light absorption capacity of the second doped sublayer 142 is balanced, thereby improving the performance of the solar cell.

[0063] In some embodiments, the thickness of the first doped sublayer 132 is 200nm~500nm, for example, 200nm, 230nm, 250nm, 280nm, 300nm, 350nm, 400nm, 450nm or 500nm, etc., and the thickness of the second doped sublayer 142 is ≤200nm, for example, 50nm, 70nm, 100nm, 120nm, 150nm, 180nm or 200nm, etc.

[0064] If the thickness of the first doped sublayer 132 is less than 200 nm, the doped conductive layer 102 may have a strong parasitic light absorption capacity, which is not conducive to improving the photoelectric conversion efficiency of the solar cell. If the thickness of the first doped sublayer 132 is greater than 500 nm, the doped conductive layer 102 will be too thick, resulting in wasted costs and reduced conductivity. In addition, an excessively thick first doped sublayer 132 will prolong the time for charge carriers to reach the electrode, increasing the probability of charge carrier recombination. If the thickness of the second doped sublayer 142 is greater than 200 nm, the doped conductive layer 102 will have a strong parasitic light absorption capacity, and an excessively thick second doped sublayer 142 will introduce more defects, increasing the probability of charge carrier recombination.

[0065] In some embodiments, the doping concentration of the first doped sublayer 132 is ≤1x10⁻⁶. 20 cm -3 The doping concentration of the second doped sublayer 142 is ≥1x10⁻⁶. 21 cm -3 It is understandable that if the doping concentration of the first doped sublayer 132 is greater than 1 x 10⁻⁶, then... 20 cm -3 This will cause the first doped sublayer 132 to also have a certain parasitic light absorption capacity, which is not conducive to improving the performance of the solar cell. If the doping concentration of the second doped sublayer 142 is less than 1x10, 21 cm -3 This may result in a weaker ability of the second doped sublayer 142 to collect and transport charge carriers, and may also lead to an increase in the contact resistance between the second doped sublayer 142 and the back electrode 104. Therefore, the doping concentration of the first doped sublayer 132 is set to ≤1x10⁻⁶. 20 cm -3 The doping concentration of the second doped sublayer 142 is ≥1x10⁻⁶. 21 cm -3 .

[0066] It should be noted that the doping concentration of the first doped sublayer 132 here refers to the doping concentration of the surface of the first doped sublayer 132 facing the back electrode 104, and the doping concentration of the second doped sublayer 142 refers to the doping concentration of the surface of the second doped sublayer 142 facing the back electrode 104.

[0067] In some embodiments, the width of each first region 112 is 20 μm to 50 μm, for example, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm, etc., and the width of each back electrode 104 is 30 μm to 50 μm, for example, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm, etc. Setting the width of the first region 112 to be approximately the same as the width of the back electrode 104 allows the back electrode 104 to cover the entire second doped sublayer 142, so that the second doped sublayer 142 with a higher doping concentration is precisely positioned opposite the back electrode 104, thereby reducing parasitic absorption. At the same time, it can also avoid the increase in series resistance caused by misalignment between the back electrode 104 and the second doped sublayer 142, thereby further improving the performance of the solar cell.

[0068] The passivation layer 103 can effectively passivate the back surface 120 of the substrate 100. For example, it can effectively chemically passivate the dangling bonds on the back surface 120 of the substrate 100, saturate the dangling bonds, reduce the defect state density on the back surface 120 of the substrate 100, and suppress carrier recombination on the back surface 120 of the substrate 100. The material of the passivation layer 103 can be one of silicon oxide, aluminum oxide, silicon nitride, or silicon oxynitride.

[0069] The majority carriers in the substrate 100 tunnel through the tunneling layer 101 to the doped conductive layer 102. The majority carriers transported to the doped conductive layer 102 are then transported to the back electrode 104, which is electrically connected to the doped conductive layer 102, and are collected by the back electrode 104.

[0070] The material of the back electrode 104 may include silver-coated copper, silver paste, or other conductive materials.

[0071] In some embodiments, the solar cell may further include: an emitter 105 covering the front surface 110 of the substrate 100, wherein the doping type of the emitter 105 is opposite to that of the substrate 100, and forms a PN junction with the substrate 100. The solar cell may further include: a second passivation layer 106 located on the surface of the emitter 105 away from the substrate 100, which provides good passivation for the front surface 110 of the substrate 100, reduces the defect state density of the front surface 110 of the substrate 100, and effectively suppresses carrier recombination on the front surface 110 of the substrate 100. The second passivation layer 106 also provides good anti-reflection effect, reducing the reflection of incident light by the front surface 110 of the substrate 100 and improving the utilization rate of incident light by the substrate 100.

[0072] The material of the second passivation layer 106 can be at least one of silicon oxide, aluminum oxide, silicon nitride, or silicon oxynitride.

[0073] In some embodiments, the second passivation layer 106 may be a single-layer structure. In some embodiments, the second passivation layer 106 may also be a multilayer structure, wherein the materials of each layer in the multilayer structure may be different from each other, or, a portion of the layers may be made of different materials, while the remaining portion may be made of the same material. For example, the second passivation layer 106 may be a multilayer structure of silicon nitride and aluminum oxide layers.

[0074] The solar cell may also include a front electrode 107, which is electrically connected to the emitter 105 for collecting charge carriers.

[0075] In this embodiment, a first doped sublayer 132 and a second doped sublayer 142 are stacked in a first region 112 of the doped conductive layer 102 for electrical contact with the back electrode 104. The second doped sublayer 142, which is closer to the back electrode 104, has a higher doping concentration to reduce the contact resistance between the doped conductive layer 102 and the back electrode 104. At the same time, the first doped sublayer 132, which is closer to the substrate 100, has a lower doping concentration to reduce parasitic absorption and ion recombination in the first doped sublayer 132. On the other hand, during the formation of the doped conductive layer 102, the material of the second doped sublayer 142 is nanocrystalline silicon or amorphous silicon, so that the second doped sublayer 142 can accommodate more doped ions during the formation of the second doped sublayer 142. Moreover, there is no large lattice difference between nanocrystalline silicon or amorphous silicon and polycrystalline silicon, which reduces the interface states at the contact interface between the first doped sublayer 132 and the second doped sublayer 142.

[0076] This disclosure also provides another solar cell, which is basically the same as the above embodiments, except that the structure of the doped conductive layer is different. The following will describe the other solar cell provided by this disclosure in conjunction with the accompanying drawings. It should be noted that the parts that are the same as or corresponding to those in the above embodiments can be referred to the above embodiments, and will not be repeated hereafter.

[0077] refer to Figure 2 , Figure 2 This is a schematic diagram of another solar cell structure provided in an embodiment of the present disclosure.

[0078] In some embodiments, the doped conductive layer 202, projected onto the surface of the substrate 200 within the second region 222, comprises a first doped sublayer 232 and a second doped sublayer 242 stacked together. In other words, the entire doped conductive layer 202 is composed of the first doped sublayer 232 and the second doped sublayer 242. Thus, when the back electrode 204 is formed later, it is not necessary to align the back electrode 204 with the first region 212, thereby reducing the process difficulty of forming the back electrode 204. At the same time, due to the high doping concentration of the second doped sublayer 242, band bending is formed within the doped conductive layer 202, which can slow down the collection of charge carriers, thereby improving the photoelectric conversion efficiency of the solar cell.

[0079] The front side 210, back side 220, first region 212, tunneling layer 201, passivation layer 203, emitter 205, second passivation layer 206, and front electrode 207 in the figure correspond one-to-one with the front side 110, back side 120, first region 112, tunneling layer 101, passivation layer 103, emitter 105, second passivation layer 106, and front electrode 107 in the above embodiment, and will not be described again here.

[0080] This disclosure also provides another type of solar cell, which is basically the same as the above embodiments, except that the structure of the doped conductive layer is different. The following will describe another type of solar cell provided by this disclosure in conjunction with the accompanying drawings. It should be noted that the parts that are the same as or corresponding to those in the above embodiments can be referred to the above embodiments, and will not be repeated hereafter.

[0081] refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of another solar cell provided in an embodiment of the present disclosure.

[0082] In some embodiments, the doped conductive layer 302 further includes a transition layer 352, which is located between the first doped sub-layer 332 and the second doped sub-layer 342. The doping concentration of the transition layer 352 is greater than that of the first doped sub-layer 332, and the doping concentration of the transition layer 352 is less than that of the second doped sub-layer 342. By providing a transition layer 352 between the first doped sub-layer 332 and the second doped sub-layer 342, interface recombination caused by abrupt changes in doping concentration within the doped conductive layer 302 can be avoided. Simultaneously, the transition layer 352 can also generate a gradient electric field to drive charge carriers to move from the first doped sub-layer 332 towards the second doped sub-layer 342, thereby improving the carrier collection efficiency.

[0083] In some embodiments, the doped conductive layer 302 includes a transition layer 352. The thickness of the first doped sublayer 332 can be 200nm~350nm, for example, 200nm, 250nm, 300nm, or 350nm, etc. The thickness of the transition layer 352 can be 50nm~150nm, for example, 70nm, 90nm, 100nm, 120nm, 130nm, or 150nm, etc. The thickness of the second doped sublayer 342 is ≤200nm, for example, 50nm, 70nm, 100nm, 120nm, 150nm, 180nm, or 200nm, etc.

[0084] For the doped conductive layer 302, due to the setting of the transition layer 352, the thickness of the first doped sublayer 332 is adjusted to balance the overall thickness of the doped conductive layer 302, thereby avoiding the doped conductive layer 302 from being too thick. Moreover, if the thickness of the transition layer 352 is less than 50nm, the ability to improve the sudden change in doping concentration is poor. If the thickness of the transition layer 352 is greater than 150nm, the carrier transport path will be too long, and the recombination probability will increase.

[0085] In some embodiments, the doping concentration of the transition layer 352 is 5 x 10⁻⁶. 20 cm -3 ~1x10 21 cm -3 For example, 5x10 20 cm -3 6x10 20 cm -3 7x10 20 cm -3 8x10 20 cm -3 9x10 20 cm -3 Or 1x10 21 cm -3 Wait. If the doping concentration of transition layer 352 is less than 5 x 10⁻⁶... 20 cm -3 The doping concentration of the transition layer 352 is approximately the same as that of the first doped sublayer 332. If the doping concentration of the transition layer 352 is greater than 1 x 10⁻⁶, then... 21 cm -3 The doping concentration of transition layer 352 is similar to that of the second doped sublayer 342, which will reduce the transition effect of transition layer 352. Therefore, the doping concentration of transition layer 352 is set to 5 x 10. 20 cm -3 ~1x10 21 cm -3 It can gradually adjust the band bending, reduce the carrier barrier at the interface, and lower the recombination probability.

[0086] In some embodiments, the transition layer may be a mixture of nanocrystalline silicon and polycrystalline silicon, or a mixture of amorphous silicon and polycrystalline silicon.

[0087] The substrate 300, front side 310, back side 320, first region 312, tunneling layer 301, passivation layer 303, back electrode 304, emitter 305, second passivation layer 306, and front electrode 307 in the figure correspond one-to-one with the substrate 100, front side 110, back side 120, first region 112, tunneling layer 101, passivation layer 103, back electrode 104, emitter 105, second passivation layer 106, and front electrode 107 in the above embodiment, and will not be described in detail here.

[0088] Another embodiment of this disclosure also provides a method for manufacturing a solar cell. This method can be used to form the solar cell in the above embodiment. The method for manufacturing a solar cell provided by another embodiment of this disclosure will be described below with reference to the accompanying drawings. It should be noted that the same or corresponding parts as in the above embodiment can be referred to the above embodiment, and will not be repeated below.

[0089] Combination Figure 1 ,refer to Figures 4 to 7 ,in, Figure 4 This is a flowchart illustrating a method for manufacturing a solar cell according to an embodiment of the present disclosure. Figures 5 to 7 This is a schematic diagram showing the structural steps of a method for manufacturing a solar cell according to an embodiment of this disclosure.

[0090] refer to Figure 4 In some embodiments, the method of manufacturing a solar cell may include: S10: providing a substrate, the substrate including opposing front and back sides, the substrate also having alternating first and second regions.

[0091] The method of manufacturing solar cells may also include: S11: forming a tunneling layer that covers the back side of the substrate.

[0092] The method for manufacturing a solar cell may further include: S12: forming a doped conductive layer, the doped conductive layer covering the surface of the tunneling layer away from the front side, wherein the doped conductive layer, projected onto the substrate surface in a first region, includes: a first doped sublayer and a second doped sublayer stacked together, the first doped sublayer covering the surface of the tunneling layer, the second doped sublayer covering the surface of the first doped sublayer, the doping concentration of the first doped sublayer being less than the doping concentration of the second doped sublayer, the material of the second doped sublayer being nanocrystalline silicon, or part of the material of the second doped sublayer being amorphous silicon, and the material of the first doped sublayer being polycrystalline silicon.

[0093] The method for manufacturing solar cells may also include: S13: forming a passivation layer, the passivation layer covering the surface of the doped conductive layer.

[0094] The method for manufacturing solar cells may also include: S14: forming a back electrode, wherein the back electrode is electrically connected to a second doped sublayer.

[0095] During the formation of the doped conductive layer 102, the doped conductive layer 102 located in the first region 112 is controlled to include a first doped sublayer 132 and a second doped sublayer 142. The second doped sublayer 142 reduces the contact resistance between the doped conductive layer 102 and the back electrode 104, and the first doped sublayer 132 reduces the parasitic absorption of the doped conductive layer 102.

[0096] refer to Figure 5 and Figure 6 , Figure 5 To form a structural diagram of the functional layers, Figure 6 This is a schematic diagram of the structure for forming a doped conductive layer.

[0097] In some embodiments, the method of forming a doped conductive layer 102 includes: forming a functional layer 162 covering the surface of the tunneling layer 101; coating a dopant on the surface of the functional layer 162; performing a laser doping process, wherein the laser doping process provides a laser, the laser irradiates the functional layer 162 orthogonally projected onto the first region 112, so that a portion of the thickness of the functional layer 162 is converted into a molten state, and during the laser irradiation of the functional layer 162, dopants in the dopant diffuse into the functional layer 162, the molten functional layer 162 is converted into a second doped sublayer 142, and the remaining functional layer 162 is converted into a first doped sublayer 132. Laser doping is used to incorporate dopant ions from the dopant into the functional layer 162 to form a doped conductive layer 102. During the laser doping process, the instantaneous high temperature of the laser irradiation causes a portion of the functional layer 162 to completely melt, transforming the solid functional layer 162 into a liquid state. The dopant ions from the dopant mix within the liquid functional layer 162 to form a second doped sublayer 142. For the first doped sublayer 132, the dopant is incorporated into the unmelted functional layer 162 via solid-phase diffusion to form the first doped sublayer 132. Converting a portion of the functional layer 162 into a molten state using laser doping improves the doping uniformity of the second doped sublayer 142, while solid-phase diffusion reduces the doping concentration of the first doped sublayer 132. This achieves both a reduction in carrier recombination in the formed doped conductive layer 102 and a reduction in the contact resistance between the doped conductive layer 102 and the back electrode 104.

[0098] Taking polycrystalline silicon as an example, after melting, the functional layer 162 transforms from polycrystalline silicon into nanocrystalline silicon or amorphous silicon. The melting process is that the functional layer 162 becomes liquid due to the instantaneous high temperature reached by laser irradiation.

[0099] Understandably, the molten functional layer 162 will cool and solidify as the process progresses. This transition from liquid to solid will transform the polycrystalline silicon material of the functional layer 162 into a nanocrystalline or amorphous silicon structure. The formed doped conductive layer 102 can be tested using transmission electron microscopy (TEM) or Raman spectroscopy. TEM irradiation of the second doped sublayer 142 will reveal a nanocrystalline or amorphous silicon structure, while irradiation of the first doped sublayer 132 will reveal a polycrystalline structure. Raman spectroscopy will show amorphous silicon characteristic peaks in the second doped sublayer 142 and polycrystalline silicon peaks in the first doped sublayer 132.

[0100] The dopant can be coated by spin-coating a phosphoric acid ethanol solution or a boric acid ethanol solution onto the entire surface of the functional layer 162. The appropriate dopant can be selected according to the doping requirements, wherein the mass fraction of the solute can be 3~8wt%. By coating the dopant, a doped layer 172 is formed on the surface of the functional layer 162. Since the dopant uses an ethanol solution as a solvent, the surface tension of the dopant can be reduced, thereby facilitating the coating of the dopant and improving the uniformity of the doped layer 172.

[0101] In some embodiments, the process parameters for spin-coating the dopant may include: a spin speed of 2000 rpm to 4000 rpm, such as 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, or 4000 rpm; a spin time of 30 s to 60 s, such as 30 s, 35 s, 40 s, 45 s, 50 s, 55 s, or 60 s; and an ambient temperature and humidity of 20°C to 25°C and RH ≤ 40%. Controlling the spin speed to 2000 rpm to 4000 rpm and the spin time to 30 s to 60 s can improve the uniformity of the formed doped layer 172. The ambient temperature and humidity of 20°C to 25°C and RH ≤ 40% can prevent excessively rapid ethanol evaporation leading to agglomeration.

[0102] In some embodiments, after coating the dopant, the doped layer 172 may be pre-dried to fix the dopant onto the surface of the functional layer 162.

[0103] In some embodiments, the doping process may include: a laser wavelength of 532 nm, a laser energy density of 0.5 J / cm² to 1.5 J / cm², such as 0.5 J / cm², 0.7 J / cm², 0.9 J / cm², 1 J / cm², 1.2 J / cm², 1.4 J / cm², or 1.5 J / cm², etc., and a scanning speed of 1 m / s to 5 m / s, such as 1 m / s, 2 m / s, 3 m / s, 4 m / s, or 5 m / s, etc. The 532nm laser wavelength matches the absorption characteristics of polycrystalline silicon, ensuring that more than 85% of the laser energy is absorbed by the functional layer 162, which is a portion of the thickness away from the substrate 100. This avoids damage to the functional layer 162 near the substrate 100, facilitating the formation of the first doped sublayer 132 and the second doped sublayer 142. Regarding laser energy density, too low a laser energy density may reduce the doping concentration of the second doped sublayer 142, while too high a laser energy density may damage the first doped sublayer 132. On the other hand, too slow a scanning speed will affect the production efficiency of the solar cell, while too fast a scanning speed will result in too short a residence time of the laser on the dopant surface, leading to insufficient energy input and reducing the doping effect.

[0104] In some embodiments, the laser doping process further includes: detecting the doping depth of dopant ions within the functional layer 162; if the doping depth of the dopant ions is less than 200 nm, controlling the laser energy density of the laser doping process to be 1.2 J / cm² to 1.5 J / cm², for example, 1.2 J / cm², 1.3 J / cm², 1.4 J / cm², or 1.5 J / cm², etc.; if the doping depth of the dopant ions within the functional layer 162 is 200 nm to 350 nm, controlling the laser energy density of the laser doping process to be 0.8 J / cm² to 1.2 J / cm²; if the doping depth of the dopant ions within the functional layer 162 is greater than 350 nm, controlling the laser energy density of the laser doping process to be 0.5 J / cm² to 0.8 J / cm². In other words, as the doping depth increases, the laser energy density of the laser doping process is reduced. When the doping depth is less than 200 nm, the second doped sublayer 142 is being formed, requiring a higher doping concentration and the functional layer 162 to be converted into a molten state. Therefore, sufficient energy is needed. When the doping depth is 200 nm to 350 nm, the transition layer 152 is being formed. The transition layer 152 is in a solid-liquid mixed state during its formation and needs to serve as a transition between the doping concentration of the second doped sublayer 142 and the first doped sublayer 132. Therefore, the laser energy density of the laser doping process is appropriately reduced so that the doping concentration of the transition layer 152 is between that of the first doped sublayer 132 and the second doped sublayer 142. When the doping depth is greater than 350 nm, the first doped sublayer 132 is being formed. The laser energy density is further reduced to avoid damage to the remaining functional layer 162, as well as to the tunneling layer 101 and the substrate 100.

[0105] In some embodiments, the initial laser energy density can be 1.5 J / cm², and after the doping depth of the doped ions reaches 200 nm, the laser energy density can be reduced by 0.3 J / cm² for every 50 nm of doping to form a doped conductive layer 102 with a doping concentration gradient distribution.

[0106] A substrate 100 is provided and a tunneling layer 101 is formed before the functional layer 162 is formed.

[0107] refer to Figure 7 , Figure 7 In order to be in Figure 6 A passivation layer and a back electrode are formed on the basis of this.

[0108] In some embodiments, a passivation layer 103 is formed at a low-temperature environment. During the formation of the passivation layer 103, dopant ions in the doped conductive layer 102 diffuse toward the substrate 100. The low-temperature environment is defined as an ambient temperature ≤ 400°C. In other words, the ambient temperature at which the passivation layer 103 is formed further increases the diffusion depth of charge carriers, thereby improving the conductivity of the formed doped conductive layer 102.

[0109] In some embodiments, the back electrode 104 is silver-clad copper. The low compatibility of the silver-clad copper electrode can further reduce the impact of high-temperature processes on the substrate 100 and the tunneling layer 101, thereby avoiding problems such as warping of the substrate 100 and damage to the tunneling layer 101.

[0110] In some embodiments, it further includes an emitter 105, a second passivation layer 106, and a front electrode 107.

[0111] In some embodiments, another embodiment of this disclosure provides a tandem battery, wherein the base cell in the tandem battery can be a solar cell as described in the above embodiments, or a solar cell formed by the method described above for manufacturing solar cells. The tandem battery provided in the embodiments of this disclosure will be described below with reference to the accompanying drawings. Parts that are the same as or corresponding to those in the above embodiments can be referred to the above embodiments, and will not be repeated hereafter.

[0112] refer to Figure 8 , Figure 8 This is a schematic diagram of a stacked battery provided in an embodiment of the present disclosure.

[0113] The tandem solar cell may include: a bottom cell 400, a composite layer 401, and a perovskite top cell 402 stacked sequentially along a preset direction; wherein, the bottom cell 400 is a solar cell as described above, or a solar cell formed by the method of manufacturing a solar cell as described above.

[0114] The back electrode 404 in the bottom battery 400 can refer to the back electrode 104 in the above embodiment.

[0115] The composite layer 401 is made of a transparent conductive oxide (TCO) to provide lateral conductivity and light transmission. For example, the material can be indium tin oxide (ITO), indium hydride oxide (IO:H), or zinc oxide (ZnO).

[0116] The top cell 402 may include: a hole transport layer 412, a perovskite absorber layer 422, an electron transport layer 432, and an electrode 442.

[0117] Another embodiment of this disclosure also provides a photovoltaic module, comprising: a battery string, the battery string including: a plurality of solar cells as described above, or a plurality of solar cells formed by the method of manufacturing solar cells as described above, or a plurality of tandem cells as described above; a solder ribbon electrically connected to at least two solar cells to connect adjacent solar cells in series, or the solder ribbon electrically connected to at least two tandem cells to connect adjacent tandem cells in series; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film away from the battery string.

[0118] In some embodiments, the encapsulating film includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the solar cell, and the second encapsulating layer covers the other of the front or back sides of the solar cell. Specifically, at least one of the first or second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first or second encapsulating layer can also be an EP film, an EPE film, or a PVP film. Here, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film + POE film + EVA film; and PVP film refers to a co-extruded film formed by stacking POE film + EVA film + POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0119] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module no longer has the concept of a first encapsulation layer and a second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film.

[0120] In some embodiments, the cover plate can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate facing the encapsulating film can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0121] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A method for manufacturing a solar cell, characterized in that, include: A substrate is provided, the substrate including opposing front and back sides, the substrate further having alternating first and second regions; A tunneling layer is formed, which covers the back side of the substrate; A doped conductive layer is formed, the doped conductive layer covering the surface of the tunneling layer away from the front side, wherein the doped conductive layer, projected onto the first region on the substrate surface, comprises: a first doped sublayer and a second doped sublayer stacked together, the first doped sublayer covering the surface of the tunneling layer, the second doped sublayer covering the surface of the first doped sublayer, the doping concentration of the first doped sublayer being less than the doping concentration of the second doped sublayer, the material of the second doped sublayer being nanocrystalline silicon, or the material of the second doped sublayer being amorphous silicon, and the material of the first doped sublayer being polycrystalline silicon; A passivation layer is formed, which covers the surface of the doped conductive layer; A back electrode is formed, which is electrically connected to the second doped sublayer; A method for forming a doped conductive layer includes: forming a functional layer covering the surface of the tunneling layer; coating the surface of the functional layer with a dopant; performing a laser doping process, wherein the laser doping process provides a laser beam that irradiates the functional layer orthogonally projected onto the first region, causing a portion of the functional layer to molten, wherein during the laser irradiation of the functional layer, dopant ions in the dopant diffuse into the functional layer, the molten functional layer is converted into a second doped sublayer, and the remaining functional layer is converted into the first doped sublayer; and reducing the laser energy density of the laser doping process as the doping depth increases.

2. The method for manufacturing a solar cell according to claim 1, characterized in that, The laser doping process includes: a laser wavelength of 532 nm, a laser energy density of 0.5 J / cm² to 1.5 J / cm², and a scanning speed of 1 m / s to 5 m / s.

3. The method for manufacturing a solar cell according to claim 1 or 2, characterized in that, The laser doping process further includes: detecting the doping depth of doped ions in the functional layer; if the doping depth of doped ions is less than 200 nm, controlling the laser energy density of the laser doping process to be 1.2 J / cm²~1.5 J / cm². If the doping depth of the internal doped ions in the functional layer is 200nm~350nm, the laser energy density of the laser doping process is controlled to be 0.8J / cm²~1.2J / cm². If the doping depth of the internal dopant ions in the functional layer is greater than 350 nm, the laser energy density of the laser doping process is controlled to be 0.5 J / cm²~0.8 J / cm².

4. The method for manufacturing a solar cell according to claim 1, characterized in that, The passivation layer is formed in a low-temperature environment. During the formation of the passivation layer, the doped ions in the doped conductive layer diffuse toward the substrate. The low-temperature environment is an ambient temperature ≤ 400°C.

5. A solar cell, characterized in that, The solar cell is formed using the method of manufacturing a solar cell as described in any one of claims 1 to 4, comprising: The substrate includes opposing front and back sides, and the substrate further has alternating first and second regions; A tunneling layer that covers the back side of the substrate; A doped conductive layer covers the surface of the tunneling layer away from the front side, wherein the doped conductive layer, projected onto the substrate surface within the first region, comprises: a first doped sublayer and a second doped sublayer stacked together, the first doped sublayer covering the surface of the tunneling layer, the second doped sublayer covering the surface of the first doped sublayer, the doping concentration of the first doped sublayer being less than the doping concentration of the second doped sublayer, the material of the second doped sublayer being nanocrystalline silicon, or a portion of the material of the second doped sublayer being amorphous silicon, and the material of the first doped sublayer being polycrystalline silicon; A passivation layer that covers the surface of the doped conductive layer; A back electrode, which is electrically connected to the second doped sublayer.

6. The solar cell according to claim 5, characterized in that, The doped conductive layer, whose orthogonal projection onto the substrate surface is located within the second region, comprises: a first doped sublayer and a second doped sublayer stacked together.

7. The solar cell according to claim 5 or 6, characterized in that, The thickness of the first doped sublayer is greater than or equal to the thickness of the second doped sublayer.

8. The solar cell according to claim 7, characterized in that, The thickness of the first doped sublayer is 200nm~500nm, and the thickness of the second doped sublayer is ≤200nm.

9. The solar cell according to claim 5 or 6, characterized in that, The doping concentration of the first doped sublayer is ≤1x10 20 cm -3 The doping concentration of the second doped sublayer is ≥1x10⁻⁶. 21 cm -3 .

10. The solar cell according to claim 5, characterized in that, The doped conductive layer further includes a transition layer, which is located between the first doped sublayer and the second doped sublayer, and the doping concentration of the transition layer is greater than that of the first doped sublayer and less than that of the second doped sublayer.

11. The solar cell according to claim 5, characterized in that, The width of each of the first regions is 20μm to 50μm, and the width of each of the back electrodes is 30μm to 50μm.

12. A stacked battery, characterized in that, include: A bottom cell, a composite layer, and a perovskite top cell are stacked sequentially along a predetermined direction; Wherein, the bottom cell is a solar cell formed by the method of manufacturing a solar cell as described in any one of claims 1 to 4, or a solar cell as described in any one of claims 5 to 11.

13. A photovoltaic module, characterized in that, include: A battery string, comprising: a plurality of solar cells formed by a method of manufacturing solar cells according to any one of claims 1 to 4, or a plurality of solar cells according to any one of claims 5 to 11, or a plurality of tandem cells according to claim 12; a solder ribbon electrically connected to at least two solar cells to connect adjacent solar cells in series, or the solder ribbon electrically connected to at least two tandem cells to connect adjacent tandem cells in series. An encapsulating film, the encapsulating film being used to cover the surface of the battery string; A cover plate for covering the surface of the encapsulating film away from the battery string.

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