A solar cell and photovoltaic module

Abstract

The application discloses a solar cell and a photovoltaic module. The solar cell comprises a semiconductor substrate, a doped conductive layer, and a plurality of current collecting electrodes extending along a first direction. The current collecting electrodes comprise at least one section of current collecting electrodes along the first direction, each section comprising a plurality of contact portions and a transmission portion. The plurality of contact portions are spaced along the first direction. The transmission portion is arranged on a side of the contact portion away from the semiconductor substrate and is in contact with the plurality of contact portions. The transmission portion comprises end portions at both ends along the first direction. Among the plurality of contact portions, a contact portion comprises an excess portion beyond the end portion along the first direction and a lap portion covered by the transmission portion, and 1≤a≤4. The excess portion enables the contact portion to collect more carriers in a region of the transmission portion that is not covered by the doped conductive layer, reduces the contact between the transmission portion and the doped conductive layer, reduces recombination, and enables timely discovery of excessive offset of a subsequently printed transmission portion and fast adjustment, thereby reducing the offset of the current collecting electrodes and improving the printing accuracy of the electrodes.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Technology

[0002] Currently, in the fabrication of solar cells, a common process involves first printing a high-temperature paste onto a passivation layer to form electrodes, followed by sintering. This allows the high-temperature paste to burn through the passivation layer and contact the doped conductive layer. The industry widely uses high-temperature sintered silver paste as the conductive material for screen printing. Silver paste has become an indispensable traditional material in this application field due to its excellent conductivity, good printability, and ability to form good ohmic contacts with silicon substrates. However, silver, as a precious metal, is expensive and its price fluctuates wildly. Statistics show that silver paste costs account for a significant proportion (approximately 30%-50%) of the non-silicon cost of solar cells, severely restricting further reductions in photovoltaic cell costs and hindering the grid parity process for photovoltaic power generation.

[0003] Furthermore, because the entire electrode burns through the passivation layer to contact the doped conductive layer, the passivation effect of the passivation layer is poor. Multi-layer overprinted electrodes are prone to misalignment during fabrication, resulting in electrode performance loss. In summary, a solution is needed that balances electrode contact performance, manufacturing cost, passivation performance, and overprinting accuracy. Utility Model Content

[0004] The purpose of this invention is to provide a solar cell and photovoltaic module that balances electrode contact performance, manufacturing cost, passivation performance, and overprinting accuracy.

[0005] In a first aspect, this utility model provides a solar cell, comprising: The semiconductor substrate includes a first surface and a second surface opposite to each other, and four sides connecting the first surface and the second surface, wherein the first side and the second side are parallel to a first direction, and the third side and the fourth side are parallel to a second direction. Doped conductive layer; and Multiple collector electrodes are disposed on the side of the doped conductive layer away from the semiconductor substrate. The multiple collector electrodes extend along a first direction and are spaced apart along a second direction. Each collector electrode along the first direction includes at least one segment, and each segment of the at least one collector electrode includes multiple contact portions and a transmission portion. The multiple contact portions are electrically connected to the doped conductive layer and are spaced apart along the first direction. The transmission portion is disposed on the side of the contact portion away from the semiconductor substrate and is in contact with the multiple contact portions. The transmission portion extends along the first direction. The transmission section includes ends located at both ends along a first direction. Among the plurality of contact sections, a contact section includes an overhanging portion extending beyond the ends along the first direction and an overlapping portion covered by the transmission section, where 1≤a≤4.

[0006] In the above technical solution, the current collector electrode is electrically connected to the doped conductive layer through multiple contact portions spaced apart along the first direction, while the transport portion is connected to the side of the multiple contact portions away from the semiconductor substrate. The contact portions can be made of silver paste with good conductivity to achieve good contact performance with the doped conductive layer, reduce contact resistance, and improve conductivity. The transport portion can be made of other lower-cost metal materials, thereby reducing the cost of the electrode paste. Furthermore, since the multiple contact portions are spaced apart and not continuous along the first direction, the consumption of silver paste is further reduced, thus reducing the overall unit silver consumption of the current collector electrode and lowering the cost. When a passivation layer exists on the semiconductor substrate, the current collector electrode does not burn through the passivation layer completely before contacting the doped conductive layer; instead, it only burns through the passivation layer through spaced contact portions (i.e., seed layers). Therefore, the area of ​​the passivation layer damaged is reduced, improving the passivation performance of the passivation layer. In addition, the transport portion includes ends located at both ends along the first direction. Among the multiple contact portions, 'a' contact portions include an extension portion extending beyond the ends along the first direction and an overlapping portion covered by the transport portion, where 1 ≤ a ≤ 4. Specifically, 'a' can be 1, 2, 3, or 4. The contact portions can include two rows spaced apart along the second direction. That is, when 'a' is greater than or equal to 1, along the extension direction of the current collector electrode, i.e., the first direction, the end of at least one contact portion extends beyond the transport portion. This allows the contact portion to collect more charge carriers from the region of the doped conductive layer not covered by the transport portion, reducing the contact between the transport portion and the doped conductive layer, reducing recombination. Simultaneously, it allows for timely detection of excessive offset in subsequent overprinted transport portions, thereby deduce problems with equipment or process parameters, and make adjustments as quickly as possible, reducing current collector electrode offset and improving electrode overprinting accuracy. When 'a' is greater than 4, it indicates that there are too many contact portions corresponding to one transport portion, increasing the use of silver paste and increasing costs.

[0007] In some embodiments, along the first direction: The length of the overlap ranges from 0-500 μm; and / or, The length of the protruding portion ranges from 0 to 500 μm; and / or, The ratio of the length of the overlapping portion to the length of the transmission portion is 0.01-100; and / or, The ratio of the length of the extended section to the length of the transmission section is 0.01-100.

[0008] By adopting the above technical solution, the lengths of the overlapping and overhanging parts are reasonably set to facilitate the collection of charge carriers from the doped conductive layer located at the edge by the contact part, thus balancing cost and printing quality.

[0009] In some embodiments, along the second direction: The width of the overlap is less than or equal to the width of the transmission section; and / or, The width of the overhang is less than or equal to the width of the transmission section; and / or, The ratio of the width of the overhang to the width of the transmission section is 0.2-1; and / or, The width of the protruding portion ranges from 2μm to 50μm; and / or, The width of the transmission section ranges from 10μm to 100μm.

[0010] With the above technical solution, the width of the overlapping portion and the extended portion is less than or equal to the width of the transmission portion, which increases the process window. The wider transmission portion can maximize the coverage of the contact portion, providing sufficient offset space for the printing of the transmission portion and increasing the effective contact area of ​​the electrode. The ratio of the width of the extended portion along the second direction to the width of the transmission portion along the second direction is 0.2~1, balancing the improvement of the carrier collection capacity of the extended portion and the reduction of the unit silver consumption of the contact portion. The width range of the extended portion satisfies the carrier collection capacity while minimizing damage to the passivation layer, maintaining the passivation performance of the solar cell, reducing carrier recombination, and reducing the unit silver consumption. The width range of the transmission portion along the second direction satisfies the current transmission capacity while minimizing light shading, ensuring light absorption capacity, and reducing material costs.

[0011] In some embodiments, the distance between the contact portion and the third side is greater than or equal to 0.3 mm; and / or, the distance between the contact portion and the fourth side is greater than or equal to 0.3 mm. This distance provides space for printing the current collector electrode, reducing printing precision while ensuring printing yield. Furthermore, the carrier concentration is lower at the edge of the solar cell, and placing too many contacts at the edge has limited actual collection effect. This design balances the carrier collection effect and further reduces unit silver consumption.

[0012] In some embodiments, the doped conductive layer includes a first doped conductive layer and a second doped conductive layer alternately disposed on the first surface; The plurality of collector electrodes includes a plurality of first collector electrodes and a plurality of second collector electrodes, wherein the plurality of first collector electrodes are disposed on the side of the first doped conductive layer away from the semiconductor substrate, the plurality of first collector electrodes extend along a first direction and are spaced apart along a second direction; each of the first collector electrodes includes at least one segment along the first direction, each segment of the at least one segment of the first collector electrode including a plurality of first contact portions and a first transmission portion, the plurality of first contact portions being electrically connected to the first doped conductive layer, and the plurality of first contact portions being spaced apart along the first direction; the first transmission portion is disposed on the side of the first contact portion away from the semiconductor substrate and is in contact with the plurality of first contact portions, the first transmission portion extending along the first direction; A plurality of second collector electrodes are disposed on the side of the second doped conductive layer away from the semiconductor substrate. The plurality of second collector electrodes extend along a first direction and are spaced apart along a second direction. Each of the second collector electrodes along the first direction includes at least one segment of the second collector electrode. Each segment of the at least one segment of the second collector electrode includes a plurality of second contact portions and a second transmission portion. The plurality of second contact portions are electrically connected to the second doped conductive layer and are spaced apart along the first direction. The second transmission portion is disposed on the side of the second contact portion away from the semiconductor substrate and is in contact with the plurality of second contact portions. The second transmission portion extends along the first direction. At least one of the plurality of first contact portions includes a first overlapping portion covered by the first transmission portion and a first extending portion not covered by the first transmission portion; and / or At least one of the plurality of second contact portions includes a second overlapping portion covered by the second transmission portion and a second overhang portion not covered by the second transmission portion.

[0013] In the case of the above technical solution, the solar cell is a back-contact cell. At least one contact portion of the first current collector electrode on the first doped conductive layer and / or the second current collector electrode on the second doped conductive layer has an overlapping portion and an overhanging portion. That is, the end of at least one contact portion extends beyond the transport portion, so that the contact portion can collect more charge carriers in the area of ​​the doped conductive layer not covered by the transport portion, reducing the contact between the transport portion and the doped conductive layer, reducing recombination. At the same time, it allows for timely detection when the transport portion of the subsequent overprinting is excessively offset, thereby deducing the problem of equipment or process parameters and adjusting them as soon as possible, reducing the offset of the current collector electrode and improving the electrode overprinting accuracy.

[0014] In some embodiments, in at least one first current collector electrode, the ratio of the length of at least one first contact portion along a first direction to the distance between adjacent first contact portions is a first ratio value. In at least one second current collector electrode, the ratio of the length of at least one second contact portion along the first direction to the distance between adjacent second contact portions is a second ratio, and the first ratio is greater than the second ratio.

[0015] When the above technical solution is adopted, since the current density of the first doped conductive layer is greater than that of the second doped conductive layer, the first doped conductive layer needs a denser first contact portion to collect carriers and improve the carrier collection capability.

[0016] In some embodiments, in at least one first current collector electrode, the first ratio of the length of the first contact portion along the first direction to the distance between adjacent first contact portions is 0.1 to 5; And / or, in at least one second current collector electrode, the second ratio of the length of the second contact portion along the first direction to the spacing between adjacent second contacts is 0.1 to 5.

[0017] In some embodiments, in at least one first current collector electrode, the sum of the lengths of the plurality of first contacts along the first direction is greater than the sum of the lengths of the plurality of second contacts along the first direction in at least one second current collector electrode; And / or, in at least one first current collector electrode, the length of at least one first contact portion along the first direction is greater than the length of at least one second contact portion along the first direction in at least one second current collector electrode; When the above technical solution is adopted, since the current density of the first doped conductive layer is greater than that of the second doped conductive layer, the first doped conductive layer needs a larger contact area to collect carriers. The carrier collection capability of the first doped conductive layer is improved by having a larger sum of lengths of multiple first contacts and / or having at least one first contact with a longer length.

[0018] In some embodiments, in at least one first current collector electrode, the length of the first contact portion along the first direction is 5μm-100μm, or in at least one second current collector electrode, the length of the second contact portion along the first direction is 5μm-100μm.

[0019] In some embodiments, the width of the first contact portion along the second direction is greater than the width of the second contact portion along the second direction; and / or, The width of the first transmission section along the second direction is greater than the width of the second transmission section along the second direction; and / or, The widths of the first contact portion along the second direction and the widths of the second contact portion along the second direction are 2μm-50μm, respectively; and / or, The widths of the first transmission section along the second direction and the widths of the second transmission section along the second direction are 10μm-100μm, respectively.

[0020] With the above technical solution, since the current density of the first doped conductive layer is higher, increasing the width of the first contact portion increases the contact area between the first contact portion and the first doped conductive layer, thereby improving the carrier collection capacity of the first doped conductive layer. Similarly, increasing the width of the first transmission portion increases the current transmission capacity of the first transmission portion to the first doped conductive layer. The width range of the first and second contact portions satisfies both the carrier collection capacity and reduces damage to the passivation layer, maintaining the passivation performance of the solar cell, reducing carrier recombination, and simultaneously reducing unit silver consumption. The width range of the first and second transmission portions satisfies both the current transmission capacity and reduces light shading, ensuring light absorption capacity and reducing material costs.

[0021] In some embodiments, along the first direction, the length of the first protruding portion is greater than the length of the second protruding portion; and / or, the length of the first overlapping portion is greater than the length of the second overlapping portion. Since the current density of the first doped conductive layer is greater, by increasing the lengths of the first protruding portion and the first overlapping portion, the contact area between the first contact portion and the first doped conductive layer is increased, thereby improving the carrier collection capability of the first doped conductive layer.

[0022] In some embodiments, the solar cell further includes: A first edge interconnect is disposed on the side of the first doped conductive layer away from the semiconductor substrate, close to the third side, and the first edge interconnect is electrically connected to the first collector electrode; and A first edge bus electrode is disposed between a first edge interconnect and a third side, and the first edge bus electrode extends along a second direction and is electrically connected to a first collector electrode. Among the plurality of first contact portions, at least one of the first contact portions is closer to the third side than the first edge bus electrode.

[0023] When the above technical solution is adopted, there is a distance between the first edge bus electrode located at the edge of the solar cell and the third side. At least one of the first contact portions is closer to the third side than the first edge bus electrode, so that the first contact portion can contact the first doped conductive layer located in the region between the first edge bus electrode and the third side. That is, the first contact portion contacts the first doped conductive layer located at the edge of the solar cell to collect the charge carriers between the first edge bus electrode and the third side, thereby improving the charge carrier collection capability at the edge of the solar cell.

[0024] In some embodiments, among the plurality of first contact portions, n first contact portions are in contact with the first edge bus electrode; the width of the first edge bus electrode in the first direction varies along the second direction; each of the n first contact portions includes a sub-overlap portion covered by the first edge bus electrode, and the lengths of the n sub-overlap portions in the first direction are different, where n is a positive integer and 5≤n≤15.

[0025] When the above technical solution is adopted, when multiple first current collector electrodes are electrically connected to the first edge bus electrode, n of the multiple first contact portions of these first current collector electrodes contact the first edge bus electrode, and all n first contact portions overlap with the first edge bus electrode. This overlap ensures that the current collected from the edge of the solar cell is transmitted to the first edge bus electrode. Furthermore, the width of the first edge bus electrode varies along the second direction from the first direction, meaning the first edge bus electrode is not of uniform width. While ensuring current transmission, the width of some positions of the first edge bus electrode can be appropriately changed to save paste. Due to the variation in the width of the first edge bus electrode, the overlap lengths of the n sub-overlap portions that overlap at different positions in the second direction of the first edge bus electrode vary with the width of the first edge bus electrode.

[0026] In some embodiments, among the n first contact portions, m first contact portions include sub-extension portions not covered by the first edge busbar electrode, and the lengths of the m sub-extension portions are different in the first direction, wherein 3≤m≤n.

[0027] When the above technical solution is adopted, among the n first contact portions that overlap with the first edge bus electrode, m first contact portions do not completely overlap with the first edge bus electrode, but partially overlap. The unoverlapped portions extend outward toward the third side in the first direction to form sub-extension portions. The end of the sub-extension portion closer to the third side is closer to the third side than the first edge bus electrode. The sub-extension portions collect the charge carriers of the first doped conductive layer between the first edge bus electrode and the third side, thereby enhancing the current collection of the first collector electrode at the edge of the solar cell.

[0028] In some embodiments, the length of the n sub-overlaps in the first direction is greater than or equal to 0.1 mm. If the overlap length of the sub-overlaps is less than 0.1 mm, the length of the sub-overlaps is too small, which is not conducive to the transmission of the edge current of the solar cell to the first edge bus electrode.

[0029] In some embodiments, the difference between the maximum and minimum lengths of the n sub-overlapping portions in the first direction is 0.05 mm to 0.25 mm. Due to the variation in the width of the first edge bus electrode and the different positions of the first contact portions, the overlap lengths between the n first contact portions and the first edge bus electrode are different. The difference between the overlap lengths is within the above range, which makes the overlap of each sub-overlapping portion more uniform and helps to improve the uniformity of current transmission.

[0030] In some embodiments, the length of the m sub-extensions in the first direction is less than or equal to 2 mm. If the length of the sub-extensions is greater than 2 mm, the sub-extensions are too close to the third side, leaving insufficient space for printing the first current collector electrode, which affects the printing quality. In addition, the carrier concentration is low at the edge of the solar cell, and setting too many first contact portions at the edge has limited actual collection effect. This design can balance the carrier collection effect and further reduce the unit silver consumption.

[0031] In some embodiments, the difference between the maximum and minimum lengths of the m sub-extensions in the first direction is 0.05 mm to 0.1 mm. Due to the variation in the width of the first edge busbar electrode and the different arrangement positions of the first contact portions, the lengths of the m sub-extensions in the first direction are different. The length difference between each sub-extension is within the above-mentioned range, which makes the printing positions of the first contact portions at the edges of each first current collector electrode not much different. This is beneficial for unifying the printing positions and simplifying the printing process. Furthermore, the relatively uniform lengths of each sub-extension are beneficial for the uniformity of carrier collection of the first doped conductive layer between the first edge busbar electrode and the third side by each sub-extension, further enhancing the current collection of the first current collector electrode at the edge of the solar cell.

[0032] In some embodiments, a connecting line is provided between the first edge bus electrode and the first edge interconnect, the connecting line having an overlapping portion that overlaps with the first edge bus electrode, the length of the overlapping portion in a first direction being greater than or equal to 0.08 mm. Thus, the length of the overlapping portion effectively ensures the current transmission effect while ensuring that the edge tension of the component meets the requirements.

[0033] In some embodiments, the first edge bus electrode includes ends located at both ends along a second direction and a middle portion located between the two ends, wherein the number of first current collector electrodes overlapping with the middle portion is greater than the number of first current collector electrodes overlapping with either end. That is, the middle portion of the first edge bus electrode has more and denser first current collector electrodes connected to it. This design is beneficial for the collection of edge carriers in solar cells and for improving the overall welding pull strength.

[0034] In some embodiments, the solar cell further includes: The second edge interconnect is disposed on the side of the second doped conductive layer away from the semiconductor substrate, near the fourth side, and is electrically connected to the second collector electrode; and The second edge bus electrode is disposed between the second edge interconnect and the fourth side, and the second edge bus electrode extends along the second direction and is electrically connected to the second collector electrode. In the second direction, the width of the first edge interconnect is L1, the first distance between two adjacent first collector electrodes is d1, the width of the second edge interconnect is L2, and the second distance between two adjacent second collector electrodes is d2.

[0035] When the above technical solution is adopted, there is a distance between the second edge bus electrode located at the edge of the solar cell and the fourth side. At least one of the multiple second contact portions is closer to the fourth side than the second edge bus electrode, so that the second contact portion can contact the second doped conductive layer located in the region between the second edge bus electrode and the fourth side. That is, the second contact portion contacts the second doped conductive layer located at the edge of the solar cell to collect the charge carriers between the second edge bus electrode and the fourth side, thereby improving the charge carrier collection capability at the edge of the solar cell.

[0036] In some embodiments, the number e of the first collector electrodes connected to the first edge interconnect is greater than or equal to the number f of the second collector electrodes connected to the second edge interconnect; L1 / d1≥e-1, L2 / d2≥f-1. Since the doping concentrations of the first and second doped conductive layers are different, their current densities are also different. When the current density of the first doped conductive layer is higher, more first collector electrodes are needed to collect carriers and improve current transmission capability. Therefore, the number e of the first collector electrodes connected to the first edge interconnect is greater than or equal to the number f of the second collector electrodes connected to the second edge interconnect. Furthermore, L1 / d1≥e-1 and L2 / d2≥f-1 ensure that, with a fixed width and first spacing between adjacent first collector electrodes, the first edge interconnect can connect to as many first collector electrodes as possible while still allowing the collector electrodes to fully collect carriers, thus improving current transmission capability. The connection arrangement of the second edge interconnect and the second collector electrodes serves the same purpose and will not be described further.

[0037] In some embodiments, the doped conductive layer includes a first doped conductive layer and a second doped conductive layer, wherein the first doped conductive layer is disposed on a first surface and the second doped conductive layer is disposed on a second surface. The plurality of collector electrodes includes a plurality of first collector electrodes and a plurality of second collector electrodes, wherein the plurality of first collector electrodes are disposed on the side of the first doped conductive layer away from the semiconductor substrate, the plurality of first collector electrodes extend along a first direction and are spaced apart along a second direction; each of the first collector electrodes includes at least one segment along the first direction, each segment of the at least one segment of the first collector electrode including a plurality of first contact portions and a first transmission portion, the plurality of first contact portions being electrically connected to the first doped conductive layer, and the plurality of first contact portions being spaced apart along the first direction; the first transmission portion is disposed on the side of the first contact portion away from the semiconductor substrate and is in contact with the plurality of first contact portions, the first transmission portion extending along the first direction; A plurality of second collector electrodes are disposed on the side of the second doped conductive layer away from the semiconductor substrate. The plurality of second collector electrodes extend along a first direction and are spaced apart along a second direction. Each second collector electrode includes at least one segment along the first direction. Each segment of the at least one second collector electrode includes a plurality of second contact portions and a second transmission portion. The plurality of second contact portions are electrically connected to the second doped conductive layer and are spaced apart along the first direction. The second transmission portion is disposed on the side of the second contact portion away from the semiconductor substrate and is in contact with the plurality of second contact portions. The second transmission portion extends along the first direction. A frame electrode is disposed on the first surface and the second surface. Wherein, at least one of the plurality of first contact portions includes a third protruding portion extending beyond the frame electrode; and / or, At least one of the plurality of second contact portions includes a fourth overhang portion extending beyond the frame electrode.

[0038] When the above technical solution is adopted, the solar cell is a bifacial cell. For the bifacial cell, a first current collector electrode and a second current collector electrode are respectively provided on the first surface and the second surface. The first contact portion of the first current collector electrode extends beyond the frame electrode in a first direction, and the second contact portion of the second current collector electrode extends beyond the frame electrode in a first direction, so that the third extended portion contacts the first doped conductive layer outside the frame electrode and collects the charge carriers at the edge of the first doped conductive layer. Similarly, the fourth extended portion contacts the second doped conductive layer outside the frame electrode and collects the charge carriers at the edge of the second doped conductive layer, thereby improving the charge carrier collection capability at the edge of the solar cell.

[0039] Secondly, this utility model also provides a photovoltaic module, comprising: A battery string, which is formed by electrically connecting several solar cells as described in any of the above items; Interconnectors, electrically connected to the solar cells; And the encapsulation layer, covering the surface of the battery string.

[0040] Since photovoltaic modules include solar cells as described in the first aspect, they have the same beneficial effects as those described in the first aspect, which will not be elaborated further. Attached Figure Description

[0041] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure on the first surface of a solar cell provided in an embodiment of the present invention; Figure 2 for Figure 1 A partial schematic diagram; Figure 3 A schematic diagram of a longitudinal section of a solar cell parallel to a second direction, provided for an embodiment of this utility model; Figure 4 A schematic diagram of a longitudinal cross-section of a solar cell parallel to a first direction, provided for an embodiment of this utility model; Figure 5 A schematic diagram of the structure on the first surface of another solar cell provided in an embodiment of this utility model.

[0042] Reference numerals: 100 is a semiconductor substrate, 110 is a tunneling oxide layer, 120 is a first doped conductive layer, 130 is a passivation layer, 140 is a second doped conductive layer, 150 is a passivation antireflection layer, 11 is a first side edge, 13 is a third side edge, 14 is a fourth side edge, 200 is a first collector electrode, 210 is a first contact portion, 211 is a sub-overlap portion, 212 is a sub-extension portion, 213 is an overlap portion, 214 is an extension portion, 215 is a third extension portion, 220 is a first transmission portion, 300 is a second collector electrode, 310 is a second contact portion, 320 is a second transmission portion, 400 is a first edge bus electrode, 500 is a connecting line, 600 is a second edge bus electrode, 700 is a first edge interconnect, 800 is a second edge interconnect, and 900 is a frame electrode. Detailed Implementation

[0043] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0044] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0046] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0047] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0048] like Figures 1-5As shown, this utility model embodiment provides a solar cell, including a semiconductor substrate 100, a doped semiconductor layer, and a plurality of current collector electrodes; wherein, the semiconductor substrate 100 includes a first surface and a second surface opposite to each other, and four sides connecting the first surface and the second surface, such as a first side 11, a second side (not shown in the figure), a third side 13, and a fourth side 14, wherein the first side 11 and the second side are parallel to a first direction, the third side 13 and the fourth side 14 are parallel to a second direction, and the first direction and the second direction intersect, specifically, they can be perpendicular; the doped conductive layer is disposed on at least one side of the semiconductor substrate; the plurality of current collector electrodes are disposed on the side of the doped conductive layer away from the semiconductor substrate 100, for collecting charge carriers of the doped conductive layer, the plurality of current collector electrodes extend along the first direction and are spaced apart along the second direction; the current collector electrodes include at least one segment of current collector electrode along the first direction, each of these segments of current collector electrode including a plurality of contact portions (e.g. Figures 1-4 The first contact portion 210 and the second contact portion 310 in the middle) and the transmission portion (such as Figure 1 and Figure 2 The first transmission section 220 and the second transmission section 320 are included. Multiple contacts are electrically connected to the doped conductive layer, and the multiple contacts are spaced apart along a first direction. A transmission section is disposed on the side of the contacts away from the semiconductor substrate 100 and is in contact with the multiple contacts. The transmission section extends along the first direction and includes ends located at both ends along the first direction. Among the multiple contacts in the same collector electrode segment, 'a' contacts include an extension portion extending beyond the end along the first direction and an overlapping portion covered by the transmission section, where 1 ≤ a ≤ 4. Specifically, 'a' can be 1, 2, 3, or 4. The contacts can include two rows spaced apart along a second direction. That is, along the first direction, among the four contacts located at the ends of the same collector electrode segment, any one contact can extend beyond the transmission section along the first direction, with the extended portion forming an extension portion 214 and the non-extending portion forming an overlapping portion 213; or all four contacts extend beyond the transmission section from both ends along the first direction, with the extended portions forming four extension portions 214 and the non-extending portions forming four overlapping portions 213. In at least one contact portion located at both ends of a current collector electrode, at least one contact portion has both an overlapping portion 213 and an overhang portion 214.

[0049] In the above technical solution, the collector electrode is electrically connected to the doped conductive layer through multiple contact portions spaced apart along the first direction, while the transport portion is connected to the side of the multiple contact portions away from the semiconductor substrate 100. The contact portions, acting as seed layers, can be made of silver paste with good conductivity to achieve good contact with the doped conductive layer, reduce contact resistance, and improve conductivity. The transport portion can be made of other low-cost metal materials. Furthermore, since the multiple contact portions are spaced apart and not continuous along the first direction, the consumption of silver paste is further reduced, thereby reducing the overall unit silver consumption of the collector electrode and lowering the cost. When a passivation layer exists on the surface of the semiconductor substrate (i.e., the passivation layer is located on the side of the doped conductive layer away from the semiconductor substrate, and the collector electrode is located on the side of the passivation layer away from the semiconductor substrate), the collector electrode does not burn through the passivation layer completely before contacting the doped conductive layer. Instead, it only burns through the passivation layer through the spaced contact portions (i.e., the seed layer). Therefore, the area of ​​the passivation layer damaged is reduced, improving the passivation performance of the passivation layer, reducing recombination, and increasing the on-state voltage. Furthermore, among the multiple contact portions in the same segment of the current collector electrode, 'a' contact portions include an overlapping portion 213 covered by the transport portion and an extended portion 214 not covered by the transport portion, where 1 ≤ a ≤ 4. That is, when a is greater than or equal to 1, along the extension direction of the current collector electrode, i.e., the first direction, the end of at least one contact portion extends beyond the transport portion, allowing the contact portion to collect more charge carriers from the region of the doped conductive layer not covered by the transport portion, reducing the contact between the transport portion and the doped conductive layer, reducing recombination. Simultaneously, it allows for timely detection of excessive offset in subsequent overprinted transport portions, thereby deducing equipment or process parameter problems and adjusting them as quickly as possible, reducing current collector electrode offset and improving electrode overprinting accuracy. When a is greater than 4, it indicates that there are too many contact portions corresponding to one transport portion, i.e., increasing the use of silver paste and increasing costs.

[0050] For ease of understanding, the following will use... Figures 1-4 The first contact portion 210 and the first transmission portion 220 are used as examples to describe the contact portion and the transmission portion, and the same applies to the second contact portion 310 and the second transmission portion 320.

[0051] like Figure 2As shown, in some embodiments, along the first direction, the length of the overlapping portion 213 ranges from 0 to 500 μm, specifically it can be 1 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, etc. And / or, the length of the extended portion 214 ranges from 0 to 500 μm, specifically it can be 1 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, etc. And / or, the ratio of the length of the overlapping portion 213 to the length of the first transmission portion 220 is 0.01-100, and the specific length ratio can be 0.01, 1, 10, 30, 50, 80, 100, etc.; and / or, the ratio of the length of the extended portion 214 to the length of the first transmission portion 220 is 0.01-100, and the specific length ratio can be 0.01, 1, 10, 30, 50, 80, 100, etc.

[0052] When the above technical solution is adopted, by reasonably setting the lengths of the overlapping part 213 and the extended part 214, it is beneficial for the contact part to collect the charge carriers of the doped conductive layer located at the edge, thereby reducing recombination, reducing costs and improving printing quality.

[0053] In some embodiments, along the second direction: the width of the overlapping portion 213 is less than or equal to the width of the first transmission portion 220; and / or, the width of the protruding portion 214 is less than or equal to the width of the first transmission portion 220; and / or, the ratio of the width of the protruding portion 214 to the width of the first transmission portion 220 is 0.2-1, specifically 0.2, 0.5, 0.8, 1, etc.; and / or, the width of the protruding portion 214 ranges from 2μm to 50μm. Specifically, the width can be 2μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, etc.; and / or, the width of the first transmission section 220 is in the range of 10μm-100μm, specifically 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0054] With the above technical solution, the widths of the overlapping portion 213 and the extended portion 214 are less than or equal to the width of the transmission portion, which increases the process window. The wider transmission portion can cover the contact portion to the maximum extent, providing sufficient offset space for the printing of the transmission portion and increasing the effective contact area of ​​the electrode. The ratio of the width of the extended portion 214 along the second direction to the width of the transmission portion along the second direction is 0.2 to 1, balancing the improvement of the carrier collection capacity of the extended portion 214 with the reduction of the unit silver consumption of the contact portion. The width range of the extended portion 214 satisfies both the carrier collection capacity and reduces damage to the passivation layer, maintaining the passivation performance of the solar cell, reducing carrier recombination, and reducing the unit silver consumption. The width range of the transmission portion along the second direction satisfies both the current transmission capacity and reduces light shading, ensuring light absorption capacity and reducing material costs.

[0055] In some embodiments, the distance between the contact portion and the third side 13 is greater than or equal to 0.3 mm, that is, the distance between the first contact portion 210 disposed near the third side 13 and the third side 13 is greater than or equal to 0.3 mm, specifically 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 2 mm, 5 mm, etc. And / or, the distance between the contact portion and the fourth side 14 is greater than or equal to 0.3 mm, that is, the distance between the second contact portion 310 disposed near the fourth side 14 and the fourth side 14 is greater than or equal to 0.3 mm, specifically 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 2 mm, 5 mm, etc. Thus, this distance provides space for printing the current collector electrode, reducing printing precision and ensuring printing yield; furthermore, the carrier concentration at the edge of the solar cell is low, and setting too many contacts at the edge has limited actual collection effect. This design can balance the carrier collection effect and further reduce unit silver consumption.

[0056] like Figures 1-4As shown, this embodiment provides a specific solar cell, which is a back-contact cell, including a semiconductor substrate 100, a first doped conductive layer 120, a second doped conductive layer 140, a plurality of first current collectors 200, and a plurality of second current collectors 300. The first doped conductive layer 120 and the second doped conductive layer 140 are alternately disposed on a first surface (i.e., the back side) along a second direction, and the first doped conductive layer 120 and the second doped conductive layer 140 have different conductivity types. The plurality of first current collectors 200 are disposed on the side of the first doped conductive layer 120 away from the semiconductor substrate 100, for collecting charge carriers of the first doped conductive layer 120. The plurality of first current collectors 200 extend along a first direction and are spaced apart along a second direction. Each first current collector 200 includes at least one segment along the first direction, and each segment of the at least one segment of the first current collector 200 includes a plurality of first contact portions 210 and a first transmission portion 220. The plurality of first contact portions 210 are electrically connected to the first doped conductive layer 120, and the plurality of first contact portions 210 are electrically connected to the first doped conductive layer 120. The contacts 210 are spaced apart along a first direction; the first transmission portion 220 is disposed on the side of the first contact portion 210 away from the semiconductor substrate 100 and is in contact with the plurality of first contact portions 210, and the first transmission portion 220 extends along the first direction; the plurality of second collector electrodes 300 are disposed on the side of the second doped conductive layer 140 away from the semiconductor substrate 100 for collecting carriers of the second doped conductive layer 140, the plurality of second collector electrodes 300 extend along the first direction and are spaced apart along a second direction; the second collector electrode 300 includes at least one segment of the second collector electrode 300 along the first direction, each segment of the at least one segment of the second collector electrode 300 includes a plurality of second contact portions 310 and a second transmission portion 320, the plurality of second contact portions 310 are electrically connected to the second doped conductive layer 140, the plurality of second contact portions 310 are spaced apart along the first direction; the second transmission portion 320 is disposed on the side of the second contact portion 310 away from the semiconductor substrate 100 and is in contact with the plurality of second contact portions 310, and the second transmission portion 320 extends along the first direction. Among them, at least one of the multiple first contact portions 210 includes a first overlapping portion (such as) covered by the first transmission portion 220. Figure 2 The overlapping portion 213 shown) and the first extended portion not covered by the first transmission portion 220 (such as...) Figure 2 (Extended portion 214 shown); and / or, at least one of the plurality of second contact portions 310 includes a second overlapping portion covered by the second transmission portion 320 and a second extended portion not covered by the second transmission portion.

[0057] In the case of the above technical solution, the solar cell is a back contact cell. At least one contact portion of the first current collector electrode 200 on the first doped conductive layer 120 and / or the second current collector electrode 300 on the second doped conductive layer 140 has an overlapping portion 213 and an overhang portion 214, that is, the end of at least one contact portion extends beyond the transmission portion, so that the contact portion can collect more charge carriers in the area of ​​the doped conductive layer not covered by the transmission portion, and reduce the contact between the transmission portion and the doped conductive layer, thereby reducing recombination. At the same time, it allows for timely detection when the transmission portion of the subsequent overprinting is excessively offset, thereby deducing the problem of equipment or process parameters, adjusting them as soon as possible, reducing the offset of the current collector electrode, and improving the electrode overprinting accuracy.

[0058] like Figure 2 and Figure 4 As shown, in some embodiments, in at least one first current collector electrode 200, the ratio of the length of at least one first contact portion 210 along a first direction to the distance between adjacent first contact portions 210 is a first ratio. Taking one first contact portion 210 as an example, in the first direction, the length of one first contact portion 210 is L3, and the distance between adjacent first contact portions 210 is d3, so the first ratio is L3 / d3. In at least one second current collector electrode 300, the ratio of the length of at least one second contact portion 310 along a first direction to the distance between adjacent second contact portions 310 is a second ratio. Taking one second contact portion 310 as an example, in the first direction, the length of one second contact portion 310 is L4, and the distance between adjacent second contact portions 310 is d4, so the second ratio is L4 / d4, and the first ratio is greater than the second ratio.

[0059] When the current density of the first doped conductive layer 120 is greater than that of the second doped conductive layer 140, the first doped conductive layer 120 needs a denser first contact portion 210 to collect carriers and improve the carrier collection capability.

[0060] For example, in at least one first current collector electrode 200, the first ratio of the length L3 of the first contact portion 210 along the first direction to the distance d3 between adjacent first contact portions 210 is 0.1 to 5. Specifically, the first ratio L3 / d3 can be 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc.

[0061] Similarly, in at least one second current collector electrode 300, the second ratio of the length L4 of the second contact portion 310 along the first direction to the distance d4 between adjacent second contact portions 310 is 0.01 to 100. Specifically, the second ratio L4 / d4 can be 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc.

[0062] like Figure 1 and 2 As shown, in some embodiments, in at least one first collector electrode 200, the sum of the lengths of a plurality of first contact portions 210 along the first direction is x, and in at least one second collector electrode 300, the sum of the lengths of a plurality of second contact portions 310 along the first direction is y, where x is greater than y.

[0063] like Figure 1 , Figure 2 and Figure 4 As shown, in some embodiments, in at least one first collector electrode 200, at least one first contact portion 210 has a length of L3 along the first direction, and in at least one second collector electrode 300, at least one second contact portion 310 has a length of L4 along the first direction, where L3 is greater than L4. When the current density of the first doped conductive layer 120 is greater than that of the second doped conductive layer 140, the first doped conductive layer 120 needs a larger contact area to collect carriers. This is achieved by increasing the sum of the lengths of the multiple first contact portions 210 and / or by making at least one first contact portion 210 longer, thereby improving the carrier collection capability of the first doped conductive layer 120.

[0064] like Figure 2 As shown, in some embodiments, in at least one first collector electrode 200, the length L3 of the first contact portion 210 along the first direction is 5μm-100μm, specifically it can be 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.; or in at least one second collector electrode 300, the length L4 of the second contact portion 310 along the first direction is 5μm-100μm, specifically it can be 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0065] In some embodiments, the ratio d1 / d3 of the distance d1 between at least one pair of adjacent first collector electrodes 200 in the second direction and the distance d3 between at least one pair of adjacent first contact portions 210 in the first direction is greater than or equal to 1 / 2 and less than or equal to 20; specifically, d1 / d3 can be 1 / 2, 1, 3, 5, 8, 10, 13, 15, 18, 20, etc.

[0066] And / or, the ratio d2 / d4 of the distance d2 between at least one pair of adjacent second collector electrodes 300 in the second direction and the distance d4 between at least one pair of adjacent second contact portions 310 in the first direction is greater than or equal to 1 / 2 and less than or equal to 20. Specifically, d2 / d4 can be 1 / 2, 1, 3, 5, 8, 10, 13, 15, 18, 20, etc.

[0067] By adopting the above technical solution, the arrangement spacing of the first current collector 200 and the spacing of the adjacent first contact portion 210 in the first direction, as well as the arrangement spacing of the second current collector 300 and the spacing of the adjacent second contact portion 310 in the first direction, can simultaneously improve the carrier collection capability and the current transmission capability, thereby matching the carrier collection capability and the current transmission capability and improving the battery efficiency.

[0068] In some embodiments, the width of the first contact portion 210 along the second direction is greater than the width of the second contact portion 310 along the second direction. When the current density of the first doped conductive layer 120 is greater, the contact area between the first contact portion 210 and the first doped conductive layer 120 is increased by increasing the width of the first contact portion 210, thereby improving the carrier collection capability of the first doped conductive layer 120.

[0069] In some embodiments, the width of the first transmission section 220 along the second direction is greater than the width of the second transmission section 320 along the second direction. When the current density of the first doped conductive layer is greater, the current transmission capability of the first transmission section 220 to the first doped conductive layer 120 is increased by increasing the width of the first transmission section 220.

[0070] like Figure 1 and Figure 2As shown, in some embodiments, the width of the first contact portion 210 along the second direction is smaller than the width of the first transmission portion 220 along the second direction; the width of the second contact portion 310 along the second direction is smaller than the width of the second transmission portion 320 along the second direction. This arrangement increases the process window, as the wider widths of the first and second transmission portions 220 and 320 maximize coverage of the first and second contact portions 210 and 310, providing sufficient offset space for printing the first and second transmission portions 220 and increasing the effective contact area of ​​the electrodes.

[0071] For example, the ratio of the width of the first contact portion 210 along the second direction to the width of the first transmission portion 220 along the second direction is 0.02 to 1, specifically 0.02, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc. The ratio of the width of the second contact portion 310 along the second direction to the width of the second transmission portion 320 along the second direction is also 0.02 to 1, specifically 0.02, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc. This achieves a balance between improving the carrier collection capability of the first contact portion 210 and the second contact portion 310 and reducing the unit silver consumption of the first contact portion 210 and the second contact portion 310.

[0072] In some embodiments, the width of the first contact portion 210 along the second direction and the width of the second contact portion 310 along the second direction are respectively 2μm to 50μm, specifically 2μm, 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, etc. This configuration ensures that the width range of the first contact portion 210 and the second contact portion 310 satisfies the carrier collection capacity while reducing damage to the passivation layer 130, maintaining the passivation performance of the solar cell, reducing carrier recombination, and simultaneously reducing unit silver consumption.

[0073] In some embodiments, the width of the first transmission section 220 along the second direction and the width of the second transmission section 320 along the second direction are respectively 10μm to 100μm, specifically 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc. Thus, the width range of the first transmission section 220 and the second transmission section 320 can satisfy the current transmission capability while reducing light shading, ensuring light absorption capability, and reducing material costs.

[0074] In some embodiments, along the first direction, the length of the first protruding portion is greater than the length of the second protruding portion; and / or, the length of the first overlapping portion is greater than the length of the second overlapping portion. Since the current density of the first doped conductive layer 120 is greater, by increasing the lengths of the first protruding portion and the first overlapping portion, the contact area between the first contact portion and the first doped conductive layer 120 is increased, thereby improving the carrier collection capability of the first doped conductive layer 120.

[0075] like Figure 1 and Figure 2 As shown, in some embodiments, the solar cell further includes a first edge interconnect 700 and a first edge bus electrode 400; wherein, the first edge interconnect 700 is disposed on the side of the first doped conductive layer 120 away from the semiconductor substrate 100, close to the third side 13, and the first edge interconnect 700 is electrically connected to the first current collector 200. Specifically, there can be two first edge interconnects 700, located at both ends close to the third side 13, that is, one first edge interconnect 700 is close to both the first side 11 and the third side 13, and the other first edge interconnect is close to both sides 11 and 200. The second side and the third side 13, the first edge interconnect 700 can be a pad structure for conductive connection with the solder strip; the first edge bus electrode 400 is disposed between the first edge interconnect 700 and the third side 13, and the first edge bus electrode 400 extends along the second direction, the first edge bus electrode 400 is electrically connected to the end of the first collector electrode 200 for collecting the current collected by the first collector electrode 200; wherein, at least one of the plurality of first contact portions 210 is closer to the third side 13 than the first edge bus electrode 400.

[0076] With the above technical solution, there is a distance between the first edge bus electrode 400 located at the edge of the solar cell and the third side 13. At least one of the multiple first contact portions 210 is closer to the third side 13 than the first edge bus electrode 400, so that the first contact portion 210 can contact the first doped conductive layer 120 located in the region between the first edge bus electrode 400 and the third side 13. That is, the first contact portion 210 contacts the first doped conductive layer 120 located at the edge of the solar cell to collect the charge carriers between the first edge bus electrode 400 and the third side 13, thereby improving the charge carrier collection capability at the edge of the solar cell.

[0077] It should be noted that in practical applications, the semiconductor substrate can be any type of semiconductor material, such as silicon, germanium-silicon, germanium, or gallium arsenide. The semiconductor substrate can be N-type or P-type single-crystal silicon, polycrystalline silicon, microcrystalline silicon, etc. The materials of the first and second doped conductive layers can include doped single-crystal silicon, doped polycrystalline silicon, doped microcrystalline silicon, doped nanocrystalline silicon, doped amorphous silicon, etc. The semiconductor substrate, the material of the doped conductive layer, and the doping type should be selected appropriately according to the battery type. For example, ... Figure 3 As shown, when the doped conductive layer is doped polycrystalline silicon, it can form a tunneling passivation contact structure with the tunneling oxide layer 110; when the doped conductive layer is doped amorphous silicon, it can form a heterojunction contact structure with intrinsic amorphous silicon. The resulting solar cell can be a solar cell with a tunneling passivation contact structure and / or a heterojunction contact structure, which is not specifically limited here.

[0078] In some embodiments, the first contact portion 210 and the second contact portion 310 serve as seed layers, and their material can be silver. The first transmission portion 220 and the second transmission portion 320 can be made of copper or silver-clad copper, etc. The seed layer uses a material with good electrical conductivity, and the first transmission portion 220 and the second transmission portion 320 use a material with low cost, easy to weld with solder strips, and good mechanical properties.

[0079] For example, the first contact portion 210 and the second contact portion 310 can be one or more combinations of the following structures: dotted, linear, alternating dotted and linear, alternating long and short lines, edge dotted or short lines, and middle long lines. As long as it can serve as a seed layer, it can make local contacts of the first current collector 200 and the second current collector 300 electrically connected to the first doped conductive layer 120 and the second doped conductive layer 140, respectively. It is not limited to the structural forms listed in this embodiment.

[0080] like Figure 3 and Figure 4As shown, a passivation layer 130 is also disposed on the first surface of the solar cell. The passivation layer 130 is disposed on the side of the first doped conductive layer 120 and the second doped conductive layer 140 away from the semiconductor substrate 100. The first current collector 200 and the second current collector 300 are both located on the side of the passivation layer 130 away from the semiconductor substrate 100. The first contact portion 210 passes through the passivation layer 130 and is electrically connected to the first doped conductive layer 120. The first transmission portion 220 is located on the side of the passivation layer 130 away from the semiconductor substrate 100. Similarly, the second contact portion 310 passes through the passivation layer 130 and is electrically connected to the second doped conductive layer 140. The second transmission portion 320 is located on the side of the passivation layer 130 away from the semiconductor substrate 100. Since the first current collector 200 passes through the passivation layer 130 only through the first contact portion 210, the damage to the passivation layer 130 is reduced, the passivation performance is guaranteed, recombination is reduced, and the turn-on voltage is improved. The passivation layer 130 may include one or more of the following materials: silicon oxide, silicon carbide, aluminum oxide, silicon nitride, silicon oxynitride, and silicon carbide.

[0081] like Figure 3 As shown, the second surface of the solar cell is also provided with a passivation and antireflection layer 150. The passivation and antireflection layer 150 may include one or more of the following materials: silicon oxide, silicon carbide, silicon nitride, aluminum oxide, silicon oxynitride, and silicon carbide, which serve to passivate and reduce reflection.

[0082] like Figure 1 and Figure 2 As shown, in some embodiments, among the plurality of first contact portions 210, n first contact portions 210 contact the first edge bus electrode 400; the width of the first edge bus electrode 400 in the first direction varies along the second direction; each of the n first contact portions 210 includes a sub-overlap portion 211 covered by the first edge bus electrode 400. Specifically, the projection of the sub-overlap portion 211 of the first contact portion 210 on the first surface completely coincides with the projection of the first edge bus electrode 400 on the first surface. The sub-overlap portion 211 may be located on the side of the first edge bus electrode 400 away from the semiconductor substrate 100, or the sub-overlap portion 211 may be located on the side of the first edge bus electrode 400 close to the semiconductor substrate 100, or the sub-overlap portion 211 may overlap with the first edge bus electrode 400 in the thickness direction. The lengths of the n sub-joints 211 in the first direction are different, where n is a positive integer and 5≤n≤15, specifically 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15.

[0083] When the above technical solution is adopted, when multiple first current collectors 200 are electrically connected to the first edge bus electrode 400, among the multiple first contact portions 210 of these first current collectors 200, n first contact portions 210 contact the first edge bus electrode 400, and all n first contact portions 210 overlap with the first edge bus electrode 400. The overlapping part is the sub-overlap portion 211. The sub-overlap portion 211 ensures that the current collected from the edge of the solar cell is transmitted to the first edge bus electrode 400. In addition, the width of the first edge bus electrode 400 in the first direction varies along the second direction, that is, the first edge bus electrode 400 is not of uniform width. On the basis of satisfying the current transmission, the width of some positions of the first edge bus electrode 400 can be appropriately changed to achieve the purpose of saving paste. Due to the width variation of the first edge bus electrode 400, the n sub-overlapping portions 211 that overlap at different positions in the second direction of the first edge bus electrode 400 have different overlap lengths as the width of the first edge bus electrode 400 varies.

[0084] like Figure 2 As shown, in some embodiments, among the n first contact portions 210 that overlap with the first edge bus electrode 400, m of the first contact portions 210 include sub-extension portions 212 that are not covered by the first edge bus electrode 400. That is, the m first contact portions 210 simultaneously include sub-overlapping portions 211 and sub-extension portions 212. The lengths of the m sub-extension portions 212 in the first direction are different, where 3 ≤ m ≤ n. All the remaining first contact portions 210 besides the m ones overlap with the first edge bus electrode 400 but do not extend beyond it, i.e., they only include sub-overlapping portions 211. Here, m can be 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

[0085] In the above technical solution, among the n first contact portions 210 that overlap with the first edge busbar 400, m of the first contact portions 210 do not completely overlap with the first edge busbar 400, but only partially overlap. The unoverlapped portion extends outward along the first direction toward the third side 13, forming a sub-extension portion 212. The end of the sub-extension portion 212 closer to the third side 13 is closer to the third side 13 than the first edge busbar 400. The sub-extension portion 212 collects the charge carriers of the first doped conductive layer 120 between the first edge busbar 400 and the third side 13, thereby enhancing the current collection of the first current collector 200 at the edge of the solar cell. Due to the variation in the width of the first edge busbar 400, the lengths of the m sub-extension portions 212 extending outward at different positions in the second direction of the first edge busbar 400 vary with the width of the first edge busbar 400.

[0086] For example, the length of each of the n sub-overlapping portions 211 in the first direction is greater than or equal to 0.1 mm. Specifically, it can be 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, etc. The length of the sub-overlapping portion 211 is determined based on the width of the overlap position of the first edge bus electrode 400 in the first direction, the length of the first contact portion 210 in the first direction, and the overlap position. If the overlap length of the sub-overlapping portion 211 is less than 0.1 mm, the length of the sub-overlapping portion 211 is too small, which is not conducive to the transmission of edge current from the solar cell to the first edge bus electrode 400.

[0087] In some embodiments, the difference between the maximum and minimum lengths of the n sub-overlapping portions 211 in the first direction is 0.05mm to 0.25mm, specifically, the difference can be 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, etc. Due to the variation in the width of the first edge bus electrode 400 and the different positions of the first contact portions 210, the overlap lengths between the n first contact portions 210 and the first edge bus electrode 400 are different. By controlling the difference between the overlap lengths within the above range, the overlap of each sub-overlapping portion 211 can be made more uniform, which is beneficial to improving the uniformity of current transmission at the edges of each first collector electrode 200.

[0088] like Figure 2 As shown, in some embodiments, the length of the m sub-extensions 212 in the first direction is less than or equal to 2 mm, specifically 0.01 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc. If the length of the sub-extensions 212 is greater than 2 mm, the sub-extensions 212 are too close to the third side 13, leaving insufficient space for printing the first current collector electrode 200, affecting the printing quality. Furthermore, the carrier concentration is low at the edge of the solar cell, and providing too many first contact portions 210 at the edge has limited actual collection effect. The aforementioned length setting of the sub-extensions 212 can balance the carrier collection effect and further reduce unit silver consumption.

[0089] In some embodiments, the difference between the maximum and minimum lengths of the m sub-extensions 212 in the first direction is 0.05 mm to 0.1 mm. Specifically, the difference can be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, etc. Due to the variation in width of the first edge busbar electrode 400 and the different arrangement positions of the first contact portions 210, the lengths of the m sub-extensions 212 in the first direction are different. The length difference between each sub-extension 212 is within the above range, so that the printing positions of the first contact portions 210 at the edges of each first collector electrode 200 are not significantly different. This is beneficial for unifying the printing positions and simplifying the printing process. Furthermore, the relatively uniform lengths of each sub-extension 212 are beneficial for the uniformity of carrier collection of the first doped conductive layer 120 between the first edge busbar electrode 400 and the third side 13 by each sub-extension 212, further enhancing the current collection of the first collector electrode 200 at the edge of the solar cell.

[0090] like Figure 1 and Figure 2 As shown, in some embodiments, a connecting line 500 is provided between the first edge bus electrode 400 and the first edge interconnect 700. The number of connecting lines 500 can be one, two, three, or more. The connecting line 500 has an overlapping portion that overlaps with the first edge bus electrode 400. The first edge bus electrode 400 and the first edge interconnect 700 are further connected and conductive through the connecting line 500. The length of the overlapping portion in the first direction is greater than or equal to 0.08 mm, specifically 0.08 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, etc. In this way, the length of the overlapping portion being greater than or equal to 0.08 mm effectively ensures the current transmission effect while ensuring that the edge tension of the component meets the requirements.

[0091] like Figure 1 As shown, in some embodiments, the first edge bus electrode 400 includes end portions located at both ends along a second direction and a middle portion located between the two end portions. The number of first collector electrodes 200 overlapping with the middle portion is greater than the number of first collector electrodes 200 overlapping with any one end. That is, the middle portion of the first edge bus electrode 400 has more and denser first collector electrodes 200 connected to it. This design is beneficial for the collection of edge carriers in solar cells and for improving the overall welding pull force.

[0092] In some embodiments, in the first direction, the width of the end portion of the first edge bus electrode 400 is smaller than the width of the middle portion. The minimum width of the end portion is greater than or equal to 0.02 mm, specifically 0.02 mm, 0.04 mm, 0.07 mm, etc., and the maximum width of the middle portion is less than or equal to 1 mm, specifically 0.1 mm, 0.2 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, etc. Thus, the first edge bus electrode 400 is wider in the middle and narrower at both ends, which facilitates the connection of the wider middle portion with more first current collector electrodes 200, increasing the connection area and thereby improving the overall welding pull force.

[0093] like Figure 1 and Figure 2 As shown, in some embodiments, the solar cell further includes a second edge interconnect 800 and a second edge bus electrode 600; wherein, the second edge interconnect 800 is disposed on the side of the second doped conductive layer 140 away from the semiconductor substrate 100, close to the fourth side 14, the second edge interconnect 800 is electrically connected to the second current collector 300, and the number of second edge interconnects 800 can be two, respectively located at both ends close to the fourth side 14, that is, one second edge interconnect 800 is close to both the first side 11 and the fourth side 14, and the other second edge interconnect is close to both the second side and the fourth side 14; the second edge interconnect 800 can be a pad structure for conductive connection with the solder strip; The second edge bus electrode 600 is disposed between the second edge interconnect 800 and the fourth side 14, and the second edge bus electrode 600 extends along the second direction. The second edge bus electrode 600 is electrically connected to the second collector electrode 300. Among the multiple second contact portions 310 of the multiple second collector electrodes 300, at least one of the second contact portions 310 is closer to the fourth side 14 than the second edge bus electrode 600. In the second direction, the width of the first edge interconnect 700 is L1, the first distance between two adjacent first collector electrodes 200 is d1, the width of the second edge interconnect 800 is L2, and the second distance between two adjacent second collector electrodes 300 is d2.

[0094] With the above technical solution, there is a distance between the second edge bus electrode 600 located at the edge of the solar cell and the fourth side 14. At least one of the multiple second contact portions 310 is closer to the fourth side 14 than the second edge bus electrode 600, so that the second contact portion 310 can contact the second doped conductive layer 140 located in the region between the second edge bus electrode 600 and the fourth side 14. That is, the second contact portion 310 contacts the second doped conductive layer 140 located at the edge of the solar cell to collect the charge carriers between the second edge bus electrode 600 and the fourth side 14, thereby improving the charge carrier collection capability at the edge of the solar cell.

[0095] The second edge bus electrode 600 and the second edge interconnect 800 are also connected by a connecting line. For details, please refer to the connecting line configuration between the first edge bus electrode 400 and the first edge interconnect 700. It will not be described in detail here.

[0096] like Figure 1 As shown, as an optional implementation, the number e of the first collector electrodes 200 connected to the first edge interconnect 700 is greater than or equal to the number f of the second collector electrodes 300 connected to the second edge interconnect 800. Since the doping concentrations of the first doped conductive layer 120 and the second doped conductive layer 140 are different, their current densities are also different. When the current density of the first doped conductive layer 120 is higher, more first collector electrodes 200 are needed to collect carriers and improve current transport capability. Therefore, the number e of the first collector electrodes 200 connected to the first edge interconnect 700 is adjusted to be greater than or equal to the number f of the second collector electrodes 300 connected to the second edge interconnect 800.

[0097] For example, the first doped conductive layer 120 is a P-type doped conductive layer, and the second doped conductive layer 140 is an N-type doped conductive layer. Since the P-type doped conductive layer has a higher current density, more first collector electrodes 200 are needed to collect the charge carriers from the P-type doped conductive layer. This allows for the connection of more first collector electrodes 200 with the first edge interconnect 700, thereby improving current transmission capability. Of course, the first doped conductive layer 120 can also be an N-type doped conductive layer, and the second doped conductive layer 140 can be a P-type doped conductive layer. When the current density of the N-type doped conductive layer is higher, more first collector electrodes 200 are also needed to collect the charge carriers from the N-type doped conductive layer, thus improving current transmission capability.

[0098] For example, the number of first collector electrodes 200 connected to the first edge interconnect 700 can be one, two, three, etc., and the number of second collector electrodes 300 connected to the second edge interconnect 800 can be one, two, three, etc.

[0099] Based on the premise that the number e of the first collector electrodes 200 connected to the first edge interconnect 700 is greater than or equal to the number f of the second collector electrodes 300 connected to the second edge interconnect 800, L1 / d1 ≥ e-1, L2 / d2 ≥ f-1. For example, when 1 ≤ L1 / d1 < 2, L1 / d1 is rounded down to 1, 1 ≥ e-1, then e ≤ 2, and e can be 1 or 2. Similarly, when 1 ≤ L2 / d2 < 2, L2 / d2 is rounded down to 1, 1 ≥ f-1, then f ≤ 2, and f can be 1 or 2. In this way, with a fixed width and first spacing between adjacent first collector electrodes 200, and with the collector electrodes fully collecting charge carriers, the first edge interconnect 700 can be connected to as many first collector electrodes 200 as possible, improving current transmission capability. The connection arrangement of the second edge interconnect 800 and the second collector electrodes 300 is for the same purpose and will not be described further.

[0100] In some embodiments, the solar cell further includes a plurality of first busbars, which extend along a second direction and are spaced apart along a first direction. The first busbars are electrically connected to the first current collector 200. The first busbars can be solder strips, which can be conductively connected to the solder pads on the solar cell or the thickened section on the first current collector 200. The current collected by the first current collector 200 is collected through the first busbars, and the current is discharged through the first busbars.

[0101] And / or, the solar cell also includes a plurality of second busbars, which extend along a second direction and are spaced apart along a first direction. The second busbars are electrically connected to the second current collector 300. The second busbars can be solder strips, which can be conductively connected to solder pads on the solar cell or to a thickened section on the second current collector 300. The current collected by the second current collector 300 is collected through the second busbars and then discharged through them.

[0102] like Figure 5As shown, this embodiment also provides another type of solar cell, which is a bifacial cell, i.e., the doped conductive layer includes a first doped conductive layer and a second doped conductive layer, wherein the first doped conductive layer is disposed on a first surface and the second doped conductive layer is disposed on a second surface, and the first doped conductive layer and the second doped conductive layer have different conductivity types; the multiple current collectors include multiple first current collectors 200 and multiple second current collectors, wherein the multiple first current collectors 200 are disposed on the side of the first doped conductive layer away from the semiconductor substrate, and the multiple first current collectors 200 extend along a first direction and are spaced apart along a second direction; The first collector electrode 200 includes at least one segment of the first collector electrode 200 along the first direction. Each segment of the at least one first collector electrode 200 includes a plurality of first contact portions and a first transmission portion. The plurality of first contact portions are electrically connected to the first doped conductive layer and are spaced apart along the first direction. The first transmission portion is disposed on the side of the first contact portion away from the semiconductor substrate and is in contact with the plurality of first contact portions. The first transmission portion extends along the first direction. The arrangement of the first contact portion and the first transmission portion of the bifacial battery can be referred to the relevant description of the first contact portion 210 and the first transmission portion 220 of the back contact battery described above.

[0103] Multiple second current collectors are disposed on the side of the second doped conductive layer away from the semiconductor substrate. The multiple second current collectors extend along a first direction and are spaced apart along a second direction. Each second current collector along the first direction includes at least one segment of the second current collector, and each segment of the at least one second current collector includes multiple second contact portions and a second transmission portion. The multiple second contact portions are electrically connected to the second doped conductive layer and are spaced apart along the first direction. The second transmission portion is disposed on the side of the second contact portion away from the semiconductor substrate and is in contact with the multiple second contact portions. The second transmission portion extends along the first direction. A frame electrode 900 is disposed on the first surface and the second surface. The frame electrode 900 is disposed at the periphery of the first surface and the second surface. The arrangement of the second contact portion and the second transmission portion of the bifacial battery can be referred to the relevant description of the second contact portion 310 and the second transmission portion 320 of the back contact battery described above.

[0104] Wherein, at least one of the plurality of first contact portions of the first collector electrode 200 includes a third extending portion 215 that extends beyond the frame electrode 900, that is, at least one first contact portion of the first collector electrode 200 near the frame electrode 900 extends beyond the frame electrode 900 along a first direction, and the extended portion forms the third extending portion 215. And / or, at least one of the plurality of second contact portions of the second collector electrode includes a fourth extending portion that extends beyond the frame electrode, that is, at least one second contact portion of the second collector electrode near the frame electrode extends beyond the frame electrode along a first direction, and the extended portion forms the fourth extending portion.

[0105] When the above technical solution is adopted, the solar cell is a bifacial cell. For the bifacial cell, a first current collector electrode and a second current collector electrode are respectively provided on the first surface and the second surface. The first contact portion of the first current collector electrode extends beyond the frame electrode in a first direction, and the second contact portion of the second current collector electrode extends beyond the frame electrode in a first direction, so that the third extended portion contacts the first doped conductive layer outside the frame electrode and collects the charge carriers at the edge of the first doped conductive layer. Similarly, the fourth extended portion contacts the second doped conductive layer outside the frame electrode and collects the charge carriers at the edge of the second doped conductive layer, thereby improving the charge carrier collection capability at the edge of the solar cell.

[0106] It should be noted that this bifacial cell can be a tunneling passivated contact solar cell, meaning that one side of the cell has a tunneling oxide layer, which is stacked with a doped conductive layer (which can be doped polycrystalline silicon, doped microcrystalline silicon, etc.) to form a tunneling passivated contact structure. Alternatively, the bifacial cell can also be a heterojunction solar cell, meaning one side of the cell has an intrinsic amorphous silicon layer, which is stacked with a doped conductive layer (which can be doped amorphous silicon) to form a heterojunction structure.

[0107] Based on the solar cells described in any of the above embodiments, this utility model also provides a photovoltaic module, including a cell string, interconnects, and an encapsulation layer. The cell string is formed by electrically connecting a plurality of solar cells as described in any of the above embodiments; the interconnects are electrically connected to the solar cells and are busbars; the encapsulation layer covers the surface of the cell string. The encapsulation layer may include cover plates and back plates located on both sides of the cell string, as well as encapsulating films and other structures for encapsulation. Since this photovoltaic module uses the solar cells described in any of the above embodiments, it has the same beneficial effects as any of the above embodiments. Since the photovoltaic module includes the solar cells of the first aspect, it has the same beneficial effects as the first aspect, and will not be described again.

[0108] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0109] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A solar cell, characterized in that, include: A semiconductor substrate, the semiconductor substrate including a first surface and a second surface opposite to each other, and four sides connecting the first surface and the second surface, wherein the first side and the second side are parallel to a first direction, and the third side and the fourth side are parallel to a second direction; Doped conductive layer; as well as A plurality of current collector electrodes are disposed on the side of the doped conductive layer away from the semiconductor substrate. The plurality of current collector electrodes extend along a first direction and are spaced apart along a second direction. Each current collector electrode includes at least one segment along the first direction. Each segment of the at least one current collector electrode includes a plurality of contact portions and a transmission portion. The plurality of contact portions are electrically connected to the doped conductive layer and are spaced apart along the first direction. The transmission portion is disposed on the side of the contact portion away from the semiconductor substrate and is in contact with the plurality of contact portions. The transmission portion extends along the first direction. The transmission section includes ends located at both ends along the first direction. Among the plurality of contact sections, a of the contact sections includes an overhanging portion extending beyond the ends along the first direction and an overlapping portion covered by the transmission section, where 1 ≤ a ≤ 4.

2. The solar cell according to claim 1, characterized in that, Along the first direction: The length of the overlapping portion ranges from 0-500 μm; and / or, The length of the protruding portion ranges from 0-500 μm; and / or, The ratio of the length of the overlapping portion to the length of the transmission portion is 0.01-100; and / or, The ratio of the length of the extended portion to the length of the transmission portion is 0.01-100.

3. The solar cell according to claim 1, characterized in that, Along the second direction: The width of the overlapping portion is less than or equal to the width of the transmission portion; and / or, The width of the overhanging portion is less than or equal to the width of the transmission portion; and / or, The ratio of the width of the overhang to the width of the transmission section is 0.2-1; and / or, The width of the protruding portion ranges from 2μm to 50μm; and / or, The width of the transmission section ranges from 10μm to 100μm.

4. The solar cell according to claim 1, characterized in that, The distance between the contact portion and the third side is greater than or equal to 0.3 mm; and / or, The distance between the contact portion and the fourth side is greater than or equal to 0.3 mm.

5. The solar cell according to claim 1, characterized in that, The doped conductive layer includes a first doped conductive layer and a second doped conductive layer alternately disposed on the first surface. The plurality of collector electrodes includes a plurality of first collector electrodes and a plurality of second collector electrodes, wherein the plurality of first collector electrodes are disposed on the side of the first doped conductive layer away from the semiconductor substrate, the plurality of first collector electrodes extend along the first direction and are spaced apart along the second direction; each of the first collector electrodes includes at least one segment along the first direction, each segment of the at least one first collector electrode including a plurality of first contact portions and a first transmission portion, the plurality of first contact portions being electrically connected to the first doped conductive layer, the plurality of first contact portions being spaced apart along the first direction; the first transmission portion is disposed on the side of the first contact portion away from the semiconductor substrate and is in contact with the plurality of first contact portions, the first transmission portion extending along the first direction; The plurality of second collector electrodes are disposed on the side of the second doped conductive layer away from the semiconductor substrate. The plurality of second collector electrodes extend along the first direction and are spaced apart along the second direction. Each second collector electrode includes at least one segment along the first direction. Each segment of the at least one second collector electrode includes a plurality of second contact portions and a second transmission portion. The plurality of second contact portions are electrically connected to the second doped conductive layer and are spaced apart along the first direction. The second transmission portion is disposed on the side of the second contact portion away from the semiconductor substrate and is in contact with the plurality of second contact portions. The second transmission portion extends along the first direction. At least one of the plurality of first contact portions includes a first overlapping portion covered by the first transmission portion and a first extending portion not covered by the first transmission portion; and / or At least one of the plurality of second contact portions includes a second overlapping portion covered by the second transmission portion and a second overhang portion not covered by the second transmission portion.

6. The solar cell according to claim 5, characterized in that, In at least one of the first current collector electrodes, the ratio of the length of at least one first contact portion along the first direction to the distance between first contact portions adjacent to the first contact portion is a first ratio value. In at least one of the second current collector electrodes, the ratio of the length of at least one second contact portion along the first direction to the distance between adjacent second contact portions is a second ratio value. The first ratio is greater than the second ratio; And / or, In at least one of the first current collector electrodes, the first ratio of the length of the first contact portion along the first direction to the distance between the first contact portions adjacent to the first contact portion is 0.1-5; And / or, In at least one of the second current collector electrodes, the second ratio of the length of the second contact portion along the first direction to the spacing between adjacent second contact portions is 0.1-5.

7. The solar cell according to claim 5, characterized in that, In at least one first current collector electrode, the sum of the lengths of the plurality of first contacts along the first direction is greater than the sum of the lengths of the plurality of second contacts along the first direction in at least one second current collector electrode; And / or, in at least one of the first current collector electrodes, the length of at least one of the first contact portions along the first direction is greater than the length of at least one of the second current collector electrodes along the first direction; And / or, in at least one of the first current collector electrodes, the length of the first contact portion along the first direction is 5μm-100μm, or in at least one of the second current collector electrodes, the length of the second contact portion along the first direction is 5μm-100μm.

8. The solar cell according to claim 5, characterized in that, The width of the first contact portion along the second direction is greater than the width of the second contact portion along the second direction; and / or, The width of the first transmission section along the second direction is greater than the width of the second transmission section along the second direction; and / or, The width of the first contact portion along the second direction and the width of the second contact portion along the second direction are 2μm-50μm, respectively; and / or, The width of the first transmission section along the second direction and the width of the second transmission section along the second direction are 10μm-100μm, respectively.

9. The solar cell according to claim 5, characterized in that, Along the first direction, the length of the first protruding portion is greater than the length of the second protruding portion; and / or, The length of the first overlapping portion is greater than the length of the second overlapping portion.

10. The solar cell according to claim 5, characterized in that, Also includes: A first edge interconnect is disposed on the side of the first doped conductive layer away from the semiconductor substrate and close to the third side, and the first edge interconnect is electrically connected to the first collector electrode; as well as A first edge bus electrode is disposed between the first edge interconnect and the third side, and the first edge bus electrode extends along the second direction and is electrically connected to the first collector electrode; Among the plurality of first contact portions, at least one of the first contact portions is closer to the third side than the first edge bus electrode.

11. The solar cell according to claim 10, characterized in that, Of the plurality of first contact portions, n of the first contact portions are in contact with the first edge busbar electrode; The width of the first edge bus electrode in the first direction varies along the second direction; each of the n first contact portions includes a sub-overlap portion covered by the first edge bus electrode, and the lengths of the n sub-overlap portions are different in the first direction, where n is a positive integer and 5≤n≤15.

12. The solar cell according to claim 11, characterized in that, Of the n first contact portions, m of the first contact portions include sub-extension portions not covered by the first edge busbar electrode, and the lengths of the m sub-extension portions are different in the first direction, wherein 3≤m≤n.

13. The solar cell according to claim 11, characterized in that, The length of each of the n sub-overlapping portions in the first direction is greater than or equal to 0.1 mm; And / or, the difference between the maximum and minimum lengths of the n sub-overlapping portions in the first direction is 0.05mm to 0.25mm.

14. The solar cell according to claim 12, characterized in that, The length of each of the m sub-protrusions in the first direction is less than or equal to 2 mm; And / or, the difference between the maximum and minimum lengths of the m sub-protrusions in the first direction is 0.05 mm to 1 mm.

15. The solar cell according to claim 10, characterized in that, A connecting line is provided between the first edge bus electrode and the first edge interconnect, the connecting line having an overlapping portion that overlaps with the first edge bus electrode, the length of the overlapping portion in the first direction being greater than or equal to 0.08 mm.

16. The solar cell according to claim 10, characterized in that, The first edge bus electrode includes ends located at both ends along the second direction and a middle portion located between the two ends, wherein the number of first collector electrodes overlapping the middle portion is greater than the number of first collector electrodes overlapping any one of the ends.

17. The solar cell according to claim 10, characterized in that, The solar cell also includes: A second edge interconnect is disposed on the side of the second doped conductive layer away from the semiconductor substrate, close to the first side and the fourth side, and the second edge interconnect is electrically connected to the second collector electrode; and The second edge bus electrode is disposed between the second edge interconnect and the fourth side, and the second edge bus electrode extends along the second direction and is electrically connected to the second collector electrode; In the second direction, the width of the first edge interconnect is L1, the first spacing between two adjacent first collector electrodes is d1, the width of the second edge interconnect is L2, and the second spacing between two adjacent second collector electrodes is d2.

18. The solar cell according to claim 17, characterized in that, The number e of the first collector electrodes that overlap with the first edge interconnect is greater than or equal to the number f of the second collector electrodes that overlap with the second edge interconnect; L1 / d1≥e-1, L2 / d2≥f-1.

19. The solar cell according to claim 1, characterized in that, The doped conductive layer includes a first doped conductive layer and a second doped conductive layer, wherein the first doped conductive layer is disposed on the first surface and the second doped conductive layer is disposed on the second surface; The plurality of collector electrodes includes a plurality of first collector electrodes and a plurality of second collector electrodes, wherein the plurality of first collector electrodes are disposed on the side of the first doped conductive layer away from the semiconductor substrate, the plurality of first collector electrodes extend along the first direction and are spaced apart along the second direction; each of the first collector electrodes includes at least one segment along the first direction, each segment of the at least one first collector electrode including a plurality of first contact portions and a first transmission portion, the plurality of first contact portions being electrically connected to the first doped conductive layer, the plurality of first contact portions being spaced apart along the first direction; the first transmission portion is disposed on the side of the first contact portion away from the semiconductor substrate and is in contact with the plurality of first contact portions, the first transmission portion extending along the first direction; The plurality of second collector electrodes are disposed on the side of the second doped conductive layer away from the semiconductor substrate. The plurality of second collector electrodes extend along the first direction and are spaced apart along the second direction. Each second collector electrode includes at least one segment along the first direction. Each segment of the at least one second collector electrode includes a plurality of second contact portions and a second transmission portion. The plurality of second contact portions are electrically connected to the second doped conductive layer and are spaced apart along the first direction. The second transmission portion is disposed on the side of the second contact portion away from the semiconductor substrate and is in contact with the plurality of second contact portions. The second transmission portion extends along the first direction. The first surface and the second surface are provided with frame electrodes. Wherein, at least one of the plurality of first contact portions includes a third protruding portion extending beyond the frame electrode; and / or, At least one of the plurality of second contact portions includes a fourth extension portion that extends beyond the frame electrode.

20. A photovoltaic module, characterized in that, include: A battery string, the battery string being formed by electrically connecting a plurality of solar cells as described in any one of claims 1 to 19; Interconnectors are electrically connected to the solar cells; And an encapsulation layer that covers the surface of the battery string.

Images