Solar cell, laminated cell and photovoltaic module

Abstract

The invention relates to a solar cell, a laminated cell and a photovoltaic module, and the solar cell comprises a substrate, a first surface of the substrate comprises a first region and a second region, the first region comprises a first sub-region, a tunneling layer is disposed on the first region, and a doped conductive layer is disposed on the side, away from the substrate, of the tunneling layer. The first passivation layer is arranged on the side, away from the tunneling layer, of the doped conductive layer and on the second area, the first anti-reflection layer is arranged on the side, away from the substrate, of the first passivation layer, the first fine grids are arranged on the first sub-areas in a one-to-one correspondence mode, and at least part of structures of the first fine grids penetrate through the first anti-reflection layer and the first passivation layer. The distance L1 between the first fine grid and the edge of the first sub-region corresponding to the first fine grid in the first direction meets the condition that L1 is larger than or equal to 50 micrometers and smaller than or equal to 800 micrometers, and therefore light parasitic absorption of the doped conductive layer can be reduced, meanwhile, the performance of carrier transverse transmission is guaranteed, and the photoelectric 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 a solar cell, a stacked cell and a photovoltaic module. Background Art

[0002] Solar cells can convert sunlight into electrical energy. Usually, the back of the solar cell can form a tunnel passivation contact structure using a tunnel layer and a doped conductive layer. Currently, the doped conductive layer has serious light parasitic absorption, which affects the short-circuit current of the solar cell. Summary of the invention

[0003] In view of this, the present application provides a solar cell, a stacked cell and a photovoltaic module to solve the above-mentioned problems in the prior art and improve the performance of lateral carrier transport.

[0004] In a first aspect, an embodiment of the present application provides a solar cell, comprising: a substrate, a tunneling layer, a doped conductive layer, a first passivation layer, a first anti-reflection layer and a first fine grid, wherein the substrate has a first surface along its own thickness direction, the first surface comprises a first region and a second region, the first region comprises a first sub-region, the first sub-region is alternately arranged with the second region along a first direction, the first direction is orthogonal to the thickness direction of the substrate, the tunneling layer is arranged on the first region, the doped conductive layer is arranged on a side of the tunneling layer away from the substrate, the first passivation layer is arranged on a side of the doped conductive layer away from the tunneling layer and on the second region, the first anti-reflection layer is arranged on a side of the first passivation layer away from the substrate, the first fine grid is distributed along the first direction and is arranged one-to-one on the first sub-region, at least a portion of the structure of the first fine grid penetrates the first anti-reflection layer and the first passivation layer, and is electrically connected to the doped conductive layer; a distance L1 between the first fine grid and an edge of the first sub-region corresponding to it in the first direction satisfies: 50μm≤L1≤800μm.

[0005] In a possible implementation, along the first direction, the first fine gate located at the center of the substrate is a central fine gate, and the first fine gate located at the edge of the substrate is an edge fine gate, and the distance between the central fine gate and the edge of the first sub-region corresponding thereto in the first direction is L11, and the distance between the edge fine gate and the edge of the first sub-region corresponding thereto in the first direction is L12, and L11 is greater than L12, or L11 is less than L12.

[0006] In a possible implementation, a distance L11 between the central fine grid and an edge of the first sub-region corresponding thereto in the first direction satisfies: 100 μm ≤ L11 ≤ 400 μm, and a distance L12 between the edge fine grid and an edge of the first sub-region corresponding thereto in the first direction satisfies: 50 μm ≤ L2 ≤ 800 μm.

[0007] In a possible embodiment, the solar cell also includes a first main grid, which is arranged along a second direction orthogonal to the first direction, and along the thickness direction of the substrate, the first main grid is located on a side of the first fine grid away from the substrate and is electrically connected to the first fine grid, the first region also includes a second sub-region, the second sub-region is connected between any two adjacent first sub-regions, the second sub-regions are alternately arranged with the second regions along the second direction, and are arranged corresponding to the first main grid; along the thickness direction of the substrate, the projection of a portion of the structure of the first main grid is located in the first sub-region, and the projection of another portion of the structure of the first main grid is located in the second sub-region.

[0008] In a possible implementation manner, a distance L2 between the first main gate and an edge of the second sub-region corresponding thereto in the second direction satisfies: 0 μm≤L11≤400 μm.

[0009] In a possible implementation, the first main gate located at the center of the substrate is a center main gate, and the first main gate located at the edge of the substrate is an edge main gate. The distance between the center main gate and the edge of the second sub-region corresponding thereto in the second direction is L21, and the distance between the edge main gate and the edge of the second sub-region corresponding thereto in the second direction is L22, and L21 is greater than L22, or L21 is less than L22.

[0010] In a possible implementation manner, along the thickness direction of the substrate, a thickness D1 of the doped conductive layer satisfies: 60 nm≤D1≤300 nm.

[0011] In a possible implementation, along the thickness direction of the substrate, a distance from the first region to the second region is H, and H satisfies: 0.5 μm≤H≤10 μm.

[0012] In a possible embodiment, the solar cell includes an emitter, a second passivation layer and a second anti-reflection layer, the substrate has a second surface opposite to the first surface along its own thickness direction, the emitter is formed inside or above the second surface, along the thickness direction of the substrate, the second passivation layer is located on the side of the emitter away from the substrate, and the second anti-reflection layer is located on the side of the second passivation layer away from the substrate.

[0013] In a second aspect, an embodiment of the present application provides a photovoltaic module, comprising a cover plate, a packaging layer and at least one battery string, wherein the battery string comprises a plurality of solar cells as described in any one of the above items, the packaging layer is located between the cover plate and the battery string, and the cover plate is connected to the battery string through the packaging layer.

[0014] In a third aspect, an embodiment of the present application provides a stacked cell, comprising a crystalline silicon bottom cell and a perovskite top cell, wherein the crystalline silicon bottom cell comprises the solar cell given in any one of the above items, and the perovskite top cell is electrically connected to the crystalline silicon bottom cell.

[0015] The embodiments of the present application provide a solar cell, a stacked cell and a photovoltaic module, comprising a substrate, wherein the substrate has a first surface along its own thickness direction, the first surface comprises a first region and a second region, the first region comprises a first sub-region, the first sub-region is alternately arranged with the second region along a first direction, the first direction is orthogonal to the thickness direction of the substrate, a tunneling layer is arranged on the first region, a doped conductive layer is arranged on a side of the tunneling layer away from the substrate, a first passivation layer is arranged on a side of the doped conductive layer away from the tunneling layer and on the second region, a first anti-reflection layer is arranged on a side of the first passivation layer away from the substrate, first fine grids are distributed along the first direction and are arranged one-to-one on the first sub-region, at least a portion of the structure of the first fine grid penetrates the first anti-reflection layer and the first passivation layer, and is electrically connected to the doped conductive layer; a distance L1 between the first fine grid and an edge of the first sub-region corresponding thereto in the first direction satisfies: 50μm≤L1≤800μm.

[0016] In an embodiment of the present application, the tunneling layer and the doped conductive layer are only arranged on the first region, so that the first fine grid can form a good ohmic contact with the doped conductive layer. The tunneling layer and the doped conductive layer are not arranged on the second region, which reduces the light parasitic absorption, improves the short-circuit current of the solar cell, and improves the photoelectric conversion efficiency of the solar cell. At the same time, the first passivation layer and the first anti-reflection layer are arranged on the second region, and the first passivation layer and the first anti-reflection layer can have a good passivation effect on the second region. Therefore, the embodiment of the present application can reduce the light parasitic absorption of the doped conductive layer while ensuring the passivation performance and contact performance of the first surface of the solar cell substrate. Among them, the distance L1 is designed to be 50μm to 800μm, which can reduce the light parasitic absorption of the doped conductive layer while ensuring the rate of lateral carrier transmission, so as to improve the photoelectric conversion efficiency of the solar cell and facilitate the preparation of the first fine grid.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A partial schematic diagram of a solar cell in one embodiment of the present application;

[0020] Figure 2 It is a partial schematic diagram of a first surface of a substrate of a solar cell in one embodiment of the present application;

[0021] Figure 3 It is a partial schematic diagram of a first surface of a substrate of a solar cell in another embodiment of the present application;

[0022] Figure 4 It is a partial schematic diagram of a first fine gate and a first sub-region corresponding thereto in an embodiment of the present application;

[0023] Figure 5 A partial schematic diagram of a central fine grid and a first sub-region corresponding thereto in an embodiment of the present application;

[0024] Figure 6 A partial schematic diagram of an edge fine grid and a first sub-region corresponding thereto in an embodiment of the present application;

[0025] Figure 7 is a partial schematic diagram of a first surface of a substrate of a solar cell in another embodiment of the present application;

[0026] Figure 8 is a partial schematic diagram of a first surface of a substrate of a solar cell in another embodiment of the present application;

[0027] Fig. 9 is a partial schematic diagram of a first surface of a substrate of a solar cell in another embodiment of the present application;

[0028] Fig.10 It is a partial schematic diagram of a first main grid and a second sub-region corresponding thereto in an embodiment of the present application;

[0029] Fig.11 It is a partial schematic diagram of a central main grid and a second sub-region corresponding thereto in an embodiment of the present application;

[0030] Fig.12 It is a partial schematic diagram of an edge main grid and a second sub-region corresponding thereto in an embodiment of the present application;

[0031] Fig.13 A partial schematic diagram of a solar cell in another embodiment of the present application;

[0032] Fig.14 Schematic diagram of a photovoltaic module in one embodiment of the present application.

[0033] Reference numerals:

[0034] 1-solar cell; 11-substrate; 111-first surface; 1111-first region; 1111a-first sub-region; 1111b-second sub-region; 1112-second region; 112-second surface; 12-tunneling layer; 13-doped conductive layer; 14-first passivation layer; 15-first anti-reflection layer; 16-first fine grid; 161-central fine grid; 162-edge fine grid; 17-first main grid; 171-central main grid; 172-edge main grid; 18-emitter; 191-second passivation layer; 192-second anti-reflection layer; 193-second fine grid; 100-photovoltaic module; 10-cell string; 20-first cover plate; 30-first encapsulation layer; 40-second encapsulation layer; 50 second cover plate. DETAILED DESCRIPTION

[0035] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0036] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0037] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0038] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0039] like Figure 1 As shown, an embodiment of the present application provides a solar cell 1, including a substrate 11, and the substrate 11 can be an N-type substrate or a P-type substrate. The N-type substrate can be a silicon substrate doped with an N-type element, and the N-type element can specifically be one or a combination of pentavalent elements such as phosphorus, arsenic, or antimony. The P-type substrate can be a silicon substrate doped with a P-type element, and the P-type element can specifically be one or a combination of trivalent elements such as boron, indium, or gallium. The structure of the solar cell 1 is described below using an N-type substrate as an example.

[0040] The substrate 11 has a first surface 111 and a second surface 112 that are oppositely disposed along its own thickness direction Z. The first surface 111 may be the back surface of the substrate 11, that is, the surface that is not directly irradiated by sunlight. The second surface 112 may be the front surface of the substrate 11, that is, the surface that can be directly irradiated by sunlight. Both the first surface 111 and the second surface 112 can receive sunlight and convert light energy into electrical energy.

[0041] Combined with the shown Figure 2 The first surface 111 includes a first region 1111 and a second region 1112. The first region 1111 includes first sub-regions 1111a, and the first sub-regions 1111a are arranged alternately with the second regions 1112 along a first direction X, and the first direction X is orthogonal to a thickness direction Z of the substrate 11.

[0042] The tunneling layer 12 is disposed on the first region 1111, and the tunneling layer 12 may include at least one of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, amorphous silicon, and polycrystalline silicon. The lattice of the tunneling layer 12 may be well matched with the lattice of the substrate 11, that is, the tunneling layer 12 may well passivate the first surface 111 of the substrate 11 to reduce the rate at which photogenerated electrons and photogenerated holes in the substrate 11 recombine at the first surface 111 of the substrate 11.

[0043] In some embodiments, along the thickness direction Z of the substrate 11, the thickness of the tunneling layer 12 can be 0.5nm to 2nm, for example, 0.5nm, 0.8nm, 1nm, 1.2nm, 1.4nm, 1.6nm, 1.8nm or 2nm. Of course, it can also be other values ​​within the range of methods. By limiting the thickness of the tunneling layer 12, the tunneling layer 12 has good passivation properties and is easy to transport carriers.

[0044] Along the thickness direction Z of the substrate 11, a doped conductive layer 13 is provided on the side of the tunneling layer 12 away from the substrate 11. The tunneling layer 12 and the doped conductive layer 13 can form a tunneling passivation contact structure, so that the energy band of the first surface 111 of the substrate 11 is bent, forming a field passivation effect, thereby realizing the selective transmission of carriers and reducing the recombination loss. Specifically, the doping element in the doped conductive layer 13 is the same as the doping element in the substrate 11. For example, when the substrate 11 is an N-type substrate 11, the doped conductive layer 13 can be an N-type doped conductive layer, which can include at least one of N-type doped amorphous silicon, N-type doped polycrystalline silicon, N-type doped microcrystalline silicon and N-type doped silicon carbide. The tunneling passivation contact structure formed by the tunneling layer 12 and the doped conductive layer 13 can improve the efficiency of the doped conductive layer 13 in collecting electrons, so that the probability of electron tunneling is greatly increased, which is beneficial to improve the open circuit voltage and short circuit current of the solar cell 1, and then improve the photoelectric conversion efficiency of the solar cell 1.

[0045] Along the thickness direction Z of the substrate 11 , the projection of the tunneling layer 12 coincides with the first region 1111 , and the projection of the doped conductive layer 13 also coincides with the first region 1111 .

[0046] The first passivation layer 14 is disposed on the side of the doped conductive layer 13 away from the tunneling layer 12 and on the second region 1112. The first passivation layer 14 may be an aluminum oxide layer. The first passivation layer 14 can enhance the surface carrier concentration of the solar cell 1, improve the short-circuit current and open-circuit voltage of the solar cell 1, and thus improve the photoelectric conversion efficiency of the solar cell 1. Along the thickness direction Z of the substrate 11.

[0047] In some embodiments, the thickness of the first passivation layer 14 is 2nm to 10nm, for example, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm or 10nm. Of course, it can also be other values ​​within the above range. By limiting the thickness of the first passivation layer 14, the first passivation layer 14 can have a good passivation effect.

[0048] The first anti-reflection layer 15 is arranged on the side of the first passivation layer 14 away from the substrate 11. The first anti-reflection layer 15 can be one or a combination of silicon oxide, silicon nitride, and silicon oxynitride. Taking silicon nitride as an example, silicon nitride can play a field passivation role and reduce the recombination of carriers. At the same time, silicon nitride also has an anti-reflection function and can reduce the reflection of sunlight. Arranging it on the first surface 111 of the substrate 11 can improve the light transmittance of the back of the solar cell 1, enhance the carrier concentration on the surface of the substrate 11, increase the short-circuit current and open-circuit voltage of the solar cell 1, and improve the photoelectric conversion efficiency of the solar cell 1.

[0049] In some embodiments, along the thickness direction Z of the substrate 11, the thickness of the first anti-reflection layer 15 is 30nm to 150nm, for example, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm or 150nm, and of course, it can also be other values ​​within the range. By limiting the thickness of the first anti-reflection layer 15, it is helpful to ensure the passivation effect and anti-reflection effect of the first anti-reflection layer 15, thereby helping to improve the photoelectric conversion efficiency of the solar cell 1.

[0050] The first fine grid 16 (ie, the metal electrode) may be made of metal paste. Specifically, the metal paste may be one or a combination of aluminum, silver, nickel, copper, and molybdenum. Figure 3 As shown, the first fine grids 16 are distributed along the first direction X and are arranged one by one on the first sub-region 1111a, that is, along the thickness direction Z of the substrate 11, the projection of the first fine grids 16 is located in the corresponding first sub-region 1111a. At least part of the structure of the first fine grids 16 penetrates the first anti-reflection layer 15 and the first passivation layer 14, and is electrically connected to the doped conductive layer 13 (i.e., ohmic connection) to collect and transmit the current to the solar cell 1.

[0051] In the related art, a tunneling layer and a doped conductive layer are arranged on both the first region and the second region of the first surface of the substrate, that is, it can be understood that the tunneling layer and the doped conductive layer are arranged on the entire surface of the first surface. Among them, the thickness of the tunneling layer on the first region and the tunneling layer on the second region are usually the same, and the thickness of the doped conductive layer on the first region and the doped conductive layer on the second region are usually the same. The first fine grid of the solar cell is only arranged on the first region, so the doped conductive layer on the first region plays a passivation role and forms an ohmic connection with the first fine grid. The first fine grid is not arranged on the second region, so the doped conductive layer on the second region only plays a passivation role. In order to ensure that a good ohmic contact is formed between the doped conductive layer and the first fine grid, and to ensure the passivation effect of the doped conductive layer, the thickness of the doped conductive layer on the first region is usually above 100nm. However, for the doped conductive layer on the second region, usually only a thickness of about 30nm can meet the passivation requirements. As the thickness of the doped conductive layer on the second region increases, the light parasitic absorption of the doped conductive layer on the second region will increase, resulting in a decrease in the short-circuit current of the solar cell, affecting the photoelectric conversion efficiency of the solar cell.

[0052] In the embodiment of the present application, the tunneling layer 12 and the doped conductive layer 13 are only arranged on the first region 1111, so that the first fine grid 16 can form a good ohmic contact with the doped conductive layer 13. The tunneling layer 12 and the doped conductive layer 13 are not arranged on the second region 1112, so as to reduce the light parasitic absorption, increase the short-circuit current of the solar cell 1, and improve the photoelectric conversion efficiency of the solar cell 1. At the same time, the first passivation layer 14 and the first anti-reflection layer 15 are arranged on the second region 1112, and the first passivation layer 14 and the first anti-reflection layer 15 can have a good passivation effect on the second region 1112. Therefore, the embodiment of the present application can reduce the light parasitic absorption of the doped conductive layer 13 while ensuring the passivation performance and contact performance of the first surface 111 of the substrate 11 of the solar cell 1, thereby improving the photoelectric conversion efficiency of the solar cell 1.

[0053] like Figure 3As shown, the distance L1 between the first fine gate 16 and the edge of the first sub-region 1111a corresponding thereto in the first direction X satisfies: 50μm≤L1≤800μm. As mentioned above, along the thickness direction Z of the substrate 11, the projection of the doped conductive layer 13 coincides with the first region 1111, so the distance between the first fine gate 16 and the edge of the first sub-region 1111a corresponding thereto in the first direction X can also be understood as the distance between the first fine gate 16 and the edge of the doped conductive layer 13 on the first sub-region 1111a corresponding thereto in the first direction X. Specifically, L1 can be 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, 550μm, 600μm, 650μm, 700μm, 750μm or 80μm, and of course can also be other values ​​within the above range.

[0054] The first fine grid 16 is electrically connected to the doped conductive layer 13 (ohmic contact). After the carriers enter the doped conductive layer 13 through the tunneling layer 12, the carriers can move in the doped conductive layer 13 along the first direction X, so as to be collected by the first fine grid 16. The movement of the carriers in the doped conductive layer 13 along the first direction X is also called the lateral transmission of the carriers. If the distance L1 is too small, for example, L1 is less than 50 μm, the size of the first sub-region 1111a in the first direction X is too small, that is, the size of the doped conductive layer 13 in the first direction X is too small, which reduces the channel for the lateral transmission of the carriers and affects the rate of the lateral transmission of the carriers, thereby affecting the photoelectric conversion efficiency of the solar cell 1. At the same time, if the size of the first sub-region 1111a in the first direction X is too small, it will also affect the stability of the electrical connection between the first fine grid 16 and the doped conductive layer 13, and affect the printing of the metal paste in the metallization process, thereby increasing the difficulty of preparing the first fine grid 16. If the distance L1 is too large, for example, L1 is greater than 800 μm, the size of the first sub-region 1111a in the first direction X is too large, that is, the size of the doped conductive layer 13 in the first direction X is too large, which is easy to increase the light parasitic absorption of the doped conductive layer 13, resulting in a decrease in the short-circuit current of the solar cell 1. Therefore, the distance L1 is designed to be 50 μm to 800 μm, which can reduce the light parasitic absorption of the doped conductive layer 13 while ensuring the rate of lateral carrier transmission, so as to improve the photoelectric conversion efficiency of the solar cell 1 and facilitate the preparation of the first fine grid 16.

[0055] like Figure 4As shown, in some embodiments, along the first direction X, the first fine gate 16 includes a first end and a second end, and the first sub-region 1111a corresponding to the first fine gate 16 includes a first edge and a second edge. The distance from the first end to the first edge is L1a, and L1a satisfies: 50μm≤L1a≤800μm. The distance from the second end to the second edge is L1b, and L1b satisfies: 50μm≤L1b≤800μm. Among them, L1a and L1b can be the same or different.

[0056] like Figure 5 and Figure 6 As shown, in a possible implementation manner, along the first direction X, the first fine gate 16 located at the center of the substrate 11 is a central fine gate 161, and the first fine gate 16 located at the edge of the substrate 11 is an edge fine gate 162. The distance between the central fine gate 161 and the edge of the first sub-region 1111a corresponding thereto in the first direction X is L11, and the distance between the edge fine gate 162 and the edge of the first sub-region 1111a corresponding thereto in the first direction X is L12, and L11 is greater than L12, or L11 is less than L12.

[0057] As mentioned above, along the thickness direction Z of the substrate 11, the projection of the doped conductive layer 13 coincides with the first region 1111, therefore, the distance between the central fine gate 161 and the edge of the first sub-region 1111a corresponding thereto in the first direction X is the distance between the central fine gate 161 and the edge of the doped conductive layer 13 on the first sub-region 1111a corresponding thereto in the first direction X. Similarly, the distance between the edge fine gate 162 and the edge of the first sub-region 1111a corresponding thereto in the first direction X is the distance between the edge fine gate 162 and the edge of the doped conductive layer 13 on the first sub-region 1111a corresponding thereto in the first direction X.

[0058] During the preparation of the solar cell 1, the doped conductive layer 13 may be deposited on the side of the tunneling layer 12 away from the substrate 11 by physical vapor deposition, chemical vapor deposition, plasma enhanced chemical vapor deposition, or the like. Due to the limitation of the production process, the thickness of the doped conductive layer 13 may be uneven, for example, the thickness of the doped conductive layer 13 corresponding to the center position of the substrate 11 is larger, and the thickness of the doped conductive layer 13 corresponding to the edge position of the substrate 11 is smaller. At this time, the distance L11 between the center fine gate 161 and the edge of the first sub-region 1111a corresponding thereto in the first direction X may be reduced, while the distance L12 between the edge fine gate 162 and the edge of the first sub-region 1111a corresponding thereto in the first direction X may be increased, so that the distance L11 is smaller than the distance L12. Since the thickness of the doped conductive layer 13 corresponding to the center position of the substrate 11 is relatively large, the distance L11 is reduced to reduce the size of the doped conductive layer 13 in the first sub-region 1111a corresponding to the central fine grid 161 in the first direction X, that is, the size of the doped conductive layer 13 corresponding to the center position of the substrate 11 in the first direction X is reduced, so as to reduce the light parasitic absorption of the doped conductive layer 13. Since the thickness of the doped conductive layer 13 corresponding to the edge position of the substrate 11 is relatively small, the distance L12 is increased to increase the size of the doped conductive layer 13 in the first sub-region 1111a corresponding to the edge fine grid 162 in the first direction X, that is, the size of the doped conductive layer 13 corresponding to the edge position of the substrate 11 in the first direction X is increased, so as to improve the passivation performance of the doped conductive layer 13 corresponding to the edge position of the substrate 11, and at the same time ensure that the edge fine grid 162 can form a good ohmic connection with the doped conductive layer 13.

[0059] In other embodiments, the thickness of the doped conductive layer 13 corresponding to the center position of the substrate 11 is smaller, and the thickness of the doped conductive layer 13 corresponding to the edge position of the substrate 11 is larger. In this case, the distance L11 between the center fine gate 161 and the edge of the first sub-region 1111a corresponding thereto in the first direction X can be increased, and the distance L12 between the edge fine gate 162 and the edge of the first sub-region 1111a corresponding thereto in the first direction X can be reduced, so that the distance L11 is greater than the distance L12.

[0060] In summary, in view of the uneven thickness of the doped conductive layer 13, the above-mentioned distance L12 and distance L11 can be adjusted, so as to adjust the size of the first sub-region 1111a at different positions of the substrate 11, that is, the size of the doped conductive layer 13 on the first sub-region 1111a is adjusted, so as to reduce the light parasitic absorption of the doped conductive layer 13 while ensuring the passivation performance and contact performance of the doped conductive layer 13, thereby improving the photoelectric conversion efficiency of the solar cell 1 and ensuring the performance of the solar cell 1.

[0061] It should be noted that the center position of the above-mentioned substrate 11 is an area range, not a certain point at the center of the substrate 11. Multiple first fine grids 16 can be set within this area range, that is, the number of central fine grids 161 can be one, two, three or more. Similarly, the edge position of the substrate 11 is also an area range, not a certain point at the edge of the substrate 11. Multiple first fine grids 16 can be set within this area range, that is, the number of edge fine grids 162 can be one, two, three or more.

[0062] like Figure 5 As shown, in a possible implementation, the distance L11 between the edge of the central fine grid 161 and the corresponding first sub-region 1111a in the first direction X satisfies: 100μm≤L11≤400μm, for example, 100μm, 120μm, 140μm, 150μm, 160μm, 180μm, 200μm, 220μm, 220μm, 250μm, 260μm, 280μm, 300μm, 320μm, 350μm, 360μm, 380μm or 400μm, and of course it can also be other values ​​within the above range.

[0063] like Figure 6 As shown, the distance L12 between the edge of the edge grating 162 and the edge of the first sub-region 1111a corresponding thereto in the first direction X satisfies: 50 μm≤L2≤800 μm, for example, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm or 800 μm. Of course, other values ​​within the above range are also possible.

[0064] As mentioned above, due to the limitation of the production process, the thickness of the doped conductive layer 13 is uneven, and the size of the first sub-region 1111a at different positions of the substrate 11 can be adjusted, that is, the size of the doped conductive layer 13 at different positions of the substrate 11 can be adjusted to make the above distance L12 greater than the distance L11, or to make the distance L12 less than the distance L11, so as to reduce the light parasitic absorption of the doped conductive layer 13 while ensuring the passivation performance and contact performance of the doped conductive layer 13, thereby improving the photoelectric conversion efficiency of the solar cell 1 and ensuring the performance of the solar cell 1. At the same time, by limiting the range of values ​​of the distance L11 and the distance L12, the size of the doped conductive layer 13 at various locations is kept within a reasonable range to ensure the rate of lateral carrier transmission, thereby further improving the photoelectric conversion efficiency of the solar cell 1.

[0065] In some embodiments, the solar cell may be a 0-busbar solar cell, that is, no busbar is provided on the first surface and the second surface of the substrate, and the solar cell may use a welding tape to replace the original busbar. Since no busbar is required, the consumption of metal slurry is reduced, thereby reducing the production cost of the solar cell.

[0066] like Figure 7 As shown, in some embodiments, the solar cell 1 further includes a first main grid 17, and the first main grid 17 is arranged along a second direction Y orthogonal to the first direction X. Along the thickness direction Z of the substrate 11, the first main grid 17 is located on a side of the first fine grid 16 away from the substrate 11, and is electrically connected to the first fine grid 16. The first main grid 17 can collect the current collected by the first fine grid 16 to facilitate the derivation of the current. Along the thickness direction Z of the substrate 11, the projection of a part of the structure of the first main grid 17 is located in the first sub-region 1111a, and the projection of another part of the structure of the first main grid 17 is located in the second region 1112.

[0067] like Figure 8 As shown, in some embodiments, the first region 1111 further includes a second sub-region 1111b, the second sub-region 1111b is connected between any two adjacent first sub-regions 1111a, and the second sub-region 1111b is arranged alternately with the second region 1112 along the second direction Y. The second sub-region 1111b can connect two adjacent first sub-regions 1111a, so that the carriers between the doped conductive layers on the two adjacent first sub-regions 1111a can be transmitted along the first direction X through the doped conductive layer provided on the second sub-region 1111b. Therefore, by providing the second sub-region 1111b, it is beneficial for the carriers to be transmitted laterally along the first direction X, so that it is convenient for the first fine grid 16 to collect the carriers, thereby improving the efficiency of the solar cell 1.

[0068] like Fig. 9 As shown, in a possible implementation, the solar cell 1 further includes a first main grid 17, which is arranged along a second direction Y orthogonal to the first direction X. Along the thickness direction Z of the substrate 11, the first main grid 17 is located on a side of the first fine grid 16 away from the substrate 11, and is electrically connected to the first fine grid 16. The first main grid 17 can collect the current collected by the first fine grid 16 to facilitate the derivation of the current. Along the thickness direction Z of the substrate 11, the projection of a part of the structure of the first main grid 17 is located in the first sub-region 1111a, and the projection of another part of the structure of the first main grid 17 is located in the second sub-region 1111b. In other words, the projection of the first main grid 17 falls entirely into the first region 1111.

[0069] The first region 1111 also includes a second sub-region 1111b, and the second sub-region 1111b is connected between any two adjacent first sub-regions 1111a, that is, the second sub-region 1111b can connect two adjacent first sub-regions 1111a. The second sub-regions 1111b are alternately arranged with the second regions 1112 along the second direction Y, and are arranged corresponding to the first main grid 17. As mentioned above, the second sub-region 1111b is arranged to facilitate the lateral transmission of carriers along the first direction X, so as to facilitate the first fine grid 16 to collect carriers, thereby improving the efficiency of the solar cell 1.

[0070] like Fig. 9 As shown, in a possible implementation manner, the distance L2 between the first main gate 17 and the edge of the corresponding second sub-region 1111b in the second direction Y satisfies: 0μm≤L11≤400μm. As mentioned above, along the thickness direction Z of the substrate 11, the projection of the doped conductive layer 13 coincides with the first region 1111, therefore, the distance between the first main gate 17 and the edge of the corresponding second sub-region 1111b in the second direction Y is the distance between the first main gate 17 and the edge of the doped conductive layer 13 on the corresponding second sub-region 1111b.

[0071] Specifically, L2 can be 0μm, 10μm, 50μm, 100μm, 120μm, 140μm, 160μm, 180μm, 200μm, 220μm, 240μm, 260μm, 280μm, 300μm, 320μm, 340μm, 360μm, 380μm, or 400μm, and of course, it can also be other values ​​within the above range. As mentioned above, carriers can be laterally transported through the doped conductive layer 13 on the second sub-region 1111b. Therefore, by limiting the distance L2 between the first main grid 17 and the edge of the corresponding second sub-region 1111b in the second direction Y, it is possible to reduce the light parasitic absorption of the doped conductive layer 13 while providing a channel for the lateral transport of carriers, thereby improving the photoelectric conversion efficiency of the solar cell 1.

[0072] In some embodiments, the distance L2 between the edge of the first main gate 17 and the corresponding second sub-region 1111b in the second direction Y is greater than 0 μm, which makes the size of the second sub-region 1111b in the second direction Y larger than the size of the first main gate 17, facilitating the printing of metal paste, i.e., facilitating the preparation of the first main gate 17.

[0073] like Fig.10As shown, in some embodiments, along the second direction Y, the first main gate 17 includes a third end and a fourth end, and the second sub-region 1111b corresponding to the first fine gate 16 includes a third edge and a fourth edge. The distance from the third end to the third edge is L2a, and L2a satisfies: 0μm≤L11≤400μm. The distance from the fourth end to the fourth edge is L2b, and L2b satisfies: 0μm≤L11≤400μm. Among them, L2a and L2b can be the same or different.

[0074] like Fig.11 and Fig.12 As shown, in a possible embodiment, along the second direction Y, the first main gate 17 located at the center of the substrate 11 is a central main gate 171, and the first main gate 17 located at the edge of the substrate 11 is an edge main gate 172. The distance between the central main gate 171 and the edge of the corresponding second sub-region 1111b in the second direction Y is L21, and the distance between the edge main gate 172 and the edge of the corresponding second sub-region 1111b in the second direction Y is L22, and L21 is greater than L22, or L21 is less than L22.

[0075] The distance between the central bus gate 171 and the edge of the corresponding second sub-region 1111b in the second direction Y is the distance between the central bus gate 171 and the edge of the doped conductive layer 13 on the corresponding second sub-region 1111b in the second direction Y. Similarly, the distance between the edge bus gate 172 and the edge of the corresponding second sub-region 1111b in the second direction Y is the distance between the edge bus gate 172 and the edge of the doped conductive layer 13 on the corresponding second sub-region 1111b in the second direction Y.

[0076] As mentioned above, due to the limitations of the production process, the thickness of the doped conductive layer 13 may be uneven. Therefore, the distance L22 and the distance L21 mentioned above can be adjusted to adjust the size of the second sub-region 1111b at different positions of the substrate 11, that is, the size of the doped conductive layer 13 on the second sub-region 1111b is adjusted to reduce the light parasitic absorption of the doped conductive layer 13 while ensuring the passivation performance and contact performance of the doped conductive layer 13, thereby improving the photoelectric conversion efficiency of the solar cell 1 and ensuring the performance of the solar cell 1.

[0077] like Fig.13As shown, in a possible implementation manner, along the thickness direction Z of the substrate 11, the thickness D1 of the doped conductive layer 13 satisfies: 60nm≤D1≤300nm, for example, D1 can be 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 260nm, 280nm or 300nm, and of course, it can also be other values ​​within the above range. If the thickness D1 of the doped conductive layer 13 is too small, for example, less than 60nm, the contact area between the first fine grid 16 and the doped conductive layer 13 will be reduced, and the contact resistivity of the first fine grid 16 will be increased, thereby affecting the photoelectric conversion efficiency of the solar cell 1, and also affecting the passivation performance of the doped conductive layer 13. If the thickness D1 of the doped conductive layer 13 is too large, for example, greater than 300nm, the optical parasitic absorption of the doped conductive layer 13 will be increased, resulting in a decrease in the short-circuit current of the solar cell 1, and also affecting the photoelectric conversion efficiency of the solar cell 1. Therefore, designing the thickness D1 of the doped conductive layer 13 to be between 60nm and 300nm is beneficial to reducing the contact resistivity of the first fine gate 16, ensuring the passivation performance of the doped conductive layer 13, and reducing the optical parasitic absorption of the doped conductive layer 13, so as to ensure the photoelectric conversion efficiency of the solar cell 1.

[0078] like Fig.13 As shown, in a possible implementation manner, along the thickness direction Z of the substrate 11 , the distance from the first region 1111 to the second region 1112 is H, and H satisfies: 0.5 μm≤H≤10 μm.

[0079] Along the thickness direction Z of the substrate 11, there is a height difference H between the first region 1111 and the second region 1112, and H can be 0.5μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, 8μm, 8.5μm, 9μm, 9.5μm or 10μm, and of course it can be other values ​​within the above range. There is a height difference between the first region 1111 and the second region 1112, so that the first surface 111 of the substrate 11 presents an uneven shape, so that sunlight can be reflected multiple times on the surface of the substrate 11, thereby improving the absorption efficiency of the solar cell 1 to sunlight, and then improving the light conversion efficiency of the solar cell 1. If the height difference between the first region 1111 and the second region 1112 is too small, for example, H is less than 0.5 μm, it is difficult to make the sunlight reflect multiple times on the first surface 111 of the substrate 11, which affects the absorption of sunlight by the solar cell 1. If the height difference between the first region 1111 and the second region 1112 is too large, for example, H is greater than 10 μm, it will affect the stability of the film layer (such as the first passivation layer 14 and the first anti-reflection layer 15) above the connection between the first region 1111 and the second region 1112, causing the film layer to rupture, thereby affecting the passivation effect of the film layer on the surface of the substrate 11. Therefore, designing the height difference between the first region 1111 and the second region 1112 to be 0.5 μm to 10 μm is conducive to improving the solar cell 1's absorption efficiency of sunlight while ensuring the passivation effect of the substrate 11 surface, so as to achieve the best performance of the solar cell 1.

[0080] like Fig.13 As shown, in some embodiments, along the thickness direction Z of the substrate 11, the first region 1111 is located on a side of the second region 1112 away from the second surface 112 of the substrate 11, that is, the first region 1111 protrudes toward the outside of the substrate 11 relative to the second region 1112, thereby forming the above-mentioned height difference H between the first region 1111 and the second region 1112. Such a design is conducive to identifying and aligning the first region 1111 during the process of preparing the first fine gate 16, thereby facilitating the preparation of the first fine gate 16.

[0081] like Fig.13 As shown, in a possible embodiment, the solar cell 1 includes an emitter 18, a second passivation layer 191 and a second anti-reflection layer 192, the substrate 11 has a second surface 112 opposite to the first surface 111 along its own thickness direction Z, the emitter 18 is formed inside or above the second surface 112, along the thickness direction Z of the substrate 11, the second passivation layer 191 is located on the side of the emitter 18 away from the substrate 11, and the second anti-reflection layer 192 is located on the side of the second passivation layer 191 away from the substrate 11.

[0082] The emitter 18 and the substrate 11 can form a PN junction structure together, wherein when the substrate 11 is the above-mentioned N-type substrate 11, the emitter 18 can be a P-type emitter 18. A second passivation layer 191 is provided on the side of the emitter 18 away from the substrate 11, and the second passivation layer 191 can be an aluminum oxide layer. The second passivation layer 191 can have a good passivation effect on the second surface 112 of the substrate 11, thereby facilitating the improvement of the photoelectric conversion efficiency of the solar cell 1. The second anti-reflection layer 192 can be one or a combination of silicon oxide, silicon nitride, and silicon oxynitride. The second anti-reflection layer 192 can play a field passivation role, reduce the recombination of carriers, and at the same time, it also has an anti-reflection function, which can reduce the reflection of sunlight. Arranging it on the second surface 112 of the substrate 11 can improve the light transmittance of the front side of the solar cell 1, enhance the carrier concentration on the surface of the substrate 11, increase the short-circuit current and open-circuit voltage of the solar cell 1, and improve the photoelectric conversion efficiency of the solar cell 1.

[0083] like Fig.13 As shown, in some embodiments, the solar cell 1 includes a second fine grid 193, which is disposed on a side of the emitter 18 away from the substrate 11, and at least a portion of the structure of the second fine grid 193 penetrates the second passivation layer 191 and the second anti-reflection layer 192, and is electrically connected to the emitter 18. The second fine grid 193 can be made of metal paste, specifically, the metal paste can be one or a combination of aluminum, silver, nickel, copper, and molybdenum.

[0084] An embodiment of the present application provides a stacked cell, including a crystalline silicon bottom cell and a perovskite top cell, wherein the crystalline silicon bottom cell includes any of the above solar cells, and the perovskite top cell is electrically connected to the crystalline silicon bottom cell.

[0085] Among them, the perovskite top cell may include substrate materials, conductive films, electron transport layers (titanium dioxide), perovskite absorption layers (hole transport layers), and metal cathodes. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrode with low loss, so they can generate higher photo-generated voltage and current, making the perovskite exhibit a higher photoelectric conversion efficiency.

[0086] By combining the above-mentioned solar cell and perovskite cell into a stacked cell, it is possible to absorb a wider range of the solar spectrum, thereby improving the photoelectric conversion efficiency of the stacked cell. Since the solar cell has the above-mentioned technical effects, the stacked assembly having the solar cell also has the above-mentioned technical effects, which will not be repeated here.

[0087] like Fig.14As shown, an embodiment of the present application provides a photovoltaic module 100, including a cover plate, a packaging layer and at least one battery string 10, wherein the packaging layer is located between the cover plate and the battery string 10, and the cover plate is connected to the battery string 10 through the packaging layer, and the battery string 10 includes a plurality of solar cells 1 of any of the above items.

[0088] The cover plate may include a first cover plate 20 and a second cover plate 50, the first cover plate 20 may be located on the upper layer of the photovoltaic module 100, and the second cover plate 50 may be located on the lower layer of the photovoltaic module 100. The encapsulation layer includes a first encapsulation layer 30 and a second encapsulation layer 40, the first encapsulation layer 30 may be located between the first cover plate 20 and the battery string 10, and the second encapsulation layer 40 may be located between the second cover plate 50 and the battery string 10.

[0089] The first cover plate 20, the first encapsulation layer 30, the battery string 10, the second encapsulation layer 40 and the second cover plate 50 can be arranged along the thickness direction ZZ of the photovoltaic module 100 and laminated together. Among them, the first cover plate 20 can be a glass cover plate, and the first cover plate 20 has a high light transmittance. The first encapsulation layer 30 bonds the first cover plate 20 to the battery string 10 to provide encapsulation protection for the battery string 10. The material of the first encapsulation layer 30 can be one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE) and polyvinyl butyral (PVB). The second encapsulation layer 40 connects the battery layer to the second cover plate 50, which also provides encapsulation protection for the battery string 10. The material of the second encapsulation layer 40 can be one or more of the above-mentioned EVA, POE, and PVB. The material of the second cover plate 50 can be glass, or the second cover plate 50 can also be composited with multiple polymer film layers.

[0090] Since the solar cell 1 has the above-mentioned technical effects, the photovoltaic module 100 having the solar cell 1 also has the above-mentioned technical effects, which will not be described in detail here.

[0091] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A solar cell, characterized in that: include: A substrate, wherein the substrate has a first surface along its thickness direction, the first surface includes a first region and a second region, the first region includes a first sub-region, the first sub-region is alternately arranged with the second region along a first direction, and the first direction is orthogonal to the thickness direction of the substrate; a tunneling layer, wherein the tunneling layer is disposed on the first region; A doped conductive layer, wherein the doped conductive layer is disposed on a side of the tunneling layer away from the substrate; a first passivation layer, wherein the first passivation layer is disposed on a side of the doped conductive layer away from the tunneling layer and on the second region; A first anti-reflection layer, wherein the first anti-reflection layer is disposed on a side of the first passivation layer away from the substrate; A first fine gate, wherein the first fine gate is distributed along the first direction and is arranged one-to-one on the first sub-region, at least a portion of the structure of the first fine gate penetrates the first anti-reflection layer and the first passivation layer, and is electrically connected to the doped conductive layer; a distance L1 between the first fine gate and an edge of the first sub-region corresponding thereto in the first direction satisfies: 50μm≤L1≤800μm.

2. The solar cell according to claim 1, characterized in that: Along the first direction, the first fine grid located at the center of the substrate is a central fine grid, and the first fine grid located at the edge of the substrate is an edge fine grid; The distance between the central fine grid and the edge of the first sub-region corresponding thereto in the first direction is L11; The distance between the edge fine grid and the edge of the first sub-region corresponding thereto in the first direction is L12; L11 is greater than L12, or L11 is smaller than L12.

3. The solar cell according to claim 2, characterized in that: The distance L11 between the central fine grid and the edge of the first sub-region corresponding thereto in the first direction satisfies: 100 μm≤L11≤400 μm, and; A distance L12 between the edge fine grid and the edge of the first sub-region corresponding thereto in the first direction satisfies: 50 μm≤L2≤800 μm.

4. The solar cell according to claim 1, characterized in that The solar cell further includes a first main grid, which is arranged along a second direction orthogonal to the first direction, and along the thickness direction of the substrate, the first main grid is located on a side of the first fine grid away from the substrate, and is electrically connected to the first fine grid; The first region also includes a second sub-region, which is connected between any two adjacent first sub-regions, and is arranged alternately with the second region along the second direction and is arranged corresponding to the first main grid; along the thickness direction of the substrate, the projection of a part of the structure of the first main grid is located in the first sub-region, and the projection of another part of the structure of the first main grid is located in the second sub-region.

5. The solar cell according to claim 4, characterized in that: A distance L2 between the first main gate and an edge of the second sub-region corresponding thereto in the second direction satisfies: 0 μm≤L11≤400 μm.

6. The solar cell according to claim 5, characterized in that: Along the second direction, the first main grid located at the center of the substrate is a central main grid, and the first main grid located at the edge of the substrate is an edge main grid; The distance between the central main grid and the edge of the second sub-region corresponding thereto in the second direction is L21; The distance between the edge main gate and the edge of the second sub-region corresponding thereto in the second direction is L22; L21 is greater than L22, or L21 is smaller than L22.

7. The solar cell according to any one of claims 1 to 6, characterized in that Along the thickness direction of the substrate, the thickness D1 of the doped conductive layer satisfies: 60nm≤D1≤300nm.

8. The solar cell according to any one of claims 1 to 6, characterized in that Along the thickness direction of the substrate, a distance from the first region to the second region is H, and H satisfies: 0.5 μm≤H≤10 μm.

9. The solar cell according to claim 8, characterized in that The solar cell comprises an emitter, a second passivation layer and a second anti-reflection layer; The substrate has a second surface opposite to the first surface along its thickness direction; The emitter is formed inside or above the second surface. Along the thickness direction of the substrate, the second passivation layer is located on a side of the emitter away from the substrate, and the second anti-reflection layer is located on a side of the second passivation layer away from the substrate.

10. A photovoltaic module, characterized in that: include: Cover plate; At least one battery string, the battery string comprising a plurality of solar cells according to any one of claims 1 to 9; The encapsulation layer is located between the cover plate and the battery string, and the cover plate is connected to the battery string through the encapsulation layer.

11. A laminated battery, characterized in that: include: A crystalline silicon bottom cell, wherein the crystalline silicon bottom cell comprises the solar cell according to any one of claims 1 to 9; A perovskite top cell is electrically connected to the crystalline silicon bottom cell.

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