Solar cell and photovoltaic module

Abstract

The present application relates to the technical field of photovoltaics. Disclosed are a solar cell and a photovoltaic module, aiming to reduce the risk of cracking of a solar cell. The solar cell comprises a cell body, collector electrodes and first interconnection structures, wherein at least some regions of different first interconnection structures distributed at intervals in a second direction are located on the same connecting line; the number of connecting lines located in the same target surface is N1, the number of first interconnection structures intersecting with a target line segment located in the target surface is N2, where (I), and the target line segment is a connecting line segment between a midpoint of the longer one of two edges of the target surface that extend in a first direction and distributed opposite each other and an endpoint of a vertex angle corresponding to the shorter one of the two edges; alternatively, the number of connecting lines intersecting with a vector line segment having an inclination angle of 45° is N3, and the number of first interconnection structures intersecting with at least one the same vector line segment having the inclination angle of 45° is N4, where N3>N4.

Description

Solar cell and photovoltaic module

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority of the Chinese patent application number 202410517763.7 filed with the Patent Office of China on April 28, 2024, with the invention name “A solar cell and photovoltaic module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Art

[0004] Solar cells are increasingly being used as a new energy alternative. Photovoltaic solar cells convert sunlight into electricity. Specifically, they use the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, facilitating efficient use of the electrical energy.

[0005] However, in existing solar cells, the distribution position of the interconnection structure on the cell body is unreasonable, resulting in large interconnection stress after interconnecting adjacent solar cells, greatly increasing the risk of cracking, and reducing the structural reliability of photovoltaic modules.

[0006] Summary of the Invention

[0007] The purpose of the present application is to provide a solar cell and a photovoltaic module for reducing the interconnection stress formed after interconnecting adjacent solar cells, thereby reducing the risk of solar cell cracking and improving the structural reliability of the photovoltaic module.

[0008] In order to achieve the above-mentioned objectives, in a first aspect, the present application provides a solar cell, which includes: a cell body, a collecting electrode and a first interconnection structure. The cell body has a first and a second opposite surface. At least one of the first and the second surfaces is a target surface. The collecting electrode is arranged on the target surface. Different collecting electrodes located on the same target surface all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structure forms an array on the target surface. Each first interconnection structure is electrically connected to at least one collecting electrode. At least part of the areas of the different first interconnection structures spaced apart along the second direction are located on the same connecting line, and the different connecting lines are spaced apart along the first direction. Among them, the number of connecting lines located in the same target surface is N1, and the number of first interconnection structures intersecting with the target line segment located in the target surface is N2, The target line segment is a line segment connecting the midpoint of the longer one of the two relatively distributed edges of the target surface extending along the first direction and the vertex endpoint corresponding to the smaller one of the two edges; or, the number of connecting lines intersecting with the vector line segment with an inclination angle of 45° is N3, and the number of first interconnect structures intersecting with at least one vector line segment with an inclination angle of 45° is N4, where N3>N4.

[0009] When the above technical solution is adopted, in the solar cell provided by the present application, a first interconnection structure is provided on the target surface of the battery body, and the first interconnection structures form an array on the target surface. Each first interconnection structure is electrically connected to at least one collecting electrode. Moreover, at least part of the regions of the different first interconnection structures spaced apart along the second direction are located on the same connecting line, and the different connecting lines are spaced apart along the first direction. In this case, when adjacent solar cells are interconnected along the extension direction of the connecting line through in-string interconnections such as welding strips, the in-string interconnections corresponding one to one with the connecting line can be electrically connected to the collecting electrode with the same polarity located on the target surface at least through the first interconnection structure, so that the carriers collected by the collecting electrode are sequentially conducted through the first interconnection structure and the in-string interconnection to form a photocurrent. After the adjacent solar cells are interconnected, due to the different materials and thermal expansion coefficients of the first interconnection structure and the battery body, interconnection stress will be generated after the interconnection. Based on this, the target line segment only contacts at most half of all the connecting lines located on the same target surface. Moreover, when When the target surface is connected to the target line segment, it can be ensured that the first interconnection structure electrically contacting each of the at least one connecting line that can intersect with the target line segment is not arranged on the target line segment. Therefore, after the adjacent solar cells are interconnected along the extension direction of the connecting line through the intra-string interconnection member, all corresponding first interconnection structures electrically contacting each of the at least one intra-string interconnection member will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress formed along the extension direction of the target line segment. In this case, because the diagonal lines within the surface of the semiconductor wafer used to manufacture solar cells are roughly parallel to the cleavage plane, a cleavage plane is a plane that breaks a mineral crystal strictly along a specific crystallographic direction under the action of external force, leaving a smooth surface. Corresponding to silicon wafers, a single crystal silicon ingot undergoes wire sawing to form a nearly square silicon wafer. The cleavage planes intersect the wafer surface and are not parallel to the wafer edge. It can be understood that there are countless mutually parallel cleavage planes within the ingot, forming countless mutually parallel target line segments with the wafer surface. Among them, the target line segments corresponding to the diagonals of the silicon wafer are the longest and face greater stress challenges. Since the position of the target line segments after the silicon wafer is cut in half remains unchanged from before the cut, when the target line segment is a line segment connecting the midpoint of the longer of two oppositely distributed edges of the target surface extending along the first direction (e.g., the non-chamfered edge) and the vertex endpoint corresponding to the shorter of the two edges (e.g., the chamfered edge), the extension direction of the target line segment is roughly parallel to the direction of the cleavage plane of the cell body. At this time, reducing the interconnection stress formed along the extension direction of the target line segment is equivalent to reducing the interconnection stress formed along the cleavage plane direction, reducing the risk of solar cells cracking after being subjected to external forces due to large interconnection stress, and improving the structural reliability of photovoltaic modules formed based on solar cells. Secondly, when the number N3 of connecting lines corresponding to a vector line segment with an inclination angle of 45° is greater than the number N4 of first interconnection structures intersecting with itself, all first interconnection structures on at least one connecting line are not arranged on the vector line segment with an inclination angle of 45°. Therefore, after adjacent solar cells are interconnected along the extension direction of the connecting line via the intra-string interconnector, all corresponding first interconnection structures that are in electrical contact with each of the at least one intra-string interconnector will not generate interconnection stress on the vector line segment with an inclination angle of 45°, thereby shortening the length of the interconnection stress band formed along the extension direction of the vector line segment with an inclination angle of 45°. Secondly, the cleavage plane of the battery body is roughly parallel to the vector line segment with an inclination angle of 45°. Therefore, when shortening the length of the interconnection stress band formed along the extension direction of the vector line segment with an inclination angle of 45°, it is also beneficial to shorten the length of the interconnection stress band formed along the cleavage plane direction, thereby reducing the risk of cracking of the solar cell after being subjected to external force due to the long interconnection stress band, and improving the structural reliability of the photovoltaic module formed based on the solar cell.

[0010] As a possible implementation, the thickness of the battery body is H1, the thickness of the first interconnection structure is H2, and the ratio of H2 to H1 is greater than or equal to 0.005 and less than or equal to 0.1.

[0011] By adopting the above technical solution, it is possible to prevent the inability to effectively electrically interconnect with the interconnectors within the string due to the smaller thickness of the first interconnect structure caused by the smaller ratio (reducing interconnection tension), thereby ensuring that the photovoltaic module obtained after interconnection has higher structural and electrical reliability. It also prevents the indirect increase in carrier transmission loss at the first interconnect structure caused by the smaller thickness of the first interconnect structure caused by the smaller ratio, thereby ensuring that the solar cell has higher power. Furthermore, it can also prevent the increased interconnection stress between the first interconnect structure and the cell body caused by the larger thickness of the first interconnect structure caused by the larger ratio, further reducing the risk of cracking of the solar cell under external force after interconnection, thereby improving the structural reliability of the photovoltaic module.

[0012] As a possible implementation, the cross-sectional area of ​​the battery body is S1, the cross-sectional area of ​​the first interconnect structure is S2, and the ratio of S2 to S1 is greater than or equal to 0.0003 and less than or equal to 0.02. In this case, the smaller the cross-sectional area of ​​the first interconnect structure due to the smaller ratio, the greater the carrier transfer resistance at the first interconnect structure, ensuring that the solar cell has a higher power. In addition, the larger the cross-sectional area of ​​the first interconnect structure due to the larger ratio, the greater the shading loss of the battery, ensuring that the solar cell has a higher conversion efficiency.

[0013] As a possible implementation, N2 is equal to 0. In this case, the number of first interconnect structures intersecting the target line segment is zero. Because the diagonal lines of the surface of the semiconductor wafer used to manufacture the solar cell are roughly parallel to the cleavage plane, the number of first interconnect structures provided on the cleavage plane of the cell body parallel to the extension direction of the target line segment is zero. This can minimize the risk of the solar cell fracturing at the cleavage plane after being subjected to external force, thereby improving the structural reliability of the photovoltaic module formed based on the solar cell.

[0014] As a possible implementation scheme, the distance between the geometric center of the first interconnect structure intersecting the target line segment or the vector line segment with an inclination of 45° and the centerline of the solar cell along the second direction is D3, and the distance between the geometric center of the first interconnect structure intersecting the target line segment or the vector line segment with an inclination of 45° and the edge of the solar cell along the second direction is D4. D3>D4 corresponding to at least one first interconnect structure. In this case, the distance between the geometric center of the first interconnect structure intersecting the target line segment or the vector line segment with an inclination of 45° and the edge of the solar cell along the second direction is smaller, which helps prevent the first interconnect structures intersecting the target line segment or the vector line segment with an inclination of 45° from being densely distributed at the centerline of the solar cell along the second direction, reducing the risk of cracking at the intersection of the centerline of the solar cell along the second direction and the target line segment (or the vector line segment with an inclination of 45°) after interconnection, further improving the structural reliability of the photovoltaic module formed based on the solar cell. Secondly, as the number of first interconnect structures increases, it is also possible to achieve a balance between the uniformity of current collection by the collector electrode and the feasibility of interconnecting adjacent solar cells, which helps improve the operating performance of the photovoltaic module.

[0015] As a possible implementation, the solar cell is a busbar-less solar cell. Along the second direction, the target surface includes a middle region and an edge region. At least a portion of the collector electrode located in the edge region is in direct contact with the first interconnect structure.

[0016] When the above technical solution is adopted, when the solar cell is a main grid-less solar cell, the carriers collected by the corresponding collecting electrode can be directly transmitted to the welding ribbon and other intra-string interconnections through the first interconnection structure in contact with itself and exported, without the need to conduct the carriers through the bus electrode and transmit them in turn to the first interconnection structure and the intra-string interconnections, thereby eliminating the transmission loss of the carriers on the bus electrode, while reducing the shading loss and improving the working efficiency of the solar cell.

[0017] As one possible implementation, the solar cell has a back-contact substrate structure, and the collector electrodes include a first collector electrode and a second collector electrode of opposite polarity. The first collector electrodes and the second collector electrodes are alternately spaced along the second direction. At least a portion of the first collector electrode in the edge region directly contacts the first interconnect structure, and at least a portion of the second collector electrode in the edge region directly contacts the first interconnect structure.

[0018] As a possible implementation scheme, the above-mentioned solar cell also includes a second interconnect structure arranged on the target surface. Each second interconnect structure is electrically connected to at least one collector electrode, and the size of the second interconnect structure is smaller than that of the first interconnect structure. At least part of the area of ​​the second interconnect structure is located on the same straight line and is collinear with the connecting line. Among all the collector electrodes located on the same target surface, some of the collector electrodes are in contact with the first interconnect structure, and the remaining collector electrodes are in contact with the second interconnect structure. Among them, the collector electrode in contact with the first interconnect structure is a connecting electrode. Along the second direction, the spacing between two adjacent connecting electrodes is D1. At least one connecting electrode located on the edge area is in contact with multiple first interconnect structures, and different first interconnect structures in contact with the same connecting electrode are spaced apart along the first direction. The geometric center spacing between two adjacent first interconnect structures in contact with the same connecting electrode is D2. D2 corresponding to at least one pair of first interconnect structures is not equal to D1, and each pair of first interconnect structures is two adjacent first interconnect structures in contact with the same connecting electrode.

[0019] When the above technical solution is adopted, among all the collecting electrodes located on the same target surface, some of the collecting electrodes are in contact with the larger first interconnection structure to increase the contact area between the collecting electrodes and the interconnection parts within the string, which is beneficial to reducing the contact resistance between the interconnection parts within the string and the collecting electrodes, and is beneficial to improving the connection strength between the interconnection parts within the string and the collecting electrodes. Secondly, the remaining collecting electrodes are in contact with the smaller second interconnection structure to reduce the metal composite loss on one side of the target surface and improve the working efficiency of the solar cell. In addition, in the solar cell, the first interconnection structures that contact different connection electrodes and are in the same layer are aligned along the first direction to reduce the connection difficulty of automatic interconnection equipment such as string welding machines that interconnect adjacent solar cells. In this case, when D2 corresponding to at least one pair of first interconnect structures is not equal to D1, the inclination angle of the line between a certain layer of first interconnect structure arranged on a certain connecting electrode and the adjacent layer of first interconnect structure arranged on an adjacent connecting electrode is not equal to 45°, so that the inclination angle of the interconnection stress band corresponding to the pair of first interconnect structures is not equal to 45°, which is beneficial to shortening the length of the interconnection stress band formed in the extension direction of the vector line segment with an inclination angle of 45°, and is also beneficial to shortening the length of the interconnection stress band formed along the cleavage plane direction, thereby reducing the risk of cracking problems in solar cells after being subjected to external force due to the long interconnection stress band, and improving the structural reliability of photovoltaic modules formed based on solar cells.

[0020] As a possible implementation solution, the number of second interconnect structures intersecting the target line segment or the vector line segment with an inclination angle of 45° is N7. And / or, N7<N1.

[0021] When the above technical solution is adopted, the number N7 of the second interconnected structures intersecting the target line segment or the vector line segment with an inclination angle of 45° is greater than When the second interconnect structure is connected to the target surface, the second interconnect structure can be made to have a larger distribution density on the target surface to ensure sufficient interconnection strength. In addition, for the high-temperature process of manufacturing solar cells, the sintering temperature of the electrode is generally above 600°C. During the sintering and cooling process, due to the difference in thermal expansion coefficient, there will be relatively large stress between the larger first interconnect structure and the battery body. When the stress is too large, the battery will easily crack. Although the size of the above-mentioned second interconnect structure is relatively small, for a busbar-less solar cell, the distribution density of the second interconnect structure on the target surface may be large, which will aggravate the formation of hidden cracks inside the busbar-less solar cell and bring the hidden danger of battery cracking. Based on this, when N7 is less than N1, it can be ensured that the second interconnection structures on at least one connecting line on the target surface that can intersect with the target line segment (or a vector line segment with an inclination angle of 45°) are not arranged on the target line segment (or a vector line segment with an inclination angle of 45°). Therefore, after the adjacent solar cells are interconnected along the extension direction of the connecting line through the intra-string interconnection member, all corresponding second interconnection structures intersecting with at least one intra-string interconnection member will not generate sintering stress on the target line segment, thereby reducing the sintering stress formed along the extension direction of the target line segment, preventing the risk of solar cells from cracking due to the large distribution density of the second interconnection structure on the target surface, and ensuring that the solar cells have a high yield.

[0022] As a possible implementation, when the collector electrode in contact with the first interconnect structure is a connection electrode, the ratio of D1 to D2 corresponding to at least one pair of first interconnect structures is greater than or equal to 6 and less than or equal to 12.

[0023] When employing the above technical solution, the ratio of D1 to D2 corresponding to at least one pair of first interconnect structures is within the above range. This helps prevent the extension direction of the interconnect stress band corresponding to the at least one pair of first interconnect structures from approaching the extension direction of the cleavage plane due to a small ratio, thereby ensuring that the length of the interconnect stress band formed along the cleavage plane can be shortened. It also helps prevent the spacing between two adjacent first interconnect structures intersecting the same connecting electrode from being large due to a large ratio, which could lead to large carrier transmission losses on the connecting electrode, thereby improving the operating efficiency of the solar cell.

[0024] As a possible implementation, the solar cell further includes a busbar electrode disposed on the target surface. Different busbar electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction. Each busbar electrode is electrically connected to a collector electrode having the same polarity as itself and is in contact with at least one first interconnect structure. Different busbar electrodes correspond to different connecting wires.

[0025] When using the above technical solution, in actual applications, the collector electrode line width is usually small to reduce its own light shielding area, but this makes the collector electrode relatively easy to break. The presence of the busbar electrode allows the carriers collected by the collector electrode on both sides of the break to be transferred and discharged to the connected busbar electrode, improving the current collection capacity and reducing power loss.

[0026] As a possible implementation scheme, the above-mentioned bus electrode is a connecting electrode. Particularly, along the first direction, the spacing between two adjacent connecting electrodes is D1. At least one connecting electrode contacts multiple first interconnect structures, and different first interconnect structures contacting the same connecting electrode are spaced apart along the second direction. The spacing between the geometric centers of two adjacent first interconnect structures contacting the same connecting electrode is D2. D2 corresponding to at least one pair of first interconnect structures is not equal to D1, and each pair of first interconnect structures is two adjacent first interconnect structures contacting the same connecting electrode. The beneficial effects in this case can be referred to above and will not be repeated here.

[0027] As a possible implementation, the collector electrode includes a first collector electrode and a second collector electrode of opposite polarity. The first collector electrode and the second collector electrode are alternately spaced along the second direction. Furthermore, the bus electrode includes a first bus electrode and a second bus electrode of opposite polarity. The first bus electrode and the second bus electrode are alternately spaced along the first direction. The bus electrodes of opposite polarity and the collector electrode are insulated from each other.

[0028] As a possible implementation solution, when the bus electrode is a connecting electrode, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures is greater than or equal to 1 and less than or equal to 1.7.

[0029] When employing the above technical solution, it can be understood that, given a fixed length of the connecting electrode, the greater the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures, the greater the spacing between adjacent first interconnect structures intersecting the same connecting electrode. Conversely, the smaller the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures, the smaller the spacing between adjacent first interconnect structures intersecting the same connecting electrode. However, as this ratio approaches 1, the inclination angle of the line connecting the pair of first interconnect structures approaches 45°, i.e., the closer it approaches the extension direction of the cleavage plane. In this case, a ratio of D2 to D1 corresponding to at least one pair of first interconnect structures within the above range helps prevent the extension direction of the interconnect stress band corresponding to the at least one pair of first interconnect structures from approaching the extension direction of the cleavage plane due to a small ratio, thereby ensuring that the length of the interconnect stress band formed along the cleavage plane is shortened. Furthermore, it helps prevent the spacing between adjacent first interconnect structures intersecting the same connecting electrode from being larger due to a large ratio, which could result in greater carrier transmission loss on the connecting electrode, thereby improving the operating efficiency of the solar cell.

[0030] In a second aspect, the present application provides another solar cell, which includes: a cell body, a collecting electrode and a first interconnection structure. The cell body has a first surface and a second surface opposite to each other. At least one of the first surface and the second surface is a target surface. The collecting electrode is arranged on the target surface. Different collecting electrodes located on the same target surface all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structure forms an array on the target surface. Each first interconnection structure is electrically connected to at least one collecting electrode. At least part of the areas of the different first interconnection structures spaced apart along the second direction are located on the same connecting line, and the different connecting lines are spaced apart along the first direction. The number of connecting lines located in the same target surface is N1, and the number of first interconnection structures intersecting with the target line segment located in the target surface is N2, N1>N2, and the target line segment is a diagonal line of the target surface and intersects with each connecting line.

[0031] When the above technical solution is employed, the target line segment is a diagonal line of the target surface and intersects each connecting line. Furthermore, when N2 < N1, it is ensured that none of the first interconnect structures electrically contacting each of the at least one connecting line on the target surface that can intersect the target line segment are disposed on the target line segment. Consequently, after adjacent solar cells are interconnected along the extending direction of the connecting line via the intra-string interconnectors, all corresponding first interconnect structures electrically contacting each of the at least one intra-string interconnectors will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress generated along the extending direction of the target line segment. In this case, the diagonal lines within the surface of the semiconductor wafer used to manufacture solar cells are roughly parallel to the cleavage planes. Cleavage planes are planes that break strictly along a specific crystallographic direction under external force, leaving smooth, flat surfaces. Corresponding to silicon wafers, wire-slicing a single-crystal silicon ingot produces nearly square wafers. The cleavage planes intersect the wafer surface and are not parallel to the wafer edge. It can be understood that the ingot contains countless mutually parallel cleavage planes, which form countless mutually parallel target line segments with the wafer surface. The target line segments corresponding to the diagonals of the wafer are the longest and face greater stress challenges. Therefore, when the target line segments are diagonals of the target surface, the extension direction of the target line segments is roughly parallel to the direction of the cleavage planes of the cell body. In this case, reducing the interconnect stress generated along the extension direction of the target line segments is equivalent to reducing the interconnect stress generated along the cleavage planes, reducing the risk of solar cell cracking caused by excessive interconnect stress, thereby improving the structural reliability of photovoltaic modules based on solar cells.

[0032] As a possible implementation scheme, the above-mentioned solar cell also includes a bus electrode arranged on the target surface. Different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction. Each bus electrode is electrically connected to a collector electrode with the same polarity as itself and is in contact with at least one first interconnection structure. Different bus electrodes correspond one-to-one to different connecting lines. In this case, in actual application, the line width of the collector electrode is usually small to reduce its own shading area, but this will make the collector electrode relatively easy to break. The presence of the bus electrode can make the carriers collected by the part of the collector electrode on both sides of the break be transmitted and conducted to the bus electrodes connected thereto respectively, thereby improving the current collection capacity and reducing power loss.

[0033] As a possible implementation scheme, in the case where the solar cell includes at least two slice battery units spaced apart and distributed along the second direction, there is a cutting path between two adjacent slice battery units. The collector electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or the first interconnection structures with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or the bus electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path. In this case, in the two adjacent slice battery units, at least one of the collector electrodes with opposite polarities, the first interconnection structure, and the bus electrodes are symmetrically arranged about the cutting path, which facilitates the interconnection between the two, prevents misalignment, improves the interconnection yield, and reduces the difficulty of interconnection.

[0034] As a possible implementation, the solar cell includes M slice battery units spaced apart along the second direction, where M is a positive integer greater than or equal to 1. In the same slice battery unit, the geometric centers of two first interconnect structures located at the edges along the second direction are symmetrically arranged with respect to a midline of the slice battery unit along the second direction.

[0035] When the above technical solution is adopted, for the same slice battery unit, the geometric centers of the two first interconnection structures located on the edge along the second direction are symmetrically arranged relative to the center of the slice battery unit along the second direction, which is conducive to enabling automatic interconnection equipment such as a string welding machine to interconnect different slice battery units at the same starting position, and prevent the misalignment between the intra-string interconnection parts such as welding strips and the first interconnection structure arranged on the battery body due to the different starting positions corresponding to different slice battery units, thereby causing the carriers on the connecting electrode corresponding to the first interconnection structure that is not electrically connected to the intra-string interconnection part to be unable to be extracted through the intra-string interconnection part, resulting in power loss, or causing the corresponding first interconnection structure to become a load, resulting in reduced working efficiency of the solar cell, ensuring that the photovoltaic module formed by the solar cell provided by this application has good working performance.

[0036] As one possible implementation, the solar cell has a back-contact substrate structure, and the collector electrodes include a first collector electrode and a second collector electrode of opposite polarity. The first collector electrodes and the second collector electrodes are alternately spaced along the second direction. At least a portion of the first collector electrode in the edge region directly contacts the first interconnect structure, and at least a portion of the second collector electrode in the edge region directly contacts the first interconnect structure.

[0037] As a possible implementation, when the polarities of the two outer bus electrodes along the first direction are opposite, at least two of all first interconnect structures intersecting the target line segment are equidistant from the centerline of the target surface along the second direction and have the same polarity. This improves the uniformity of distribution among different first interconnect structures with the same polarity located on the same target surface, and reduces the difficulty of interconnecting adjacent solar cells using automated interconnection equipment such as stringers.

[0038] As a possible implementation, when a solar cell includes two slice battery cells spaced apart along the second direction, the N2 values ​​corresponding to the two slice battery cells are equal. In the same slice battery cell, the two busbar electrodes located outwardly along the first direction have opposite polarities. Two oppositely disposed busbar electrodes located outwardly along the first direction and belonging to different slice battery cells have opposite polarities. This improves the symmetry between different first interconnect structures with opposite polarities located on the same target surface, thereby reducing the difficulty of interconnecting adjacent solar cells using automated interconnection equipment such as stringing machines.

[0039] As a possible implementation scheme, when a solar cell includes two slice battery cells spaced apart along the second direction, the N2 corresponding to the two slice battery cells are unequal. In the same slice battery cell, the polarity of the two busbar electrodes located on the outside along the first direction is the same. The polarity of the two oppositely arranged busbar electrodes located on the outside along the first direction, belonging to different slice battery cells, is opposite. In this case, another possible implementation method is provided for the solar cell provided in this application, improving the applicability of the solar cell provided in this application in different application scenarios.

[0040] As a possible implementation scheme, the above-mentioned solar cell is a busbar-free solar cell. The solar cell also includes a second interconnect structure arranged on the target surface. Each second interconnect structure is electrically connected to at least one collector electrode, and the size of the second interconnect structure is smaller than that of the first interconnect structure. At least part of the area of ​​the second interconnect structure is located on the same straight line and is collinear with the connecting line. Among all the collector electrodes located on the same target surface, some of the collector electrodes are in contact with the first interconnect structure, and the remaining collector electrodes are in contact with the second interconnect structure. The number of second interconnect structures intersecting with the target line segment is N8; wherein, And / or, N8<1.5N1. The application principle of the beneficial effect in this case can refer to the above-mentioned The application principle of the beneficial effect of N7<N1 will not be elaborated here.

[0041] In a third aspect, the present application provides a photovoltaic assembly, which includes the solar cell provided by the first aspect and its various implementations, or includes the solar cell provided by the second aspect and its various implementations.

[0042] The beneficial effects of the third aspect and its various implementations in this application can refer to the analysis of the beneficial effects in the first aspect and its various implementations, or can refer to the analysis of the beneficial effects in the second aspect and its various implementations, and will not be repeated here.

[0043] In a fourth aspect, the present application provides another photovoltaic module, comprising: a solar cell; and an intra-string interconnector connecting two adjacent solar cells in series. The solar cell comprises: a cell body, a collector electrode, and a first interconnection structure. The cell body has a first and a second opposing surface. At least one of the first and second surfaces is a target surface. The collector electrode is disposed on the target surface. Different collector electrodes located on the same target surface extend along a first direction and are spaced apart along a second direction. The first direction is perpendicular to the second direction. Each first interconnection structure is electrically connected to at least one collector electrode. Each intra-string interconnector is electrically in contact with a corresponding first interconnection structure. The number of first interconnection structures that intersect a target line segment located within the target surface is N2. The target line segment is a line segment connecting the midpoint of the longer of two oppositely disposed edges of the target surface extending along the first direction and the vertex endpoints corresponding to the shorter of the two edges is N5. The number of first interconnection structures that intersect at least one vector line segment with a common inclination angle of 45° is N4. The number of interconnects in a string that intersects the same vector line segment with an inclination angle of 45° is N6. Or, N6>N4.

[0044] As a possible implementation solution, N2 corresponding to at least two solar cells in a same photovoltaic module is equal.

[0045] The beneficial effects of the fourth aspect and its various implementations in this application can be referred to the analysis of the beneficial effects of the first aspect and its various implementations, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0047] FIG1 is a schematic diagram of the first structure of a solar cell provided in an embodiment of the present application;

[0048] FIG2 is a schematic diagram of a second structure of a solar cell provided in an embodiment of the present application;

[0049] FIG3 is a schematic diagram of a third structure of a solar cell provided in an embodiment of the present application;

[0050] FIG4 is a schematic diagram of a fourth structure of a solar cell provided in an embodiment of the present application;

[0051] FIG5 is a schematic diagram of a square cutout of a semiconductor substrate used to manufacture a battery body in an embodiment of the present application;

[0052] FIG6 is a schematic diagram of the distribution of diagonals on a target surface in an embodiment of the present application;

[0053] FIG7 is a schematic diagram showing a distribution relationship between some connecting electrodes and some interconnecting structures in an embodiment of the present application;

[0054] FIG8 is a schematic diagram of a fifth structure of a solar cell provided in an embodiment of the present application;

[0055] FIG9 is a schematic diagram of a sixth structure of a solar cell provided in an embodiment of the present application;

[0056] FIG10 is a schematic diagram of a seventh structure of a solar cell provided in an embodiment of the present application;

[0057] FIG11 is a schematic diagram of an eighth structure of a solar cell provided in an embodiment of the present application;

[0058] FIG12 is a schematic diagram showing another distribution relationship between some connecting electrodes and some interconnecting structures in an embodiment of the present application;

[0059] FIG13 is a schematic diagram of a ninth structural embodiment of a solar cell provided in an embodiment of the present application;

[0060] FIG14 is a schematic diagram of the tenth structure of a solar cell provided in an embodiment of the present application.

[0061] Reference numerals: 11 is a battery body, 12 is a collecting electrode, 13 is a first interconnection structure, 14 is a second interconnection structure, 15 is a connecting electrode, and 16 is a bus electrode. DETAILED DESCRIPTION

[0062] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present application. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion in the concepts of the present application.

[0063] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments of the present application. These figures are not drawn to scale, and for the purpose of clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0064] In the context of this application, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intervening layer / element between them. Furthermore, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element. To make the technical problems, technical solutions, and beneficial effects to be solved by this application more clearly understood, the application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain this application and are not intended to limit this application.

[0065] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0066] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0067] Solar cells are increasingly being used as a new energy alternative. Photovoltaic solar cells convert sunlight into electricity. Specifically, they use the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, facilitating efficient use of the electrical energy.

[0068] Specifically, existing solar cells typically include a cell body, a current collecting electrode, and an interconnection structure. The current collecting electrode is disposed on the first and / or second surface of the solar cell. Different current collecting electrodes located on the same surface extend along a first direction and are spaced apart along a second direction. The first direction is different from the second direction. The interconnection structure is disposed on the side of the cell body bearing the current collecting electrode. The interconnection structure is a conductive structure used to electrically connect the solar cell to the intra-string interconnection member. Each interconnection structure contacts at least one current collecting electrode, interconnecting adjacent solar cells via the interconnection structure and intra-string interconnection members such as solder ribbons. Different interconnection structures located on the same surface form an array. At least portions of the different interconnection structures spaced apart along the second direction lie on the same connecting line, with different connecting lines spaced apart along the first direction. The specific meaning of the connecting line can be determined by the type of solar cell. Specifically, when the solar cell is a busbar-less solar cell, the connecting line coincides with the orthographic projection of the intra-string interconnection member on the cell body; alternatively, the connecting line refers to a virtual line formed along the interconnection direction by interconnection structures of the same polarity. When the solar cell is a busbar-supported solar cell, the connecting line coincides with the orthographic projection of the busbar electrode on the cell body. When solar cells are used in photovoltaic modules, the connecting wires coincide with the orthographic projection of the interconnects within the string onto the cell body. For a whole cell, the number of connecting wires refers to the number of connecting wires within a single cell within the same plane. For solar cells with a back-contact matrix structure, the number of connecting wires refers to the sum of the connecting wires corresponding to the positive and negative interconnects on the back of the cell.

[0069] However, in the above-mentioned existing solar cells, the distribution position of the interconnection structure on the cell body is unreasonable. Specifically, taking the whole cell as an example, in the existing solar cell, the number of connecting lines is equal to or less than the number of interconnection structures intersecting with the diagonal line. Moreover, the diagonal line is the longest line segment within the surface of the cell body. In this case, after the adjacent solar cells are interconnected by electrically connecting the interconnection structure along the extension direction of the connecting line through the interconnection members such as the welding ribbon, stress will be generated between the interconnection structure and the cell body on the side where the interconnection structure is formed after the interconnection. In general, the thermal expansion coefficient of the cell body will be smaller, while the thermal expansion coefficient of the interconnection structure will be larger, and a stress difference will be formed between the two. The main material of the cell body is generally silicon material, which is brittle. If the stress on its surface is too large, it will cause cracks. Usually, the ratio of the thermal expansion coefficient of the cell body and the interconnection structure is greater than 10. Taking the case where the material of the cell body is silicon material, the electrode is silver electrode, and the interconnection member in the string is copper welding ribbon as an example, the thermal expansion coefficient of the cell body is 2.6×10 -6 / ℃, the thermal expansion coefficient of the silver electrode is 1.9×10 -5 / ℃, the thermal expansion coefficients of the two are quite different; the thermal expansion coefficient of the copper welding strip is 1.7×10 -5 / ℃, and the interconnection and packaging temperature is generally around 150℃ or even higher. The difference in thermal expansion coefficient between it and the battery body is also large, and stress will be concentrated at the location of the interconnection structure. Based on this, when the number of connecting lines is equal to or less than the number of interconnection structures intersecting with the diagonal line, there is at least one interconnection structure on each connecting line that intersects with the diagonal line. After interconnection, a stress band extending along the diagonal direction and having a large length will be formed, making the interconnection stress along the diagonal extension direction too large. The diagonal direction is roughly parallel to the cleavage plane of the battery body. When the interconnection stress along the diagonal direction is too large, it is easy to cause a significant increase in the risk of cracking, resulting in a reduction in the structural reliability of the photovoltaic module.

[0070] To solve the above technical problems, in a first aspect, embodiments of the present application provide a solar cell. Specifically, the solar cell provided in embodiments of the present application can be any type of cell that can convert solar light energy into electrical energy.

[0071] In terms of the placement of the positive and negative electrodes, the solar cell provided in the embodiments of the present application may have a double-sided contact substrate structure, i.e., one of the positive and negative electrodes of the solar cell is disposed on the front side of the solar cell, and the other is disposed on the back side. Alternatively, the solar cell provided in the embodiments of the present application may have a back-contact substrate structure, i.e., both the positive and negative electrodes of the solar cell are disposed on the back side of the solar cell.

[0072] In terms of the specific electrode structure of the positive electrode and the negative electrode, the solar cell provided in the embodiment of the present application can be a "busbar solar cell"; in this case, the solar cell includes not only a collecting electrode but also a bus electrode, and different bus electrodes correspond one-to-one to different connecting lines. Alternatively, the solar cell provided in the embodiment of the present application can also be a "busbarless solar cell"; in this case, the busbarless solar cell does not have the bus electrode of the above-mentioned busbar solar cell; specifically, the electrode structure of the busbarless solar cell can include only the collecting electrode, or can also include the collecting electrode and a bus electrode segment that plays an auxiliary busbar role (the bus electrode segment can be electrically connected to the first interconnect structure located at the edge along the second direction and extend toward the edge of the battery body along the second direction). There is no limitation on the specific shape of the bus electrode segment, for example, it can be a straight line, a curve, or a harpoon structure.

[0073] Specifically, as shown in Figures 2 and 4, and Figures 5 and 6, the solar cell provided in the embodiment of the present application includes: a battery body 11, a collecting electrode 12 and a first interconnection structure 13. The battery body 11 has a first and a second opposite surface. At least one of the first and second surfaces is a target surface. The collecting electrode 12 is arranged on the target surface. Different collecting electrodes 12 located on the same target surface all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structure 13 forms an array on the target surface. Each first interconnection structure 13 is electrically connected to at least one collecting electrode 12. At least part of the areas of the different first interconnection structures 13 spaced apart along the second direction are located on the same connecting line, and the different connecting lines are spaced apart along the first direction. Among them, the number of connecting lines located in the same target surface is N1, and the number of first interconnection structures 13 intersecting with the target line segment located in the target surface is N2, The target line segment is a line segment connecting the midpoint of the longer one of the two relatively distributed edges of the target surface extending along the first direction and the vertex endpoint corresponding to the smaller one of the two edges; or, the number of connecting lines intersecting with the vector line segment with an inclination angle of 45° is N3, and the number of first interconnect structures 13 intersecting with at least one vector line segment with an inclination angle of 45° is N4, where N3>N4.

[0074] Specifically, the number N1 of the aforementioned connecting lines is a positive integer greater than or equal to 1. The number N2 of the first interconnect structures intersecting the target line segment located within the target surface is an integer greater than or equal to 0. Secondly, it can be understood that within the target surface of the solar cell, there are an infinite number of vector line segments with an inclination angle of 45°, of which at least one vector line segment with an inclination angle of 45° satisfies N3>N4.

[0075] When the above technical solution is adopted, as shown in Figures 2 and 4, in the solar cell provided by the embodiment of the present application, a first interconnection structure 13 is provided on the target surface of the battery body 11, and the first interconnection structures 13 form an array on the target surface. Each first interconnection structure 13 is electrically connected to at least one collecting electrode 12. Moreover, at least part of the regions of the different first interconnection structures 13 spaced apart along the second direction are located on the same connecting line, and the different connecting lines are spaced apart along the first direction. In this case, when adjacent solar cells are interconnected along the extension direction of the connecting line through an intra-string interconnection member such as a welding ribbon, the intra-string interconnection member corresponding to the connecting line can be electrically connected to the collecting electrode 12 with the same polarity located on the target surface at least through the first interconnection structure 13, so that the carriers collected by the collecting electrode 12 are sequentially conducted through the first interconnection structure 13 and the intra-string interconnection member to form a photocurrent. After the adjacent solar cells are interconnected, due to the different materials and thermal expansion coefficients of the first interconnection structure 13 and the battery body 11, interconnection stress will be generated after the interconnection. Based on this, the target line segment only contacts at most half of the number of connecting lines located on the same target surface. Moreover, when When the target surface is connected to the target line segment, it can be ensured that the first interconnection structure 13 electrically contacting each of the at least one connecting line that can intersect with the target line segment is not arranged on the target line segment. Therefore, after the adjacent solar cells are interconnected along the extension direction of the connecting line through the intra-string interconnection member, all corresponding first interconnection structures 13 electrically contacting each of the at least one intra-string interconnection member will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress formed along the extension direction of the target line segment. In this case, because the diagonal lines within the surface of the semiconductor wafer used to manufacture the solar cell are roughly parallel to the cleavage plane, and the cleavage plane is a plane with the property that a mineral crystal breaks strictly along a certain crystallographic direction under the action of external force and can produce a smooth surface, corresponding to the silicon wafer, a single crystal silicon ingot will be formed into a nearly square silicon wafer after wire cutting. The cleavage plane intersects with the silicon wafer surface and is not parallel to the edge of the silicon wafer. It can be understood that there are countless mutually parallel cleavage planes in the ingot, which form countless mutually parallel target line segments with the silicon wafer surface. Among them, the target line segment corresponding to the diagonal line of the silicon wafer is the longest and faces a greater stress challenge. After the silicon wafer is cut in half, the position of the target line segment remains unchanged from before the cut. Therefore, when the target line segment is a line segment connecting the midpoint of the longer of the two oppositely distributed edges of the target surface extending along the first direction (such as the non-chamfered edge) and the vertex endpoint corresponding to the shorter of the two edges (such as the chamfered edge), the extension direction of the target line segment is roughly parallel to the direction of the cleavage plane of the battery body 11. At this point, reducing the interconnection stress generated along the extension direction of the target line segment is equivalent to reducing the interconnection stress generated along the cleavage plane direction, reducing the risk of solar cells cracking after being subjected to external forces due to large interconnection stress, and improving the structural reliability of photovoltaic modules formed based on solar cells. Secondly, when the number N3 of connecting lines intersecting a vector line segment with an inclination angle of 45° is greater than the number N4 of first interconnection structures 13 intersecting with itself, all first interconnection structures 13 on at least one connecting line are not disposed on the vector line segment with an inclination angle of 45°. Therefore, after adjacent solar cells are interconnected along the extension direction of the connecting line via the intra-string interconnector, all corresponding first interconnection structures 13 electrically contacting each of the at least one intra-string interconnector will not generate interconnection stress on the vector line segment with an inclination angle of 45°, thereby shortening the length of the interconnection stress zone formed along the extension direction of the vector line segment with an inclination angle of 45°. Secondly, the cleavage surface of the battery body 11 is roughly parallel to the vector line segment with an inclination angle of 45°. Therefore, when shortening the length of the interconnection stress band formed along the extension direction of the vector line segment with an inclination angle of 45°, it is also beneficial to shorten the length of the interconnection stress band formed along the cleavage surface direction, thereby reducing the risk of the solar cell cracking problem after being subjected to external force due to the long interconnection stress band, and improving the structural reliability of the photovoltaic module formed based on the solar cell.

[0076] It should be noted that the solar cell provided in the first aspect of the embodiment of the present application is a half-cell solar cell. Secondly, the direction of the surface inner diagonal of the semiconductor wafer used to manufacture the solar cell (i.e., the target inner diagonal of the battery body of the whole cell), the direction of the vector line segment with an inclination angle of 45°, and the direction of the target line segment in the half-cell solar cell mentioned above are all roughly parallel to the cleavage plane. Therefore, replacing the direction of the target inner diagonal of the battery body of the whole cell, the direction of the vector line segment with an inclination angle of 45°, and the direction of the target line segment in the half-cell solar cell with the extension direction of the cleavage plane also satisfies the corresponding relationship.

[0077] In addition, in actual application, the number N1 of connecting lines located on the target surface and the number N2 of first interconnect structures intersecting with the target line segments within the target surface can be determined based on the spacing between two adjacent connecting lines along the second direction or the spacing between two adjacent collecting electrodes electrically contacting the first interconnect structure, as well as the distribution of the first interconnect structure on the connecting lines, as long as they can be applied to the solar cell provided in the embodiments of the present application.

[0078] For example, as shown in FIG4 , N2 can be equal to 0. In this case, the number of first interconnecting structures 13 intersecting the target line segment is 0. Because the direction of the surface inner diagonal of the semiconductor wafer used to manufacture the solar cell is roughly parallel to the cleavage plane, and after the semiconductor wafer is cut in half, the position of the line segment (i.e., the target line segment) connecting the midpoint of the longer of the two relatively distributed edges of the target surface extending along the first direction and the vertex endpoint corresponding to the shorter of the two edges is part of the surface inner diagonal of the original entire semiconductor wafer, it can be seen that the target line segment is roughly parallel to the cleavage plane. Therefore, at this time, the number of first interconnecting structures 13 arranged on the cleavage plane of the battery body 11 parallel to the extension direction of the target line segment is 0, which can minimize the risk of cracking problems at the cleavage plane after the solar cell is subjected to external force, thereby improving the structural reliability of the photovoltaic module formed based on the solar cell. It should be noted that the case where N2 is equal to 0 is applicable to busbarless solar cells, busbar solar cells, back contact substrate structures, and double-sided contact substrate structures.

[0079] As for the number N3 of connecting lines intersecting with the vector line segment with an inclination angle of 45°, and the number N4 of first interconnecting structures intersecting with the same vector line segment with an inclination angle of 45°, they can also be determined based on the spacing between two adjacent connecting lines along the second direction or the spacing between two adjacent collecting electrodes electrically contacting the first interconnecting structure, and the distribution of the first interconnecting structure on the connecting lines, as long as they can be applied to the solar cell provided in the embodiment of the present application.

[0080] As for the first interconnect structure, in terms of material, the material of the first interconnect structure may include any conductive material such as silver, copper, aluminum or tungsten.

[0081] Secondly, as mentioned above, the materials and thermal expansion coefficients of the battery body and the first interconnect structure are different. Therefore, after interconnection, interconnection stress will be generated at the junction of the battery body and the first interconnect structure. When the size of the first interconnect structure is different, the magnitude of the interconnection stress generated at the junction of the battery body and the first interconnect structure after interconnection may also be different. Specifically, when other factors are the same and within a certain range, after interconnecting adjacent solar cells, the magnitude of the interconnection stress at the junction of the first interconnect structure and the battery body is proportional to the thickness of the first interconnect structure. In addition, within a certain range, the thickness of the first interconnect structure is inversely proportional to its own transmission loss. In the above case, the size of the first interconnect structure can be determined at least based on the requirements for the transmission loss and interconnection stress of the first interconnect structure in the actual application scenario, and is not specifically limited here.

[0082] For example, the thickness of the battery body is H1, and the thickness of the first interconnect structure is H2. Based on this, the ratio of H2 to H1 can be greater than or equal to 0.005 and less than or equal to 0.1. For example, the ratio between the thickness H2 of the interconnect structure and the thickness H1 of the battery body can be 0.005, 0.01, 0.02, 0.04, 0.06, 0.08 or 0.1, etc. In this case, the ratio between the thickness H2 of the first interconnect structure and the thickness H1 of the battery body is within the above range. This can prevent the first interconnect structure from being too thin due to the smaller ratio, which leads to an inability to effectively electrically interconnect with the interconnection member in the string (reducing the interconnection tension), thereby ensuring that the photovoltaic module obtained after interconnection has higher structural and electrical reliability; at the same time, it can prevent the first interconnect structure from being too thin due to the smaller ratio, which indirectly leads to higher carrier transmission loss at the first interconnect structure, thereby ensuring that the solar cell has higher power. Furthermore, this can prevent the increased thickness of the first interconnect structure due to a larger ratio, which could lead to greater interconnect stress between the first interconnect structure and the cell body after interconnection. This further reduces the risk of solar cell cracking under external forces after interconnection, and improves the structural reliability of the photovoltaic module. It should be noted that the ratio of H2 to H1 can be greater than or equal to 0.005 and less than or equal to 0.1, which is applicable to both busbar-less solar cells and busbar-equipped solar cells, back-contact substrate structures, and double-sided contact substrate structures.

[0083] For example, the cross-sectional area of ​​the battery body is defined as S1, and the cross-sectional area of ​​the first interconnect structure is defined as S2. Based on this, the ratio of S2 to S1 can be greater than or equal to 0.0003 and less than or equal to 0.02. For example, the ratio between the cross-sectional area S2 of the interconnect structure and the cross-sectional area S1 of the battery body can be 0.0003, 0.0008, 0.001, 0.003, 0.005, 0.008, 0.01 or 0.02, etc. When the ratio of S2 to S1 is within the above range, it can prevent the cross-sectional area of ​​the first interconnect structure from being smaller due to the smaller ratio, which leads to a larger carrier transmission resistance at the first interconnect structure, thereby ensuring that the solar cell has a higher power. In addition, it can also prevent the cross-sectional area of ​​the first interconnect structure from being larger due to the larger ratio, which leads to a larger shading loss of the battery, thereby ensuring that the solar cell has a higher conversion efficiency. It should be noted that the situation where the ratio of S2 to S1 is greater than or equal to 0.0003 and less than or equal to 0.02 is applicable to busbar-free solar cells, busbar-equipped solar cells, back-contact substrate structures, and double-sided contact substrate structures.

[0084] In addition, when the first interconnection structure simultaneously satisfies the ratio of H2 to H1 being greater than or equal to 0.005 and less than or equal to 0.1, and the ratio of S2 to S1 being greater than or equal to 0.0003 and less than or equal to 0.02, it can take into account the balance of interconnection tension, resistance loss, interconnection stress and shading loss, ensuring that the solar cell has a higher conversion efficiency, and the photovoltaic module including the solar cell provided in the embodiment of the present application has a higher structural reliability and electrical performance.

[0085] As for the distribution of the first interconnection structure on the target surface, it can be determined based on the distribution and number of the above-mentioned collecting electrodes and / or bus electrodes on the target surface, as long as it can be applied to the solar cell provided in the embodiment of the present application.

[0086] For example, as shown in Figures 2 and 4, the distance between the geometric center of the first interconnect structure 13 intersecting the target line segment and the centerline of the solar cell along the second direction is defined as D3 (not shown in the figures). In this application, the centerline along the second direction refers to the centerline extending along the first direction and located at the middle position of the second direction; and the distance between the geometric center of the first interconnect structure 13 intersecting the target line segment and the edge of the solar cell along the second direction is defined as D4 (not shown in the figures). Based on this, D3>D4 for at least one first interconnect structure 13. In this case, the distance between the geometric center of the first interconnect structure 13 intersecting the target line segment and the edge of the solar cell along the second direction is smaller, which helps prevent the first interconnect structures 13 intersecting the target line segment from being densely distributed at the centerline of the solar cell along the second direction, reducing the risk of cracking at the intersection of the centerline of the solar cell along the second direction and the target line segment after interconnection, and further improving the structural reliability of the photovoltaic module formed based on the solar cell. Secondly, as the number of first interconnect structures 13 increases, it is possible to achieve a balance between the uniformity of current collection by the collector electrode 12 and the feasibility of interconnecting adjacent solar cells, which helps improve the performance of the photovoltaic module. It should be noted that the situation of D3>D4 corresponding to at least one first interconnect structure 13 is applicable to busbar-free solar cells, busbar-equipped solar cells, back-contact substrate structures, and double-sided contact substrate structures.

[0087] Of course, as shown in Figures 9 and 11, the distance D3 between the geometric center of the first interconnect structure 13 intersecting the target line segment and the midline of the solar cell along the second direction may also be less than or equal to the distance D4 between the geometric center of the first interconnect structure 13 intersecting the target line segment and the edge of the solar cell along the second direction. The specific values ​​of D3 and D4 can be determined based on the distribution of the first interconnect structure 13 and the collector electrode 12 on the target surface and are not specifically limited here.

[0088] In addition, the embodiments of the present application do not specifically limit the structure and materials of the battery body, which can be determined according to the type of solar cell and the actual application scenario, as long as they can be applied to the solar cell provided in the embodiments of the present application.

[0089] For example, when the solar cell provided in an embodiment of the present application has a double-sided contact substrate structure, the cell body may include at least a semiconductor substrate, a first doped semiconductor layer, and a second doped semiconductor layer. One of the first doped semiconductor layer and the second doped semiconductor layer is formed on a side of the semiconductor substrate corresponding to the front surface, and the other is formed on a side of the semiconductor substrate corresponding to the back surface. Furthermore, the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types.

[0090] The semiconductor substrate may be a substrate made of any semiconductor material, such as a silicon substrate, a silicon germanium substrate, a germanium substrate, or a gallium arsenide substrate, etc. The conductivity type of the semiconductor substrate may be N-type, P-type, or intrinsic type.

[0091] For the above-mentioned first doped semiconductor layer and second doped semiconductor layer, the material of the first doped semiconductor layer and / or the second doped semiconductor layer may include any semiconductor material such as silicon, silicon germanium or germanium. In terms of the arrangement of the material, the crystal phase of the first doped semiconductor layer and / or the second doped semiconductor layer may be amorphous, microcrystalline, nanocrystalline, single crystal or polycrystalline, etc. In terms of conductivity type, the conductivity type of the first doped semiconductor layer may be N-type, in which case the conductivity type of the second doped semiconductor layer is P-type; or the conductivity type of the first doped semiconductor layer may be P-type, in which case the conductivity type of the second doped semiconductor layer is N-type. As for the thickness of the first doped semiconductor layer and the second doped semiconductor layer, it can be set according to actual needs and is not specifically limited here. For example, the thickness of the first doped semiconductor layer or the second doped semiconductor layer may be greater than or equal to 100nm and less than or equal to 500nm.

[0092] Exemplarily, the solar cell has a back-contact substrate structure, and the cell body may include at least a semiconductor substrate, a first doped semiconductor layer, and a second doped semiconductor layer. The first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types, and are both disposed on one side of the corresponding back side of the semiconductor substrate. At least a portion of the first doped semiconductor layer is separated from at least a portion of the second doped semiconductor layer. Information such as the materials and thicknesses of the semiconductor substrate, the first doped semiconductor layer, and the second doped semiconductor layer can be found in the previous text and will not be repeated here.

[0093] The battery body has a first and second opposing sides, where the first side of the battery body can correspond to the front side of the solar cell, and the second side of the battery body can correspond to the back side of the solar cell. In this case, because the connecting wire is provided on the target side of the battery body, the specific target side, whether the first side or the second side of the battery body is the target side, or whether both the first side and the second side are the target sides, can be determined based on the type of solar cell and the actual application scenario.

[0094] When the solar cell has a double-sided contact substrate structure, the target surface of the cell body can be only the first surface of the cell body, only the second surface of the cell body, or both the first and second surfaces of the cell body. When the solar cell has a back-contact substrate structure, the target surface of the cell body is the one of the first and second surfaces of the cell body that corresponds to the back surface of the solar cell.

[0095] Secondly, it should be noted that, when the vertex angle of the target surface is a sharp angle, the target line segment can be a line segment connecting the midpoint of one of two edges of the target surface extending along the first direction and being relatively distributed and the vertex angle endpoint corresponding to the other edge. When the vertex angle of the target surface is a chamfer with a smooth transition or the like, the target line segment can be a line segment connecting the midpoint of the longer of the two edges of the target surface extending along the first direction and being relatively distributed (i.e., the non-chamfered edge) and the vertex angle endpoint corresponding to the shorter of the two edges (i.e., the chamfered edge) (the vertex angle endpoint being the endpoint of the chamfer extension line).

[0096] Furthermore, the specific structure and distribution of the electrode structure formed on the target surface of the solar cell may be determined according to the type of the solar cell.

[0097] For example, as shown in FIG2 , along the second direction, the target surface includes a middle region and an edge region. At least a portion of the collector electrode 12 located in the edge region is in electrical contact with the first interconnect structure 13. In this case, when the solar cell is a busbar-less solar cell, at least a portion of the collector electrode 12 located in the middle region is in contact with the second interconnect structure. Carriers collected by the corresponding collector electrode 12 can be directly transferred to and conducted out of the intra-string interconnect, such as the solder ribbon, through the first interconnect structure 13 in contact with the collector electrode, without having to be transferred to the first interconnect structure 13 and the intra-string interconnect through the busbar electrode. This eliminates carrier transmission losses on the busbar electrode, reduces shading losses, and improves the operating efficiency of the solar cell. When the solar cell is a busbar-equipped solar cell, at least a portion of the collector electrode 12 located in the middle region is in contact with the first interconnect structure 13. The contact between at least a portion of the collector electrode 12 located in the edge and middle regions and the first interconnect structure 13 can improve interconnection strength. For example, the size of the first interconnect structure 13 located in the middle region is smaller than that of the first interconnect structure 13 located in the edge region.

[0098] Specifically, the size of the first interconnect structure on the edge region being larger than the size of the first interconnect structure in the middle region may mean that: along the first direction, only the length of the first interconnect structure on the edge region is larger than the length of the first interconnect structure in the middle region; or, it may mean that along the second direction, only the width of the first interconnect structure on the edge region is larger than the width of the first interconnect structure in the middle region; or, it may mean that the length and width of the first interconnect structure on the edge region are respectively larger than the length and width of the first interconnect structure on the middle region.

[0099] In the target surface, the area between the two first interconnect structures located at the edge along the second direction (i.e., there is a first interconnect structure located at the edge at each end along the second direction) and the edge of the battery body is defined as the edge area of ​​the target surface, and the remaining area is defined as the middle area of ​​the target surface. In addition, in the above case, when the solar cell has a double-sided contact base structure, the polarity of the different collector electrodes located on the same target surface is the same (all collector electrodes included in the positive electrode or negative electrode). In this case, if the solar cell is a busbar-less solar cell, the number of all connecting lines includes the sum of the number of connecting lines intersecting with the first interconnect structures of the same polarity, that is, the number of connecting lines formed by the first interconnect structures contacting the collector electrodes; secondly, the number of first interconnect structures intersecting with the target line segment located within the target surface also includes the number of first interconnect structures contacting the collector electrodes of the same polarity and intersecting with the target line segment. If the solar cell is a busbar-supported solar cell, the number of all connecting lines includes the sum of the number of busbar electrodes of the same polarity; secondly, the number of first interconnect structures intersecting with the target line segment located within the target surface also includes the number of first interconnect structures contacting the busbar electrodes of the same polarity and intersecting with the target line segment.

[0100] In the case of a solar cell with a back-contact substrate structure, all collector electrodes located on the same target surface include a first collector electrode and a second collector electrode of opposite polarity. The first collector electrode and the second collector electrode are alternately spaced along the second direction to prevent leakage; at least a portion of the first collector electrode in the edge region contacts the first interconnect structure, and at least a portion of the second collector electrode in the edge region electrically contacts the first interconnect structure. Specifically, the first collector electrode can be a collector electrode included in the positive electrode, in which case the second collector electrode is a collector electrode included in the negative electrode; alternatively, the first collector electrode can be a collector electrode included in the negative electrode, in which case the second collector electrode is a collector electrode included in the positive electrode. In the above case, when the solar cell is a busbar-less solar cell, the number of all connecting lines includes the sum of the number of connecting lines intersecting with the first interconnect structures of both polarities, i.e., the sum of the number of first connecting lines formed by the first interconnect structures contacting the first collector electrode and the number of second connecting lines formed by the first interconnect structures contacting the second collector electrode. Furthermore, the number of first interconnect structures intersecting with a target line segment located within the target surface also includes the sum of the first interconnect structures of both polarities intersecting with the target line segment located within the same target surface, i.e., the sum of the number of first interconnect structures contacting the first collector electrode and the target line segment, and the sum of the number of first interconnect structures contacting the second collector electrode and the target line segment. When the solar cell is a busbar-equipped solar cell, the number of all connecting lines includes the sum of the number of busbars of both polarities. Furthermore, the number of first interconnect structures intersecting with the target line segment located within the target surface also includes the number of first interconnect structures directly contacting the busbars of both polarities and the target line segment.

[0101] In addition, the solar cell provided in the embodiment of the present application may only include a first interconnect structure. The sizes of different first interconnect structures may be the same or different. For example: as shown in Figures 3 and 4, in the case where the solar cell is a main grid solar cell, the sizes of different first interconnect structures 13 may be the same. For another example: in the case where the solar cell is a main grid solar cell, the sizes of different first interconnect structures may also be different, and the size difference between the first interconnect structures of different sizes is small (such as along the second direction, the ratio between the size of the larger first interconnect structure and the size of the smaller first interconnect structure is greater than 1 and less than 2); optionally, along the second direction, the target surface includes a middle area and an edge area, the larger first interconnect structure may be arranged in the edge area, and the smaller first interconnect structure may be arranged in the middle area.

[0102] Alternatively, in the case where the solar cell is a busbar-less solar cell, as shown in Figures 2, 13, and 14, the solar cell may further include a second interconnect structure 14 disposed on the target surface. Each second interconnect structure 14 is electrically connected to at least one collector electrode 12, and the size of the second interconnect structure 14 is smaller than that of the first interconnect structure 13. At least part of the second interconnect structure 14 is located on the same straight line and is collinear with the connecting line. Furthermore, among all the collector electrodes 12 located on the same target surface, some of the collector electrodes 12 are in contact with the first interconnect structure 13, and the remaining collector electrodes 12 are in contact with the second interconnect structure 14, so that the carriers collected by the collector electrodes 12 located on the same target surface are respectively extracted through the first interconnect structure 13 and the second interconnect structure 14. In this case, among all the collecting electrodes 12 located on the same target surface, some of the collecting electrodes 12 are in contact with the first interconnection structure 13 with a larger size, so as to increase the contact area between the part of the collecting electrodes 12 and the interconnection parts in the string, which is beneficial to reducing the contact resistance between the interconnection parts in the string and the collecting electrodes 12, and is beneficial to improving the connection strength between the interconnection parts in the string and the collecting electrodes 12. Secondly, the remaining collecting electrodes 12 are in contact with the second interconnection structure 14 with a smaller size, so as to reduce the metal composite loss on one side of the target surface and improve the working efficiency of the solar cell. For example, the collecting electrodes 12 in the edge area are in contact with the first interconnection structure 13 with a larger size, and the collecting electrodes 12 in the middle area are in contact with the first interconnection structure 13 with a smaller size. The second interconnection structure 14 can be a thickened section of the collecting electrode 12 or a design for auxiliary electrical connection. For a main grid-free solar cell, the size difference between the first interconnection structure 13 and the second interconnection structure 14 is large.

[0103] Specifically, the size of the first interconnect structure being larger than the size of the second interconnect structure may mean that: along the first direction, only the length of the first interconnect structure is larger than the length of the second interconnect structure; or, it may mean that along the second direction, only the width of the first interconnect structure is larger than the width of the second interconnect structure; or, it may mean that the length and width of the first interconnect structure are respectively larger than the length and width of the second interconnect structure.

[0104] It should be noted that for the high-temperature process of manufacturing solar cells, the sintering temperature of the electrodes is generally above 600°C. During the sintering and cooling process, due to the difference in thermal expansion coefficients, stress will exist between the larger first interconnection structure and the smaller second interconnection structure and the battery body. When the stress is too large, the battery will easily crack. Although the size of the above-mentioned second interconnection structure is relatively small, for busbar-less solar cells, the distribution density of the second interconnection structure on the target surface may be large, which will aggravate the formation of hidden cracks inside the busbar-less solar cell and bring the hidden danger of battery cracking. Therefore, the specific sizes of the first interconnection structure and the second interconnection structure, as well as the distribution of the second interconnection structure on the target surface, can be determined according to the yield requirements of the solar cell in the actual application scenario, and no specific restrictions are made here.

[0105] For example, when the solar cell is a busbar-less solar cell, the number of second interconnect structures intersecting the target line segment or the vector line segment with an inclination angle of 45° is defined as N7. And / or, N7<N1. For example, N7 may be equal to 0.35N1, 0.4N1, 0.5N1, 0.6N1, 0.7N1, 0.8N1 or 0.9N1. In this case, the number N7 of the second interconnect structures intersecting the target line segment or the vector line segment with an inclination angle of 45° is greater than , the second interconnect structure can be made to have a larger distribution density on the target surface to ensure sufficient interconnection strength. In addition, for the high-temperature process of manufacturing solar cells, the sintering temperature of the electrodes is generally above 600°C. During the sintering and cooling process, due to the difference in thermal expansion coefficient, stress will exist between the larger first interconnect structure and the smaller second interconnect structure and the battery body. When the stress is too large, the battery will easily crack. Although the size of the above-mentioned second interconnect structure is relatively small, for a busbar-less solar cell, the distribution density of the second interconnect structure on the target surface may be large, which will aggravate the formation of hidden cracks inside the busbar-less solar cell and bring the hidden danger of battery cracking. Based on this, when N7 is less than N1, it can be ensured that the second interconnection structures on at least one connecting line on the target surface that can intersect with the target line segment (or a vector line segment with an inclination angle of 45°) are not arranged on the target line segment (or a vector line segment with an inclination angle of 45°). Therefore, after the adjacent solar cells are interconnected along the extension direction of the connecting line through the intra-string interconnection member, all corresponding second interconnection structures intersecting with at least one intra-string interconnection member will not generate sintering stress on the target line segment, thereby reducing the sintering stress formed along the extension direction of the target line segment, preventing the risk of solar cells from cracking due to the large distribution density of the second interconnection structure on the target surface, and ensuring that the solar cells have a high yield.

[0106] For example, in the case of a busbar-less solar cell, along the second direction, the size of the second interconnect structure is L1, and the size of the first interconnect structure is L2, where 9L1>L2>3L1. In this case, the smaller size of the second interconnect structure can be prevented from resulting in a smaller interconnection area between the solar cell and the intra-string interconnect, thereby ensuring a higher interconnection strength between the two. Furthermore, the larger size of the second interconnect structure can be prevented from resulting in higher slurry consumption, metal cladding, and larger light-shielding areas in the manufacture of the first and second interconnect structures, thereby reducing the manufacturing cost of the solar cell and improving the conversion efficiency of the solar cell.

[0107] It should be noted that when the solar cell provided in the embodiments of the present application is a busbarless solar cell, the thickness and cross-sectional area of ​​the second interconnect structure can be determined based on the actual application scenario and are not specifically limited here. In addition, when the solar cell is a busbarless solar cell, the solar cell may also include only the above-mentioned first interconnect structure without including the second interconnect structure.

[0108] For example, as shown in FIG4 , the solar cell may further include a bus electrode 16 disposed on the target surface. Different bus electrodes 16 located on the same target surface extend along the second direction and are spaced apart along the first direction. Each bus electrode 16 is electrically connected to a collector electrode 12 having the same polarity as itself and is in contact with at least one first interconnect structure 13. Different bus electrodes 16 correspond one-to-one to different connecting lines. In this case, the solar cell provided in the embodiment of the present application is a "main grid solar cell". Based on this, in actual application, the line width of the collector electrode 12 is usually small to reduce its own shading area, but this will make the collector electrode 12 relatively easy to break. The presence of the bus electrode 16 can enable the carriers collected by the collector electrode 12 on both sides of the break to be transmitted and conducted to the bus electrodes 16 connected thereto, thereby improving the current collection capability and reducing power loss.

[0109] In the above case, if the solar cell has a double-sided contact substrate structure, the busbar electrodes located on the same target surface are electrically connected to all the collecting electrodes. If the solar cell has a back-contact substrate structure, the collecting electrodes include a first collecting electrode and a second collecting electrode with opposite polarities, and the first collecting electrode and the second collecting electrode are alternately spaced along the second direction; the busbar electrodes include a first busbar electrode and a second busbar electrode with opposite polarities, and the first busbar electrode and the second busbar electrode are alternately spaced along the first direction; and the busbar electrodes and the collecting electrodes with opposite polarities are insulated from each other. Specifically, the bus electrode and the collecting electrode can both be continuous electrodes, and in this case the bus electrode can be electrically insulated from the collecting electrode of the opposite polarity to itself by an insulating material such as an insulating glue; or the collecting electrode can be a discontinuous collecting electrode, and the bus electrode can be a continuous bus electrode, and the bus electrode can be electrically insulated from the collecting electrode of the opposite polarity to itself by the discontinuity of the discontinuous collecting electrode; or, the bus electrode can be a discontinuous bus electrode, and the collecting electrode can be a continuous collecting electrode, and the collecting electrode can be electrically insulated from the bus electrode of the opposite polarity to itself by the discontinuity of the discontinuity. The positive electrode of the back-contact matrix structure can include the above-mentioned first collecting electrode and the first bus electrode, and in this case the negative electrode of the back-contact matrix structure can include the above-mentioned second collecting electrode and the second bus electrode; or the negative electrode of the back-contact matrix structure can include the above-mentioned first collecting electrode and the first bus electrode, and in this case the positive electrode of the back-contact matrix structure can include the above-mentioned second collecting electrode and the second bus electrode.

[0110] It should be noted that the collector electrode included in the positive electrode has opposite polarity to the collector electrode included in the negative electrode, and the first interconnect structure (or second interconnect structure) electrically connected to the collector electrode included in the negative electrode. Furthermore, if the solar cell is a "busbar solar cell," the bus electrode included in the positive electrode has opposite polarity to the collector electrode included in the negative electrode, the bus electrode included in the negative electrode, and the first interconnect structure electrically connected to the bus electrode included in the negative electrode.

[0111] In addition, the embodiment of the present application does not specifically limit the number and morphology of the collecting electrodes included in the solar cell, nor the spacing between adjacent collecting electrodes. Specifically, the spacing between different pairs of collecting electrodes may be equal or unequal. It can be understood that when the size of the collecting electrode is a fixed value, the carrier collection range corresponding to the collecting electrode is fixed. At this time, as shown in Figures 2 and 4, the spacing between different pairs of collecting electrodes 12 is equal, so that along the second direction, different collecting electrodes 12 are evenly distributed, which helps to prevent at least one of the pair of collecting electrodes 12 from having difficulty in collecting and exporting carriers within a larger spacing range in a timely manner due to the spacing between two adjacent collecting electrodes 12 with the same polarity in at least one pair of collecting electrodes 12 being greater than the spacing between two adjacent collecting electrodes 12 with the same polarity in the remaining pairs of collecting electrodes 12, thereby ensuring that one side of the target surface has a lower carrier recombination rate. At the same time, it is also beneficial to prevent the situation where the spacing between two adjacent collecting electrodes 12 with the same polarity in at least one pair of collecting electrodes 12 is smaller than the spacing between two adjacent collecting electrodes 12 with the same polarity in the remaining pairs of collecting electrodes 12, resulting in a larger distribution density of the collecting electrodes 12 on some areas on one side of the target surface, resulting in a larger shading area of ​​the collecting electrodes 12 and a larger metal composite loss between the collecting electrodes 12 and the battery body 11, which is beneficial to improving the photoelectric conversion efficiency of the solar cell.

[0112] Secondly, in the case where the solar cell provided in the embodiment of the present application includes a bus electrode, the number and morphology of the bus electrodes, and the spacing between adjacent bus electrodes in the embodiment of the present application can be determined based on the number and morphology of the connecting wires, and the spacing between adjacent connecting wires in the actual application scenario, and no specific limitation is made here.

[0113] The specific directions referred to in the first and second directions can be determined based on actual needs, as long as they can be applied to the solar cell provided in the embodiments of the present application. For example, when the target surface is rectangular, the rectangle has alternating first and second sides. The first direction can be parallel to the first side of the rectangle, and the second direction can be parallel to the second side of the rectangle.

[0114] In actual applications, as shown in Figures 2 and 12 , in the case of a busbarless solar cell, the collector electrode 12 in contact with the first interconnect structure 13 is defined as a connecting electrode 15. The spacing between two adjacent connecting electrodes 15 along the second direction is defined as D1. At least one connecting electrode 15 located in the edge region contacts multiple first interconnect structures 13, and different first interconnect structures 13 electrically contacting the connecting electrode 15 are spaced apart along the first direction. The geometric center spacing between two adjacent first interconnect structures 13 in contact with the connecting electrode 15 is defined as D2. In this case, it is understood that different connecting electrodes 15 are positioned differently on the target surface. Accordingly, the first interconnect structures 13 electrically contacting different connecting electrodes 15 are positioned differently on the target surface. The positioning of the first interconnect structures 13 on the target surface affects the value of N2. For example, a smaller second interconnect structure 14 may be positioned between the two connecting electrodes 15 in Figure 12 , electrically connecting to the collector electrode 12 between the two connecting electrodes 15. In the above case, among all the collecting electrodes 12 located on the same target surface, which part of the collecting electrodes 12 is electrically in contact with the first interconnection structure 13, and which part of the collecting electrodes 12 is electrically in contact with the second interconnection structure 14 can be determined according to the size requirements of N2 in the actual application scenario, and no specific limitation is made here.

[0115] For example, in the case where the solar cell is a busbar-less solar cell, the two end first interconnect structures located in the edge region are electrically contacted with the collecting electrodes located in the edge region, and the second interconnect structure located in the middle region is electrically contacted with the collecting electrode located in the middle region. At this time, D1 is the distance between the two collecting electrodes that are in contact with the first interconnect structure located at the end and are adjacent along the second direction, and D2 is the distance between the geometric centers of the two first interconnect structures adjacent in the first direction.

[0116] Next, as shown in Figures 4 and 7 , when the solar cell is a busbar solar cell, the busbar electrode 16 is defined as a connecting electrode 15. Furthermore, the spacing between two adjacent connecting electrodes 15 along the first direction is defined as D1. At least one connecting electrode 15 is in contact with multiple first interconnect structures 13, and different first interconnect structures 13 in contact with the same connecting electrode 15 are spaced apart along the second direction. The spacing between the geometric centers of two adjacent first interconnect structures 13 in contact with the same connecting electrode 15 is defined as D2.

[0117] For example, in the case of a busbar solar cell, the first interconnect structures at the two ends of the edge region are relatively large and electrically contact the collector electrode located in the edge region, while the first interconnect structures in the middle region are relatively small and electrically contact the collector electrode located in the middle region. In this case, D1 is the distance between two adjacent bus electrodes along the first direction. D2 is the distance between the geometric centers of two adjacent first interconnect structures along the first direction that are in contact with the same bus electrode.

[0118] In the above situation, in the solar cell, first interconnect structures that contact different connecting electrodes and are located in the same layer are aligned along a first direction to reduce the connection difficulty of automatic interconnection equipment such as stringers that interconnect adjacent solar cells. Based on this, as shown in Figures 7 and 12, if D2 corresponding to each pair of first interconnect structures 13 is equal to D1, then the inclination angle of the line connecting a first interconnect structure 13 of a certain layer disposed on each connecting electrode 15 and the first interconnect structure 13 of an adjacent layer disposed on an adjacent connecting electrode 15 is equal to 45°, thereby making N3 corresponding to each vector line segment with a 45° inclination angle equal to N4. When D2 corresponding to at least one pair of first interconnect structures is not equal to D1, the inclination angle of the line between a certain layer of first interconnect structure arranged on a certain connecting electrode and an adjacent layer of first interconnect structure arranged on an adjacent connecting electrode is not equal to 45°, so that the inclination angle of the interconnection stress band corresponding to the pair of first interconnect structures is not equal to 45°, which is beneficial to shortening the length of the interconnection stress band formed in the extension direction of the vector line segment with an inclination angle of 45°, and is also beneficial to shortening the length of the interconnection stress band formed along the cleavage plane direction, thereby reducing the risk of cracking problems in solar cells after being subjected to external force due to the long interconnection stress band, and improving the structural reliability of photovoltaic modules formed based on solar cells.

[0119] Specifically, it can be understood that, when the length of the connecting electrode is fixed, the greater the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures, the greater the spacing between the two adjacent first interconnect structures intersecting the same connecting electrode. Conversely, the smaller the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures, the smaller the spacing between the two adjacent first interconnect structures intersecting the same connecting electrode. However, when the ratio is closer to 1, the inclination angle of the connection line between the pair of first interconnect structures is closer to 45°, that is, closer to the extension direction of the cleavage plane. In the above case, when D2 corresponding to at least one pair of first interconnect structures is not equal to D1, the specific ratio of D2 to D1 can be determined based on at least the inclination angle of the interconnect stress band formed after interconnection in the actual application scenario, and the transmission loss of carriers on the bus electrode, and is not specifically limited here.

[0120] For example, in the case of a busbar solar cell, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures can be greater than or equal to 1 and less than or equal to 1.7. For example, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures can be 1, 1.06, 1.1, 1.12, 1.14, 1.16, 1.2, 1.3, 1.4, 1.5, 1.6, or 1.7. In this case, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures being within the above range helps prevent the extension direction of the interconnect stress band corresponding to the at least one pair of first interconnect structures from approaching the extension direction of the cleavage plane due to a small ratio, thereby ensuring that the length of the interconnect stress band formed along the cleavage plane can be shortened. It also helps prevent the spacing between two adjacent first interconnect structures intersecting the same connecting electrode from being large due to a large ratio, which can lead to large carrier transmission losses on the connecting electrode, thereby improving the operating efficiency of the solar cell.

[0121] For example, when the solar cell is a busbar-less solar cell, the ratio of D1 to D2 corresponding to at least one pair of first interconnect structures may be greater than or equal to 6 and less than or equal to 12. For example, the ratio of D1 to D2 corresponding to at least one pair of first interconnect structures may be 6, 7, 8, 9, 10, 11, or 12.

[0122] In addition, in actual applications, the spacing between two adjacent first interconnect structures in all first interconnect structures contacting the same connecting line can be equal or unequal. Along the second direction, the spacing between the geometric centers of two adjacent first interconnect structures in all first interconnect structures contacting the same connecting line affects the number of pairs of collector electrodes disposed between the geometric centers of the two adjacent first interconnect structures. Each pair of collector electrodes includes two collector electrodes having the same polarity as the corresponding first interconnect structure and adjacent to each other along the second direction. Specifically, when the spacing between different pairs of collector electrodes is equal, if the spacing between the geometric centers of two adjacent first interconnect structures is equal, then the number of pairs of collector electrodes between the geometric centers of the two adjacent first interconnect structures is also equal; conversely, if the spacing between the geometric centers of two adjacent first interconnect structures is unequal, then the number of pairs of collector electrodes between the geometric centers of the two adjacent first interconnect structures is also unequal. In the above case, the spacing between the geometric centers of the two adjacent first interconnect structures can be controlled by adjusting the number of collector electrodes located between the geometric centers of the two adjacent first interconnect structures, thereby achieving regulation of the extension direction of the interconnection stress band formed by the two adjacent first interconnect structures after interconnection.

[0123] In a second aspect, embodiments of the present application provide another solar cell. Specifically, the solar cell provided in embodiments of the present application can be any cell that can convert solar light energy into electrical energy.

[0124] In terms of the placement of the positive and negative electrodes, the solar cell provided in the embodiments of the present application may have a double-sided contact substrate structure, i.e., one of the positive and negative electrodes of the solar cell is disposed on the front side of the solar cell, and the other is disposed on the back side. Alternatively, the solar cell provided in the embodiments of the present application may have a back-contact substrate structure, i.e., both the positive and negative electrodes of the solar cell are disposed on the back side of the solar cell.

[0125] In terms of the specific electrode structure of the positive electrode and the negative electrode, the solar cell provided in the embodiment of the present application can be a "busbar solar cell"; in this case, the solar cell includes not only a collecting electrode but also a bus electrode, and different bus electrodes correspond one-to-one to different connecting lines. Alternatively, the solar cell provided in the embodiment of the present application can also be a "busbarless solar cell"; in this case, the busbarless solar cell does not have the bus electrode of the above-mentioned busbar solar cell; specifically, the electrode structure of the busbarless solar cell can include only a collecting electrode, or can also include a collecting electrode and a bus electrode segment that plays a busbar role (the bus electrode segment can be electrically connected to the first interconnect structure located at the edge along the second direction and extend toward the edge of the battery body along the second direction). There is no limitation on the specific shape of the bus electrode segment, for example, it can be a straight line, a curve, or a harpoon structure.

[0126] Specifically, as shown in Figures 1 and 3, the solar cell includes: a cell body 11, a collecting electrode 12, and a first interconnection structure 13. The cell body 11 has a first surface and a second surface opposite to each other. At least one of the first surface and the second surface is a target surface. The collecting electrode 12 is arranged on the target surface. Different collecting electrodes 12 located on the same target surface all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structures 13 form an array on the target surface. Each first interconnection structure 13 is electrically connected to at least one collecting electrode 12. At least part of the areas of different first interconnection structures 13 spaced apart along the second direction are located on the same connecting line, and different connecting lines are spaced apart along the first direction. The number of connecting lines located in the same target surface is N1, and the number of first interconnection structures 13 intersecting with a target line segment located in the target surface is N2, N1>N2, and the target line segment is a diagonal line of the target surface and intersects with each connecting line. It should be noted that the situation of N1>N2 is applicable to solar cells without a busbar, solar cells with a busbar, back-contact substrate structures, and double-sided contact substrate structures.

[0127] Specifically, the number N1 of connecting lines refers to the number of connecting lines in each battery cell (generally, the number of connecting lines in two battery cells is the same), and the number N1 of connecting lines is a positive integer greater than or equal to 1. The number N2 of first interconnect structures intersecting with the target line segment located within the target surface is an integer greater than or equal to 0. The specific values ​​of the number N1 of connecting lines and the number N2 of first interconnect structures intersecting with the target line segment located within the target surface can be determined based on the actual application scenario and are not specifically limited here.

[0128] When the above technical solution is employed, the target line segment is a diagonal line of the target surface and intersects each connecting line. Furthermore, when N2 < N1, it is ensured that none of the first interconnect structures electrically contacting each of the at least one connecting line on the target surface that can intersect the target line segment are disposed on the target line segment. Consequently, after adjacent solar cells are interconnected along the extending direction of the connecting line via the intra-string interconnectors, all corresponding first interconnect structures electrically contacting each of the at least one intra-string interconnectors will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress generated along the extending direction of the target line segment. In this case, the diagonal lines within the surface of the semiconductor wafer used to manufacture solar cells are roughly parallel to the cleavage planes. Cleavage planes are planes that break strictly along a specific crystallographic direction under external force, leaving smooth, flat surfaces. Corresponding to silicon wafers, wire-slicing a single-crystal silicon ingot produces nearly square wafers. The cleavage planes intersect the wafer surface and are not parallel to the wafer edge. It can be understood that the ingot contains countless mutually parallel cleavage planes, which form countless mutually parallel target line segments with the wafer surface. The target line segments corresponding to the diagonals of the wafer are the longest and face greater stress challenges. Therefore, when the target line segments are diagonals of the target surface, the extension direction of the target line segments is roughly parallel to the direction of the cleavage planes of the cell body. In this case, reducing the interconnect stress generated along the extension direction of the target line segments is equivalent to reducing the interconnect stress generated along the cleavage planes, reducing the risk of solar cell cracking caused by excessive interconnect stress, thereby improving the structural reliability of photovoltaic modules based on solar cells.

[0129] It should be noted that, as can be seen from the above description, the solar cell provided in the first aspect of the embodiment of the present application is a half-sheet solar cell. The solar cell provided in the second aspect of the embodiment of the present application is a whole-sheet solar cell. In this case, the solar cell provided in the first aspect of the embodiment of the present application can be regarded as being obtained by cutting the solar cell provided in the second aspect of the embodiment of the present application into half a sheet. Based on this, the structure and materials of the cell body in the solar cell provided in the second aspect of the embodiment of the present application, as well as the distribution of the collector electrode and the first interconnection structure, can be referred to in the above description and will not be repeated here.

[0130] The following describes only the differences between the solar cell provided in the second aspect of the embodiment of the present application and the solar cell provided in the first aspect of the embodiment of the present application:

[0131] Specifically, in the solar cell provided in the second aspect of the embodiment of the present application, the specific distribution position of the target line segment within the target surface can be determined based on the distribution of the intersection line segments between the cleavage plane of the cell body and the target surface, as well as the shape of the target surface, and is not specifically limited here. Specifically, when the top angle of the target surface is a sharp angle, the target line segment can be a line segment connecting the diagonal endpoints of the target surface. When the top angle of the target surface is a chamfer with a smooth transition, the target line segment can be a line segment connecting the endpoints of the diagonal extension line of the target surface.

[0132] In addition, in actual applications, as shown in Figures 1 and 3, the number of connecting lines that intersect the target line segment is defined as N3. Based on this, N3>N2. In this case, the target line segment only intersects with the extension of at least one connecting line, so that interconnection stress is not generated at this intersection, ensuring that the interconnection stress formed along the extension direction of the target line segment can be reduced. In other words, it is beneficial to shorten the length of the interconnection stress band formed along the cleavage plane, further reducing the risk of solar cells cracking after being subjected to external forces due to long interconnection stress bands, and improving the structural reliability of photovoltaic modules formed based on solar cells. Secondly, the number of connecting lines on the target surface, N1, is greater than or equal to the number of connecting lines that intersect with the target line segment, N3. In this case, when part of the first interconnect structure included in the solar cell is arranged at the edge of the target surface along the first direction and its connecting lines do not intersect with the target line segment, N1 is greater than N3; or when the four vertex corners of the target surface have large chamfers, some of the connecting lines pass through the chamfers, in which case N1 may be greater than N3. When all the first interconnect structures included in the solar cell are arranged in the middle of the target surface along the first direction, N1 is equal to N3; or, when the four top corners of the target surface have no chamfers or have small chamfers, all connecting lines do not pass through the chamfers, in which case N1 may be equal to N3.

[0133] Secondly, the distribution of the collecting electrodes between different first interconnect structures and the distribution between the first interconnect structure at the edge and the boundary of the battery body along the second direction can be determined according to the sizes of N1 and N2 in the actual application scenario, and no specific limitation is given here.

[0134] For example, as shown in Figures 1 and 3, the solar cell may include M slice battery cells spaced apart along the second direction, where M is a positive integer greater than or equal to 1. In the same slice battery cell, the geometric centers of the two first interconnecting structures 13 located at the edge along the second direction are symmetrically arranged relative to the midline of the slice battery cell along the second direction. In this case, for the same slice battery cell, the geometric centers of the two first interconnecting structures 13 located at the edge along the second direction are symmetrically arranged relative to the midline of the slice battery cell along the second direction, which facilitates automatic interconnection equipment such as a string welding machine to interconnect different slice battery cells at the same starting position, preventing misalignment between the intra-string interconnection members such as welding ribbons and the first interconnection structures 13 provided on the battery body 11 due to the different starting positions corresponding to different slice battery cells, thereby causing carriers on the connection lines corresponding to the first interconnection structures 13 that are not electrically connected to the intra-string interconnection members to be unable to be conducted through the intra-string interconnection members, resulting in power loss, or causing the corresponding first interconnection structures 13 to become a load, resulting in reduced efficiency of the solar cell, thereby ensuring that the photovoltaic module formed by the solar cell provided by the embodiment of the present application has good operating performance. Of course, for the same slice battery cell, the geometric centers of the two first interconnect structures 13 located at the edge along the second direction and the number of pairs of collector electrodes 12 between the edges of the slice battery cell can also be set asymmetrically to reduce manufacturing requirements. It should be noted that in the same slice battery cell, the situation where the geometric centers of the two first interconnect structures 13 located at the edge along the second direction are symmetrically arranged relative to the midline of the slice battery cell along the second direction is applicable to both busbar-free solar cells, busbar-equipped solar cells, back-contact substrate structures, and double-sided contact substrate structures.

[0135] For example, when the number of first interconnect structures located on the same connection line is an odd number, along the second direction, in the same slice battery cell, except for the first interconnect structure located in the middle and the other two first interconnect structures adjacent to the first interconnect structure located in the middle, the remaining first interconnect structures are edge first interconnect structures; the number of pairs of collector electrodes located between the geometric centers of the two adjacent edge first interconnect structures is symmetrically arranged about the central axis of the first interconnect structure located in the middle. Alternatively, when the number of first interconnect structures located on the same connection line is an even number, along the second direction, in the same slice battery cell, except for the pair of first interconnect structures located in the middle, the remaining first interconnect structures are edge first interconnect structures; the number of pairs of collector electrodes 12 located between the geometric centers of the two adjacent edge first interconnect structures is symmetrically arranged about the central axis of the pair of first interconnect structures located in the middle.

[0136] When the above technical solution is adopted, for the same slice battery unit, when the number of first interconnect structures contacted by the same connecting line is an odd number, it is defined that along the second direction, in the same slice battery unit, except for the first interconnect structure located in the middle and the other two first interconnect structures adjacent to the first interconnect structure located in the middle, the remaining first interconnect structures are edge first interconnect structures. In the above case, when the pairs of collector electrodes located between the geometric centers of two adjacent edge first interconnect structures are symmetrically arranged about the central axis of the first interconnect structure located in the middle, it is beneficial to arrange different collector electrodes as evenly as possible between the geometric centers of the two adjacent first interconnect structures along the second direction, thereby facilitating the overlap of the corresponding collector electrodes and the first interconnect structures, maximizing current collection, and facilitating the debugging of the interconnection equipment that interconnects adjacent solar cells to prevent interconnection misalignment. In addition, when the number of pairs of first interconnection structures located on the same connecting line is an even number, along the second direction, in the same segmented battery unit, except for a pair of first interconnection structures located in the middle, the remaining first interconnection structures are edge first interconnection structures; and the beneficial effects of the pairs of collecting electrodes located between the geometric centers of two adjacent edge first interconnection structures being symmetrically arranged about the central axis of the pair of first interconnection structures located in the middle can be referred to the previous text and will not be repeated here.

[0137] The following takes the case where the number of first interconnect structures in contact with the same connecting line is 7 and 92 collecting electrodes with the same polarity (91 pairs of collecting electrodes) are provided in the same slice battery unit as an example. When the number of first interconnect structures in contact with the same connecting line is an odd number, the number of pairs of collecting electrodes located between the geometric centers of two adjacent first interconnect structures in the same slice battery unit along the second direction is explained: the different first interconnect structures intersecting the same connecting line are sorted from top to bottom. At this time, the first interconnect structure located in the middle is the fourth first interconnect structure. In the same slice battery unit, the first to second first interconnect structures, and the sixth to seventh first interconnect structures are edge first interconnect structures. In the above case, the number of pairs of collecting electrodes between the geometric centers of the first and second first interconnect structures is 12 pairs. The number of pairs of collecting electrodes between the geometric centers of the second first interconnect structure and the third first interconnect structure is 11 pairs. The number of pairs of collecting electrodes between the geometric centers of the fifth first interconnect structure and the sixth first interconnect structure is 11 pairs. The number of pairs of current collecting electrodes between the geometric centers of the sixth and seventh first interconnect structures is 12. Along the second direction, the number of pairs of current collecting electrodes between the geometric centers of the first interconnect structures located at the edge (i.e., the first and seventh first interconnect structures) and the edge of the battery body is 11.

[0138] Taking the structures shown in Figures 1 and 3 as an example, the following describes the number of pairs of collector electrodes located between the geometric centers of two adjacent first interconnect structures in the same battery cell along the second direction, when the number of first interconnect structures contacting the same connection line is an even number: As shown in Figures 1 and 3, the number of first interconnect structures 13 contacting the same connection line is 6, and the same battery cell is provided with 27 collector electrodes 12 with the same polarity (26 pairs of collector electrodes 12). The different first interconnect structures 13 intersecting the same connection line are sorted from top to bottom. In this case, the middle pair of first interconnect structures 13 are the third first interconnect structure 13 and the fourth first interconnect structure 13. The first first interconnect structure 13, the second first interconnect structure 13, the fifth first interconnect structure 13, and the sixth first interconnect structure 13 are all edge first interconnect structures. Specifically, the number of pairs of collector electrodes 12 between the geometric centers of the first first interconnect structure 13 and the second first interconnect structure 13 is 4 pairs. The number of pairs of current collecting electrodes 12 between the geometric centers of the fifth and sixth first interconnect structures 13 , 13 is also 4. Along the second direction, the number of pairs of current collecting electrodes 12 between the geometric centers of the first interconnect structures 13 located at the edges (i.e., the first and sixth first interconnect structures 13 , 13 ) and the edges of the battery body 11 is 3.

[0139] In actual applications, the number of first interconnect structures contacting the same connection line is defined as a, the length of the portion of the battery body corresponding to each battery cell along the second direction is defined as b, and the spacing between adjacent collector electrodes of the same polarity is defined as c. Dividing b by c yields the number d1 of pairs of collector electrodes that can be placed on the battery cell. Dividing d1 by (a+1) yields the average number d2 of pairs of collector electrodes that can be placed within the spacing between the geometric centers of two adjacent first interconnect structures corresponding to the same connection line, or between the geometric centers of first interconnect structures located at the edge along the second direction and the edge of the battery body. If d2 is an integer, the spacing between the geometric centers of different pairs of first interconnect structures contacting the same connection line (each pair of first interconnect structures is defined as two adjacent first interconnect structures intersecting the same connection line) is equal. If d2 has a remainder, the spacing between the geometric centers of at least one pair of first interconnect structures contacting the same connection line is not equal to the spacing between the geometric centers of the remaining pairs of first interconnect structures. Specifically, when d2 has a remainder, the actual number of pairs of collector electrodes located between the geometric centers of each pair of first interconnect structures can be set according to the symmetry rule described above, which will not be further described here.

[0140] Exemplarily, when the solar cell is a back-contact base structure and the solar cell includes at least two slice battery units spaced apart and distributed along the second direction, there is a cutting path between two adjacent slice battery units. In addition, the collector electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or the first interconnection structures with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or the bus electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path. In this case, in the two adjacent slice battery units, at least one of the collector electrodes, the first interconnection structure and the bus electrode with opposite polarity is symmetrically arranged about the cutting path, which facilitates the interconnection between the two, prevents misalignment, improves the interconnection yield, and reduces the difficulty of interconnection. It should be noted that the aforementioned situation in which the collector electrodes (and / or the first interconnection structure, and / or the bus electrode) with opposite polarity in the two adjacent slice battery units are symmetrically arranged about the cutting path is applicable to both the back-contact base structures of solar cells without main grids and solar cells with main grids.

[0141] For example, when the target line segment is a diagonal line of the target surface, among all the first interconnect structures intersecting the target line segment, at least two first interconnect structures are symmetrically distributed about the geometric center of the target surface, and the polarity of the symmetrically distributed first interconnect structures can be the same. In this case, the first interconnect structures intersecting the target line segment are evenly distributed, and the interconnection stress generated by the first interconnect structures on the target line segment after interconnection is evenly distributed about the geometric center of the target surface. This prevents the uneven distribution of the first interconnect structures on the target line segment, which results in concentrated interconnection stress in certain areas of the target line segment and a higher risk of rupture of the battery body in those areas, thereby further improving the structural reliability of the photovoltaic module formed based on the solar cell.

[0142] Alternatively, as shown in Figures 8 and 10, when the target line segment is a diagonal line of the target surface, among all the first interconnect structures 13 intersecting the target line segment, at least two first interconnect structures 13 are symmetrically distributed around the geometric center of the target surface, and the polarities of the symmetrically distributed first interconnect structures 13 may also be opposite.

[0143] For example, when a solar cell includes two slice battery cells spaced apart along the second direction, the N2 values ​​corresponding to the two slice battery cells are equal. As shown in FIG10 , in the same slice battery cell, the polarity of the two bus electrodes 16 located on the outside along the first direction is opposite. The polarity of two oppositely disposed bus electrodes 16 located on the outside along the first direction and belonging to different slice battery cells is opposite. In this case, the symmetry between different first interconnect structures 13 with opposite polarity located on the same target surface is improved, and the difficulty of interconnecting adjacent solar cells using automatic interconnection equipment such as stringing machines is reduced.

[0144] It should be noted that the situation described above where the solar cell includes two segmented battery units spaced apart along the second direction and the N2 corresponding to the two segmented battery units are equal is applicable to the back contact substrate structures of both the busbarless solar cell and the busbar solar cell.

[0145] For example, when a solar cell includes two slice battery cells spaced apart along the second direction, the N2 values ​​corresponding to the two slice battery cells are not equal. In the same slice battery cell, the polarity of the two bus electrodes located on the outside along the first direction is the same. The polarity of the two oppositely arranged bus electrodes located on the outside along the first direction, belonging to different slice battery cells, is opposite. In this case, another possible implementation method is provided for the solar cell provided in the embodiment of the present application, thereby improving the applicability of the solar cell provided in the embodiment of the present application in different application scenarios.

[0146] For example, when the polarities of the two outer bus electrodes along the first direction are opposite, at least two of the first interconnect structures intersecting the target line segment can be equidistant from the centerline of the target surface along the second direction and have the same polarity. This improves the uniformity of distribution among different first interconnect structures with the same polarity located on the same target surface, and reduces the difficulty of interconnecting adjacent solar cells using automated interconnection equipment such as stringers.

[0147] Alternatively, as shown in FIG11 , when the polarities of the two bus electrodes 16 located on the outside along the first direction are opposite, among all the first interconnect structures 13 intersecting with the target line segment, the distances between at least two first interconnect structures 13 and the center line of the target surface along the second direction can be equal, and the polarities can also be opposite.

[0148] Exemplarily, in the case where the above-mentioned solar cell is a busbar-less solar cell, the solar cell may further include a second interconnect structure arranged on the target surface. Each second interconnect structure is electrically connected to at least one collecting electrode, and the size of the second interconnect structure is smaller than the size of the first interconnect structure. At least part of the area of ​​the second interconnect structure is located on the same straight line and is collinear with the connecting line. Among all the collecting electrodes located on the same target surface, some of the collecting electrodes are in contact with the first interconnect structure. Exemplarily, the first interconnect structure is located at the two edge areas of the busbar-less solar cell along the second direction; the remaining collecting electrodes are in contact with the second interconnect structure. Exemplarily, the second interconnect structure is located in the middle area of ​​the busbar-less battery along the second direction. The number of second interconnect structures intersecting with the target line segment is N8; wherein, And / or, N8 < 1.5N1. For example, N8 can be equal to 0.6N1, 0.7N1, 0.8N1, 0.9N1, N1, 1.1N1, 1.2N1, 1.3N1 or 1.4N1, etc. The application principle of the beneficial effect in this case can be referred to the above The application principle of the beneficial effect of N7<N1 will not be elaborated here.

[0149] In a third aspect, embodiments of the present application provide a photovoltaic assembly comprising solar cells and an intra-string interconnector connecting two adjacent solar cells in series. The solar cells are the solar cells provided by the first aspect and its various implementations, or the solar cells provided by the second aspect and its various implementations. Each intra-string interconnector is in electrical contact with a corresponding first interconnection structure.

[0150] It is understood that, when the solar cell has a double-sided contact substrate structure, a busbar-less solar cell, or a busbar-equipped solar cell, the intra-string interconnector may be located on different sides of two adjacent solar cells. Alternatively, when the solar cell has a back-contact substrate structure, the intra-string interconnector may be located on the same side of two adjacent solar cells.

[0151] The beneficial effects of the third aspect and its various implementations in the embodiments of the present application can refer to the analysis of the beneficial effects in the first aspect and its various implementations, or can refer to the analysis of the beneficial effects in the second aspect and its various implementations, and will not be repeated here.

[0152] Fourthly, embodiments of the present application provide another photovoltaic module comprising: a solar cell; and an intra-string interconnector connecting two adjacent solar cells in series. As shown in Figures 2 and 4, the solar cell comprises: a cell body 11, a collector electrode 12, and a first interconnector structure 13. The cell body 11 has a first and a second opposing surface. At least one of the first and second surfaces is a target surface. The collector electrode 12 is disposed on the target surface. Different collector electrodes 12 located on the same target surface extend along a first direction and are spaced apart along a second direction. The first direction is perpendicular to the second direction. Each first interconnector structure 13 is electrically connected to at least one collector electrode 12. Each intra-string interconnector is in electrical contact with a corresponding first interconnector structure 13. The number of first interconnector structures 13 that intersect a target line segment located within the target surface is N2. The target line segment is a line segment connecting the midpoint of the longer of two oppositely disposed edges of the target surface extending along the first direction and the vertex endpoints corresponding to the shorter of the two edges. The number of intra-string interconnectors located on the same target surface is N5. The number of first interconnect structures 13 intersecting at least one vector line segment with a same inclination angle of 45° is N4. The number of intra-string interconnects intersecting at least one vector line segment with a same inclination angle of 45° is N6. Or, N6>N4.

[0153] As a possible implementation solution, N2 corresponding to at least two solar cells in a same photovoltaic module is equal.

[0154] The beneficial effects of the fourth aspect and its various implementations in the embodiments of the present application can be analyzed with reference to the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0155] While the above description does not provide detailed technical details regarding patterning and etching of each layer, those skilled in the art will appreciate that various technical means can be employed to form layers, regions, and the like in desired shapes. Furthermore, those skilled in the art may devise methods that differ from those described above to form the same structure. Furthermore, while each embodiment has been described separately, this does not mean that the measures in each embodiment cannot be advantageously combined.

[0156] The above describes the embodiments of the present application. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. The scope of this application is defined by the appended claims and their equivalents. Without departing from the scope of this application, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of this application.

Claims

1. A solar cell, wherein: include: A battery body, the battery body having a first surface and a second surface opposite to each other; at least one of the first surface and the second surface is a target surface; A collector electrode is arranged on the target surface; different collector electrodes located on the same target surface all extend along a first direction and are spaced apart along a second direction; the first direction is perpendicular to the second direction; first interconnect structures, forming an array on the target surface; each of the first interconnect structures is electrically connected to at least one of the collector electrodes; at least partial areas of different first interconnect structures spaced apart along the second direction are located on the same connection line, and different connection lines are spaced apart along the first direction; The number of the connecting lines located in the same target surface is N1, the number of the first interconnecting structures intersecting with the target line segments located in the target surface is N2, The target line segment is a line segment connecting the midpoint of the larger one of the two relatively distributed edges of the target surface extending along the first direction and the vertex endpoints corresponding to the smaller one of the two edges; or, the number of the connecting lines intersecting with the vector line segment with an inclination angle of 45° is N3, and the number of the first interconnecting structures intersecting with at least one vector line segment with an inclination angle of 45° is N4, N3>N4.

2. The solar cell according to claim 1, wherein: The thickness of the battery body is H1, the thickness of the first interconnection structure is H2, and the ratio of H2 to H1 is greater than or equal to 0.005 and less than or equal to 0.1; And / or, the cross-sectional area of ​​the battery body is S1, the cross-sectional area of ​​the first interconnection structure is S2, and the ratio of S2 to S1 is greater than or equal to 0.0003 and less than or equal to 0.

02.

3. The solar cell according to claim 1, wherein: N2 is equal to 0.

4. The solar cell according to claim 1, wherein: The distance between the geometric center of the first interconnect structure intersecting the target line segment or the vector line segment with an inclination angle of 45° and the midline of the solar cell along the second direction is D3; The distance between the geometric center of the first interconnect structure intersecting the target line segment or the vector line segment with an inclination angle of 45° and the edge of the solar cell along the second direction is D4; D3>D4 corresponding to at least one of the first interconnect structures.

5. The solar cell according to claim 1, wherein: The solar cell is a busbar-less solar cell; along the second direction, the target surface includes a middle area and an edge area; at least part of the collector electrode located on the edge area is in electrical contact with the first interconnection structure.

6. The solar cell according to claim 5, wherein: The solar cell has a back contact substrate structure, the collecting electrode comprises a first collecting electrode and a second collecting electrode with opposite polarities, the first collecting electrode and the second collecting electrode are alternately spaced along the second direction, at least a portion of the first collecting electrode on the edge region is in electrical contact with the first interconnect structure, and at least a portion of the second collecting electrode on the edge region is in electrical contact with the first interconnect structure.

7. The solar cell according to claim 5, wherein: The solar cell further comprises a second interconnect structure arranged on the target surface; each of the second interconnect structures is electrically connected to at least one of the collector electrodes, and the size of the second interconnect structure is smaller than the size of the first interconnect structure; At least a portion of the second interconnection structure is located on the same straight line and is collinear with the connection line; Among all the collector electrodes located on the same target surface, some of the collector electrodes are in contact with the first interconnection structure, and the remaining collector electrodes are in contact with the second interconnection structure; wherein the collector electrodes in contact with the first interconnection structure are connection electrodes; Along the second direction, the distance between two adjacent connecting electrodes is D1; ​​at least one connecting electrode located on the edge region contacts with a plurality of the first interconnecting structures, and different first interconnecting structures contacting the same connecting electrode are spaced apart along the first direction; The geometric center distance between two adjacent first interconnect structures contacted by the connecting electrode is D2; D2 corresponding to at least one pair of the first interconnect structures is not equal to D1, and each pair of the first interconnect structures is two adjacent first interconnect structures contacting the same connecting electrode.

8. The solar cell according to claim 7, wherein: The number of the second interconnect structures intersecting the target line segment or the vector line segment with an inclination angle of 45° is N7; in, And / or, N7<N1.

9. The solar cell according to claim 7, wherein: A ratio of D1 to D2 corresponding to at least one pair of the first interconnect structures is greater than or equal to 6 and less than or equal to 12.

10. The solar cell according to claim 1, wherein: The solar cell also includes a bus electrode arranged on the target surface; different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction; each bus electrode is electrically connected to the collector electrode with the same polarity as itself, and is electrically in contact with at least one of the first interconnection structures; different bus electrodes correspond one-to-one to different connecting lines.

11. The solar cell according to claim 10, wherein: The bus electrode is a connecting electrode; wherein, Along the first direction, the distance between two adjacent connecting electrodes is D1; At least one of the connecting electrodes is in contact with a plurality of the first interconnect structures, and different first interconnect structures in contact with the same connecting electrode are spaced apart along the second direction; the distance between the geometric centers of two adjacent first interconnect structures in contact with the same connecting electrode is D2; D2 corresponding to at least one pair of the first interconnect structures is not equal to D1, and each pair of the first interconnect structures is two adjacent first interconnect structures in contact with the same connecting electrode.

12. The solar cell according to claim 11, wherein: A ratio of D2 to D1 corresponding to at least one pair of the first interconnect structures is greater than or equal to 1 and less than or equal to 1.

7.

13. A solar cell, wherein: include: A battery body, the battery body having a first surface and a second surface opposite to each other; at least one of the first surface and the second surface is a target surface; A collector electrode is arranged on the target surface; different collector electrodes located on the same target surface all extend along a first direction and are spaced apart along a second direction; the first direction is perpendicular to the second direction; first interconnect structures, forming an array on the target surface; each of the first interconnect structures is electrically connected to at least one of the collector electrodes; at least partial areas of different first interconnect structures spaced apart along the second direction are located on the same connection line, and different connection lines are spaced apart along the first direction; The number of the connecting lines located in the same target surface is N1, the number of the first interconnecting structures intersecting with the target line segments located in the target surface is N2, N1>N2, the target line segments are diagonals of the target surface, and intersect with each of the connecting lines.

14. The solar cell according to claim 13, wherein: The solar cell comprises at least two slice battery units spaced apart and distributed along the second direction, and a cutting path is provided between two adjacent slice battery units; Wherein, the collector electrodes with opposite polarities in two adjacent slice battery units are symmetrically arranged about the cutting path; And / or, the first interconnection structures with opposite polarities in two adjacent sliced ​​battery units are symmetrically arranged about the cutting path; And / or, the solar cell further comprises a bus electrode arranged on the target surface; different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction; each bus electrode is electrically connected to the collector electrode with the same polarity as itself and is in contact with at least one of the first interconnect structures; different bus electrodes correspond to different connecting lines one by one; the bus electrodes with opposite polarities in two adjacent slice battery units are connected with respect to the The cutting paths are set symmetrically.

15. The solar cell according to claim 13, wherein: The solar cell includes M slice battery units spaced apart along the second direction, where M is a positive integer greater than or equal to 1; in the same slice battery unit, the geometric centers of the two first interconnection structures located on the edge along the second direction are symmetrically arranged relative to the midline of the slice battery unit along the second direction.

16. The solar cell according to claim 13, wherein: The solar cell further comprises a bus electrode disposed on the target surface; different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction; each bus electrode is electrically connected to the collector electrode having the same polarity as itself and is in contact with at least one of the first interconnection structures; different bus electrodes correspond to different connection lines one by one; The collecting electrode includes a first collecting electrode and a second collecting electrode with opposite polarities, and the first collecting electrode and the second collecting electrode are alternately spaced along the second direction; the bus electrode includes a first bus electrode and a second bus electrode with opposite polarities, and the first bus electrode and the second bus electrode are alternately spaced along the first direction; the bus electrode and the collecting electrode with opposite polarities are insulated from each other.

17. The solar cell according to claim 16, wherein: When the polarities of the two bus electrodes located outside along the first direction are opposite, among all the first interconnect structures intersecting the target line segment, at least two of the first interconnect structures are equidistant from the midline of the target surface along the second direction and have the same polarity.

18. The solar cell according to claim 16, wherein: In the case where the solar cell includes two slice battery units spaced apart along the second direction, N2 corresponding to the two slice battery units are equal; in the same slice battery unit, the polarities of the two bus electrodes located on the outside along the first direction are opposite; the polarities of the two oppositely arranged bus electrodes located on the outside along the first direction and belonging to different slice battery units are opposite; Or, in the case where the solar cell includes two slice battery units spaced apart along the second direction, N2 corresponding to the two slice battery units are not equal; in the same slice battery unit, the polarities of the two bus electrodes located on the outside along the first direction are the same; the polarities of the two bus electrodes located on the outside along the first direction that belong to different slice battery units are opposite.

19. The solar cell according to claim 13, wherein: The solar cell is a busbar-free solar cell; the solar cell further comprises a second interconnect structure arranged on the target surface; each of the second interconnect structures is electrically connected to at least one of the collector electrodes, and the size of the second interconnect structure is smaller than the size of the first interconnect structure; At least a portion of the second interconnection structure is located on the same straight line and is collinear with the connection line; Among all the collector electrodes located on the same target surface, some of the collector electrodes are in contact with the first interconnection structure, and the remaining collector electrodes are in contact with the second interconnection structure; The number of the second interconnect structures intersecting the target line segment is N8; wherein, And / or, N8<1.5N1.

20. A photovoltaic module, wherein: include: The solar cell according to any one of claims 1 to 12; Or a solar cell as claimed in any one of claims 13 to 19.

21. A photovoltaic module, wherein: The photovoltaic module comprises: a solar cell, and an intra-string interconnector for connecting two adjacent solar cells in series; The solar cell comprises: a cell body, a collector electrode and a first interconnection structure; the cell body has a first surface and a second surface opposite to each other; at least one of the first surface and the second surface is a target surface; the collector electrode is arranged on the target surface; different collector electrodes located on the same target surface extend along a first direction and are spaced apart along a second direction; the first direction is perpendicular to the second direction; each of the first interconnection structures is electrically connected to at least one of the collector electrodes; each of the interconnections in the string is electrically in contact with the corresponding first interconnection structure; and the first interconnection structure is electrically connected to the first interconnection structure located on the target surface. The number of the first interconnect structures intersecting with the target line segment in the target surface is N2, and the target line segment is a line segment connecting the midpoint of the longer one of the two edges extending along the first direction and relatively distributed on the target surface and the vertex endpoint corresponding to the smaller one of the two edges; the number of the interconnects in the string located on the same target surface is N5; the number of the first interconnect structures intersecting with at least one vector line segment with the same inclination angle of 45° is N4; the number of the interconnects in the string intersecting with the same vector line segment with the inclination angle of 45° is N6; in, Or, N6>N4.

22. The photovoltaic module according to claim 21, wherein: N2 corresponding to at least two solar cells in the same photovoltaic module is equal.

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