A solar cell and photovoltaic module

Abstract

The application discloses a solar cell and a photovoltaic module, relates to the photovoltaic technical field, and aims to increase the carrier collection range of a partial region in a first doped semiconductor layer. The solar cell comprises a semiconductor substrate, a first doped semiconductor layer and a first electrode. The first doped semiconductor layer comprises a plurality of first strip-shaped parts. In a first direction, the first strip-shaped part comprises a first region and a second region other than the first region, and the width of the first region is greater than the width of the second region. The first region comprises a first edge and a second edge which are oppositely arranged and extend in the first direction. In the same first region in the first direction, two end points of the first edge are arranged staggeredly with two end points of the corresponding second edge; and / or, the first edge and the second edge are both provided with at least one first protruding unit which is distributed at intervals in the first direction and protrudes in a second direction, and the first protruding unit of the first edge and the first protruding unit of the second edge are arranged staggeredly in the first direction.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and more particularly to a solar cell and a photovoltaic module. Background Technology

[0002] A solar cell is a device that converts sunlight into electrical energy. Specifically, when a solar cell is in operation, sunlight shines on it, creating new electron-hole pairs. Under the influence of the built-in electric field of the pn junction, photogenerated holes flow to the p-region, and photogenerated electrons flow to the n-region. Once the circuit is connected through the electrode structure, an electric current is generated.

[0003] However, in existing solar cells, the doped semiconductor part has a weak ability to collect charge carriers, which in turn affects the working performance of the solar cell. Utility Model Content

[0004] The purpose of this application is to provide a solar cell and a photovoltaic module for increasing the carrier collection range in a portion of the doped semiconductor layer, improving the carrier collection efficiency of the doped semiconductor layer, and thus improving the working performance of the solar cell.

[0005] To achieve the above objectives, in a first aspect, this application provides a solar cell, comprising: a semiconductor substrate, a first doped semiconductor layer, and a first electrode. The semiconductor substrate includes a first surface and a second surface facing each other. The first doped semiconductor layer is disposed on a local region of the first surface. The first doped semiconductor layer includes a plurality of first strip-shaped portions extending along a first direction and spaced apart along a second direction. The first direction and the second direction intersect. Along the first direction, the first strip-shaped portions include a first region and a second region other than the first region, the width of the first region being greater than the width of the second region. The first electrode is disposed on a side of the first doped semiconductor layer facing away from the semiconductor substrate. The first region includes a first edge and a second edge facing each other and extending along the first direction. Along the first direction, within the same first region, the two endpoints of the first edge are respectively offset from the two endpoints of the corresponding second edge; and / or, both the first edge and the second edge are provided with at least one first protruding unit spaced apart along the first direction and protruding along the second direction, the first protruding units of the first edge and the first protruding units of the second edge being offset along the first direction.

[0006] The first doped semiconductor layer includes a first strip-shaped portion for collecting charge carriers and discharging them through a first electrode disposed thereon. Within the first strip-shaped portion, there is a first region with a larger width and a second region with a smaller width. Charge carriers collected by the first electrode located in the second region can flow to the first electrode located in the first region and be discharging through the first electrode in the first region to an intra-string interconnect (the intra-string interconnect is used to interconnect adjacent solar cells; the intra-string interconnect can be a conductive structure such as a solder ribbon). The larger width of the first region is beneficial for increasing the interconnect area between the intra-string interconnect and the first region, thus reducing the interconnect resistance. The smaller width of the second region is beneficial for reducing parasitic absorption in the first doped semiconductor layer.

[0007] Furthermore, when the two endpoints of the first edge within the same first region are staggered from the two endpoints of the corresponding second edge along the first direction, the first edge within the same first region shifts relative to the second edge along the first direction, effectively widening the actual carrier collection range of the first region along the first direction and improving carrier collection efficiency. Simultaneously, even if interconnecting elements are disposed on the first surface of the solar cell, and operational errors cause the actual placement position to shift relative to the designed position along the first direction, it can still be located on the first region, increasing the contact probability between the interconnecting elements and the first region. When both the first and second edges are provided with at least one first protruding unit spaced apart along the first direction and protruding along the second direction, the boundaries of different regions corresponding to the first protruding unit along the first direction and the recessed portion adjacent to the first protruding unit within the same first region shift along the second direction, effectively widening the actual carrier collection range of the first region along the second direction. Furthermore, when the first protruding units on the first edge and the second edge are staggered along the first direction, the recessed portions adjacent to the first protruding units in one of the first and second edges can be staggered, resulting in different regions along the first direction within the same first region having a larger width. This facilitates a larger actual carrier collection range along the second direction in different regions along the first direction within the same first region, improving the carrier collection efficiency of the first doped semiconductor layer and thus enhancing the performance of the solar cell. Especially in situations with limited design space, such as when it is necessary to control the coverage area of ​​the doped semiconductor layer on the first surface, or when a dense grid scheme requires a more compact arrangement of the doped semiconductor layer, the actual carrier collection range can be improved through the above two methods, thereby enhancing cell performance.

[0008] As one possible implementation, the first electrode includes multiple first electrical junctions and multiple first collector electrodes. The first electrical junctions are disposed on a first region. The first collector electrodes are disposed on a second region and are electrically connected to the first electrical junctions. Along a second direction, the width of the first electrical junctions is greater than the width of the first collector electrodes.

[0009] The width of the first electrical junction is greater than the width of the first current collector electrode, which increases the contact area between the first electrical junction and the interconnecting elements in the string, reduces the contact resistance between them, facilitates the collection and discharging of charge carriers, and reduces transmission losses. Secondly, the first region in the first strip has a larger width (relative to the second region). Therefore, even if the first electrical junction has a larger width, it can prevent excessive metal recombination losses caused by the edge region of the first electrical junction extending along the first direction crossing the boundary of the first region, or the risk of leakage and short circuit caused by the contact between the first electrical junction and the heterodyne-doped semiconductor layer for back-contact cells. This improves the electrical reliability of the solar cell and also reduces the process difficulty of forming the first electrical junction on the first region, thereby improving the yield of the solar cell.

[0010] As one possible implementation, along the first direction, the ratio of the length of at least one first protruding unit to the length of the first region is greater than or equal to one-fiftieth and less than or equal to one-half.

[0011] The ratio of the length of at least one first protruding unit to the length of the first region is within the aforementioned range. This prevents the first protruding unit from being too small, which would limit the growth of the actual carrier collection range corresponding to the first protruding unit and thus ensure a higher carrier collection efficiency in the first region. Furthermore, it prevents the proportion of the wider portion of the first region due to the presence of the first protruding unit from being too large, which helps reduce parasitic absorption of the first doped semiconductor layer in the first region. Secondly, for back-contact cells, this also prevents the leakage risk between the second doped semiconductor layer and the first region from being too high due to the excessive length of the wider portion of the first region, thus improving the performance of the solar cell.

[0012] As one possible implementation, along the first direction, the ratio of the distance between two adjacent first protruding units to the length of the first region is greater than or equal to one-fiftieth and less than or equal to three-quarters.

[0013] The ratio of the spacing between two adjacent first protruding units to the length of the first region is within the aforementioned range. This prevents the proportion of the length of the first protruding units in the first edge and / or the second edge from being too large due to an excessively small ratio, thus preventing the portion of the first region with a larger width due to the presence of the first protruding units from becoming too large. Furthermore, this ratio also prevents the proportion of the length of the first protruding units in the first edge and / or the second edge from becoming too small due to an excessively large ratio, thus preventing the effective increase in the actual carrier collection range corresponding to the first protruding units in the first region. The application principle of this beneficial effect can be referred to the preceding text and will not be repeated here.

[0014] As one possible implementation, the ratio of the width of the first region along the second direction to the distance by which at least one first protruding unit protrudes along the second direction is greater than or equal to 2 and less than or equal to 1000.

[0015] The ratio of the width of the first region along the second direction to the distance by which at least one first protruding unit protrudes along the second direction is within the aforementioned range. This prevents the width growth of the corresponding region within the first region from being limited due to the presence of the first protruding unit at the first edge and / or second edge, thus ensuring a higher carrier collection efficiency in the first region. Furthermore, it prevents the width of the region corresponding to the first protruding unit within the first region from being excessively large due to an excessively large ratio, which helps reduce parasitic absorption of the first doped semiconductor layer in the first region. Secondly, for back-contact cells, it also prevents a high risk of leakage between the second doped semiconductor layer and the region corresponding to the first protruding unit in the first region, thereby improving the performance of the solar cell.

[0016] As one possible implementation, the ratio of the width of the first zone to the width of the second zone is greater than or equal to 1.2 and less than or equal to 3.

[0017] The ratio of the widths of the first region and the second region being within the aforementioned range prevents the first region from being too narrow due to an excessively small ratio, ensuring a large interconnect area between the first region and the interconnect components within the string, and / or reducing the manufacturing difficulty of the wider first electrical junction portion on the first region. Furthermore, it prevents the first region from being too wide and / or the second region from being too narrow due to an excessively large ratio, reducing the risk of parasitic absorption and leakage of the first doped semiconductor layer in the first region, while also lowering the required process precision when manufacturing the first collector electrode on the second region, thus reducing manufacturing difficulty.

[0018] As one possible implementation, along the first direction, the ratio of the length of the first region to the distance offset from at least one endpoint of the first edge and the corresponding endpoint of the second edge is greater than 0 and less than or equal to 14.5.

[0019] The ratio of the length of the first region to the distance by which it is offset from at least one endpoint of the first edge and the corresponding endpoint of the second edge is within the aforementioned range. This prevents the growth of the actual carrier collection range of the first region along the first direction from being limited due to a small ratio, thus ensuring that the first region has a high carrier collection efficiency along the first direction. Furthermore, it prevents the length of the edge portions with smaller widths at both ends of the first region along the first direction from being excessively long due to the offset of the first and second edges along the second direction. This ensures that the edge portions at both ends of the first region along the first direction also have a certain carrier collection range in the second direction, and also helps to reduce the manufacturing difficulty of the first electrical connection portion at the edge portions at both ends of the first region along the first direction.

[0020] As one possible implementation, along the first direction, the length of at least one first protruding unit located on the outer side of the first edge and / or the second edge is less than the length of the remaining first protruding units. This configuration differentiates the lengths of the outer first protruding units on the first edge and / or the second edge from the remaining first protruding units. Since there is a certain distance between the edge portion of the first electrical junction along the first direction and the edge of the first region extending along the second direction, when the length of at least one first protruding unit on the outer side of the first edge and / or the second edge is smaller, and the lengths of the remaining first protruding units are larger, the width of the first region can be increased by using the larger first protruding units located in the middle. This reduces the manufacturing difficulty of the first electrical junction and also reduces the risk of parasitic absorption and leakage current at the edge portion of the first region along the first direction where no first electrical junction is provided, resulting in higher performance of the solar cell.

[0021] As one possible implementation, the number of first protruding units on the first edge is greater than the number of first protruding units on the second edge; and / or, along the first direction, the length of at least one first protruding unit on the first edge is different from the length of the first protruding unit on the second edge; and / or, the distance by which at least one first protruding unit on the first edge protrudes along the second direction is different from the distance by which the first protruding unit on the second edge protrudes along the second direction. With this configuration, the first protruding units on the first edge and the second edge are differentiated, achieving a diversified configuration of the carrier collection range on the side corresponding to the first edge and the side corresponding to the second edge of the first region.

[0022] As one possible implementation, the solar cell further includes a second doped semiconductor layer. The second doped semiconductor layer is disposed on a local region of the first surface, and the conductivity type of the second doped semiconductor layer is opposite to that of the first doped semiconductor layer. The second doped semiconductor layer includes a plurality of second stripes extending along a first direction and spaced apart along a second direction, with the first and second stripes alternately spaced along the second direction.

[0023] As one possible implementation, at least one second strip includes a third region and a fourth region other than the third region. The width of the third region is smaller than the width of the fourth region. The third region included in at least one second strip is correspondingly arranged with the first region included in the adjacent first strip.

[0024] At least one of the narrower third regions in the second stripe is correspondingly positioned to the wider first region in the adjacent first stripe. This facilitates the effective utilization of the surface area in the first surface and promotes timely splitting and collection of charge carriers. Furthermore, the correspondence between the narrower third region and the wider first region ensures a certain distance between them, reducing the risk of leakage and making the corresponding patterns of the first and second stripes relatively regular, thus reducing the difficulty of patterning.

[0025] As one possible implementation, the end of the first region immediately adjacent to the second region has a first inflection point protruding outward along the second direction, and the end of the fourth region immediately adjacent to the third region has a second inflection point protruding outward along the second direction. The line connecting at least one first inflection point and an adjacent second inflection point is parallel to the first direction; or, the extension line of at least one first inflection point in the first direction is located on the side of the extension line of the adjacent second inflection point in the first direction closer to the second region. This arrangement helps to increase the distance between the end of the first region immediately adjacent to the second region and the adjacent third region, which has the opposite conductivity type, along the second direction, thus reducing the risk of leakage between them.

[0026] As one possible implementation, the region located between the first doped semiconductor layer and the second doped semiconductor layer in the first surface is a spacer region. Specifically, along the first direction, the length of the third region is greater than the length of the adjacent first region, and the portion of the spacer region located between the end of the third region along the first direction and the end of the adjacent first region along the first direction is a corner region. The width of the corner region along the second direction is greater than the width of the remaining portion of the spacer region excluding the corner regions; and / or, the width of the spacer region between the first region and the adjacent third region is s, and the width of the spacer region between the second region and the adjacent fourth region is r, where 0.5r ≤ s ≤ 2r.

[0027] There are corners at the ends of the first and second regions, and at the ends of the fourth and third regions, where the electric field is relatively concentrated, leading to a higher risk of leakage. Increasing the width of the corner region along the second direction to be greater than the width of the remaining spaces between the corner regions increases the distance between the ends of the first and second regions, and between the ends of the fourth and third regions, thus reducing the carrier recombination rate at the corners. Furthermore, when the relationship between r and s satisfies the above, the width of the spacer at different locations can be set according to actual needs, which is beneficial for reducing the risk of leakage.

[0028] As one possible implementation, the second region has multiple second protruding units that are spaced apart along the first direction and protrude along the second direction on both sides of its two-sided boundary. Specifically, at least one first protruding unit protrudes a distance greater than or equal to the distance at least one second protruding unit protrudes along the second direction; and / or, along the first direction, the distance between two adjacent first protruding units is less than the distance between two adjacent second protruding units.

[0029] The distance that charge carriers travel from the first region to the interconnect within the string is less than the distance that charge carriers travel from the second region to the interconnect within the string. Therefore, when at least one first protruding unit protrudes a large distance along the second direction, it is beneficial to increase the actual charge carrier collection range of the first region along the second direction, while enabling more charge carriers to be exported over a shorter distance, thus reducing the transmission resistance.

[0030] As one possible implementation, the second and / or third protruding units are provided on the side boundaries of the third and / or fourth regions extending along the first direction, and are spaced apart along the first direction and protrude along the second direction. Specifically, the distance by which at least one first protruding unit protrudes along the second direction is greater than the distance by which at least one third protruding unit protrudes along the second direction; and / or, along the first direction, the length of at least one first protruding unit is greater than the length of at least one third protruding unit; and / or, along the first direction, the spacing between two adjacent first protruding units is greater than the spacing between two adjacent third protruding units; and / or, the undulation morphology of the side boundaries of the third region extending along the first direction is different from the undulation morphology of the side boundaries of the first region extending along the first direction; and / or, the undulation morphology of the side boundaries of the fourth region extending along the first direction is different from the undulation morphology of the side boundaries of the second region extending along the first direction.

[0031] When the distance of at least one first protruding unit protruding along the second direction and / or the length of at least one first protruding unit along the first direction are large, it is beneficial to increase the actual carrier collection range of the first region along the second direction and improve the carrier collection capability of the first region. Conversely, when the spacing between two adjacent first protruding units is large, it can prevent the proportion of the wider portion in the first region from becoming too large, which helps reduce the leakage risk between the first region and the adjacent third region. Furthermore, when the distance of at least one third protruding unit protruding along the second direction and / or the length of at least one third protruding unit along the first direction are small, it helps ensure that the gap between the first and third regions has a certain width, and that the wider gap has a certain length proportion, which helps reduce the leakage risk between the first region and the adjacent third region. In addition, when the undulating morphology of the two side boundaries of the third region extending along the first direction is different from that of the two side boundaries of the first region extending along the first direction, the polarity and position of the first and second strip-shaped portions can be accurately determined by the difference in their edge morphologies, reducing the difficulty of subsequent operations such as printing electrodes. As for the beneficial effects of the third protruding unit in the fourth region having the above-mentioned features, please refer to the previous text, which will not be repeated here.

[0032] As one possible implementation, along the second direction, the ratio of the width of the first area to the width of the third area is greater than or equal to 1.2 and less than or equal to 3; and / or, along the second direction, the ratio of the width of the first area to the width of the fourth area is greater than or equal to 0.6 and less than or equal to 1.8.

[0033] The ratio of the widths of the first and third regions being within the aforementioned range can prevent the first region from being too narrow and / or the third region from being too wide due to an excessively small ratio. This ensures that the first region has a large actual carrier collection range along the second direction, reduces the manufacturing difficulty of the first electrical junction in the first region, reduces parasitic absorption in the third region, and reduces the risk of leakage between the first and third regions due to a smaller distance caused by a larger width in the third region. Furthermore, it can also prevent the first region from being too wide and / or the third region from being too narrow due to an excessively large ratio. The application principle of preventing the first region from being too wide can refer to the application principle of preventing the third region from being too wide, and the application principle of preventing the third region from being too narrow can refer to the application principle of preventing the first region from being too narrow, which will not be repeated here. The application principle of the beneficial effect of the ratio of the widths of the first and fourth regions being within the aforementioned range can refer to the application principle of the beneficial effect of the ratio of the widths of the first and third regions being within the aforementioned range, which will not be repeated here.

[0034] As one possible implementation, the angle β between one end boundary of at least one first protruding unit along the first direction and the first direction is greater than or equal to 60° and less than or equal to 150°. This setting can prevent one end of the first protruding unit along the first direction from having an excessively large protrusion distance while the other end has an excessively small protrusion distance due to an excessively large or small angle β, thus making the carrier collection capacity of different parts of the first protruding unit along the length direction more balanced and reducing the carrier recombination rate; at the same time, it prevents the distance of the first protruding unit protruding too far from one end along the first direction from being too small, thus reducing the risk of leakage.

[0035] Secondly, this application provides a photovoltaic module including a cell string and an encapsulation layer. The cell string is formed by electrically connecting multiple solar cells as provided in the first aspect and its various implementations; the encapsulation layer covers the surface of the cell string.

[0036] The beneficial effects of the second aspect and its various implementations in this application can be found in the analysis of the beneficial effects of the first aspect and its various implementations, and will not be repeated here. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a partial illustration of the first and second doped semiconductor layers in the solar cell provided in the embodiments of this application. Figure 1 ; Figure 2 This is a partial illustration of the first and second doped semiconductor layers in the solar cell provided in the embodiments of this application. Figure 2 ; Figure 3 This is a partial illustration of the first and second doped semiconductor layers in the solar cell provided in the embodiments of this application. Figure 3 ; Figure 4 This is a partial illustration of the first and second doped semiconductor layers in the solar cell provided in the embodiments of this application. Figure 4 .

[0038] Reference numerals: 11 is a semiconductor substrate, 12 is a first doped semiconductor layer, 13 is a first strip, 14 is a first region, 15 is a second region, 16 is a first electrode, 17 is a first edge, 18 is a second edge, 19 is a first protruding unit, 20 is a first electrical junction, 21 is a first collector electrode, 22 is a second doped semiconductor layer, 23 is a second strip, 24 is a third region, 25 is a fourth region, 26 is a first inflection point, 27 is a second inflection point, 28 is a spacer region, 29 is a second protruding unit, and 30 is a third protruding unit. Detailed Implementation

[0039] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0040] The accompanying drawings show various structural schematic diagrams according to embodiments of this application. These drawings are not drawn to scale, and some details have been enlarged and may have been omitted for clarity. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0041] In the context of this application, when a layer / element is referred to as being "on top of" another layer / element, the layer / element can be directly on top of the other layer / element, or there can be an intermediate layer / element between them. Furthermore, if a layer / element is "on top of" another layer / element in one orientation, then when the orientation is reversed, the layer / element can be "below" the other layer / element. To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0042] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly specified. "Several" means one or more, unless otherwise expressly specified.

[0043] In the description of this application, it should be noted that, unless otherwise expressly 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 application according to the specific circumstances.

[0044] A solar cell is a device that converts sunlight into electrical energy. Specifically, when a solar cell is in operation, sunlight shines on it, creating new electron-hole pairs. Under the influence of the built-in electric field of the pn junction, photogenerated holes flow to the p-region, and photogenerated electrons flow to the n-region. Once the circuit is connected through the electrode structure, an electric current is generated.

[0045] However, in existing solar cells, the width of each strip in the doped semiconductor section is roughly the same, resulting in a weak ability to collect charge carriers, which in turn affects the working performance of the solar cell.

[0046] To address the aforementioned technical problems, in a first aspect, embodiments of this application provide a solar cell. The solar cell can be a double-contact cell, meaning that one of the positive and negative electrodes of the solar cell is disposed on the front side, and the other on the back side. Alternatively, the solar cell provided in embodiments of this application can also be a back-contact cell, meaning that the positive and negative electrodes of the solar cell are disposed alternately on the back side.

[0047] like Figure 1 and Figure 2 As shown, the solar cell provided in this embodiment includes a semiconductor substrate 11, a first doped semiconductor layer 12, and a first electrode 16. The semiconductor substrate 11 includes a first surface and a second surface facing each other. The first doped semiconductor layer 12 is disposed on a local area of ​​the first surface. The first electrode 16 is disposed on the side of the first doped semiconductor layer 12 facing away from the semiconductor substrate 11. The first doped semiconductor layer 12 includes a plurality of first strip-shaped portions 13 extending along a first direction and spaced apart along a second direction. The first direction and the second direction intersect. With this arrangement, the first strip-shaped portions 13 of the first doped semiconductor layer 12 are used to collect charge carriers and conduct them through the first electrode 16 disposed thereon, which facilitates the formation of photocurrent.

[0048] This application does not specifically limit the conductivity type of the first doped semiconductor layer. The conductivity type of the first doped semiconductor layer can be N-type (in which case the first electrode is the negative electrode) or P-type (in which case the first electrode is the positive electrode). As for the specific directions referred to by the first direction and the second direction, they can be set according to the shape of the first surface and actual needs. Optionally, the first direction and the second direction are perpendicular. For example, when the first surface is a rectangle, one of the first direction and the second direction is parallel to the extension direction of the long side of the rectangle, and the other is parallel to the extension direction of the short side of the rectangle.

[0049] The specific structure of the first electrode can be set according to actual needs.

[0050] For example, such as Figure 2 As shown, the first electrode 16 may include a plurality of first current collector electrodes 21 extending along a first direction and spaced apart along a second direction. The first current collector electrodes 21 are disposed on the first strip portion 13. The widths of different portions of the first current collector electrodes 21 along the first direction may be approximately the same.

[0051] For example, such as Figure 2 As shown, the first electrode 16 may include a plurality of first electrical connection portions 20 and a plurality of first collector electrodes 21. The first electrical connection portions 20 and the first collector electrodes 21 are disposed on the first strip portion 13. Each first strip portion 13 is provided with at least one first collector electrode 21 and at least one first electrical connection portion 20. When at least one first strip portion 13 is provided with a plurality of first electrical connection portions 20, different first electrical connection portions 20 located on the same first strip portion 13 are spaced apart along a first direction. Along a second direction, the width of the first electrical connection portion 20 may be greater than the width of the first collector electrode 21 to increase the contact area between the interconnect and the first electrode 16, reduce contact resistance, facilitate carrier collection and discharge, and reduce transmission loss. The first electrical connection portion 20 may be a thickened section disposed in a portion of the first collector electrode 21, or it may be a conductive structure additionally fabricated on a portion of the first collector electrode 21 for electrical connection. Along the first direction, the difference in width between the first collector electrode 21 and the first electrical connection portion 20 can be set according to actual needs.

[0052] like Figure 1 and Figure 2As shown, along the first direction, the first strip 13 may include a first region 14 and a second region 15 other than the first region 14, and the width w1 of the first region 14 is greater than the width w2 of the second region 15. The first region 14 includes a first edge 17 and a second edge 18 that are disposed opposite to each other and extend along the first direction. Along the first direction, within the same first region 14, the two endpoints of the first edge 17 are respectively offset from the two endpoints of the corresponding second edge 18; and / or, both the first edge 17 and the second edge 18 are provided with at least one first protruding unit 19 that is spaced apart along the first direction and protrudes along the second direction, the first protruding units 19 of the first edge 17 and the first protruding units 19 of the second edge 18 being offset along the first direction.

[0053] It should be noted that the embodiments of this application do not specifically limit the morphology of the first and second regions included in the first strip-shaped portion, and can be set according to actual needs. For example, the first and / or second regions can have morphologies such as square, rectangle, parallelogram, or ellipse. Furthermore, the first edge and second edge in the first region refer to two boundary lines in the outline of the first region that are opposite to each other along the second direction and extend approximately along the first direction. For example: Figure 1 and Figure 2 As shown, when the first area 14 is a rectangle, the first edge 17 and the second edge 18 refer to the two long sides of the rectangle.

[0054] When the width of the first area is greater than the width of the second area, such as Figure 3 As shown, one of the first edge 17 and the second edge 18 of the first region 14 may be substantially aligned with the boundary on the same side of the second region 15, and the other may be disposed to protrude in a second direction relative to the edge on the same side of the second region 15. Alternatively, as Figure 1 and Figure 2 As shown, each of the first edge 17 and the second edge 18 included in the first region 14 may be arranged to protrude along a second direction from the boundary on the same side of the second region 15 (wherein, the distance from which each of the first edge 17 and the second edge 18 included in the first region 14 protrudes along the second direction relative to the boundary on the same side of the second region 15 may be the same or different).

[0055] The shape of the first protruding unit set on the first edge and the second edge can be determined according to actual needs and the actual manufacturing process. For example, the first protruding unit can be rectangular, parallelogram-like, or triangular in shape.

[0056] For example, the angle β between one end boundary of at least one first protruding unit along the first direction and the first direction can be greater than or equal to 60° and less than or equal to 150°. For instance, the angle β between one end boundary of at least one first protruding unit along the first direction and the first direction can be 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, or 150°. This setting can prevent the protrusion distance of one end of the first protruding unit along the first direction from being too large and the protrusion distance of the other end from being too small due to the angle β being too large or too small. This makes the carrier collection capacity of different parts of the first protruding unit along the length direction more balanced, reducing the carrier recombination rate. At the same time, it prevents the distance of the first protruding unit protruding from one end along the first direction from being too large, resulting in a small distance between itself and the second strip, reducing the risk of leakage. In the actual manufacturing process, the size of the included angle β can be controlled by adjusting the tilt angle of the laser spot used to pattern the first doped semiconductor layer using laser etching technology.

[0057] The first and second edges have undulating morphologies along the second direction due to the presence of first protruding units. Therefore, the undulating morphologies of the first and second edges can be determined based on the shape of the first protruding units and the number of first protruding units. For example, the undulating morphologies of the first and second edges can be square-wave-like, sawtooth-like, or wavy, etc.

[0058] like Figure 1 and Figure 2 As shown, one of the two endpoints of the same first edge 17 and the same second edge 18 is located above the other along the first direction. Along the first direction, within the same first region 14, the two endpoints of the first edge 17 are offset from the two endpoints of the corresponding second edge 18, meaning that: the endpoint of the first edge 17 located above along the first direction is offset from the endpoint of the second edge 18 located above along the first direction; and, the endpoint of the first edge 17 located below along the first direction is also offset from the endpoint of the second edge 18 located below along the first direction.

[0059] like Figure 1 and Figure 2As shown, the first strip 13 includes a wider first region 14 and a narrower second region 15. Carriers collected by the first electrode 16 on the second region 15 can flow to the first electrode 16 on the first region 14 and be led out through the first electrode 16 on the first region 14 to the in-string interconnect (the in-string interconnect is used to interconnect adjacent solar cells; the in-string interconnect can be a conductive structure such as a solder strip). The first region 14 has a larger width w1, which helps to increase the interconnection area between the in-string interconnect and the first region 14, thus reducing the interconnection resistance. For example, when the first electrode 16 includes a first current collector 21 and a plurality of first electrical junctions 20, and the first current collector 21 is located at least in the second region 15, and the first electrical junctions 20 are located in the first region 14, the first region 14 in the first strip 13 has a larger width w1 (relative to the second region 15). Therefore, even if the first electrical junctions 20 located in the first region 14 have a larger width, it can prevent excessive metal recombination loss caused by the edge region of the first electrical junction 20 extending along the first direction crossing the boundary of the first region 14, or the risk of leakage or short circuit caused by the first electrical junction 20 contacting the heterogeneous doped semiconductor layer for back-contact cells. This improves the electrical reliability of the solar cell and also reduces the process difficulty of forming the first electrical junctions 20 in the first region 14, thereby improving the yield of the solar cell. The second region 15 has a smaller width w2, which is beneficial for reducing the parasitic absorption of the first doped semiconductor layer 12. In addition, as Figure 1 and Figure 2As shown, when the two endpoints of the first edge 17 within the same first region 14 are staggered from the two endpoints of the corresponding second edge 18 along the first direction, the first edge 17 within the same first region 14 is offset relative to the second edge 18 along the first direction. This effectively widens the actual carrier collection range of the first region 14 along the first direction and improves the carrier collection efficiency. Simultaneously, even if interconnecting elements are disposed on the first surface of the solar cell, and the actual placement position is offset relative to the design position along the first direction due to operational errors, it can still be located on the first region 14, increasing the contact probability between the interconnecting elements and the first region 14. Furthermore, when both the first edge 17 and the second edge 18 are provided with at least one first protruding unit 19 spaced apart along the first direction and protruding along the second direction, the boundaries of different regions corresponding to the first protruding unit 19 along the first direction and the recessed portion adjacent to the first protruding unit 19 within the same first region 14 are offset along the second direction. This effectively widens the actual carrier collection range of the first region 14 along the second direction. Furthermore, when the first protruding unit 19 of the first edge 17 and the first protruding unit 19 of the second edge 18 are staggered along the first direction, the recessed portion adjacent to the first protruding unit 19 in one of the first edges 17 and 18, and the recessed portion adjacent to the first protruding unit 19 in the other, can be staggered. This results in different regions in the same first region 14 having a larger width w1 along the first direction, which helps to ensure that different regions in the same first region 14 along the first direction have a larger actual carrier collection range along the second direction, thereby improving the carrier collection efficiency of the first doped semiconductor layer 12 and thus improving the working performance of the solar cell. Especially when the design space is limited, such as when it is necessary to control the coverage area of ​​the doped semiconductor layer on the first surface, such as when the doped semiconductor layer needs to be set more densely in a dense grid scheme, the actual carrier collection range can be improved through the above two methods, thus improving the battery performance.

[0060] In practical applications, the width ratio of the first region and the second region can be set according to the size of the first electrode located in the first region, the size of the first electrode located in the second region, and actual requirements. For example, Figure 1 As shown, the width w1 of the first zone 14 is defined as follows: a straight line extending along the first direction and passing through the first zone 14 intersects the outline of the first zone 14 at two points, and the distance between these two intersection points along the first direction is the width w1 of the first zone 14. The method for determining the width w2 of the second zone 15 can refer to the method for determining the width w2 of the first zone 14.

[0061] For example, the width ratio of the first region and the second region can be greater than or equal to 1.2 and less than or equal to 3. For instance, the width ratio of the first region and the second region can be 1.2, 1.5, 1.7, 1.9, 2, 2.2, 2.5, 2.7, 2.9, or 3, etc. This setting, with the width ratio of the first region and the second region within the aforementioned range, prevents the ratio from being too small, thus ensuring a large interconnect area between the first region and the interconnect components within the string, and / or reducing the manufacturing difficulty of the wider first electrical junction portion on the first region. Furthermore, it also prevents the first region from being too wide and / or the second region from being too narrow due to an excessively large ratio, reducing the risk of parasitic absorption and leakage of the first doped semiconductor layer in the first region, while simultaneously lowering the required process precision when manufacturing the first collector electrode on the second region, thus reducing manufacturing difficulty.

[0062] In addition, the distance between the two endpoints of the first edge along the first direction of the first region and the two endpoints of the second edge along the first direction can be determined according to the size of the first region in the actual application scenario and the requirements for the actual carrier collection range of the first region along the first direction.

[0063] For example, along the first direction, the ratio of the length of the first region to the distance offset from at least one endpoint of the first edge and the corresponding endpoint of the second edge can be greater than 0 and less than or equal to 14.5. For instance, the ratio of the length of the first region to the distance offset from at least one endpoint of the first edge and the corresponding endpoint of the second edge can be 0.5, 1, 2, 5, 8, 9, 10, 12, 13, 14, or 14.5, etc. This setting prevents the actual carrier collection range of the first region along the first direction from being limited due to a small ratio, thus ensuring a high carrier collection efficiency of the first region along the first direction. Furthermore, it prevents the length of the narrower edge portions of the first region along the first direction from being excessively long due to the offset of the first and second edges along the second direction, ensuring that the edge portions at both ends of the first region along the first direction also have a certain carrier collection range in the second direction. Simultaneously, it helps reduce the manufacturing difficulty of the first electrical connection portion on the edge portions at both ends of the first region along the first direction.

[0064] The length of the first protruding unit, the protrusion distance, and the spacing between two adjacent first protruding units can be determined based on the size of the first region in the actual application scenario and the requirements for the actual carrier collection range of the first region along the second direction. It should be noted that the protrusion distance of the first protruding unit along the second direction refers to the distance along the first direction between the outermost contour line of the first protruding unit along the second direction and the outermost contour line of the recessed portion adjacent to that first protruding unit along the second direction.

[0065] For example, along the first direction, the ratio of the length of at least one first protruding unit to the length of the first region can be greater than or equal to one-fiftieth and less than or equal to one-half. For instance, the ratio of the length of at least one first protruding unit to the length of the first region can be one-fiftieth, one-forty-fifth, one-forty-first, one-thirty-fifth, one-thirty-second, one-twenty-first, one-fifth, one-fifth, or one-half, etc. This setting prevents the first region from having a limited growth in the actual carrier collection range due to the first protruding unit being too small, resulting in a higher carrier collection efficiency. Furthermore, it prevents the proportion of the wider portion of the first region due to the first protruding unit being too large, which helps reduce parasitic absorption of the first doped semiconductor layer in the first region. Secondly, for back-contact cells, it also prevents the leakage risk between the second doped semiconductor layer and the first region from being too high due to the excessive length of the wider portion of the first region, thus improving the working performance of the solar cell.

[0066] For example, along the first direction, the ratio of the distance between two adjacent first protruding units to the length of the first region can be greater than or equal to one-fiftieth and less than or equal to three-quarters. For instance, the ratio of the distance between two adjacent first protruding units to the length of the first region can be one-fiftieth, one-forty-fifth, one-forty-first, one-thirty-fifth, one-thirty-second, one-twenty-fifteenth, one-tenth, one-fifth, one-half, or three-quarters, etc. This setting prevents the proportion of the length of the first protruding units in the first edge and / or the second edge from being too large due to an excessively small ratio, i.e., prevents the proportion of the wider portion of the first region from being too large due to the presence of the first protruding units. Furthermore, it also prevents the proportion of the length of the first protruding units in the first edge and / or the second edge from being too small due to an excessively large ratio, i.e., prevents the effective growth of the actual carrier collection range corresponding to the first protruding units in the first region from being ineffective. The application principle of this beneficial effect can be referred to the previous text and will not be repeated here.

[0067] For example, the ratio of the width of the first region along the second direction to the distance of the protrusion of at least one first protruding unit along the second direction can be greater than or equal to 2 and less than or equal to 1000. For instance, the ratio of the width of the first region along the second direction to the distance of the protrusion of at least one first protruding unit along the second direction can be 2, 3, 5, 8, 10, 50, 100, 200, 300, 500, 800, or 1000, etc. This setting prevents the width growth of the corresponding region within the first region from being limited due to the presence of the first protruding unit in the first edge and / or second edge, thus ensuring a higher carrier collection efficiency in the first region. Furthermore, it prevents the width of the region corresponding to the first protruding unit within the first region from being too large due to an excessively large ratio, which helps reduce parasitic absorption of the first doped semiconductor layer in the first region. Secondly, for back-contact cells, it also prevents a high risk of leakage between the second doped semiconductor layer and the region corresponding to the first protruding unit in the first region, thus improving the performance of the solar cell.

[0068] In practical applications, the first edge and / or the second edge may have only one first protruding unit, or it may have multiple first protruding units spaced apart along the first direction. When the first edge and / or the second edge has multiple first protruding units, the lengths of the different first protruding units along the first direction may be the same or different.

[0069] For example, such as Figure 2 As shown, along the first direction, the length L2 of at least one first protruding unit 19 located on the outer side of the first edge 17 and / or the second edge 18 can be smaller than the length L2 of the remaining first protruding units 19. This configuration differentiates the lengths of the first protruding units 19 located on the outer side of the first edge 17 and / or the second edge 18 from the remaining first protruding units 19. Because there is a certain distance between the edge portion of the first electrical junction 20 along the first direction and the edge of the first region 14 extending along the second direction, when the length L2 of at least one first protruding unit 19 located on the outer side of the first edge 17 and / or the second edge 18 is smaller, and the length L2 of the remaining first protruding units 19 is larger, the width w1 of the first region 14 can be increased by using the larger first protruding unit 19 located in the middle. This reduces the manufacturing difficulty of the first electrical junction 20 and also reduces the risk of parasitic absorption and leakage current at the edge portion of the first region 14 along the first direction where the first electrical junction 20 is not located, resulting in higher performance of the solar cell.

[0070] In addition, when multiple first protruding units are provided on the first edge and / or the second edge, the distance by which different first protruding units protrude along the second direction and the spacing between two adjacent first protruding units can be the same or different.

[0071] The distribution of the first protruding unit at the first edge and the first protruding unit at the second edge can be the same or different. When the distribution of the first protruding units at the first edge and the second edge is different, the first protruding units at the first edge and the second edge have differentiated settings, realizing diversified settings of the carrier collection range corresponding to the first edge side and the second edge side of the first region.

[0072] For example, the number of first protruding units on the first edge can be greater than the number of first protruding units on the second edge.

[0073] For example, along the first direction, the length of at least one first protruding unit on the first edge is different from the length of the first protruding unit on the second edge. Specifically, the length of at least one first protruding unit on the first edge may be greater than the length of the first protruding unit on the second edge. Alternatively, the length of at least one first protruding unit on the first edge may be less than the length of the first protruding unit on the second edge.

[0074] For example, the distance by which at least one first protruding unit on the first edge protrudes along the second direction is different from the distance by which the first protruding unit on the second edge protrudes along the second direction. Specifically, the distance by which at least one first protruding unit on the first edge protrudes along the second direction may be greater than the distance by which the first protruding unit on the second edge protrudes along the second direction. Alternatively, the distance by which at least one first protruding unit on the first edge protrudes along the second direction may be less than the distance by which the first protruding unit on the second edge protrudes along the second direction.

[0075] For the second region, which is narrower (relative to the first region) within the first strip, the two side boundaries extending along the first direction in the second region can be approximately straight lines. Or, as... Figure 2 and Figure 4 As shown, the second region 15 has multiple second protruding units 29 arranged at intervals along the first direction and protruding along the second direction on both sides of its first-direction extension boundary. This arrangement helps to increase the actual carrier collection range of the second region 15 along the second direction and improve the carrier collection efficiency of the second region 15. The length L4 of the second protruding unit 29 along the first direction, the distance w4 of the second protruding unit protruding along the second direction, and the spacing L5 between two adjacent second protruding units along the first direction can be set according to actual needs.

[0076] The dimensions of the second protruding unit (such as the distance of protrusion along the second direction, the length along the first direction, the spacing along the first direction, etc.) can be the same as or different from the dimensions of the first protruding unit.

[0077] For example, such as Figure 1 and Figure 2 As shown, the distance w3 by which at least one first protruding unit 19 protrudes along the second direction can be greater than or equal to the distance w4 by which at least one second protruding unit 29 protrudes along the second direction; and / or, along the first direction, the spacing L3 between two adjacent first protruding units 19 is less than the spacing L5 between two adjacent second protruding units 29. With this configuration, the distance by which charge carriers are collected and led out through the first region 14 to the interconnect within the string is less than the distance by which charge carriers are collected and led out through the second region 15 to the interconnect within the string. Therefore, when the distance by which at least one first protruding unit 19 protrudes along the second direction is large, it is beneficial to increase the actual charge carrier collection range of the first region 14 along the second direction while enabling more charge carriers to be led out over a shorter distance, thus reducing the transmission resistance.

[0078] In some cases, such as Figure 1 and Figure 2 As shown, the solar cell may further include a second doped semiconductor layer 22. The second doped semiconductor layer 22 has an opposite conductivity type to the first doped semiconductor layer 12. The formation location of the second doped semiconductor layer 22 on the semiconductor substrate 11 can be set according to the type of solar cell and actual requirements.

[0079] For example, in the case of a double-sided contact solar cell, a second doped semiconductor layer is disposed on at least a portion of the second side. When the second doped semiconductor layer is disposed only on a portion of the second side, it may include a plurality of second strip-shaped portions extending along a first direction and spaced apart along a second direction. In this case, the widths of the portions of the second strip-shaped portions along the first direction may be the same, or the second strip-shaped portion may include a third region and a fourth region excluding the third region. The width of the third region may be greater than the width of the fourth region. When the second strip-shaped portion includes both the third and fourth regions, the morphology of the second strip-shaped portion can also refer to the morphology of the first strip-shaped portion described above, and will not be repeated here.

[0080] For example: Figure 1 and Figure 2 As shown, in the case of a back-contact solar cell, a second doped semiconductor layer 22 is disposed on a local area of ​​the first surface. The second doped semiconductor layer 22 includes a plurality of second strip-shaped portions 23 extending along a first direction and spaced apart along a second direction, with the first strip-shaped portions 13 and the second strip-shaped portions 23 alternately spaced along the second direction. In this case, the first doped semiconductor layer 12 and the second doped semiconductor layer 22 on the first surface can be spaced apart, and the region between the first doped semiconductor layer 12 and the second doped semiconductor layer 22 on the first surface is defined as the spacing region 28. Furthermore, the widths of the portions of the second strip-shaped portions along the first direction can be the same; or, as shown... Figure 1 and Figure 2 As shown, at least one second strip 23 includes a third region 24 and a fourth region 25 other than the third region 24, and the width w5 of the third region 24 is smaller than the width w6 of the fourth region 25.

[0081] When at least one second strip includes a third region and a fourth region of different widths, one of the two boundaries of the third region extending along the first direction may be substantially aligned with the boundary of the fourth region on the same side, and the other may be recessed along the second direction relative to the edge of the fourth region on the same side. Alternatively, as Figure 1 and Figure 2 As shown, each of the two boundaries extending along the first direction included in the third region 24 may be recessed along the second direction with the boundary on the same side of the second region 15 (wherein, the distance between the two boundaries extending along the first direction included in the third region 24 and the boundary on the same side of the fourth region 25 recessed along the second direction may be the same or different).

[0082] In addition, such as Figure 1 and Figure 2 As shown, when at least one second strip 23 includes a third region 24 and a fourth region 25 with different widths, the third region 24 included in the at least one second strip 23 can be correspondingly arranged with the first region 14 included in the adjacent first strip 13. With this arrangement, at least a portion of the smaller third region 24 in the at least one second strip 23 overlaps with at least a portion of the larger first region 14 in the adjacent first strip 13 in the first direction. This facilitates the efficient utilization of the surface area of ​​the region in the first surface, allowing for timely diversion and collection of charge carriers. Furthermore, the corresponding arrangement of the smaller third region 24 with the larger first region 14 ensures a certain distance between them, reducing the risk of leakage and making the corresponding patterns of the first strip 13 and the second strip 23 relatively regular, reducing the difficulty of patterning.

[0083] Optional, such as Figure 2 As shown, at least one second strip 23 includes a third region 24 whose length L8 along the first direction can be greater than or equal to the length L1 of the corresponding first region 14 in the adjacent first strip 13 along the first direction. In this case, the projection of the first region 14 in the first strip 13 in the first direction can be located within the projection of the corresponding third region 24 in the adjacent second strip 23 in the first direction.

[0084] The distribution of the third zone and the corresponding first zone along the second direction can be determined based on the width requirements of the third zone and the first zone in the actual application scenario, as well as the leakage risk requirements between them.

[0085] like Figure 1 and Figure 2 As shown, the first region 14, immediately adjacent to the end of the second region 15, has a first inflection point 26 protruding outward along the second direction, and the fourth region 25, immediately adjacent to the end of the third region 24, has a second inflection point 27 protruding outward along the second direction. The specific positions of the first inflection point 26 and the second inflection point 27 can be determined according to the shapes of the first region 14 and the fourth region 25. Taking the first region 14 as an example: if the first region 14 is a polygon without rounded corners, then the first inflection point 26 is the outermost endpoint of the outline of the end of the first region 14 immediately adjacent to the second region 15 along the second direction. For example, when the first region 14 is a rectangle-like shape, the first inflection point 26 is the rectangle-like shape near the end of the second region 15.

[0086] For example, such as Figure 1 and Figure 2 As shown, the line connecting at least one first inflection point 26 and the adjacent second inflection point 27 can be parallel to the first direction. This arrangement helps to ensure that the portion of the first zone 14 that protrudes relative to the second zone 15 maintains a certain distance from the adjacent third zone 24, reducing the risk of leakage between them.

[0087] For example, such as Figure 3 As shown, at least one first inflection point 26 extending in the first direction can be located on the side of the extension line of the adjacent second inflection point 27 in the first direction closer to the second region 15. This arrangement helps to increase the distance along the second direction between the end of the first region 14 immediately adjacent to the second region 15 and the adjacent third region 24, which has the opposite conductivity type, thus reducing the risk of leakage between them.

[0088] The widths of the third and fourth regions in the same second strip, and the difference between them, can be set according to the size of the second electrode, the relative positional relationship between the third and fourth regions in the second strip and the first and second regions in the first strip, and the width difference between the first and second regions, and are not specifically limited here.

[0089] As for the differences in width between the third and fourth zones and the first and second zones, these can be set according to the dimensions of the first and second electrodes.

[0090] For example, along the second direction, the ratio of the width of the first region to the width of the third region can be greater than or equal to 1.2 and less than or equal to 3. For instance, the ratio of the width of the first region to the width of the third region can be 1.2, 1.3, 1.5, 1.6, 1.8, 2, 2.2, 2.5, 2.8, or 3, etc. This setting, with the ratio of the widths of the first and third regions within the aforementioned range, prevents the first region from being too small and / or the third region from being too large. While ensuring that the first region has a large actual carrier collection range along the second direction and reducing the manufacturing difficulty of the first electrical junction on the first region, it also reduces parasitic absorption in the third region and reduces the risk of leakage between the first and third regions due to the smaller distance between them caused by the larger width of the third region.

[0091] For example, in the second direction, the ratio of the width of the first area to the width of the fourth area can be greater than or equal to 0.6 and less than or equal to 1.8. For instance, the ratio of the width of the first area to the width of the fourth area can be 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.5, or 1.8, etc. This setting can prevent the width of the first area from being too large and / or the width of the third area from being too small due to an excessively large ratio. The application principle of preventing the width of the first area from being too large can refer to the application principle of preventing the width of the third area from being too large, and the application principle of preventing the width of the third area from being too small can refer to the application principle of preventing the width of the first area from being too small, which will not be repeated here.

[0092] In terms of morphology, the lateral boundaries of the third and / or fourth regions extending along the first direction can be flat straight lines. Or, as... Figure 1 , Figure 2 and Figure 4 As shown, the third region 24 and / or the fourth region 25 are provided with third protruding units 30 that are spaced apart along the first direction and protrude along the second direction on both sides of the boundary extending along the first direction.

[0093] The length of the third protruding unit along the first direction, the distance by which the third protruding unit protrudes along the second direction, and the spacing between two adjacent third protruding units along the first direction can be set according to actual needs.

[0094] The dimensions of the third protruding unit (such as the distance of protrusion along the second direction, the length along the first direction, the spacing along the first direction, etc.) can be the same as or different from the dimensions of the first protruding unit. When both sides of the third and fourth regions extending along the first direction are provided with third protruding units, the dimensions of the third protruding unit corresponding to the third region can be the same as or different from the dimensions of the third protruding unit corresponding to the fourth region.

[0095] It should be noted that the lateral boundaries of the third and / or fourth regions extending along the first direction have an undulating morphology along the second direction due to the presence of third protruding units. Therefore, the undulating morphology of the lateral boundaries of the third region extending along the first direction can be determined based on the shape of the third protruding unit. For example, the shape of the third protruding unit can be approximately square, rectangular, semi-circular, or parallelogram-like. The lateral boundaries of the third and / or fourth regions extending along the first direction can be approximately wavy, sawtooth, or wave-like.

[0096] like Figure 1 and Figure 2 As shown, the undulations of the two side boundaries of the third region 24 extending along the first direction can be different from the undulations of the two side boundaries of the first region 14 extending along the first direction. For example, the undulations of the two side boundaries of the first region 14 extending along the first direction can be a square-shaped waveform, while the undulations of the two side boundaries of the third region 24 extending along the first direction can be a sawtooth-shaped waveform. With this configuration, the polarity and position of the first strip 13 and the second strip 23 can be accurately determined by the difference in their edge morphologies, reducing the difficulty of subsequent operations such as electrode printing.

[0097] Alternatively, the undulating morphology of the two sides of the third region extending along the first direction can also be the same as the undulating morphology of the two sides of the first region extending along the first direction.

[0098] like Figure 1 and Figure 2 As shown, the undulations of the two side boundaries of the fourth region 25 extending along the first direction may differ from the undulations of the two side boundaries of the second region 15 extending along the first direction. Alternatively, the undulations of the two regions may be the same.

[0099] For example, such as Figure 1 As shown, the distance w3 by which at least one first protruding unit 19 protrudes along the second direction can be greater than the distance w7 by which at least one third protruding unit 30 protrudes along the second direction. This arrangement helps to increase the actual carrier collection range of the first region 14 along the second direction and improve the carrier collection capability of the first region 14. When the distance w7 by which at least one third protruding unit 30 protrudes along the second direction is small, it helps to ensure that the gap region 28 between the first region 14 and the third region 24 has a certain width, and the gap region 28 with a larger width has a certain length ratio, which helps to reduce the leakage risk between the first region 14 and the adjacent third region 24.

[0100] For example, such as Figure 2As shown, along the first direction, the length L2 of at least one first protruding unit 19 is greater than the length L6 of at least one third protruding unit 30. The beneficial effect in this case can be understood by referring to the previously described principle that the distance w3 by which at least one first protruding unit 19 protrudes along the second direction is greater than the distance w7 by which at least one third protruding unit 30 protrudes along the second direction.

[0101] For example, such as Figure 2 As shown, along the first direction, the distance L3 between two adjacent first protruding units 19 is greater than the distance L7 between two adjacent third protruding units 30. This arrangement prevents the wider portion of the first area 14 from becoming too large, which helps reduce the risk of leakage between the first area 14 and the adjacent third area 24.

[0102] It should be noted that the wider fourth region in the second strip may include a third edge and a fourth edge that are oppositely arranged and extend along the first direction. The arrangement of the third and fourth edges can refer to the arrangement of the first and second edges. For example, along the first direction, within the same fourth region, the two endpoints of the third edge are staggered from the two endpoints of the corresponding fourth edge; and / or, both the third and fourth edges are provided with at least one third protruding unit that is spaced apart along the first direction and protrudes along the second direction, with the third protruding units of the third edge and the third protruding units of the fourth edge staggered along the first direction. The application principle of the beneficial effect in this case can refer to the application principle of the beneficial effect when the first and second edges have corresponding technical features as described above.

[0103] Alternatively, the arrangement of the third and fourth edges can differ from that of the first and second edges. For example, along the first direction, within the same fourth region, the two endpoints of the third edge can be aligned with the two endpoints of the corresponding fourth edge; and / or, both the third and fourth edges are provided with at least one third protruding unit that is spaced apart along the first direction and protrudes along the second direction, with the third protruding units of the third edge and the third protruding units of the fourth edge aligned along the first direction.

[0104] For the spacer region located between the first doped semiconductor layer and the second doped semiconductor layer, the widths of different portions of the spacer region along the extension direction can be the same or different.

[0105] For example, such as Figure 2As shown, when the length L8 of the third region 24 is greater than the length L1 of the adjacent first region 14 along the first direction, the portion of the spacer 28 located between the end of the third region 24 along the first direction and the end of the adjacent first region 14 along the first direction is defined as a corner region. The width of the corner region along the second direction can be greater than the width of the remaining portion of the spacer 28 excluding the corner regions. With this configuration, there are corners at the ends of the first region 14 adjacent to the second region 15 and the fourth region 25 adjacent to the third region 24. The electric field is relatively concentrated at the corners, resulting in a higher risk of leakage. By making the width of the corner region along the second direction greater than the width of the remaining portion of the spacer 28 excluding the corner regions, the distance between the ends of the first region 14 adjacent to the second region 15 and the ends of the fourth region 25 adjacent to the third region 24 can be increased, reducing the carrier recombination rate in the corner regions.

[0106] For example, such as Figure 1 As shown, the width of the interval 28 located between the first zone 14 and the adjacent third zone 24 is s, and the width of the interval 28 located between the second zone 15 and the adjacent fourth zone 25 is r, where 0.5r ≤ s ≤ 2r. For example, s can be equal to 0.5r, 0.6r, 0.8r, r, 1.2r, 1.5r, 1.8r, or 2r. This setting allows for adjusting the width of the interval 28 at different locations according to actual needs, which helps reduce the risk of leakage current.

[0107] Secondly, embodiments of this application provide a photovoltaic module including a cell string and an encapsulation layer. The cell string is formed by electrically connecting multiple solar cells as provided in the first aspect and its various implementations; the encapsulation layer covers the surface of the cell string.

[0108] The beneficial effects of the second aspect and its various implementations in the embodiments of this application can be found by referring to the analysis of the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0109] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0110] The embodiments of this application have been described above. However, these embodiments are merely for clarity and are not intended to limit the scope of this application. The scope of this application is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this application, and all such substitutions and modifications should fall within the scope of this application.

Claims

1. A solar cell, characterized in that, include: A semiconductor substrate, the semiconductor substrate including opposing first and second surfaces; A first doped semiconductor layer is disposed on a local area of ​​the first surface; The first doped semiconductor layer includes a plurality of first strip-shaped portions extending along a first direction and spaced apart along a second direction; the first direction and the second direction intersect; along the first direction, the first strip-shaped portion includes a first region and a second region other than the first region, the width of the first region being greater than the width of the second region; The first electrode is disposed on the side of the first doped semiconductor layer away from the semiconductor substrate; The first region includes a first edge and a second edge that are disposed opposite to each other and extend along the first direction; Along the first direction, within the same first region, the two endpoints of the first edge are respectively offset from the two endpoints of the corresponding second edge; and / or, both the first edge and the second edge are provided with at least one first protruding unit that is spaced apart along the first direction and protrudes along the second direction, wherein the first protruding unit of the first edge and the first protruding unit of the second edge are offset along the first direction.

2. The solar cell according to claim 1, characterized in that, The first electrode includes a plurality of first electrical junction portions and a plurality of first current collectors; the first electrical junction portions are disposed on the first region; the first current collectors are disposed on the second region and are electrically connected to the first electrical junction portions; Along the second direction, the width of the first electrical junction is greater than the width of the first current collector electrode.

3. The solar cell according to claim 1, characterized in that, Along the first direction, the ratio of the length of at least one of the first protruding units to the length of the first region is greater than or equal to one-fiftieth and less than or equal to one-half; And / or, along the first direction, the ratio of the distance between two adjacent first protruding units to the length of the first region is greater than or equal to one-fiftieth and less than or equal to three-quarters; And / or, the ratio of the width of the first region along the second direction to the distance by which at least one of the first protruding units protrudes along the second direction is greater than or equal to 2 and less than or equal to 1000; And / or, the ratio of the width of the first area to the width of the second area is greater than or equal to 1.2 and less than or equal to 3.

4. The solar cell according to claim 1, characterized in that, Along the first direction, the ratio of the length of the first region to the distance offset from at least one endpoint of the first edge and the corresponding endpoint of the second edge is greater than 0 and less than or equal to 14.

5.

5. The solar cell according to claim 1, characterized in that, Along the first direction, the length of at least one of the first protruding units located on the outer side of the first edge and / or the second edge is less than the length of the remaining first protruding units; And / or, the first edge has a greater number of the first protruding units than the second edge has; And / or, along the first direction, the length of at least one of the first protruding units of the first edge is different from the length of the first protruding unit of the second edge; And / or, the distance by which at least one of the first protruding units of the first edge protrudes along the second direction is different from the distance by which the first protruding unit of the second edge protrudes along the second direction.

6. The solar cell according to claim 1, characterized in that, The solar cell further includes a second doped semiconductor layer; the second doped semiconductor layer is disposed on a local area of ​​the first surface, and the conductivity type of the second doped semiconductor layer is opposite to that of the first doped semiconductor layer; The second doped semiconductor layer includes a plurality of second stripes extending along the first direction and spaced apart along the second direction, wherein the first stripes and the second stripes are alternately spaced apart along the second direction.

7. The solar cell according to claim 6, characterized in that, At least one of the second strip-shaped portions includes a third region and a fourth region other than the third region; the width of the third region is smaller than the width of the fourth region; At least one of the third regions included in the second stripe portion is correspondingly arranged with the first region included in the adjacent first stripe portion.

8. The solar cell according to claim 7, characterized in that, The first region has a first inflection point protruding outward along the second direction at the end immediately adjacent to the second region, and the fourth region has a second inflection point protruding outward along the second direction at the end immediately adjacent to the third region; Wherein, at least one of the lines connecting the first inflection point and the adjacent second inflection point is parallel to the first direction; Alternatively, at least one extension of the first inflection point in the first direction is located on the side of the extension of the adjacent second inflection point in the first direction closer to the second region.

9. The solar cell according to claim 7, characterized in that, The region located between the first doped semiconductor layer and the second doped semiconductor layer in the first surface is a spacer region; Wherein, along the first direction, the length of the third region is greater than the length of the adjacent first region, and the portion of the interval region located between the end of the third region along the first direction and the end of the adjacent first region along the first direction is a corner region; the width of the corner region along the second direction is greater than the width of the remaining portion of the interval region excluding the corner regions. And / or, the width of the interval between the first region and the adjacent third region is s, and the width of the interval between the second region and the adjacent fourth region is r, 0.5r≤s≤2r.

10. The solar cell according to claim 7, characterized in that, The second region has multiple second protruding units that are spaced apart along the first direction and protrude along the second direction on both sides of its second boundary; wherein, at least one first protruding unit protrudes a distance greater than or equal to at least one second protruding unit protrudes a distance along the second direction; and / or, along the first direction, the distance between two adjacent first protruding units is less than the distance between two adjacent second protruding units. And / or, the third region and / or the fourth region are provided with third protruding units that are spaced apart along the first direction and protrude along the second direction on both sides of their sides; wherein, at least one first protruding unit protrudes a greater distance along the second direction than at least one third protruding unit; and / or, along the first direction, the length of at least one first protruding unit is greater than the length of at least one third protruding unit; and / or, along the first direction, the spacing between two adjacent first protruding units is greater than the spacing between two adjacent third protruding units; and / or, the undulation morphology of the sides of the third region extending along the first direction is different from the undulation morphology of the sides of the first region extending along the first direction; and / or, the undulation morphology of the sides of the fourth region extending along the first direction is different from the undulation morphology of the sides of the second region extending along the first direction.

11. The solar cell according to claim 7, characterized in that, Along the second direction, the ratio of the width of the first region to the width of the third region is greater than or equal to 1.2 and less than or equal to 3; And / or, in the second direction, the ratio of the width of the first region to the width of the fourth region is greater than or equal to 0.6 and less than or equal to 1.

8.

12. The solar cell according to claim 1, characterized in that, At least one of the first protruding units has an angle β between its end boundary along the first direction and the first direction that is greater than or equal to 60° and less than or equal to 150°.

13. A photovoltaic module, characterized in that, include: A battery string, wherein the battery string is formed by electrically connecting a plurality of solar cells as described in any one of claims 1 to 12; And an encapsulation layer that covers the surface of the battery string.

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