Solar battery and photovoltaic module

Abstract

To provide a solar battery and a photovoltaic module capable of improving a yield of a photovoltaic module.SOLUTION: A solar battery includes: a substrate; a passivation layer located on the substrate; first and second fine grids arranged along a first direction; a plurality of main grids arranged along a second direction; and an edge grid line extending along the second direction. The substrate includes two first boundaries arranged to face each other along the first direction. The main grid may be located on a surface of the passivation layer to be in contact with a fine grid, and the main grid may include first and second main grids alternately arranged along a second direction. The first main grid is in contact with the first fine grid and the second main grid is in contact with the second fine grid. An edge grid line is close to the first boundary, the edge grid line of some regions is connected to the substrate through the passivation layer, and the edge grid line is in contact with the first and / or second main grids.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present embodiments relate to the field of photovoltaics, and in particular to solar cells and photovoltaic modules. [Background technology]

[0002] There are two main factors that affect the photoelectric conversion efficiency and yield of solar cells: the first is optical loss, which includes shading loss, carrier recombination loss in the substrate, carrier recombination loss in the highly doped film layer, and refraction loss in the film layer, and the second is electrical loss, which includes resistance loss in the material itself, contact loss in the electrodes, contact loss between the PV ribbon and the solar cell, and poor welding between the PV ribbon and the solar cell.

[0003] Therefore, there is an urgent need in this field to provide solar cells and photovoltaic modules that can reduce electrical losses and optical losses so as to improve the photoelectric conversion efficiency of the corresponding solar cells and the yield of the photovoltaic modules. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present invention provide a solar cell and a photovoltaic module that can improve at least the yield of photovoltaic modules. [Means for solving the problem]

[0005] According to some embodiments of the present application, in one aspect of the embodiments of the present application, a solar cell is provided, which includes a substrate, a passivation layer located on the substrate, fine grids arranged along a first direction, a plurality of main grids arranged along a second direction, and at least one edge grid line extending along the second direction. Here, the substrate has two first boundaries arranged opposite to each other along the first direction, the fine grids penetrate through the passivation layer and are electrically connected to the substrate, the fine grids include first fine grids and second fine grids arranged alternately along the first direction, the main grids are located on the surface of the passivation layer and are in electrical contact with the fine grids, the main grids include m1 first main grids and m2 second main grids arranged alternately along the second direction, the first main grids are in electrical contact with the first fine grids, the second main grids are in electrical contact with the second fine grids. Here, the first main grid is one of the positive electrode and the negative electrode, the second main grid is the other of the positive electrode and the negative electrode, the edge grid line is close to the first boundary, and a part of the edge grid line penetrates through the passivation layer and is electrically connected to the substrate. The edge grid line includes a first edge grid line and is used for electrical contact with n1 first main grids, and / or the edge grid line includes a second edge grid line and is used for electrical contact with n2 second main grids. Here, 1 < n1 ≤ m1, 1 < n2 ≤ m2, and n1, m1, n2, and m2 are all natural numbers.

[0006] In some embodiments, the polarities of the edge grid line and the fine grid adjacent to the edge grid line are the same.

[0007] In some embodiments, the first edge grid line is in electrical contact with n1 first main grids, the second edge grid line is in electrical contact with n2 second main grids, 1 < n1 < m1, and 1 < n2 < m2.

[0008] In some embodiments, the first fine grid includes a plurality of first sub-grid lines separated by a plurality of first spacing regions along the second direction, such that two adjacent first sub-grid lines are separated by a corresponding first spacing region; the second main grid is located in the first spacing regions, and the first main grid is in electrical contact with the first sub-grid lines; the second fine grid includes a plurality of second sub-grid lines separated by a plurality of second spacing regions along the second direction, such that two adjacent second sub-grid lines are separated by a corresponding second spacing region; the first main grid is located in the second spacing region, and the second main grid is in electrical contact with the second sub-grid lines.

[0009] In some embodiments, the width of the edge grid lines in the first direction is greater than or equal to the width of the fine grid in the first direction.

[0010] In some embodiments, the range of the width of the edge grid lines in the first direction includes 10 μm to 55 μm.

[0011] In some embodiments, the spacing between the edge grid lines and the adjacent fine grid lines is a first spacing, and the first spacing is less than or equal to the distance between the adjacent first fine grid lines and the adjacent second fine grid lines.

[0012] In some embodiments, the first distance is in the range of 0.2 mm to 0.7 mm.

[0013] In some embodiments, the distance between adjacent first fine grids and adjacent second fine grids is in the range of 0.3 mm to 0.8 mm.

[0014] In some embodiments, the material of the edge grid lines is the same as the material of the fine grid.

[0015] In some embodiments, the first edge grid line is located between the first boundary and the second fine grid, and the second edge grid line is located between another of the first boundaries and the first fine grid.

[0016] In some embodiments, the solar cell includes at least one first connecting grid line, the first connecting grid line electrically connected to the substrate through the passivation layer, wherein the first connecting grid line is electrically connected to the remaining m1-n1 first main grids.

[0017] In some embodiments, the solar cell includes at least one second connecting grid line, the second connecting grid line electrically connected to the substrate through the passivation layer, wherein the second connecting grid line is electrically connected to the remaining m2-n2 second main grids.

[0018] In some embodiments, the material of the first connecting grid lines is the same as the material of the fine grid, and the material of the second connecting grid lines is the same as the material of the fine grid.

[0019] In some embodiments, the width of the first connection grid lines in the first direction is greater than or equal to the width of the fine grid, and the width of the second connection grid lines in the first direction is greater than or equal to the width of the fine grid.

[0020] According to some embodiments of the present application, in another aspect of the embodiments of the present application, there is provided a photovoltaic module, the photovoltaic module including: a cell string formed by connecting a plurality of solar cells according to any one of the above embodiments; a connection member for electrically connecting a first main grid and a second main grid of two adjacent solar cells; a sealing adhesive film for covering a surface of the cell string; and a cover plate for covering a surface of the sealing adhesive film away from the cell string, wherein the solar cells are provided with edge grid lines, a first main grid, and a second main grid.

[0021] In some embodiments, the solar cell further includes an electrical connection wire, wherein the edge grid line is in electrical contact with n1 of the first main grids and the electrical connection wire is electrically connected to the second main grid of the adjacent solar cell, or the edge grid line is in electrical contact with n2 of the second main grids and the electrical connection wire is electrically connected to the first main grid of the adjacent solar cell. [Effects of the Invention]

[0022] The technical solutions provided in the embodiments of the present application have at least the following advantages:

[0023] In the solar cell provided in the present embodiment, the edge grid lines are in electrical contact with the first main grid and / or the second main grid, and one grid line connects the grid lines of the same polarity (positive or negative electrode) in the solar cell in series to form a complete electrode in one solar cell. This ensures electrical continuity between the first main grid and each of the first fine grids, avoiding problems such as reduced cell efficiency and yield due to a malfunction of one of the first main grids. Furthermore, since all the first fine grids are in a conductive state, the first fine grids located at the substrate edge can be collected to improve cell collection efficiency. Similarly, improving the cell collection efficiency of the second fine grid can also improve cell efficiency.

[0024] In addition, because they are all electrically connected, the problem of poor appearance between the first main grids and first fine grids due to differences in the manufacturing process can be avoided.The interconnection between the first main grids and the second main grids also prevents the problem of reduced battery efficiency due to grid breakage of one of the fine grids or main grids. [Brief explanation of the drawings]

[0025] One or more embodiments are illustratively described in corresponding figures in the accompanying drawings, but these illustrative descriptions are not intended to limit the embodiments, and unless otherwise specified, the figures in the accompanying drawings are not limited to scale. In order to more clearly explain the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without any creative effort. [Figure 1] FIG. 1 is a diagram showing the structure of a solar cell provided in one embodiment of the present application. [Figure 2] FIG. 2 is a diagram showing the local structure of a solar cell provided in one embodiment of the present application. [Figure 3] FIG. 3 is a diagram showing a cross-sectional structure along the A1-A2 cross section of FIG. [Figure 4] FIG. 4 is a diagram showing a cross-sectional structure along the B1-B2 cross section of FIG. [Figure 5] FIG. 5 is a diagram showing another structure of a solar cell provided in one embodiment of the present application. [Figure 6] FIG. 6 is a layout diagram of grid lines in a solar cell provided in one embodiment of the present application. [Figure 7] FIG. 7 is a diagram illustrating the structure of a photovoltaic module provided in another embodiment of the present application. [Figure 8] FIG. 8 is a diagram showing a cross-sectional structure along the M1-M2 cross section of FIG. [Figure 9] FIG. 9 is a diagram showing the structure of a solar cell in a photovoltaic module provided in another embodiment of the present application. [Figure 10] FIG. 10 is a diagram illustrating the structure of a photovoltaic module provided in one embodiment of the present application. [Figure 11] FIG. 11 is a diagram showing a cross-sectional structure along the M5-M6 cross section of FIG. [Figure 12] FIG. 12 is a diagram showing another cross-sectional structure along the M3-M4 cross section of FIG. [Figure 13]FIG. 13 is a diagram showing the structure of a solar cell in a photovoltaic module provided in one embodiment of the present application. [Figure 14] FIG. 14 is a diagram showing a cross-sectional structure corresponding to FIG. [Figure 15] FIG. 15 is a diagram illustrating another structure of a solar cell in a photovoltaic module provided in one embodiment of the present application. [Figure 16] FIG. 16 is a diagram showing a cross-sectional structure corresponding to FIG. [Figure 17] FIG. 17 is a diagram illustrating another structure of a solar cell in a photovoltaic module provided in one embodiment of the present application. [Figure 18] FIG. 18 is a diagram illustrating the structure of a conductive structure in a photovoltaic module provided in one embodiment of the present application. [Figure 19] FIG. 19 is a diagram showing the structure of the conductive structure and the main grid in the photovoltaic module provided in one embodiment of the present application. [Figure 20] FIG. 20 is a diagram showing another structure of the conductive structure and the main grid in the photovoltaic module provided in one embodiment of the present application. [Figure 21] FIG. 21 is a diagram illustrating another structure of the photovoltaic module provided in one embodiment of the present application. [Figure 22] FIG. 22 is a diagram showing a cross-sectional structure along the M5-M6 cross section of FIG. [Figure 23] FIG. 23 is a diagram showing a first type of structure of a solar cell provided in one embodiment of the present application. [Figure 24] FIG. 24 is an enlarged view of a portion C in FIG. [Figure 25] FIG. 25 is a diagram showing a cross-sectional structure taken along A1-A2 in FIG. [Figure 26] FIG. 26 is a diagram showing a cross-sectional structure taken along B1-B2 in FIG. [Figure 27] FIG. 27 is a diagram showing a second type of structure of a solar cell provided in one embodiment of the present application. [Figure 28]FIG. 28 is a diagram showing a third type of structure of a solar cell provided in one embodiment of the present application. [Figure 29] FIG. 29 is a layout diagram of the first connecting grid lines and the second connecting grid lines in the solar cell provided in one embodiment of the present application. [Figure 30] FIG. 30 is another layout diagram of the first connecting grid lines and the second connecting grid lines in the solar cell provided in one embodiment of the present application. [Figure 31] FIG. 31 is a diagram showing a fourth type of structure of a solar cell provided in one embodiment of the present application. [Figure 32] FIG. 32 is a diagram showing a fifth type of structure of a solar cell provided in one embodiment of the present application. [Figure 33] FIG. 33 is a diagram showing the structure of a photovoltaic module provided in another embodiment of the present application. [Figure 34] FIG. 34 is a diagram showing a cross-sectional structure along the M1-M2 cross section of FIG. [Figure 35] FIG. 35 is a diagram showing the structure of a solar cell in a photovoltaic module provided in another embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0026] As can be seen from the background art, current solar cell and photovoltaic module yields are poor.

[0027] According to some embodiments of the present application, in this embodiment, a photovoltaic module is provided, the photovoltaic module including: a cell string formed by connecting a plurality of solar cells with a connecting member; a conductive structure located between two adjacent solar cells; a sealing adhesive film for covering a surface of the cell string and a surface of the conductive structure; and a cover plate for covering a surface of the sealing adhesive film away from the cell string, wherein the solar cells have a first main grid and a second main grid located on the same surface, the connecting member is used to electrically connect the first main grid and the second main grid of two adjacent solar cells, wherein the first main grid is one of a positive electrode or a negative electrode, and the second main grid is the other of a positive electrode or a negative electrode, the conductive structure has a first surface and a second surface arranged opposite to each other, the first surface is in contact with a surface of the solar cells, and the second surface is in electrical contact with the connecting member.

[0028] In some embodiments, the conductive structure includes an insulating layer and a conductive layer, one side of the insulating layer contacting one side of the conductive layer, the other side of the insulating layer constituting the first surface, and the other side of the conductive layer constituting the second surface.

[0029] In some embodiments, the material of the insulating layer includes PE, EVA, or PET, and the material of the conductive layer includes aluminum, aluminum tin, or copper.

[0030] In some embodiments, the insulating layer comprises an adhesive layer.

[0031] In some embodiments, the material of the adhesive layer is the same as the material of the sealing adhesive film.

[0032] In some embodiments, the solar cell further includes m1 first main grids and m2 second main grids arranged in a sequentially spaced-apart relationship, and at least one edge grid line, the first main grids being positioned on the surface of the edge grid line, and the edge grid line being in electrical contact with the n1 first main grids, wherein: <n1≦m1である。

[0033] In some embodiments, the solar cell further includes an electrical connection wire, the electrical connection wire electrically connecting to a second main grid of the solar cell adjacent to the edge grid line, and the first surface being in electrical contact with the electrical connection wire.

[0034] In some embodiments, the conductive structure has a first edge extending in a first direction toward a first main grid and along a second direction, the first main grid has a second edge extending in the first direction toward the conductive structure and along the second direction, and a spacing between the first edge and the second edge ranges from 0 mm to 2 mm, and wherein the plurality of solar cells are arranged along the first direction.

[0035] In some embodiments, a spacing between the second main grid and the first edge is greater than zero, and the conductive structure includes a conductive layer having oppositely disposed first and second surfaces.

[0036] In some embodiments, the first edge and the first main grid are in contact.

[0037] In some embodiments, there are gaps between the solar cells and some of the conductive structures are located in the gaps.

[0038] In some embodiments, the first surface 21 is in contact with the surfaces of the two solar cells adjacent to each other at both ends in the first direction.

[0039] In some embodiments, the ratio of the overlap area between the first surface and the solar cell to the surface area of ​​the first surface is in the range of 1 / 10 to 1 / 10.

[0040] The technical solutions provided in the embodiments of the present application have at least the following advantages:

[0041] In the technical solution provided in the embodiments of the present application, the photovoltaic module includes a conductive structure positioned between the solar cells, the conductive structure having oppositely disposed first and second surfaces, the first surface contacting the surface of the solar cell, the second surface electrically contacting the connecting member, and the connecting member electrically connecting to either the first main grid or the second main grid. This allows the conductive structure and the connecting member to establish electrical connection between the first main grids of the solar cells or between multiple second main grids, ensuring electrical continuity between the first main grid and each of the first fine grids and avoiding problems of reduced cell efficiency and yield due to a defect in one of the first main grids. Similarly, improving the cell collection efficiency of the second fine grids can also increase cell efficiency.

[0042] In addition, because they are all electrically connected, the problem of poor appearance between the first main grids and the first fine grids due to differences in the manufacturing process can be avoided.The interconnection between the first main grids and the second main grids also prevents the problem of reduced battery efficiency due to grid breakage of one of the fine grids or main grids.

[0043] According to some embodiments of the present application, in one aspect of the embodiments of the present application, a solar cell is provided. The solar cell includes a substrate, a passivation layer located on the substrate, fine grids arranged along a first direction, a plurality of main grids arranged along a second direction, at least two first connection grid lines, and at least two second connection grid lines. Here, the fine grids penetrate the passivation layer and are electrically connected to the substrate. The fine grids include first fine grids and second fine grids alternately arranged along the first direction. The main grids are located on the surface of the passivation layer and are electrically in contact with the fine grids. The main grids include m1 first main grids and m2 second main grids alternately arranged along the second direction. The first main grids are electrically in contact with the first fine grids, and the second main grids are electrically in contact with the second fine grids. The first main grid is one of the positive electrode or the negative electrode, and the second main grid is the other of the positive electrode or the negative electrode. The first connection grid line penetrates the passivation layer and is electrically connected to the substrate. One of the first connection grid lines is electrically connected to n1 adjacent first main grids, where 1 < n1 < m1. The second connection grid line penetrates the passivation layer and is electrically connected to the substrate. One of the second connection grid lines is electrically connected to n2 adjacent second main grids, where 1 < n2 < m2.

[0044] In some embodiments, the first main grid includes a plurality of first sub-main grids sequentially arranged along the first direction. The first connection grid line is electrically in contact with the first sub-main grids of a plurality of adjacent first main grids. The second main grid includes a plurality of second sub-main grids sequentially arranged along the first direction. The second connection grid line is electrically in contact with the second sub-main grids of a plurality of adjacent second main grids.

[0045] In some embodiments, the passivation layer between two adjacent second sub-main grids comprises a second partition area, the first connecting grid line is located in the second partition area and is electrically connected to the two adjacent first main grids, and the passivation layer between two adjacent first sub-main grids comprises a first partition area, the second connecting grid line is located in the first partition area and is electrically connected to the two adjacent second main grids.

[0046] In some embodiments, the first partition area and the second partition area are adjacent to each other along the second direction, and the second connecting grid line is located between the first sub-main grid and the first connecting grid line.

[0047] In some embodiments, the first connecting grid lines are arranged staggered along the first direction, and the second connecting grid lines are arranged staggered along the first direction.

[0048] In some embodiments, the first connection grid lines are arranged in a stepped pattern along the first direction, and the second connection grid lines are arranged in a stepped pattern along the first direction.

[0049] In some embodiments, n1≦(½)m1 and n2≦(½)m2.

[0050] In some embodiments, the material of the first connecting grid lines is the same as the material of the fine grid, and the material of the second connecting grid lines is the same as the material of the fine grid.

[0051] In some embodiments, the width of the first connection grid lines in the first direction is greater than or equal to the width of the fine grid, and the width of the second connection grid lines in the first direction is greater than or equal to the width of the fine grid.

[0052] According to some embodiments of the present application, in another aspect of the embodiments of the present application, there is further provided a photovoltaic module, the photovoltaic module including: a cell string formed by connecting a plurality of solar cells according to any one of the above embodiments; a connection member for electrically connecting a first main grid and a second main grid of two adjacent solar cells; a sealing adhesive film for covering a surface of the cell string; and a cover plate for covering a surface of the sealing adhesive film away from the cell string, wherein the solar cells are provided with a first main grid and a second main grid.

[0053] The technical solutions provided in the embodiments of the present application have at least the following advantages:

[0054] In the technical solution provided in the embodiments of the present application, at least two first connecting grid lines are used to establish communication between the first main grids, and one grid line connects grid lines of the same polarity (positive or negative electrodes) in the solar cell in series, forming a complete solar cell. This ensures electrical continuity between the first main grid and each of the first fine grids, reducing the likelihood of a malfunction in one of the first main grids, which would reduce cell efficiency and yield. Furthermore, because all of the first fine grids are in a conductive state, the first fine grids located at the substrate edge can be collected to improve cell collection efficiency. Similarly, improving the cell collection efficiency of the second fine grid can also improve cell efficiency.

[0055] In the solar cell provided in the embodiments of the present application, the first main grid and the first fine grid are electrically connected to each other, which avoids the problem of poor appearance between the first main grid and the first fine grid due to differences in the manufacturing process. The interconnection between the first main grids avoids the problem of reduced cell efficiency due to grid disconnection of one of the fine grids or the main grid, and also improves cell efficiency. The presence of at least two second connecting grid lines also improves cell efficiency between the second fine grid and the second main grid.

[0056] Furthermore, compared to connecting multiple first or second main grids with one connecting grid line, in the present application, two connecting grid lines are provided to connect multiple first or second main grids. This avoids the problem of grid disconnection due to a grid line being too long and the significant impact on the first and second main grids due to a grid line being too long, thereby increasing battery yield.

[0057] From the analysis, it can be seen that one of the reasons for the low yield of solar cells and photovoltaic modules is that the first electrode and the second electrode in the back contact type solar cell, i.e., IBC cell, are both located on the back surface of the substrate, and the back surface of the substrate further comprises a first main grid and a second main grid, the first electrode is in electrical contact with the corresponding first main grid, the second electrode is in electrical contact with the corresponding second main grid, the first electrode crosses the first main grid (the extension direction of the first main grid is the same as the arrangement direction of the first electrodes), and the second electrode crosses the second main grid (the extension direction of the second main grid is the same as the arrangement direction of the second electrodes), so that the first electrode The first main grid is electrically isolated from the second main grid of the opposite polarity, and the second electrode is electrically isolated from the first main grid of the opposite polarity. Therefore, the first main grid is electrically connected to some of the first electrodes, and is electrically isolated from the other first electrodes. Therefore, the first main grid cannot collect all the carriers of the first electrodes. If a problem occurs with one of the first main grids or if there is a poor weld between the first main grid and the PV ribbon, none of the first main grid and its corresponding first electrodes can collect carriers, which will affect the yield of solar cells and photovoltaic modules. Similarly, the second main grid may have a similar problem, which may affect the yield of solar cells and photovoltaic modules.

[0058] In the solar cell provided in the present embodiment, the solar cell includes an edge grid line electrically contacting a first main grid and / or a second main grid. Each edge grid line connects the main grid lines of the same polarity (positive or negative) in the solar cell in series, forming a complete electrode for the solar cell. This ensures electrical continuity between the first main grid and each of the first fine grids, avoiding problems with reduced cell efficiency and yield due to a malfunction of one of the first main grids. Furthermore, since all the first fine grids are electrically connected, the first fine grids located at the substrate edge can be used to collect the cells, thereby improving the cell collection efficiency. Similarly, improving the cell collection efficiency of the second fine grids can also improve cell efficiency.

[0059] In addition, because they are all conductive, the problem of poor appearance between the first main grids and first fine grids due to differences in the manufacturing process can be avoided.The interconnection between the first main grids and the second main grids also prevents the problem of reduced battery efficiency due to grid breakage of one of the main grids.

[0060] Hereinafter, each embodiment of the present disclosure will be described in detail in conjunction with the drawings. However, as will be understood by those skilled in the art, although many technical details are proposed in the embodiments of the present disclosure to help readers better understand the present disclosure, the technical solutions claimed for protection in the embodiments of the present disclosure can be realized without these technical details and various changes and modifications based on the following embodiments.

[0061] FIG. 1 is a diagram showing the structure of a solar cell provided in one embodiment of the present application, FIG. 2 is a diagram showing the local structure of a solar cell provided in one embodiment of the present application, FIG. 3 is a diagram showing the cross-sectional structure along the A1-A2 cross section of FIG. 2, and FIG. 4 is a diagram showing the cross-sectional structure along the B1-B2 cross section of FIG. 2.

[0062] As shown in FIGS. 1 and 3, in one aspect of the embodiment of the present application, a solar cell is provided. This solar cell includes a substrate 100, a passivation layer 102 located on the substrate 100, fine grids 110 arranged along the first direction Y and extending along the second direction X, a plurality of main grids 120 arranged along the second direction X, and at least one edge grid line 113 extending along the second direction X. Here, the substrate 100 has two first boundaries 101 arranged opposite to each other along the first direction Y. The fine grids 110 penetrate the passivation layer 102 and are electrically connected to the substrate 100. The fine grids 110 include a plurality of rows of first fine grid 111 and a plurality of rows of second fine grid 112 arranged alternately along the first direction Y. Each row of the first fine grid 111 includes a set of first sub-grid lines arranged at intervals along the second direction X. Each row of the second fine grid 112 includes a set of second sub-grid lines arranged at intervals along the second direction X. Each row of the first fine grid 111 is located between two adjacent rows of the second fine grid 112. The main grids 120 are located on the surface of the passivation layer 102 and are in electrical contact with the fine grids 110. The main grids 120 include m1 first main grids 121 and m2 second main grids 122 arranged alternately along the second direction X. The first main grids 121 are in electrical contact with the first fine grids 111, and the second main grids 122 are in electrical contact with the second fine grids 112. Here, the first main grid 121 is one of the positive electrode or the negative electrode, and the second main grid 122 is the other of the positive electrode or the negative electrode. The edge grid line 113 is closer to the first boundary 101 than the fine grid 110. The edge grid line 113 in a partial region penetrates the passivation layer 102 and is electrically connected to the substrate 100. The edge grid line 113 is in electrical contact with n1 first main grids 121, where 1 < n1 ≦ m1 and n1 and m1 are natural numbers.

[0063] In some embodiments, as shown in FIG. 3, the solar cell is a back-contact solar cell, which refers to a solar cell in which electrodes (positive and negative electrodes) of different polarities from those of a back-contact solar cell are both located on the back surface of the substrate.

[0064] 3, in some embodiments, the material of the substrate 100 may be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, such as silicon or germanium. Here, the elemental semiconductor material may be in a single crystalline state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state having both a single crystalline state and an amorphous state is called a microcrystalline state). For example, silicon may be at least one of single crystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0065] In some embodiments, the material of substrate 100 may be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanium, silicon carbide, gallium arsenide, indium gallide, perovskites, cadmium telluride, copper indium selenide, etc. Substrate 100 may be a sapphire substrate, a silicon-on-insulator substrate, or a germanium-on-insulator substrate.

[0066] In some embodiments, the substrate 100 may be an N-type semiconductor substrate or a P-type semiconductor substrate. An N-type semiconductor substrate is doped with an N-type doping element, which may be any of Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). A P-type semiconductor substrate is doped with a P-type doping element, which may be any of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0067] In some embodiments, the substrate 100 has a first surface 11 and a second surface 12 disposed opposite each other. The first surface 11 of the substrate can be the front surface, and the second surface 12 can be the back surface. The front surface can be used as a light-receiving surface to receive incident light, and the back surface can be used as a backlight surface. Here, the backlight surface can also receive incident light, but its efficiency in receiving incident light is weaker than that of the light-receiving surface.

[0068] The incident light received on the light-receiving surface is sunlight directly irradiating the solar cell, while the incident light received on the backlight surface is caused by reflection from the ground, reflection from other objects, and refraction by the film layer on the substrate.

[0069] In some embodiments, the first surface 11 comprises a first texture structure 13, the first texture structure 13 comprising a plurality of protrusion structures 105, the first surface 11 comprising a front surface field (FSF), the conductivity type of the dopant ions of which is the same as the conductivity type of the dopant ions of the substrate 100, and the field passivation effect can be utilized to reduce the minority carrier concentration at the surface, thereby reducing the surface recombination rate, lowering the series resistance, and improving the electron transport capacity.

[0070] In some embodiments, the substrate 100 comprises alternating first regions I and second regions II, where the first region I is one of the P or N regions and the second region II is the other of the P or N regions, with a gap region between the P and N regions, and the first fine grid 111 is located in the I region and the second fine grid 112 is located in the II region.

[0071] In some embodiments, there is no spacing region between the P region and the N region, and an insulating film layer is provided between the P region and the N region to achieve insulation between the P region and the N region, and further to achieve insulation between the first fine grid 111 and the second fine grid 112.

[0072] In some embodiments, the substrate 100 further includes a third region III, which is located at the edge of the substrate 100 and has the same characteristics as the adjacent region I, or the same characteristics as the adjacent region II. For example, the region III shown in FIG. 3 is located adjacent to the region I, with a gap between the regions III and I. The polarity of the region III is the same as the polarity of the region I; for example, if the region I is an N region, the region III is also an N region. In some embodiments, the polarity of the region III is different from the polarity of the region I; for example, if the region I is an N region, the region III is a P region. The edge grid lines located in the region III are in electrical contact with the second main grid.

[0073] In some embodiments, as shown in FIG. 3, the gap region is flush with the P region and the N region, i.e., the substrate 100 is not etched, and the isolation between the P region and the N region is achieved by some isolating film layer, which may be a passivation layer 102.

[0074] In some embodiments, the gap is lower than the P region and the gap is lower than the N region, and the second surface of the substrate has a trench at the gap, the trench extending from the second surface to the first surface, and the trench is used to achieve automatic isolation between regions of different conductivity types, and can form a PN junction in the heavily doped P and N regions in an IBC (Interdigitated Back Contact) cell to prevent leakage current that would affect the efficiency of the cell.

[0075] In some embodiments, the surface of the gap may be a polished surface structure, and the surface of the gap may be a second textured structure, where the roughness of the first textured structure is greater than or equal to the roughness of the second textured structure.

[0076] Here, "roughness" refers to the arithmetic mean of the absolute values ​​of the vertical deviations of the peaks and valleys within a sampled length from the average horizontal line, which is set at a single sampled length. Roughness can be measured by the comparative method, the light section method, the interferometry method, and the probe scanning method.

[0077] In some embodiments, the solar cell includes a first dielectric layer 143 and a first doped semiconductor layer 144 located in region I, and a second dielectric layer 153 and a second doped semiconductor layer 154 located in region II, a passivation layer 102 covering the first doped semiconductor layer 144 and the second doped semiconductor layer 154, a first fine grid 111 penetrating the passivation layer 102 in electrical contact with the first doped semiconductor layer 144, and a second fine grid 112 penetrating the passivation layer 102 in electrical contact with the second doped semiconductor layer 154. That is, the first fine grid 111 is formed on the first doped semiconductor layer 144 and is in electrical contact with a portion of the first doped semiconductor layer 144, the second fine grid 112 is formed on the second doped semiconductor layer 154 and is in electrical contact with a portion of the second doped semiconductor layer 154, and the passivation layer 102 covers the gap region, the portion of the first doped semiconductor layer 144 where the fine grid is not provided, and the portion of the second doped semiconductor layer 154 where the fine grid is not provided.

[0078] In some embodiments, the film layer in region III is configured the same as the film layer in region I, i.e., region III includes a first dielectric layer and a first doped semiconductor layer, with the edge grid lines passing through the passivation layer to electrically contact the first doped semiconductor layer. In some embodiments, the film layer in region III is configured the same as the film layer in region II, i.e., region III includes a second dielectric layer and a second doped semiconductor layer, with the edge grid lines passing through the passivation layer to electrically contact the second doped semiconductor layer.

[0079] In some embodiments, the first doped semiconductor layer 144 is doped with one of an N-type doping element or a P-type doping element, and the second doped semiconductor layer 154 is doped with the other of an N-type doping element or a P-type doping element.

[0080] In some embodiments, at least one of the first dielectric layer 143 or the second dielectric layer 153 may be a tunnel dielectric layer, and the tunnel dielectric layer material includes silicon oxide or silicon carbide.

[0081] In some embodiments, at least one of the first doped semiconductor layer 144 or the second doped semiconductor layer 154 may be at least one of a doped amorphous silicon layer, a doped polysilicon layer, a doped microcrystalline silicon layer, a doped silicon carbide layer, or a doped crystalline silicon layer.

[0082] In some embodiments, the solar cell may include a first intrinsic dielectric layer, a first doped amorphous silicon layer, and a first transparent conductive layer located in region I, and a second intrinsic dielectric layer, a second doped amorphous silicon layer, and a second transparent conductive layer located in region II, wherein the first intrinsic dielectric layer is located at the second surface, the first doped amorphous silicon layer is located on the first intrinsic dielectric layer, the first transparent conductive layer is located on the first doped amorphous silicon layer, the second intrinsic dielectric layer is located at the second surface, the second doped amorphous silicon layer is located on the second intrinsic dielectric layer, and the second transparent conductive layer is located on the second doped amorphous silicon layer, wherein the first doped amorphous silicon layer is doped with one of an N-type doping element or a P-type doping element, and the second doped amorphous silicon layer is doped with the other of an N-type doping element or a P-type doping element.

[0083] As shown in FIGS. 3 and 4, the solar cell further includes a front passivation layer 103, which covers the front surface of the substrate 100.

[0084] In some embodiments, the material of at least one of the front passivation layer 103 and the passivation layer 102 includes one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0085] In some embodiments, at least one of the front passivation layer 103 and the passivation layer 102 comprises a laminated film layer, the laminated film layer comprising at least a first passivation layer and a second passivation layer, the material of the first passivation layer may be one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide or aluminum oxide, and the material of the second passivation layer may be one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide or aluminum oxide.

[0086] In some embodiments, the material of the front passivation layer 103 is the same as the material of the passivation layer 102, and the front passivation layer 103 and the passivation layer 102 are manufactured in the same manufacturing process.

[0087] In some embodiments, the first fine grid 111, the second fine grid 112, and the edge grid lines 113 are all fabricated from a burn-through paste, where the first fine grid 111 burns through the passivation layer 102 to make electrical contact with the first doped semiconductor layer 144, the second fine grid 112 burns through the passivation layer 102 to make electrical contact with the second doped semiconductor layer 154, and the edge grid lines 113 burn through the passivation layer 102 to make electrical contact with the first doped semiconductor layer 144.

[0088] For example, a method for forming the first fine grid 111 includes using a screen printing process to print a metal paste on a portion of the surface of the passivation layer 102. The metal paste may include at least one of silver, aluminum, copper, tin, gold, lead, or nickel.

[0089] As shown in FIG. 1 , the first fine grid 111 and the second fine grid 112 extend along a second direction X, and the first direction Y and the second direction X may be perpendicular to each other or may be at an angle less than 90 degrees, such as 60 degrees, 45 degrees, or 30 degrees, as long as the first direction Y and the second direction X are not the same direction. In this embodiment, for ease of explanation and understanding, the first direction Y and the second direction X are perpendicular to each other. However, in specific applications, the angle between the first direction Y and the second direction X can be adjusted according to actual needs and application scenarios. This is not a limitation of the embodiment of the present application.

[0090] In some embodiments, the substrate includes two second boundaries, which are opposite each other along the second direction X. Chamfers are formed at the boundary between the first boundary 101 and the second boundary, at the boundary between the second boundary and another first boundary 101, at the boundary between another first boundary 101 and the second boundary, and at the boundary between the second boundary and the first boundary 101. The chamfers are formed because, in conventional solar cells, due to limitations in the monocrystalline silicon refining process used to manufacture substrates, only round monocrystalline silicon rods can currently be produced. After the silicon rods are produced, they are cut into slices, i.e., the cross sections of the silicon rods are cut into monocrystalline silicon wafers (which maximizes the light irradiation area per unit area and minimizes the material savings of the silicon rods, making it convenient for the production of battery cells and modules). Chamfers are typically formed at each boundary of the substrate to reduce external stress on the silicon wafer and prevent micro-damage to the edges and corners of the silicon wafers.

[0091] In some embodiments, the edge grid lines 113 can be placed to increase the collection rate of the current generated in the substrate at the first boundary, and the edge grid lines 113 can be placed in electrical contact with the first main grid, thereby achieving electrical connection between all of the first fine grids 111 and the first main grid 121, thereby increasing the collection rate of the batteries and reducing the defective rate of the batteries.

[0092] In some embodiments, the installation of edge grid lines 113 can increase the collection efficiency of solar cells by 1% to 5%, reduce the cell defect rate by less than 5%, and improve the photoelectric conversion efficiency of solar cells and the cost performance of photovoltaic modules.

[0093] In some embodiments, the edge grid line 113 is a single grid line connecting adjacent first main grids 121, and the direction of extension of the edge grid line 113 is perpendicular to the direction of extension of the first main grid 121, or the direction of extension of the edge grid line 113 is parallel to or intersects the direction of extension of the first fine grid 111. This makes it possible to partially modify the existing screen plate of the fine grid 110 or to perform secondary printing of the edge grid line 113, thereby reducing the need for modifications to existing processes and improving compatibility and applicability of equipment.

[0094] In some embodiments, the edge grid lines 113 are grid lines electrically connected to a portion of the first main grid, and the connecting grid lines electrically connected to the remaining portion of the first main grid are located inside the cell, and the solar cell achieves electrical connection between the first main grid and the first fine grid 111 through the edge grid lines 113 and the connecting grid lines.

[0095] In some embodiments, the material of the edge grid lines 113 is the same as the material of the fine grid 110. The paste of the edge grid lines 113 is the same as the paste of the fine grid 110, i.e., the edge grid lines 113 are made of burn-through paste, and the edge grid lines 113 also penetrate the passivation layer and electrically connect to the corresponding first doped semiconductor layer. This not only enables the edge grid lines 113 to pass through the first main grid 121, but also allows the edge grid lines 113 to collect current from the surface of the substrate near the first boundary 101, thereby increasing the collection paths and improving current collection efficiency.

[0096] In some embodiments, the paste for the edge grid lines 113 is the same as the paste for the main grid 120. That is, the edge grid lines 113 are made of a non-burn-through paste, and the edge grid lines 113 are located on the surface of the passivation layer. This eliminates the need for layout in the I and II regions of the substrate surface below the edge grid lines 113, preventing electrical contact between the edge grid lines 113 and the opposite-polarity doped regions and resulting in short circuits. Furthermore, the edge grid lines 113 do not damage the passivation layer, ensuring the integrity of the film layer of the passivation layer and improving the passivation effect of the passivation layer on the substrate, thereby reducing optical loss and increasing the photoelectric conversion efficiency of the solar cell. Furthermore, the non-burn-through paste prevents excess glass powder from damaging the PN junction, effectively reducing metal recombination, improving the open-circuit voltage of the solar cell, and increasing the solar cell's conversion efficiency.

[0097] Here, the conventional paste includes a mixture of metal powder, glass powder, and an organic carrier. The non-burn-through paste refers to a paste that contains less glass powder than the conventional paste and has weak burn-through ability during the sintering process, so that the passivation layer does not need to be burned through or cannot be burned through. The burn-through paste refers to a paste that has strong burn-through ability during the sintering process and can burn through the passivation layer.

[0098] In some embodiments, as shown in FIGS. 1 and 2 , each first fine grid 111 includes a plurality of first sub-grid lines 1111 arranged along the second direction X, a passivation layer between two adjacent first sub-grid lines 1111 forms a first spacing region 1112 (i.e., a set of first fine grids distributed at intervals along the second direction X), a second main grid 122 is located in the first spacing region 1112, and the first main grid 121 is in electrical contact with the first sub-grid lines 1111, and the second fine grid 112 includes a plurality of second sub-grid lines 1121 arranged along the second direction X, a passivation layer between two adjacent second sub-grid lines 1121 forms a second spacing region 1122, and the first main grid 121 is located in the second spacing region 1122, and the second main grid 122 is in electrical contact with the second sub-grid lines 1121.

[0099] In some embodiments, the width W1 of the edge grid lines 113 in the first direction Y is equal to or greater than the width W2 of the fine grid 110 in the first direction Y. Here, the width W2 of the fine grid 110 in the first direction Y may be at least one of the width of the first fine grid 111 in the first direction Y and the width of the second fine grid 112 in the second direction Y. This allows the edge grid lines 113 to have a large width to realize electrical connection between the first main grids 121, and the edge grid lines 113 do not significantly affect the layout of existing grid lines. If the width of the edge grid lines 113 is equal to the width of the fine grid 110, the edge grid lines 113 can be manufactured simultaneously with the fine grid 110, without affecting existing processes, improving compatibility with existing devices and equipment, and reducing solar cell manufacturing costs.

[0100] In some embodiments, the width of the edge grid lines 113 is greater than the width of the fine grid lines 110. Wide edge grid lines 113 can improve collection efficiency by increasing the collection area and collection probability at edge locations close to the first boundary 101. Wide edge grid lines 113 can also be positioned closer to the end of the first boundary as the first main grid. Wide edge grid lines 113 can increase the accuracy with which the first main grid overlaps the edge grid lines 113. Because the edge grid lines can bear the welding pressure of the first main grid, the first main grid 121 can be correspondingly shorter. That is, the end of the first main grid 121 facing the first boundary 101 can be flush with or lower than the side of the edge grid lines 113 facing the first boundary 101. This allows the distance between the weld between the PV ribbon and the first main grid 121 and the first boundary 101 to be relatively large, thereby reducing the probability of battery cell damage.

[0101] In some embodiments, the width W1 of the edge grid lines 113 in the first direction Y ranges from 10 μm to 55 μm. The width W1 of the edge grid lines 113 in the first direction Y may be 10 μm to 16 μm, 16 μm to 22 μm, 22 μm to 30 μm, 30 μm to 38 μm, 38 μm to 46 μm, or 46 μm to 55 μm. When the width W1 of the edge grid lines 113 in the first direction Y is within any of these ranges, the edge grid lines 113 have a strong ability to collect edge carriers, and there is a constant gap between the edge grid lines 113 and the first boundary 101, reducing the probability of damage to the first boundary.

[0102] In some embodiments, the spacing between the edge grid lines 113 and the adjacent fine grid 110 is a first spacing S1, which is equal to or less than the distance S2 between the adjacent first fine grid 111 and second fine grid 112. Thus, in a layout where the spacing between the edge grid lines 113 and the fine grid 110 is appropriate and the shielding area of ​​the edge grid lines 113 and the fine grid 110 is not wasted, the layout between the edge grid lines 113 and the fine grid 110 can achieve a minimum migration distance and minimum migration loss of carriers in the substrate, thereby increasing the open-circuit voltage of the solar cell.

[0103] In the embodiments of the present application, the first interval shown in FIG. 2 refers to the interval between the region where the axis of an edge grid line is located and the axis of an adjacent fine grid. The embodiments of the present application do not limit the specific meaning of the first interval. For example, the first interval may be the distance between the side of an edge grid line that is closer to the first boundary and the side of an adjacent fine grid that is farther from the first boundary, or the shortest distance between an edge grid line and an adjacent fine grid.

[0104] In some embodiments, the first spacing S1 is in the range of 0.2 mm to 0.7 mm, 0.2 mm to 0.35 mm, 0.35 mm to 0.46 mm, 0.46 mm to 0.58 mm, 0.58 mm to 0.63 mm, or 0.63 mm to 0.7 mm.

[0105] In some embodiments, the range of the distance S2 between the adjacent first fine grid 111 and the second fine grid 112 is 0.3 mm to 0.8 mm. The range of the distance S2 between the adjacent first fine grid 111 and the second fine grid 112 is 0.3 mm to 0.35 mm, 0.35 mm to 0.43 mm, 0.43 mm to 0.5 mm, 0.5 mm to 0.58 mm, 0.58 mm to 0.66 mm, 0.66 mm to 0.72 mm, or 0.72 mm to 0.8 mm.

[0106] As shown in FIG. 5, FIG. 5 is a diagram showing another structure of the solar cell provided in an embodiment of the present application. The edge grid line 113 is electrically in contact with the first main grid 121, and the edge grid line 113 is electrically in contact with n2 second main grids 122, where 1 < n2 ≤ m2, and n1, m1, n2, and m2 are all natural numbers.

[0107] In some embodiments, at least one edge grid line 113 includes a first edge grid line 1131 and a second edge grid line 1132. The first edge grid line 1131 is located between the first boundary and the second fine grid 112, and the first edge grid line 1131 is electrically in contact with the first main grid. The second edge grid line 1132 is located between the other first boundary and the first fine grid 111, and the second edge grid line 1132 is electrically in contact with the second main grid. By installing two edge grid lines 113 at the two first boundaries in the embodiment of the present application, the interconnection between the first main grids and the interconnection between the second main grids are realized, and the collection efficiency of the solar cell and the yield of the solar cell are improved.

[0108] In some embodiments, by installing the first edge grid line 1131 to be electrically connected to each first main grid and the second edge grid line 1132 to be electrically connected to each second main grid, the collection efficiency of the solar cell can be improved by 3% to 10%, and the defective rate of the battery can be reduced to within 8%.

[0109] In some embodiments, by connecting the main grid lines (positive electrode or negative electrode) of the same polarity in the solar cell in series with one grid line and forming one complete electrode with one solar cell, it is ensured that the first main grid and each of the first fine grid lines 111 are in a conductive state with each other, and it is possible to avoid a decrease in the efficiency and yield of the battery due to a defect in one of the first main grids. Also, since all the first fine grid lines 111 are in a conductive state, it is possible to collect the first fine grid lines 111 located at the substrate edge to improve the collection efficiency of the battery. Similarly, the battery efficiency can also be increased by improving the battery collection efficiency of the second fine grid lines 112.

[0110] Moreover, since they are all in a conductive state, it is also possible to avoid the problem that the appearance between each of the first main grid lines 121 and the first fine grid lines 111 is not good due to differences in the manufacturing process. By the mutual connection between the first main grid lines 121 and the mutual connection between the second main grid lines 122, it is also possible to avoid the problem of a decrease in battery efficiency due to grid disconnection of one of the fine grid lines 110 or main grid lines 120.

[0111] In some embodiments, one edge grid line 113 is in electrical contact with n1 first main grid lines 121, and the other edge grid lines 113 are in electrical contact with n2 second main grid lines 122, where 1 < n1 < m1 and 1 < n2 < m2. The connection grid lines connected to some of the remaining main grid lines are located inside the battery, and the connection grid lines realize the electrical connection between the remaining first main grid lines 121 and the electrical connection between the remaining second main grid lines 122. The solar cell realizes the electrical connection between the first main grid 121 and the first fine grid lines 111 by the edge grid lines 113 and the connection grid lines, and the solar cell realizes the electrical connection between the second main grid 122 and the second fine grid lines 112 by the edge grid lines 113 and the connection grid lines.

[0112] For example, in some embodiments, the solar cell includes at least one first connecting grid line, the first connecting grid line electrically connected to the substrate through the passivation layer, where the first connecting grid line is electrically connected to the remaining m1-n1 first main grids.

[0113] In some embodiments, the solar cell includes at least one second connecting grid line, the second connecting grid line electrically connected to the substrate through the passivation layer, wherein the second connecting grid line is electrically connected to the remaining m2-n2 second main grids.

[0114] In some embodiments, the material of the first connecting grid lines is the same as the material of the fine grid, and the material of the second connecting grid lines is the same as the material of the fine grid.

[0115] In some embodiments, the width of the first connection grid lines in the first direction is greater than or equal to the width of the fine grid, and the width of the second connection grid lines in the first direction is greater than or equal to the width of the fine grid.

[0116] In some embodiments, FIG. 6 is a layout diagram of grid lines in a solar cell provided in one embodiment of the present application. As shown in FIG. 6, m1≧8, m2≧8, the number of first main grids may be 8, the number of second main grids may be 8, and the number of main grids may be 16.

[0117] In some embodiments, the number of first main grids may be a natural number greater than eight, and the number of second main grids may be a natural number greater than eight.

[0118] In an embodiment of the present application, a solar cell is provided, which includes edge grid lines 113 electrically contacting a first main grid 121 and / or a second main grid 122. A single grid line connects grid lines of the same polarity (positive or negative) in the solar cell in series, forming a complete electrode for a single solar cell. This ensures electrical continuity between the first main grid 121 and each of the first fine grids 111, avoiding problems such as reduced cell efficiency and yield due to a defect in one of the first main grids 121. Furthermore, since all the first fine grids 111 are in a conductive state, the first fine grids 111 located at the substrate edge can be collected to improve cell collection efficiency. Similarly, improving the cell collection efficiency of the second fine grid 112 can also improve cell efficiency.

[0119] Furthermore, since they are all electrically connected, it is possible to avoid the problem of poor appearance between the first main grids 121 and the first fine grids 111 due to differences in the manufacturing process. The interconnection between the first main grids 121 and the second main grids 122 also prevents the problem of reduced battery efficiency due to grid breakage of one of the fine grids 110 or main grids 120.

[0120] Accordingly, another aspect of the present embodiment further provides a photovoltaic module including the solar cell provided in the above embodiment, and the same or corresponding technical features as those in the above embodiment will not be described here.

[0121] FIG. 7 is a diagram showing the structure of a photovoltaic module provided in another embodiment of the present application, FIG. 8 is a diagram showing the cross-sectional structure along the M1-M2 cross section of FIG. 7, and FIG. 9 is a diagram showing the structure of a solar cell in a photovoltaic module provided in another embodiment of the present application.

[0122] As shown in FIGS. 7 to 9 , according to some embodiments of the present application, in another aspect of the embodiments of the present application, there is provided a photovoltaic module, which includes: a cell string formed by connecting a plurality of solar cells 20 according to any one of the above embodiments; a connection member 209 for electrically connecting a first main grid 121 and a second main grid 122 of two adjacent solar cells 20; a sealing adhesive film 27 for covering the surface of the cell string; and a cover plate 28 for covering the surface of the sealing adhesive film away from the cell string, wherein the solar cells include edge grid lines 113, the first main grid 121, and the second main grid 122.

[0123] Specifically, in some embodiments, multiple cell strings can be electrically connected by connection members 209, and the connection members 209 and the main grids on the battery cells are welded together. For example, one end of the connection member is electrically connected to a first main grid of a first battery cell, and the other end of the connection member is electrically connected to a second main grid of an adjacent second battery cell.

[0124] In some embodiments, there is no spacing between the battery cells, i.e., the battery cells overlap.

[0125] In some embodiments, a weld is formed between the connecting member and the fine grid in the battery cell.

[0126] In some embodiments, as shown in FIG. 9, the solar cell has a weld 108 for realizing welding between the connection member 209 and the main grid.

[0127] 8 , the photovoltaic module further includes an insulating film 206 covering a portion of the surface of the solar cell 20. For example, the insulating film 206 covers a portion of the surface of the first main grid and the first fine grid, thereby achieving electrical insulation between the second main grid and the first main grid when the connecting member and the second main grid are electrically connected. The insulating film 206 exposes the surface of the weld 108, and the insulating film is also located between the connecting member 209 and the solar cell, achieving welding between the connecting member and the corresponding main grid, preventing the connecting member from electrically contacting the main grid of the opposite polarity, and improving yield. For example, when the connecting member and the first main grid are welded, the insulating film provides electrical insulation between the connecting member and the second main grid.

[0128] In some embodiments, the sealing adhesive film 27 includes a first sealing adhesive film and a second sealing adhesive film, where the first sealing adhesive film covers one of the front and back surfaces of the solar cell, and the second sealing adhesive film covers the other of the front and back surfaces of the solar cell. Specifically, at least one of the first sealing adhesive film and the second sealing adhesive film may be an organic sealing adhesive film such as a polyvinyl butyral (abbreviated as PVB) adhesive film, an ethylene vinyl acetate copolymer (EVA) adhesive film, a polyethylene-octene copolymer (POE) film, or a polyethylene terephthalate (PET) adhesive film.

[0129] Note that there is a boundary between the first sealing adhesive film and the second sealing adhesive film before lamination processing, and when the photovoltaic module is formed after lamination processing, the concepts of the first sealing adhesive film and the second sealing adhesive film no longer exist; in other words, the first sealing adhesive film and the second sealing adhesive film are already integrated to form a sealing adhesive film 27.

[0130] In some embodiments, the cover plate 28 may be a light-transmitting cover plate, such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 28 facing the sealing adhesive film 27 may be textured, thereby improving the utilization efficiency of incident light. The cover plate 28 includes a first cover plate and a second cover plate, where the first cover plate faces the first sealing adhesive film and the second cover plate faces the second sealing adhesive film, or the first cover plate faces one side of the solar cell and the second cover plate faces the other side of the solar cell.

[0131] In some embodiments, the photovoltaic module further includes an electrical connecting wire, where the edge grid line is in electrical contact with the n1 first main grids, and the electrical connecting wire is electrically connected to the second main grid of the adjacent solar cell (the edge grid line is in electrical contact with the n1 first main grids, and the first main grid is electrically connected to the second main grid of the adjacent battery cell, so that the edge grid line is electrically connected to the second main grid of the adjacent battery cell, and the electrical connecting wire is electrically connected to the edge grid line, so that the electrical connecting wire is electrically connected to the second main grid of the adjacent battery cell), or the edge grid line is in electrical contact with the n2 second main grids, and the electrical connecting wire is electrically connected to the first main grid of the adjacent solar cell (similar to the n1 first main grids). This allows the interconnection between the two solar cells to be achieved by the electrical connecting wire, improving the yield of the photovoltaic module and effectively avoiding the problem of a reduced yield due to poor welding of one of the connecting members.

[0132] This application also provides another photovoltaic module. The photovoltaic module includes a conductive structure positioned between solar cells, the conductive structure having opposing first and second surfaces, the first surface contacting the surface of the solar cells and the second surface electrically contacting a connecting member, which is electrically connected to either a first main grid or a second main grid. This allows the conductive structure and the connecting member to establish electrical connection between the first main grids of the solar cells or between multiple second main grids, ensuring electrical continuity between the first main grid and each of the first fine grids and avoiding problems of reduced cell efficiency and yield due to defects in one of the first main grids. Similarly, improving the cell collection efficiency of the second fine grids can also increase cell efficiency. Furthermore, because both are electrically connected, problems of poor appearance between the first main grids and the first fine grids due to differences in the manufacturing process can also be avoided. The interconnection between the first main grids and the interconnection between the second main grids can also avoid the problem of reduced battery efficiency due to grid disconnection of one of the fine grids or the main grid.

[0133] Figure 10 is a diagram showing the structure of a photovoltaic module provided in one embodiment of the present application, Figure 11 is a diagram showing a cross-sectional structure along the M5-M6 section of Figure 10, Figure 12 is a diagram showing another cross-sectional structure along the M3-M4 section of Figure 10, Figure 13 is a diagram showing the structure of a solar cell in a photovoltaic module provided in one embodiment of the present application, and Figure 14 is a diagram showing the cross-sectional structure corresponding to Figure 13.

[0134] As shown in FIGS. 10 to 14, according to some embodiments of the present application, in the embodiments of the present application, a photovoltaic module is provided. The photovoltaic module includes a cell string formed by connecting a plurality of solar cells 300 by a connecting member 309, a conductive structure 201 located between two adjacent solar cells 300, a sealing adhesive film 17 for covering the surfaces of the cell string and the conductive structure 201, and a cover plate 18 for covering the surface of the sealing adhesive film 17 away from the cell string. Here, the solar cell 300 includes a first main grid 321 and a second main grid 322 located on the same surface. The connecting member 309 is used to electrically connect the first main grid 321 and the second main grid 322 of two adjacent solar cells 300. The first main grid 321 is one of the positive electrode or the negative electrode, and the second main grid 322 is the other of the positive electrode or the negative electrode. The conductive structure 201 includes a first surface 21 (see FIG. 18) and a second surface 22 (see FIG. 18) arranged opposite to each other. The first surface 21 is in contact with the surface of the solar cell 300, and the second surface 22 is in electrical contact with the connecting member 309.

[0135] In some embodiments, as shown in FIG. 13, the solar cell 300 is a back-contact solar cell. A back-contact solar cell refers to a solar cell in which electrodes of different polarities (positive electrode and negative electrode) are both located on the back surface of the substrate 3,001.

[0136] As shown in FIG. 14, the solar cell includes a substrate 3001 having a first surface 31 and a second surface 32 arranged opposite to each other.

[0137] In some embodiments, the material of the substrate 3001 may be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, such as silicon or germanium. Here, the elemental semiconductor material may be in a monocrystalline state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state having both a monocrystalline state and an amorphous state is called a microcrystalline state), and for example, silicon may be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0138] In some embodiments, the material of substrate 3001 may be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanium, silicon carbide, gallium arsenide, indium gallide, perovskites, cadmium telluride, copper indium selenide, etc. Substrate 100 may be a sapphire substrate, a silicon-on-insulator substrate, or a germanium-on-insulator substrate.

[0139] In some embodiments, the substrate 100 may be an N-type semiconductor substrate or a P-type semiconductor substrate. An N-type semiconductor substrate is doped with an N-type doping element, which may be any of Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). A P-type semiconductor substrate is doped with a P-type doping element, which may be any of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0140] In some embodiments, the substrate 3001 has a first surface 31 and a second surface 32 opposite to each other, and the first surface 31 of the substrate 3001 may be the front surface and the second surface 32 may be the back surface. The solar cell is a single-sided cell, with the front surface used as the light-receiving surface to receive incident light and the back surface used as the backlight surface. Here, the backlight surface can also receive incident light, but its light-receiving efficiency is weaker than that of the light-receiving surface.

[0141] The incident light received on the light-receiving surface is sunlight directly irradiating the solar cell, while the incident light received on the backlight surface is caused by reflection from the ground, reflection from other objects, and refraction by the film layer on the substrate.

[0142] In some embodiments, the surface of the first surface 31 comprises a first textured structure 33, which includes a plurality of protrusion structures 305. The first surface 31 comprises a front surface field (FSF), in which the conductivity type of the dopant ions is the same as that of the dopant ions of the substrate 3001, and the field passivation effect is utilized to reduce the minority carrier concentration at the surface, thereby reducing the surface recombination rate, lowering the series resistance, and increasing the electron transport capacity.

[0143] In some embodiments, the substrate 3001 comprises I regions and II regions alternating along a first direction Y, the I regions being one of P or N regions, the II regions being the other of P or N regions, and there being a gap between the P and N regions. The solar cell includes a fine grid 310 arranged along the first direction Y and extending along a second direction X, the fine grid 310 including a plurality of rows of first fine grids 311 and a plurality of rows of second fine grids 312 alternating along the first direction Y, each first fine grid 311 including a set of first sub-grid lines spaced apart along the second direction X, each second fine grid 312 including a set of second sub-grid lines spaced apart along the second direction X, each first fine grid 311 being located between two adjacent rows of second fine grids 312. Each first fine grid 311 is located in a corresponding I region, and each second fine grid 312 is located in a corresponding II region.

[0144] In some embodiments, there is no gap between the P region and the N region, and an insulating film layer is provided between the P region and the N region, thereby realizing insulation between the P region and the N region, and thus realizing insulation between the first fine grid 311 and the second fine grid 312.

[0145] 14, the gap is flush with the P and N regions, i.e., the substrate 3001 is not etched, and insulation between the P and N regions is achieved by some isolating film layers, which may be passivation layers 302. Here, the gap being flush with the P and N regions means that the height difference between the gap and the P and N regions is within 1 μm.

[0146] In some embodiments, the gap region is lower than the P region and the gap region is lower than the N region, and the gap region comprises a trench extending from the second surface toward the first surface, the trench being used to achieve automatic isolation between regions of different conductivity types, and to eliminate the formation of a PN junction between the heavily doped P region and the N region in an IBC (Interdigitated Back Contact) cell, which would cause leakage current and affect cell efficiency.

[0147] In some embodiments, the surface of the gap may be a polished surface structure, and the surface of the gap may be a second textured structure, where the roughness of the first textured structure is greater than or equal to the roughness of the second textured structure.

[0148] Here, "roughness" refers to the arithmetic mean of the absolute values ​​of the vertical deviations of the peaks and valleys within a sampled length from the average horizontal line, which is set at a single sampled length. Roughness can be measured by the comparative method, the light section method, the interferometry method, and the probe scanning method.

[0149] In some embodiments, the solar cell includes a first dielectric layer 343 and a first doped semiconductor layer 344 located in region I, and a second dielectric layer 353 and a second doped semiconductor layer 354 located in region II, a passivation layer 302 covering the first doped semiconductor layer 344 and the second doped semiconductor layer 354, a first fine grid 311 penetrating the passivation layer 302 and in electrical contact with the first doped semiconductor layer 344, and a second fine grid 312 penetrating the passivation layer 302 and in electrical contact with the second doped semiconductor layer 354. That is, the first fine grid 311 is electrically connected to the first doped semiconductor layer 344 and the second doped semiconductor layer 354. 44 and in electrical contact with a portion of the first doped semiconductor layer 344, and the second fine grid 312 is formed on the second doped semiconductor layer 354 and in electrical contact with a portion of the second doped semiconductor layer 354, and the passivation layer 302 covers the gap region, the portion of the first doped semiconductor layer 344 where the fine grid is not provided, and the portion of the second doped semiconductor layer 354 where the fine grid is not provided. Here, the first fine grid 311 and the second fine grid 312 together form the fine grid 310. The first main grid 321 and the first fine grid 311 are electrically connected, and the second main grid 322 is electrically connected to the second fine grid 312, and the first main grid 321 and the second main grid 322 together form the main grid 320.

[0150] In some embodiments, the first doped semiconductor layer 344 is doped with one of an N-type doping element or a P-type doping element, and the second doped semiconductor layer 354 is doped with the other of an N-type doping element or a P-type doping element.

[0151] In some embodiments, at least one of the first dielectric layer 343 or the second dielectric layer 353 may be a tunnel dielectric layer, and the material of the tunnel dielectric layer includes silicon oxide or silicon carbide.

[0152] In some embodiments, at least one of the first doped semiconductor layer 344 or the second doped semiconductor layer 354 may be at least one of a doped amorphous silicon layer, a doped polysilicon layer, a doped microcrystalline silicon layer, a doped silicon carbide layer, or a doped crystalline silicon layer.

[0153] In some embodiments, a solar cell may include a first intrinsic dielectric layer, a first doped amorphous silicon layer, and a first transparent conductive layer located in region I, and a second intrinsic dielectric layer, a second doped amorphous silicon layer, and a second transparent conductive layer located in region II, wherein the first intrinsic dielectric layer is located at the second surface, the first doped amorphous silicon layer is located on the first intrinsic dielectric layer, the first transparent conductive layer is located on the first doped amorphous silicon layer, the second intrinsic dielectric layer is located at the second surface, the second doped amorphous silicon layer is located on the second intrinsic dielectric layer, and the second transparent conductive layer is located on the second doped amorphous silicon layer, wherein the first doped amorphous silicon layer is doped with one of an N-type doping element or a P-type doping element, and the second doped amorphous silicon layer is doped with the other of an N-type doping element or a P-type doping element.

[0154] As shown in FIG. 14, the solar cell further includes a front passivation layer 303 covering the front surface of the substrate 3001 .

[0155] In some embodiments, the material of at least one of the front passivation layer 303 and the passivation layer 302 includes one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0156] In some embodiments, at least one of the front passivation layer 303 and the passivation layer 302 comprises a laminate film layer, the laminate film layer comprising at least a first passivation layer and a second passivation layer, the material of the first passivation layer may be one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide or aluminum oxide, and the material of the second passivation layer may be one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide or aluminum oxide.

[0157] In some embodiments, the material of the front passivation layer 303 is the same as the material of the passivation layer 302, and the front passivation layer 303 and the passivation layer 302 are manufactured in the same manufacturing process.

[0158] In some embodiments, the first fine grid 311 and the second fine grid 312 are both fabricated from a burn-through paste, where the first fine grid 311 burns through the passivation layer 302 to make electrical contact with the first doped semiconductor layer 344, and the second fine grid 312 burns through the passivation layer 302 to make electrical contact with the second doped semiconductor layer 354.

[0159] For example, a method for forming the first fine grid 311 includes printing a metal paste on a portion of the surface of the passivation layer 302 by a screen printing process. The metal paste may include at least one of silver, aluminum, copper, tin, gold, lead, or nickel.

[0160] As shown in FIG. 13, the first fine grid 311 and the second fine grid 312 extend along the second direction X, and the first direction Y and the second direction X may be perpendicular to each other, or there may be an angle less than 90 degrees, such as 60 degrees, 45 degrees, 30 degrees, etc. It is only necessary that the first direction X and the second direction X are not in the same direction. In this embodiment, for ease of explanation and understanding, the case where the first direction Y and the second direction X are perpendicular to each other is described as an example. However, in specific applications, the setting of the angle between the first direction Y and the second direction X can be adjusted according to actual needs and application scenarios. In the embodiments of the present application, no limitation is imposed on this.

[0161] FIG. 15 is a diagram showing another structure of a solar cell in a photovoltaic module provided in an embodiment of the present application, and FIG. 16 is a diagram showing a cross-sectional structure corresponding to FIG. 15.

[0162] In some embodiments, as shown in FIGS. 15 and 16, the solar cell further includes m1 first main grids 321 and m2 second main grids 322 arranged at intervals in sequence, and at least one edge grid line 313. The first main grid 321 is located on the surface of the edge grid line 313, and the edge grid line 313 is in electrical contact with n1 first main grids 321, where 1 < n1 ≤ m1. In some embodiments, by installing the edge grid line 313, the current collection speed generated in the substrate at the first boundary 301 can be increased. Also, by installing the edge grid line 313 to be in electrical contact with the first main grid, the electrical connection between all the first fine grids 311 and the first main grid 321 can be realized, improving the collection speed of the battery and reducing the defective rate of the battery.

[0163] In some embodiments, by installing the edge grid line 313, the collection efficiency of the solar cell can be improved by 1% - 5%, the defective rate of the battery can be reduced within 5%, and the photoelectric conversion efficiency of the solar cell and the cost performance of the photovoltaic module can be enhanced.

[0164] In some embodiments, the edge grid line 313 is a single grid line connecting adjacent first main grids 321, and the direction of extension of the edge grid line 313 is perpendicular to the direction of extension of the first main grid 321, or the direction of extension of the edge grid line 313 overlaps the direction of extension of the first fine grid 311. This allows partial modification of the existing fine grid 310 screen plate or secondary printing of the edge grid line 313, reducing the need for modifications to existing processes and improving compatibility and applicability of equipment.

[0165] In some embodiments, the edge grid lines 313 are grid lines electrically connected to a portion of the first main grid, and the connecting grid lines electrically connected to the remaining portion of the first main grid are located inside the cell, and the solar cell achieves electrical connection between the first main grid and the first fine grid 311 through the edge grid lines 313 and the connecting grid lines.

[0166] In some embodiments, the material of the edge grid lines 313 is the same as the material of the fine grid 310. The paste of the edge grid lines 313 is the same as the paste of the fine grid 310, i.e., the edge grid lines 313 are made of a burn-through paste, and the edge grid lines 313 also penetrate the passivation layer and electrically connect to the corresponding first doped semiconductor layer. This not only enables the edge grid lines 313 to pass through the first main grid 321, but also allows the edge grid lines 313 to collect current from the substrate surface near the first boundary 301, thereby increasing the collection paths and improving current collection efficiency.

[0167] In some embodiments, the paste for the edge grid lines 313 is the same as the paste for the main grid 320. That is, the edge grid lines 313 are made of a non-burn-through paste, and the edge grid lines 313 are located on the surface of the passivation layer. This eliminates the need for layout in the I and II regions of the substrate surface below the edge grid lines 313 to prevent electrical contact between the edge grid lines 313 and doped regions of the opposite polarity, which could cause short circuits. Furthermore, the edge grid lines 313 do not damage the passivation layer, ensuring the integrity of the passivation layer film and improving the passivation effect of the passivation layer on the substrate, thereby reducing optical loss and increasing the photoelectric conversion efficiency of the solar cell. Furthermore, the non-burn-through paste prevents excess glass powder from damaging the PN junction, effectively reducing metal recombination, improving the open-circuit voltage of the solar cell, and increasing the conversion efficiency of the solar cell.

[0168] Here, the conventional paste includes a mixture of metal powder, glass powder, and an organic carrier. The non-burn-through paste refers to a paste that contains less glass powder than the conventional paste and has weak burn-through ability during the sintering process, so that the passivation layer does not need to be burned through or cannot be burned through. The burn-through paste refers to a paste that has strong burn-through ability during the sintering process and can burn through the passivation layer.

[0169] 13 , the first fine grid 311 includes a plurality of first sub-grid lines 3111 arranged along the second direction X, a passivation layer between two adjacent first sub-grid lines 3111 defines a first spacing region 3112, a second main grid 322 is located in the first spacing region 3112, and the first main grid 321 is in electrical contact with the first sub-grid lines 3111. The second fine grid 312 includes a plurality of second sub-grid lines 3121 arranged along the second direction X, a passivation layer between two adjacent second sub-grid lines 3121 defines a second spacing region 3122, the first main grid 321 is located in the second spacing region 3122, and the second main grid 322 is in electrical contact with the second sub-grid lines 3121.

[0170] In some embodiments, the width of the edge grid lines 313 in the first direction Y is equal to or greater than the width of the fine grid 310 in the first direction Y. Here, the width of the fine grid 310 in the first direction Y may be equal to or greater than the width of the first fine grid 311 in the first direction Y or the width of the second fine grid 312 in the second direction Y. This allows the edge grid lines 313 to have a large width to realize electrical connection between the first main grids 321, and the edge grid lines 313 do not significantly affect the layout of existing grid lines. If the width of the edge grid lines 313 is equal to the width of the fine grid 310, the edge grid lines 313 can be manufactured simultaneously with the fine grid 310, which does not affect existing processes, improves compatibility with existing devices and equipment, and reduces the manufacturing costs of solar cells.

[0171] In some embodiments, the width of the edge grid lines 313 is greater than the width of the fine grid lines 310. Wider edge grid lines 313 can improve collection area and collection probability at edge locations close to the first boundary 301, thereby increasing collection efficiency. Wider edge grid lines 313 can also be closer to the end of the first boundary as the first main grid. Taller edge grid lines 313 can increase the accuracy with which the first main grid overlaps the edge grid lines 313. Because the edge grid lines can bear the welding pressure of the first main grid, the first main grid 321 can be correspondingly shorter. That is, the end of the first main grid 321 close to the first boundary 301 can be flush with or lower than the side of the edge grid lines 313 close to the first boundary 301. This allows the distance between the weld between the PV ribbon and the first main grid 321 and the first boundary 301 to be relatively large, thereby reducing the probability of battery cell damage.

[0172] In some embodiments, the width of the edge grid lines 313 in the first direction Y ranges from 10 μm to 55 μm. The width of the edge grid lines 313 in the first direction Y may be 10 μm to 16 μm, 16 μm to 22 μm, 22 μm to 30 μm, 30 μm to 38 μm, 38 μm to 46 μm, or 46 μm to 55 μm. When the width of the edge grid lines 313 in the first direction Y is within any of these ranges, the edge grid lines 313 have a strong ability to collect edge carriers, there is a constant gap between the edge grid lines 313 and the first boundary 301, and the probability of damage to the first boundary can be reduced.

[0173] In some embodiments, the spacing between the edge grid lines 313 and the adjacent fine grids 310 (adjacent means that there are no other grid lines between the edge grid lines 313 and the fine grids 310) is a first spacing that is equal to or less than the distance between the adjacent first fine grids 311 and second fine grids 312 (adjacent means that there are no other grid lines between the first fine grids 311 and the second fine grids 312). Thus, in a layout where the spacing between the edge grid lines 313 and the fine grids 310 is appropriate and the shielding area of ​​the edge grid lines 313 and the fine grids 310 is not wasted, the layout between the edge grid lines 313 and the fine grids 310 can achieve a minimum carrier migration distance and minimum migration loss in the substrate, thereby increasing the open-circuit voltage of the solar cell.

[0174] Note that the first interval in the embodiments of the present application refers to the interval between the region where the axis of an edge grid line is located and the axis of an adjacent fine grid. The embodiments of the present application do not limit the specific meaning of the first interval. For example, the first interval may be the distance between the side of an edge grid line that is close to the first boundary and the side of an adjacent fine grid that is far from the first boundary, or the shortest distance between an edge grid line and an adjacent fine grid.

[0175] In some embodiments, the first spacing is in the range of 0.2 mm to 0.7 mm, 0.2 mm to 0.35 mm, 0.35 mm to 0.46 mm, 0.46 mm to 0.58 mm, 0.58 mm to 0.63 mm, or 0.63 mm to 0.7 mm.

[0176] In some embodiments, the distance S2 between adjacent first fine grids 311 and second fine grids 312 ranges from 0.3 mm to 0.8 mm. The distance S2 between adjacent first fine grids 311 and second fine grids 312 ranges from 0.3 mm to 0.35 mm, 0.35 mm to 0.43 mm, 0.43 mm to 0.5 mm, 0.5 mm to 0.58 mm, 0.58 mm to 0.66 mm, 0.66 mm to 0.72 mm, or 0.72 mm to 0.8 mm.

[0177] In some embodiments, the substrate 3001 further includes a III region located at the edge of the substrate 3001. The III region has the same characteristics as the adjacent I region or II region. For example, the III region shown in FIG. 16 is adjacent to the I region, there is a gap region gap between the III region and the I region, and the polarity of the III region is the same as that of the I region. For example, when the I region is an N region, the III region is also an N region. In some embodiments, the polarity of the III region is different from that of the I region. For example, when the I region is an N region, the III region is a P region, and the edge grid line located in the III region is in electrical contact with the second main grid.

[0178] In some embodiments, the installation of the film layer in the III region is the same as that in the I region, that is, there are a first dielectric layer and a first doped semiconductor layer in the III region, and the edge grid line penetrates through the passivation layer and is in electrical contact with the first doped semiconductor layer. In some embodiments, the installation of the film layer in the III region is the same as that in the II region, that is, there are a second dielectric layer and a second doped semiconductor layer in the III region, and the edge grid line penetrates through the passivation layer and is in electrical contact with the second doped semiconductor layer.

[0179] As shown in FIG. 17, FIG. 17 is a diagram showing another structure of a solar cell in a photovoltaic module provided in an embodiment of the present application. The edge grid line 313 is in electrical contact with n1 first main grids 321, and the edge grid line 313 is in electrical contact with n2 second main grids 322, where 1 < n2 ≤ m2, and n1, m1, n2, and m2 are all natural numbers.

[0180] In some embodiments, at least one edge grid line 313 includes a first edge grid line 3131 and a second edge grid line 3132. The first edge grid line 3131 is located between a first boundary and a second fine grid 312, the first edge grid line 3131 is in electrical contact with a first main grid, the second edge grid line 3132 is located between another first boundary and a first fine grid 311, and the second edge grid line 3132 is in electrical contact with a second main grid. By installing two edge grid lines 313 at two first boundaries in the embodiments of the present application, the interconnection between the first main grids and the interconnection between the second main grids are realized, improving the collection efficiency of the solar cell and the yield of the solar cell.

[0181] In some embodiments, by installing the first edge grid line 3131 to be electrically connected to each first main grid and the second edge grid line 3132 to be electrically connected to each second main grid, the collection efficiency of the solar cell can be improved by 3% - 10%, and the defective rate of the battery can be reduced to within 8%.

[0182] In some embodiments, the edge grid line 313 is in electrical contact with n1 first main grid lines 321, and the edge grid line 313 is in electrical contact with n2 second main grid lines 322, where 1 < n1 < m1 and 1 < n2 < m2. The connection grid lines connected to some of the remaining main grid lines are located inside the battery. The connection grid lines realize the electrical connection between the remaining first main grid lines 321 and the electrical connection between the remaining second main grid lines 322. The solar cell realizes the electrical connection between the first main grid line 321 and the first fine grid 311 by the edge grid line 313 and the connection grid lines, and the solar cell realizes the electrical connection between the second main grid line 322 and the second fine grid 312 by the edge grid line 313 and the connection grid lines.

[0183] In some embodiments, m1≧8, m2≧8, the number of first main grids may be 8, the number of second main grids may be 8, and the number of main grids may be 16.

[0184] In some embodiments, the number of first main grids may be a natural number greater than eight, and the number of second main grids may be a natural number greater than eight.

[0185] In an embodiment of the present application, a solar cell is provided, which includes edge grid lines 313 electrically connected to a first main grid 321 and / or a second main grid 322. A single grid line connects grid lines of the same polarity (positive or negative) in the solar cell in series, forming a complete electrode for a solar cell. This ensures electrical continuity between the first main grid 321 and each of the first fine grids 311, avoiding problems such as reduced cell efficiency and yield due to a defect in one of the first main grids 321. Furthermore, since all the first fine grids 311 are electrically connected, the first fine grids 311 located at the substrate edge can be collected to improve cell collection efficiency. Similarly, improving the cell collection efficiency of the second fine grid 312 can also improve cell efficiency.

[0186] Furthermore, since they are all electrically connected, it is possible to avoid the problem of poor appearance between the first main grids 321 and the first fine grids 311 due to differences in the manufacturing process. The interconnection between the first main grids 321 and the second main grids 322 also prevents the problem of reduced battery efficiency due to grid breakage of one of the fine grids 310 or main grids 320.

[0187] 10 , there are gaps 15 between the solar cells 300, and some of the conductive structures 201 are located in the gaps 15. The length of the gaps 15 in the arrangement direction of the solar cells is 0 mm to 3 mm. The length of the gaps 15 in the arrangement direction of the solar cells may be 0 mm to 0.8 mm, 0.8 mm to 1.3 mm, 1.3 mm to 1.7 mm, 1.7 mm to 2.4 mm, or 2.4 mm to 3 mm.

[0188] In some embodiments, the solar cell 300 and the adjacent solar cell 300 are stacked, i.e., a portion of the region of the solar cell 300 near the first boundary is located below the adjacent solar cell. The overlap length between the solar cell 300 and the adjacent solar cell is 0 mm to 1 mm. The overlap length between the solar cell 300 and the adjacent solar cell is in the range of 0 mm to 0.3 mm, 0.3 mm to 0.7 mm, or 0.7 mm to 1 mm.

[0189] In some embodiments, the ratio of the overlapping area of ​​first surface 21 and solar cell 300 to the surface area of ​​first surface 21 is in the range of 1 / 10 to 1. The ratio of the overlapping area of ​​first surface 21 and solar cell 300 to the surface area of ​​first surface 21 may be in the range of 1 / 10 to 0.35, 0.35 to 0.5, 0.5 to 0.67, 0.67 to 0.83, or 0.83 to 1, i.e., at least a portion of the surface of conductive structure 201 is located on solar cell 300, the area of ​​conductive structure 201 located on solar cell 300 is set within an appropriate range, conductive structure 201 is fixed to solar cell 300 and does not move significantly, ensuring contact performance between conductive structure 201 and connecting member 309 and thereby improving the yield and collection efficiency of the photovoltaic module.

[0190] In some embodiments, the length of the conductive structure 201 in the arrangement direction of the solar cells 300 is 2 mm to 9 mm. The length of the conductive structure in the arrangement direction of the solar cells 300 is 2 mm to 3.8 mm, 3.8 mm to 5 mm, 5 mm to 6.9 mm, 6.9 mm to 7.8 mm, or 7.8 mm to 9 mm. If the length of the conductive structure 201 in the arrangement direction of the solar cells 300 is within any of the above ranges, the conductive structure 201 can achieve electrical connection performance between two adjacent solar cells 300. The conductive structure may be located within the gap 15 and on a portion of the surface of the solar cells, thereby improving the contact performance between the connecting member and the conductive structure, establishing an abutting contact relationship between the connecting member and the conductive structure, and ultimately reducing the contact resistance between the connecting member and the conductive structure.

[0191] In some embodiments, by arranging the conductive structure so that it is electrically connected to the connecting member, the collection efficiency of the solar cell can be improved by 3% to 8% and the cell defect rate can be reduced by up to 6%.

[0192] FIG. 18 is a diagram illustrating the structure of a conductive structure in a photovoltaic module provided in one embodiment of the present application.

[0193] In some embodiments, as shown in FIG. 18 , the conductive structure 201 includes an insulating layer 2021 and a conductive layer 2011, one side of the insulating layer 2021 contacts one side of the conductive layer 2011, the other side of the insulating layer 2021 forms a first surface 21, and the other side of the conductive layer 2011 forms a second surface 22.

[0194] In some embodiments, the conductive layer 2011 is used to realize electrical connection between the connecting members 309. The insulating layer 2021 is used to ensure insulation between the conductive structure 201 and the battery cell, and to avoid short circuits between the first and second main grids of the solar cell.

[0195] In some embodiments, the material of the insulating layer includes polyethylene (PE), EVA, or PET, and the material of the conductive layer includes aluminum, aluminum tin, or copper.

[0196] In some embodiments, the insulating layer includes an adhesive layer, which can achieve mutual fixation between the conductive structure and the solar cell, thereby preventing the conductive structure from shifting when the encapsulating adhesive film is not encapsulated, which can affect the yield of the photovoltaic module.

[0197] In some embodiments, the material of the adhesive layer is the same as the material of the encapsulating adhesive film. This allows the adhesive layer to be mutually fused with the encapsulating adhesive film during the lamination process, i.e., the concept of an adhesive layer is eliminated in the photovoltaic module. Compared to technical solutions in which the adhesive layer and the encapsulating adhesive film are made of different materials, using the same material for the adhesive layer as the encapsulating adhesive film can reduce the occurrence of air bubbles or gaps in the photovoltaic module and increase the yield of the photovoltaic module. Furthermore, using the same material for the adhesive layer as the encapsulating adhesive film can improve the sealing effect of the photovoltaic module and extend the service life of the photovoltaic module.

[0198] In some embodiments, as shown in FIG. 11 or FIG. 12, the solar cell has a weld 308, which is used to achieve welding between the connecting member 309 and the main grid.

[0199] In some embodiments, the photovoltaic module further includes an insulating film, which covers a portion of the surface of the solar cell 300. For example, the insulating film covers a portion of the surface of the first main grid and the first fine grid, thereby achieving electrical insulation between the second main grid and the first main grid when the connecting member and the second main grid are electrically connected. The insulating film exposes the surface of the weld 308, and the insulating film is located between the connecting member 309 and the solar cell, allowing welding between the connecting member and the corresponding main grid, preventing electrical contact between the connecting member and the main grid of the opposite polarity, and improving yield. For example, when the connecting member and the first main grid are welded, the insulating film can achieve electrical insulation between the connecting member and the second main grid.

[0200] In some embodiments, the photovoltaic module does not include an insulating film, and the conductive structure is located on the surface of the solar cell, as shown in Figure 12. Here, the conductive structure includes an insulating layer and a conductive layer. Although Figure 12 shows an example in which the conductive structure and the main grid are not in contact, the conductive structure may be located on the main grid, or the side of the conductive structure may be in contact with the side of the main grid. Here, the main grid may include a first main grid and a second main grid.

[0201] Figure 19 is a diagram showing the structure of the conductive structure and main grid in a photovoltaic module provided in one embodiment of the present application, and Figure 20 is a diagram showing another structure of the conductive structure and main grid in a photovoltaic module provided in one embodiment of the present application.

[0202] As shown in FIG. 19, in some embodiments, the conductive structure 201 has a first edge 2031 facing the conductive structure in a first direction, the first main grid 321 has a second edge 1211 facing the main grid in the first direction, and the spacing S3 between the first edge 2031 and the second edge 1211 ranges from 0 mm to 2 mm, and wherein multiple solar cells are arranged along the first direction.

[0203] In some embodiments, the conductive structure is a laminated structure, i.e., the conductive structure includes an insulating layer and a conductive layer. In some embodiments, the conductive structure is a conductive layer, and a first surface of the conductive layer is the first surface of the conductive structure, and a second surface of the conductive layer is the second surface of the conductive structure.

[0204] 17 and 20, in some embodiments, the distance between the second main grid 322 and the first edge 2031 is greater than zero, i.e., the conductive structure and the second main grid 322 are insulated from each other. The conductive structure includes a conductive layer having first and second surfaces opposite each other. Note that FIG. 20 does not show the structure of the second main grid 322, and only illustrates the positional relationship between the first main grid and the conductive structure.

[0205] In some embodiments, as shown in FIG. 20 , the first edge 2031 and the first main grid 321 are in contact with each other. This allows the first main grid to be in direct contact with the conductive structure, thereby establishing electrical contact between the first main grid and the conductive layer, and between the connecting member and the second surface. Therefore, the collection path of the battery may include a path from the first main grid to the conductive structure and finally to the connecting member, i.e., a path from the first main grid to the weld and finally to the connecting member. The above technical measures can increase the collection paths of carriers and improve the collection efficiency of the photovoltaic module.

[0206] FIG. 21 is a diagram showing another structure of a photovoltaic module provided in one embodiment of the present application, and FIG. 22 is a diagram showing a cross-sectional structure along the M5-M6 cross section of FIG.

[0207] In some embodiments, as shown in FIGS. 21 and 22, the first surface 21 contacts the surfaces of two adjacent solar cells at both ends in the first direction.

[0208] In some embodiments, the sealing adhesive film 17 includes a first sealing adhesive film and a second sealing adhesive film, where the first sealing adhesive film covers one of the front and back surfaces of the solar cell, and the second sealing adhesive film covers the other of the front and back surfaces of the solar cell. Specifically, at least one of the first sealing adhesive film and the second sealing adhesive film may be an organic sealing adhesive film such as a polyvinyl butyral (abbreviated as PVB) adhesive film, an ethylene vinyl acetate copolymer (EVA) adhesive film, a polyethylene-octene copolymer (POE) adhesive film, or a polyethylene terephthalate (PET) film adhesive film.

[0209] Note that there is a boundary between the first sealing adhesive film and the second sealing adhesive film before lamination processing, and when the photovoltaic module is formed after lamination processing, the concepts of the first sealing adhesive film and the second sealing adhesive film no longer exist; in other words, the first sealing adhesive film and the second sealing adhesive film are already integrated to form a sealing adhesive film 17.

[0210] In some embodiments, the cover plate 18 may be a light-transmitting cover plate, such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 18 facing the sealing adhesive film 17 may be textured, thereby improving the utilization efficiency of incident light. The cover plate 18 includes a first cover plate and a second cover plate, where the first cover plate faces the first sealing adhesive film and the second cover plate faces the second sealing adhesive film, or the first cover plate faces one side of the solar cell and the second cover plate faces the other side of the solar cell.

[0211] In some embodiments, the photovoltaic module further includes an electrical connecting wire, where the edge grid line is in electrical contact with the n1 first main grids, the electrical connecting wire is electrically connected to the edge grid line and the second main grid of the adjacent solar cell, and the first surface is in electrical contact with the electrical connecting wire, or the edge grid line is in electrical contact with the n2 second main grids, and the electrical connecting wire is electrically connected to the edge grid line and the first main grid of the adjacent solar cell, thereby achieving interconnection between the two solar cells through the electrical connecting wire, improving the yield of the photovoltaic module and effectively avoiding the problem of yield reduction due to poor welding of one of the connecting members.

[0212] As shown in FIGS. 23 to 25, according to some embodiments of the present application, in the embodiments of the present application, a solar cell is provided. The solar cell includes a substrate 400, a passivation layer 402 located on the substrate 400, fine grids 410 arranged along a first direction Y, a plurality of main grids 420 arranged along a second direction X, at least two first connection grid lines 431, and at least two second connection grid lines 432. Here, the fine grids 410 penetrate the passivation layer 402 and are electrically connected to the substrate 400. The fine grids 410 include first fine grids 411 and second fine grids 412 alternately arranged along the first direction Y. The main grids 420 are located on the surface of the passivation layer 402 and are electrically in contact with the fine grids 410. The main grids 420 include m1 first main grids 421 and m2 second main grids 422 alternately arranged along the second direction X. The first main grids 421 are electrically in contact with the first fine grids 411, and the second main grids 422 are electrically in contact with the second fine grids 412. The first main grid 421 is one of the positive electrode or the negative electrode, and the second main grid 422 is the other of the positive electrode or the negative electrode. The first connection grid line 431 penetrates the passivation layer 402 and is electrically connected to the substrate 400. One of the first connection grid lines 431 is electrically connected to n1 adjacent first main grids 421, where 1 < n1 < m1. The second connection grid line 432 penetrates the passivation layer 402 and is electrically connected to the substrate 400. One of the second connection grid lines 432 is electrically connected to n2 adjacent second main grids 422, where 1 < n2 < m2.

[0213] In some embodiments, as shown in FIG. 25, the solar cell is a back contact solar cell. A back contact solar cell refers to a solar cell in which electrodes (positive electrode and negative electrode) of different polarities are both located on the back surface of the substrate.

[0214] In some embodiments, the material of substrate 400 may be an elemental semiconductor material. Specifically, the elemental semiconductor material may be composed of a single element, such as silicon or germanium. Here, the elemental semiconductor material may be in a monocrystalline state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state having both a monocrystalline state and an amorphous state is called a microcrystalline state). For example, silicon may be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0215] In some embodiments, the material of substrate 400 may be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanium, silicon carbide, gallium arsenide, indium gallide, perovskites, cadmium telluride, copper indium selenide, etc. Substrate 400 may be a sapphire substrate, a silicon-on-insulator substrate, or a germanium-on-insulator substrate.

[0216] In some embodiments, the substrate 400 may be an N-type semiconductor substrate or a P-type semiconductor substrate. An N-type semiconductor substrate is doped with an N-type doping element, which may be any of Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). A P-type semiconductor substrate is doped with a P-type doping element, which may be any of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0217] In some embodiments, the substrate 400 has a first surface 41 and a second surface 42 disposed opposite each other, and the first surface 41 of the substrate 400 may be the front surface and the second surface 42 may be the back surface, where the front surface is used as a light-receiving surface to receive incident light and the back surface is used as a backlight surface. Here, the backlight surface can also receive incident light, but its incident light receiving efficiency is weaker than that of the light-receiving surface.

[0218] The incident light received on the light-receiving surface is sunlight directly irradiating the solar cell, while the incident light received on the backlight surface is caused by reflection from the ground, reflection from other objects, and refraction by the film layer on the substrate.

[0219] In some embodiments, the first surface 41 comprises a first textured structure 43, which includes a plurality of protrusion structures 405. The first surface 41 comprises a front surface field (FSF), whose dopant ions have the same conductivity type as the dopant ions of the substrate 400, and the field passivation effect is utilized to reduce the minority carrier concentration at the surface, thereby reducing the surface recombination rate, lowering the series resistance, and increasing the electron transport capacity.

[0220] In some embodiments, the substrate 400 comprises alternating I and II regions, where the I regions are either P or N regions, and the II regions are the other of the P or N regions, with a gap between the P and N regions, and a first fine grid 411 located in the I regions and a second fine grid 412 located in the II regions.

[0221] In some embodiments, there is no gap between the P region and the N region, and an insulating film layer is provided between the P region and the N region to provide insulation between the P region and the N region, and thus to provide insulation between the first fine grid 411 and the second fine grid 412.

[0222] In some embodiments, as shown in FIG. 25, the gap region is flush with the P region and the N region, i.e., the substrate 400 corresponding to the gap region is not etched, and the P region and the N region are insulated from each other by some insulating film layers, which may be passivation layers 402.

[0223] In some embodiments, the gap is lower than the P region and lower than the N region, and the gap comprises a trench extending from the second surface toward the first surface, where the trench is used to achieve automatic isolation between regions of different conductivity types, and can eliminate the formation of a PN junction between the heavily doped P region and the N region in an IBC (Interdigitated Back Contact) cell, which can cause leakage current and affect cell efficiency.

[0224] In some embodiments, the surface of the gap may be a polished surface structure, and the surface of the gap may be a second textured structure, where the roughness of the first textured structure is greater than or equal to the roughness of the second textured structure.

[0225] Here, "roughness" refers to the arithmetic mean of the absolute values ​​of the vertical deviations of the peaks and valleys within a sampled length from the average horizontal line, which is set at a single sampled length. Roughness can be measured by the comparative method, the light section method, the interferometry method, and the probe scanning method.

[0226] In some embodiments, the solar cell includes a first dielectric layer 443 and a first doped semiconductor layer 444 located in region I, and a second dielectric layer 453 and a second doped semiconductor layer 454 located in region II, a passivation layer 402 covering the first doped semiconductor layer 444 and the second doped semiconductor layer 454, a first fine grid 411 penetrating the passivation layer 402 and in electrical contact with the first doped semiconductor layer 444, and a second fine grid 412 penetrating the passivation layer 402 and in electrical contact with the second doped semiconductor layer 454. That is, the first fine grid 411 is in electrical contact with the first doped semiconductor layer 444. 44 and in electrical contact with a portion of the first doped semiconductor layer 444, a second fine grid 412 formed on and in electrical contact with a portion of the second doped semiconductor layer 454, and a passivation layer 402 covering the spacing regions gap, the portion of the first doped semiconductor layer 444 not provided with the fine grid, and the portion of the second doped semiconductor layer 454 not provided with the fine grid.

[0227] In some embodiments, the first doped semiconductor layer 444 is doped with one of an N-type doping element or a P-type doping element, and the second doped semiconductor layer 454 is doped with the other of an N-type doping element or a P-type doping element.

[0228] In some embodiments, at least one of the first dielectric layer 443 or the second dielectric layer 453 may be a tunnel dielectric layer, and the material of the tunnel dielectric layer includes silicon oxide or silicon carbide.

[0229] In some embodiments, at least one of the first doped semiconductor layer 444 or the second doped semiconductor layer 454 may be at least one of a doped amorphous silicon layer, a doped polysilicon layer, a doped microcrystalline silicon layer, a doped silicon carbide layer, or a doped crystalline silicon layer.

[0230] In some embodiments, the solar cell may include a first intrinsic dielectric layer, a first doped amorphous silicon layer, and a first transparent conductive layer located in region I, and a second intrinsic dielectric layer, a second doped amorphous silicon layer, and a second transparent conductive layer located in region II, wherein the first intrinsic dielectric layer is located at the second surface, the first doped amorphous silicon layer is located on the first intrinsic dielectric layer, the first transparent conductive layer is located on the first doped amorphous silicon layer, the second intrinsic dielectric layer is located at the second surface, the second doped amorphous silicon layer is located on the second intrinsic dielectric layer, and the second transparent conductive layer is located on the second doped amorphous silicon layer, wherein the first doped amorphous silicon layer is doped with one of an N-type doping element or a P-type doping element, and the second doped amorphous silicon layer is doped with the other of an N-type doping element or a P-type doping element.

[0231] As shown in FIGS. 25 and 26, the solar cell further includes a front passivation layer 403 covering the front surface of the substrate 400.

[0232] In some embodiments, the material of at least one of the front passivation layer 403 and the passivation layer 402 includes one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0233] In some embodiments, at least one of the front passivation layer 403 and the passivation layer 402 comprises a laminated film layer, the laminated film layer comprising at least a first passivation layer and a second passivation layer, the material of the first passivation layer may be one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide or aluminum oxide, and the material of the second passivation layer may be one or more of materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbonitride, titanium oxide, hafnium oxide or aluminum oxide.

[0234] In some embodiments, the material of the front passivation layer 403 is the same as the material of the passivation layer 402, and the front passivation layer 403 and the passivation layer 402 are manufactured in the same manufacturing process.

[0235] In some embodiments, the first fine grid 411, the second fine grid 412, and the connecting grid lines 430 are all fabricated from a burn-through paste, where the first fine grid 411 burns through the passivation layer 402 to make electrical contact with the first doped semiconductor layer 444, the second fine grid 412 burns through the passivation layer 402 to make electrical contact with the second doped semiconductor layer 454, and the connecting grid lines 430 burn through the passivation layer 402 to make electrical contact with the first doped semiconductor layer 444, or the connecting grid lines 430 burn through the passivation layer 402 to make electrical contact with the second doped semiconductor layer 454. Here, the connecting grid lines 430 include a first connecting grid line 431 and a second connecting grid line 432, and the first connecting grid line 431 burns through the passivation layer 402 to make electrical contact with the first doped semiconductor layer 444, and the second connecting grid line 432 burns through the passivation layer 402 to make electrical contact with the second doped semiconductor layer 454.

[0236] For example, a method for forming the first fine grid 411 includes using a screen printing process to print a metal paste on a portion of the surface of the passivation layer 402. The metal paste may include at least one of silver, aluminum, copper, tin, gold, lead, or nickel.

[0237] 23 , the first fine grid 411 and the second fine grid 412 extend along the second direction X, and the first direction Y and the second direction X may be perpendicular to each other or may have an angle smaller than 90 degrees, such as 60 degrees, 45 degrees, or 30 degrees, as long as the first direction Y and the second direction X are not the same direction. In this embodiment, for ease of explanation and understanding, the first direction Y and the second direction X are perpendicular to each other. However, in specific applications, the angle between the first direction Y and the second direction X can be adjusted according to actual needs and application scenarios. This is not a limitation of the embodiment of the present application.

[0238] In some embodiments, the material of the connecting grid lines 430 is the same as the material of the fine grid 410. The paste of the connecting grid lines 430 is the same as the paste of the fine grid 410, i.e., the connecting grid lines 430 are made of burn-through paste, and the connecting grid lines 430 also penetrate the passivation layer to electrically connect to the corresponding first doped semiconductor layer or second doped semiconductor layer. In this way, the connecting grid lines 430 not only realize the current flow through the first main grid 421 and the second main grid 422, but also collect the current on the substrate surface by themselves, increasing the collection paths and improving the current collection efficiency.

[0239] In some embodiments, the material of the first connecting grid lines 431 is the same as the material of the fine grid 410 and the material of the second connecting grid lines 432 is the same as the material of the fine grid 410 .

[0240] In some embodiments, the paste for the connecting grid lines 430 is the same as the paste for the main grid 420. That is, the connecting grid lines 430 are made of a non-burn-through paste and are located on the surface of the passivation layer. This eliminates the need for layout in the I and II regions of the substrate surface below the connecting grid lines 430 to prevent electrical contact between the connecting grid lines 430 and the doped regions of the opposite polarity, resulting in a short circuit. Furthermore, the connecting grid lines 430 do not damage the passivation layer, ensuring the integrity of the film layer of the passivation layer and improving the passivation effect of the passivation layer on the substrate, thereby reducing optical loss and increasing the photoelectric conversion efficiency of the solar cell. Furthermore, the non-burn-through paste prevents excess glass powder from damaging the PN junction, effectively reducing metal recombination, improving the open-circuit voltage of the solar cell, and increasing the conversion efficiency of the solar cell.

[0241] Here, the conventional paste includes a mixture of metal powder, glass powder, and an organic carrier. The non-burn-through paste refers to a paste that contains less glass powder than the conventional paste and has weak burn-through ability during the sintering process, so that the passivation layer does not need to be burned through or cannot be burned through. The burn-through paste refers to a paste that has strong burn-through ability during the sintering process and can burn through the passivation layer.

[0242] In some embodiments, the first connecting grid lines are electrically connected to each of the first main grids, and the second connecting grid lines are electrically connected to each of the second main grids, thereby increasing the collection efficiency of the solar cells by 1% to 5%, reducing the cell defect rate by less than 5%, and improving the photoelectric conversion efficiency of the solar cells and the cost performance of the photovoltaic module.

[0243] 24 , each first fine grid 411 includes a plurality of first sub-grid lines 4111 arranged along the second direction X, a passivation layer between two adjacent first sub-grid lines 4111 defines a first spacing region 4112, a second main grid 422 is located in the first spacing region 4112, and the first main grid 421 is in electrical contact with the first sub-grid lines 4111. The second fine grid 412 includes a plurality of second sub-grid lines 4121 arranged along the second direction X, a passivation layer between two adjacent second sub-grid lines 4121 defines a second spacing region 4122, the first main grid 421 is located in the second spacing region 4122, and the second main grid 422 is in electrical contact with the second sub-grid lines 4121.

[0244] 24 , the first main grid 421 includes a plurality of first sub-main grids 4211 and a plurality of first partition areas 4212 sequentially arranged along the first direction Y, where a passivation layer between two adjacent first sub-main grids 4211 defines the first partition area 4212. The first connecting grid line 431 is in electrical contact with the first sub-main grids 4211 of the plurality of adjacent first main grids 421. The second main grid 422 includes a plurality of second sub-main grids 4221 and a plurality of second partition areas 4222 sequentially arranged along the first direction Y, where a passivation layer between the adjacent second sub-main grids 4221 defines the second partition area 4222. The second connecting grid line 432 is in electrical contact with the second sub-main grids 4221 of the plurality of adjacent second main grids 422.

[0245] 23, 27, and 28, the first partition region 4212 and the second partition region 4222 are adjacent to each other along the second direction X, the second connecting grid line 432 is also located in the first partition region 4212, the first connecting grid line 431 is also located in the second partition region 4222, and the second connecting grid line 432 is located between the first sub-main grid 4211 and the first connecting grid line 431. Here, FIG. 27 is a diagram illustrating a second type of structure of a solar cell provided in an embodiment of the present application, and FIG. 28 is a diagram illustrating a third type of structure of a solar cell provided in an embodiment of the present application.

[0246] As shown in FIG. 23 , the solar cell includes two first connecting grid lines 431 and two second connecting grid lines 432, where the first connecting grid lines 431 penetrate the passivation layer 402 and are electrically connected to the substrate 400, one of which is electrically connected to adjacent n1 first main grids 421, where n1=(½)m1; and the second connecting grid line 432 penetrates the passivation layer 402 and is electrically connected to adjacent n2 second main grids 422, where n2=(½)m2.

[0247] In some embodiments, the layout method of each grid line shown in FIG. 23 can improve the collection efficiency of the solar cell by 1% to 6% and reduce the defective rate of the cells by 3.5% or less.

[0248] 27 or 28, the number of first connecting grid lines 431 in the solar cell is more than two, the first connecting grid lines 431 penetrate the passivation layer 402 and are electrically connected to the substrate 400, and one first connecting grid line 431 is electrically connected to adjacent n1 first main grids 421, where n1<(½)m1. The number of second connecting grid lines 432 in the solar cell is more than two, the second connecting grid lines 432 penetrate the passivation layer 402 and are electrically connected to the substrate 400, and one second connecting grid line 432 is electrically connected to adjacent n2 second main grids 422, where n2<(½)m2.

[0249] In some embodiments, the layout method of each grid line shown in FIG. 27 can improve the collection efficiency of the solar cell by 2% to 5.8% and reduce the defective rate of the cells by 6% or less.

[0250] In some embodiments, the layout method of each grid line shown in FIG. 28 can improve the collection efficiency of the solar cell by 2% to 6.3% and reduce the defective rate of the cells by 5.5% or less.

[0251] In some embodiments, as shown in Figures 27 and 29, the first connecting grid lines 431 are arranged with a stagger along the first direction Y, and the second connecting grid lines 432 are arranged with a stagger along the first direction Y.

[0252] In some embodiments, as shown in FIGS. 25 and 30, the first connecting grid lines 431 are arranged in a stepped pattern along the first direction Y, and the second connecting grid lines 432 are arranged in a stepped pattern along the first direction Y.

[0253] Here, FIG. 29 is a layout diagram of the first and second connection grid lines in a solar cell provided in one embodiment of the present application, and FIG. 30 is another layout diagram of the first and second connection grid lines in a solar cell provided in one embodiment of the present application.

[0254] FIG. 31 is a diagram showing a fourth type of structure of a solar cell provided in an embodiment of the present application, and FIG. 32 is a diagram showing a fifth type of structure of a solar cell provided in an embodiment of the present application.

[0255] 31 and 32, the passivation layer 402 between two adjacent second sub-main grids 4221 includes a second partition area 4222, and a first connecting grid line 431 is located in the second partition area 4222 and electrically connected to the two adjacent first main grids 421. The passivation layer 402 between two adjacent first sub-main grids 4211 includes a first partition area 4212, and a second connecting grid line 432 is located in the first partition area 4212 and electrically connected to the two adjacent second main grids 422.

[0256] Here, the arrangement of the first connecting grid lines 431 and the second connecting grid lines 432 in FIG. 31 is shown in FIG. 29, and the arrangement of the first connecting grid lines 431 and the second connecting grid lines 432 in FIG. 32 is shown in FIG.

[0257] In some embodiments, the layout method of each grid line shown in FIG. 31 can improve the collection efficiency of the solar cell by 3% to 8% and reduce the defective rate of the cells by 7% or less.

[0258] In some embodiments, the layout method of each grid line shown in FIG. 32 can improve the collection efficiency of the solar cell by 2% to 7.8% and reduce the defective rate of the cells by 6% or less.

[0259] In some embodiments, the width of the connecting grid lines 430 is greater than the width of the fine grid 410, for example, as shown in Figure 24, the width W4 in the first direction Y of the first connecting grid line 431 is greater than or equal to the width W3 of the fine grid 410. The width W5 in the first direction Y of the second connecting grid line 432 is greater than or equal to the width W3 of the fine grid 410. Having wider connecting grid lines 430 can increase the collection area and collection efficiency.

[0260] In some embodiments, the range of the width W4 of the first connecting grid lines 431 in the first direction Y includes 10 μm to 55 μm. The width W4 of the first connecting grid lines 431 in the first direction Y may be 10 μm to 16 μm, 16 μm to 22 μm, 22 μm to 30 μm, 30 μm to 38 μm, 38 μm to 46 μm, or 46 μm to 55 μm.

[0261] In some embodiments, the range of the width W5 of the second connecting grid lines 432 in the first direction Y includes 10 μm to 55 μm. The width W5 of the second connecting grid lines 432 in the first direction Y may be 10 μm to 16 μm, 16 μm to 22 μm, 22 μm to 30 μm, 30 μm to 38 μm, 38 μm to 46 μm, or 46 μm to 55 μm.

[0262] In some embodiments, the spacing between the first connecting grid lines 431 and the adjacent fine grid 410 is a first spacing S4, which is equal to or less than the distance between the adjacent first fine grid 411 and second fine grid 412. As a result, in a layout where the spacing between the first connecting grid lines 431 and the fine grid 410 is appropriate and the shielding area of ​​the first connecting grid lines 431 and the fine grid 410 is not wasted, the layout between the first connecting grid lines 431 and the fine grid 410 can achieve a minimum carrier migration distance and minimum migration loss in the substrate, thereby increasing the open-circuit voltage of the solar cell.

[0263] In the embodiment of the present application, the first interval shown in FIG. 24 refers to the interval between the region in which the axis of the first connecting grid line 431 is located and the axis of the adjacent fine grid. In the embodiment of the present application, the specific meaning of the first interval is not limited. For example, the first interval may be the distance between the side of the first connecting grid line 431 that is closer to the substrate boundary and the side of the adjacent fine grid that is farther from the substrate boundary, or the shortest distance between the first connecting grid line 431 and the adjacent fine grid 410.

[0264] In some embodiments, the first spacing S4 is in the range of 0.2 mm to 0.7 mm, 0.2 mm to 0.35 mm, 0.35 mm to 0.46 mm, 0.46 mm to 0.58 mm, 0.58 mm to 0.63 mm, or 0.63 mm to 0.7 mm.

[0265] In some embodiments, the distance between adjacent first fine grids 411 and second fine grids 412 is in the range of 0.3 mm to 0.8 mm, 0.3 mm to 0.35 mm, 0.35 mm to 0.43 mm, 0.43 mm to 0.5 mm, 0.5 mm to 0.58 mm, 0.58 mm to 0.66 mm, 0.66 mm to 0.72 mm, or 0.72 mm to 0.8 mm.

[0266] Similarly, the interval between the second connecting grid line 432 and the adjacent fine grid 410 is a third interval S6, which is equal to or less than the distance between the adjacent first fine grid 411 and second fine grid 412. The range of the third interval S6 is 0.2 mm to 0.7 mm.

[0267] In some embodiments, the distance between the first connecting grid lines 431 and the second connecting grid lines 432 is a second spacing S5, which is equal to or less than the distance between adjacent first fine grid lines 411 and second fine grid lines 412. The second spacing S5 is in the range of 0.2 mm to 0.7 mm.

[0268] In some embodiments, m1≧8, m2≧8, the number of first main grids may be 8, the number of second main grids may be 8, and the number of main grids may be 16.

[0269] In some embodiments, the number of first main grids may be a natural number greater than eight, and the number of second main grids may be a natural number greater than eight.

[0270] The technical solutions provided in the embodiments of the present application utilize at least two first connecting grid lines 431 to establish communication between the first main grids 421. One grid line connects the grid lines of the same polarity (positive or negative electrodes) in the solar cell in series, forming a complete solar cell. This ensures electrical continuity between the first main grid 421 and each of the first fine grids 411, reducing the likelihood of a malfunction in one of the first main grids 421, which would reduce the cell efficiency and yield. Furthermore, since all the first fine grids 411 are in a conductive state, the first fine grids 411 located at the substrate edge can be collected to improve cell collection efficiency. Similarly, improving the cell collection efficiency of the second fine grid 412 can also improve cell efficiency.

[0271] In the solar cell provided in the embodiment of the present application, the first main grid 421 and the first fine grid 411 are ensured to be electrically connected to each other, thereby avoiding the problem of poor appearance between the first main grid 421 and the first fine grid 411 due to differences in the manufacturing process. The interconnection between the first main grids 421 prevents the problem of reduced cell efficiency due to grid disconnection of one of the fine grids or the main grid, and also improves cell efficiency. The at least two second connecting grid lines 432 also improve the cell efficiency of the second fine grid 412 and the second main grid 422.

[0272] Furthermore, compared to connecting multiple first main grids 421 or second main grids 422 with one connecting grid line, in the present application, two connecting grid lines are provided to connect multiple first main grids 421 or second main grids 422. This avoids the problem of grid disconnection caused by a grid line that is too long, and the significant impact on the first main grids 421 and second main grids 422 caused by a grid line that is too long, and can increase battery yield.

[0273] FIG. 33 is a diagram showing the structure of a photovoltaic module provided in another embodiment of the present application, FIG. 34 is a diagram showing the cross-sectional structure along the M1-M2 cross section of FIG. 33, and FIG. 35 is a diagram showing the structure of a solar cell in a photovoltaic module provided in another embodiment of the present application.

[0274] Accordingly, the embodiments of the present application further provide a photovoltaic module including the solar cell provided in the above embodiments, and the same or corresponding technical features as those in the above embodiments will not be described here.

[0275] As shown in Figures 33 to 35, according to some embodiments of the present application, another aspect of the embodiments of the present application includes a cell string formed by connecting a plurality of solar cells 401 according to any one of the above embodiments, a connecting member 409 used to electrically connect a first main grid 421 and a second main grid 422 of two adjacent solar cells, a sealing adhesive film 47 for covering the surface of the cell string, and a cover plate 48 for covering the surface of the sealing adhesive film 47 away from the cell string, wherein the solar cell 401 has a first main grid 421 and a second main grid 422.

[0276] Specifically, in some embodiments, multiple cell strings may be electrically connected by connection members 409, and the connection members 409 may be welded to the main grids of the battery cells. For example, one end of the connection member may be electrically connected to a first main grid of a first battery cell, and the other end of the connection member may be electrically connected to a second main grid of an adjacent second battery cell.

[0277] In some embodiments, there is no space between the battery cells, meaning the battery cells overlap.

[0278] In some embodiments, a weld is formed between the connecting member and the fine grid in the battery cell.

[0279] In some embodiments, as shown in FIG. 35, the solar cell has a weld 408 for realizing welding between the connection member 409 and the main grid.

[0280] 34 , the photovoltaic module further includes an insulating film 406 covering a portion of the surface of the solar cell 401. For example, the insulating film 406 covers a portion of the surface of the first main grid and the first fine grid, thereby achieving electrical insulation between the second main grid and the first main grid when the connecting member and the second main grid are electrically connected. The insulating film 406 exposes the surface of the welding portion 408, and the insulating film is also located between the connecting member 409 and the solar cell, thereby achieving welding between the connecting member and the corresponding main grid and preventing electrical contact between the connecting member and the main grid of the opposite polarity, thereby improving yield. For example, when the connecting member and the first main grid are welded, the insulating film provides electrical insulation between the connecting member and the second main grid.

[0281] In some embodiments, the sealing adhesive film 47 includes a first sealing adhesive film and a second sealing adhesive film, where the first sealing adhesive film covers one of the front and back surfaces of the solar cell, and the second sealing adhesive film covers the other of the front and back surfaces of the solar cell. Specifically, at least one of the first sealing adhesive film and the second sealing adhesive film may be an organic sealing adhesive film such as a polyvinyl butyral (abbreviated as PVB) adhesive film, an ethylene vinyl acetate copolymer (EVA) adhesive film, a polyethylene-octene copolymer (POE) film, or a polyethylene terephthalate (PET) adhesive film.

[0282] Note that there is a boundary between the first sealing adhesive film and the second sealing adhesive film before lamination processing, and when the photovoltaic module is formed after lamination processing, the concepts of the first sealing adhesive film and the second sealing adhesive film no longer exist; in other words, the first sealing adhesive film and the second sealing adhesive film are already integrated to form a sealing adhesive film 47.

[0283] In some embodiments, the cover plate 48 may be a light-transmitting cover plate, such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 48 facing the sealing adhesive film 47 may be textured, thereby improving the utilization efficiency of incident light. The cover plate 48 includes a first cover plate and a second cover plate, where the first cover plate faces the first sealing adhesive film and the second cover plate faces the second sealing adhesive film, or the first cover plate faces one side of the solar cell and the second cover plate faces the other side of the solar cell.

[0284] In some embodiments, the photovoltaic module further includes an electrical connecting wire, where the electrical connecting wire is electrically connected to the first main grid and the second main grid of the adjacent solar cell, or the electrical connecting wire is electrically connected to the second main grid and the first main grid of the adjacent solar cell, thereby achieving interconnection between the two solar cells through the electrical connecting wire, improving the yield of the photovoltaic module and effectively avoiding the problem of reduced yield due to poor welding of one of the connecting members.

[0285] 1 to 9, 10 to 22, and 23 to 35, similar elements are referred to by the same or different terms, such as solar cells 300 and 401, substrates 3001 and 400, and the like, and it is not intended to list them all here. Although different terms are used for some components, their positions and functions are similar, and details of each embodiment can be combined with each other as long as there is no contradiction.

[0286] Those skilled in the art will understand that the above embodiments are specific examples for realizing the present disclosure, but that various changes in form and details are possible in practice without departing from the scope of the present disclosure. Since anyone skilled in the art can make changes and modifications without departing from the spirit and scope of the present disclosure, the scope of protection of the present disclosure should be based on the scope limited by the claims.

Claims

1. A solar cell, a substrate; a passivation layer disposed on the substrate; fine grids arranged at intervals along a first direction; a plurality of main grids arranged at intervals along a second direction; and at least one edge grid line extending along the second direction; wherein the substrate has two first boundaries arranged opposite to each other along the first direction, the fine grid is electrically connected to the substrate through the passivation layer, and the fine grid includes first fine grids and second fine grids that are alternately arranged along the first direction; The main grid is located on the surface of the passivation layer and is in electrical contact with the fine grid, and the main grid is arranged alternately along the second direction. １ The first main grid and ２ a second main grid, the first main grid being in electrical contact with the first fine grid, and the second main grid being in electrical contact with the second fine grid, wherein the first main grid is one of a positive electrode or a negative electrode, and the second main grid is the other of a positive electrode or a negative electrode; The edge grid lines are near the first boundary, and some of the edge grid lines penetrate the passivation layer and are electrically connected to the substrate, the edge grid lines including first edge grid lines, and n １ n are used to electrically contact the first main grid, and the edge grid lines include second edge grid lines, ２ and n is a number of second main grids, each of which is electrically connected to the second main grid, １ <m １ and 1<n ２ <m ２ and n １ , m １ , n ２ and m ２ are all natural numbers, the first edge grid line is located between the first boundary and the second fine grid, and the second edge grid line is located between another of the first boundaries and the first fine grid; The solar cell includes at least one first connecting grid line, the first connecting grid line passing through the passivation layer and electrically connecting to the substrate, wherein the first connecting grid line is connected to the remaining m １ -n １ electrically connected to the first main grid, The solar cell includes at least one second connecting grid line, the second connecting grid line passing through the passivation layer and electrically connecting to the substrate, wherein the second connecting grid line is connected to the remaining m ２ -n ２ electrically connected to the second main grid; A solar cell characterized by:

2. the polarity of the edge grid lines and the fine grids adjacent to the edge grid lines are the same; The solar cell according to claim 1 .

3. the first fine grid includes a plurality of first sub-grid lines spaced apart by a plurality of first spacing regions along the second direction, whereby two adjacent first sub-grid lines are spaced apart by corresponding first spacing regions; the second main grid is located in the first spacing regions, and the first main grid is in electrical contact with the first sub-grid lines; the second fine grid includes a plurality of second sub-grid lines spaced apart by a plurality of second spacing regions along the second direction, whereby two adjacent second sub-grid lines are spaced apart by corresponding second spacing regions; the first main grid is located in the second spacing regions, and the second main grid is in electrical contact with the second sub-grid lines; The solar cell according to claim 1 .

4. a width of the edge grid line in the first direction is equal to or greater than a width of the fine grid in the first direction; The solar cell according to claim 1 .

5. the range of widths of the edge grid lines in the first direction is 10 μm to 55 μm inclusive; The solar cell according to claim 4 .

6. an interval between the edge grid line and the adjacent fine grid line is a first interval, and the first interval is equal to or less than a distance between the adjacent first fine grid line and the adjacent second fine grid line; The solar cell according to claim 1 .

7. The first spacing ranges from 0.2 mm to 0.7 mm. The solar cell according to claim 6 .

8. The distance between adjacent first fine grids and second fine grids is in the range of 0.3 mm to 0.8 mm. The solar cell according to claim 6 .

9. the material of the edge grid lines is the same as the material of the fine grid; The solar cell according to claim 1 .

10. the material of the first connecting grid lines is the same as the material of the fine grid, and the material of the second connecting grid lines is the same as the material of the fine grid; The solar cell according to claim 1 .

11. a width in the first direction of the first connection grid lines is equal to or greater than a width of the fine grid lines, and a width in the first direction of the second connection grid lines is equal to or greater than a width of the fine grid lines; The solar cell according to claim 1 .

12. a cell string formed by connecting a plurality of solar cells according to any one of claims 1 to 11; a connecting member for electrically connecting the first main grid and the second main grid of two adjacent solar cells; a sealing adhesive film for covering the surface of the cell string; a cover plate for covering a surface of the sealing adhesive film away from the cell string, The solar cell includes an edge grid line, a first main grid, and a second main grid. A photovoltaic module characterized by:

13. further comprising electrical connection wires, and the edge grid lines are １ The edge grid lines are in electrical contact with the first main grids of the solar cells adjacent to the edge grid lines, and the electrical connection wires are electrically connected to the second main grids of the solar cells adjacent to the edge grid lines, or ２ the electrical connection wire is electrically connected to the first main grid of the solar cell adjacent to the edge grid line; 13. The photovoltaic module of claim 12.

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