A solar cell and photovoltaic module

Abstract

The utility model discloses a solar cell and photovoltaic module relates to photovoltaic technical field for solving the problem that fine grid and the pad exist offset lap joint risk. Solar cell includes substrate and electrode, and electrode sets up in at least one side of substrate, and electrode includes electrically bonded part and first current collecting grid line, and first current collecting grid line extends along first direction, and first current collecting grid line includes the bending segment and straight line segment who are connected, and bending segment corresponds to set up electrically bonded part, and bending segment includes at least one bending structure who bends to the side in first direction. The bending segment of this electrode increases the area of first current collecting grid line and electrically bonded part lap joint part in the perpendicular to first direction through the bending structure who bends to the side in first direction, and therefore, even if first current collecting grid line produces certain offset in the printing process, compared with the current collecting grid line of linear type of bending segment, still can keep with the lap joint of electrically bonded part, reduced the risk of first current collecting grid line and electrically bonded part to separate lap joint.

Description

[0001] This application claims priority to Chinese Patent Application No. 202521671096.4, filed on August 6, 2025, entitled “A Solar Cell and a Photovoltaic Module”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This utility model relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Technology

[0003] Screen printing is a core process for electrode preparation in photovoltaic manufacturing. Its effect directly affects the battery's current collection capacity, series resistance, optical loss, electrical loss, and ultimately determines the battery efficiency.

[0004] Screen-printed patterns typically consist of pad patterns and grid lines. During printing, pads are usually printed first, followed by grid lines, with some grid lines extending through the pads. Electrodes obtained through screen printing usually include pads and fine grids. The fine grids extend through the pads in a straight line. If the fine grids shift during printing, there is a risk of misalignment and overlap between the fine grids and the pads. Due to cost reduction requirements, the fine grids are becoming increasingly fine, increasing the risk of misalignment and overlap. Furthermore, printing fine grids in a straight line is prone to grid breakage. Utility Model Content

[0005] The purpose of this invention is to provide a solar cell and photovoltaic module to reduce the risk of grid misalignment and overlap.

[0006] In a first aspect, the present invention provides a solar cell, including a substrate and an electrode, the electrode being disposed on at least one side of the substrate, the electrode including an electrical junction portion and a first current collector line, the first current collector line extending along a first direction, the first current collector line including a connected bent segment and a straight segment, the bent segment being disposed corresponding to the electrical junction portion; the bent segment including at least one bent structure bending laterally toward the first direction.

[0007] With the above technical solution, the first collector grid line includes a connected straight segment and a bent segment. The bent segment includes a bending structure that bends laterally toward the extension direction (first direction) of the first collector grid line. The first collector grid line overlaps with the electrical connection part (such as a pad, thickened section of the grid line, etc.) through the bent segment. Compared with the existing structure of a straight collector grid line overlapping with a pad, the bent segment in this application increases the area occupied by the overlap part of the first collector grid line and the electrical connection part in the perpendicular direction by bending laterally toward the first direction. Therefore, even if the first collector grid line is offset to a certain extent during printing, the bent segment can still maintain the overlap with the electrical connection part compared with the existing straight collector grid line, reducing the risk of the first collector grid line and the electrical connection part detaching from the overlap. In addition, with the same size of the electrical connection part in the first direction, the bent segment increases the contact area between the first collector grid line and the electrical connection part, thereby enhancing the current collection capability of the electrical connection part and improving the bonding capability between the first collector grid line and the electrical connection part. During probe testing, the increased contact area between the bent section and the test probe improves the accuracy and stability of the test. Furthermore, during screen printing, the first collector line with the bent section, compared to a straight collector line, can reduce the impact of the screen knots on the printing quality of the first collector line by allowing the bent structure of the bent section to bypass the screen mesh, thus reducing the risk of grid breakage.

[0008] In some possible implementations, the bent segment extends through the electrical connection portion along a first direction, meaning that the extension length of the bent segment and the extension length of the electrical connection portion are not significantly different in the first direction. This allows for an increase in the contact area between the first collector grid line and the electrical connection portion by maximizing the overlap length between the bent segment and the electrical connection portion, thereby enhancing the current collection capability of the electrical connection portion and improving the bonding capability between the first collector grid line and the electrical connection portion.

[0009] In some possible implementations, the linewidth of the bend segment is greater than that of the straight segment. By increasing the linewidth of the bend segment, the contact area between the bend segment and the electrical junction is further increased, improving the current collection capability. Furthermore, a wider bend segment can reduce the risk of grid breakage during printing.

[0010] In some possible implementations, in the first direction, at least one bent structure partially extends beyond the electrical junction and is partially located within the electrical junction. This can enhance the reliability of the overlap between the first collector wire and the electrical junction, and also improve the bonding capability between the first collector wire and the electrical junction.

[0011] In some possible implementations, in the first direction, the end of the bent segment extends or retracts relative to the edge of the electrical connection, and the first distance of extension or retraction is 0~0.3mm. If the first distance of the end of the bent segment extending beyond the edge of the electrical connection is greater than 0.3mm, the extension length of the bent segment in the first direction is too long, resulting in an excessively long actual line length of the bent segment, increasing the current transmission path of the first collector grid line, which is detrimental to improving transmission efficiency. If the first distance of the end of the bent segment retracting relative to the edge of the electrical connection is greater than 0.3mm, the contact area between the bent segment and the electrical connection is too small, which is detrimental to improving current collection capability and the bonding capability between the bent segment and the electrical connection. Therefore, considering the current transmission efficiency, current collection capability, and bonding capability between the bent segment and the electrical connection of the first collector grid line, the first distance of extension or retraction is selected to be 0~0.3mm.

[0012] In some possible implementations, the portion of the bent structure located inside the electrical joint is larger than the portion located outside the electrical joint in the first direction of the projected length.

[0013] When the above technical solution is adopted, along the first direction, the bent structure portion is located outside the electrical connection portion, and the proportion of the bent structure inside the electrical connection portion is greater than the proportion outside the electrical connection portion. The larger proportion inside the electrical connection portion can increase the contact area between the first collector grid line and the electrical connection portion, thereby enhancing the current collection capability of the electrical connection portion and improving the connection capability between the first collector grid line and the electrical connection portion.

[0014] In some possible implementations, in the second direction, the bent segment does not extend beyond the edge of the electrical joint, and the first and second directions are perpendicular. Thus, the entire bent segment lies within the electrical joint in the second direction, allowing the entire area of ​​the bent segment in the second direction to collect current from the electrical joint. This avoids the underutilization of current collection capacity caused by the bent segment extending beyond the edge of the electrical joint in the second direction, thereby improving the current collection capacity of the bent segment for the electrical joint.

[0015] In some possible implementations, in the second direction, the second distance between the two furthest points on the bent segment is 10% to 90% of the width of the electrical joint, and the first and second directions are perpendicular. If the proportion of the bent segment in the second direction of the electrical joint is less than 10%, the area occupied by the bent segment in the second direction is too small. This is detrimental to improving the current collection capability of the bent segment in the electrical joint, and also to the stability of the connection between the bent segment and the electrical joint. Furthermore, if there is a printing offset during the printing of the first collector grid line, it is not conducive to reducing the risk of detachment and overlap between the bent segment and the electrical joint. If the proportion of the bent segment in the second direction of the electrical joint is greater than 90%, the area occupied by the bent segment in the second direction is too large, resulting in an excessively long current transmission path, which is detrimental to improving current transmission efficiency. Therefore, considering the current collection capability of the bent segment, the stability of the connection with the electrical joint, and the current transmission efficiency, the proportion of the area occupied by the bent segment in the second direction of the electrical joint is chosen to be 10% to 90%.

[0016] In some possible implementations, the second distance is 0.01mm to 0.3mm. If the second distance is less than 0.01mm, the bending distance of the bent segment in the second direction is too small. This is detrimental to improving the current collection capability of the bent segment for the electrical connection, and also to the stability of the connection between the bent segment and the electrical connection. Furthermore, if there is a printing offset during the printing of the first collector grid line, it is not conducive to reducing the risk of detachment and overlap between the bent segment and the electrical connection. If the second distance is greater than 0.3mm, the bending distance of the bent segment in the second direction is too large, resulting in an excessively long current transmission path, which is detrimental to improving current transmission efficiency.

[0017] In some possible implementations, the two bent structures at both ends of the bent segment bend relative to the straight segment to the same or different sides. The goal is simply to enhance the overlap between the bent segment and the electrical connection.

[0018] In some possible implementations, the bending structure can be a broken line or a curved line. The broken line structure is a short straight line, and the curved line structure is a short curve, serving as the smallest unit constituting the bending segment.

[0019] In some possible implementations, the bending structure at the end of the bending segment is a broken line structure, with the angle between the broken line structure and the connected straight line segment being greater than or equal to 90° and less than or equal to 170°; and / or, the bending structure at the end of the bending segment is a curved structure, with the angle between the tangent at the intersection of the curved structure and the straight line segment being greater than or equal to 90° and less than or equal to 170°. The angle between the end bending structure of the bending segment connected to the adjacent straight line segment and the straight line segment, or the angle between the tangent of the arc at the intersection and the straight line segment, can be selected according to the position of the mesh knot in the actual screen printing process to avoid mesh knots, thereby resulting in better quality of the printed bending segment and less likelihood of broken grid lines.

[0020] In some possible implementations, the bend segment is composed of multiple continuous broken line structures and / or curved structures forming a wave shape, with a bend angle between two adjacent broken line structures ranging from 20° to 160°. The wave shape of the bend segment ensures uniform distribution in the second direction, resulting in a balanced current transmission path and enabling even current collection at the electrical junction, thus improving current collection capability. Furthermore, the wave-shaped bend segment enhances the uniformity of the connection with the electrical junction, resulting in a more balanced bonding force and improved bonding reliability. The bend angle between two adjacent broken line structures is related to the density of the wave structure. If the bend angle is less than 20°, the broken line structures of the bend segment are too densely arranged in the first direction, increasing the amount of electrode material used and cost. Additionally, the actual length of the bend segment is too long, leading to an excessively long current transmission path, which is detrimental to improving current transmission efficiency. If the bend angle is greater than 160°, the broken line structures of the bend segment are too sparsely arranged in the first direction, which is not conducive to increasing the contact area between the first collector grid line and the electrical junction, thus hindering the improvement of current collection capability and bonding capability. Therefore, considering current transmission efficiency, current collection capability, and bonding capability, the bending angle is selected as 20°~160°.

[0021] In some possible implementations, the bending segment is discontinuous at the electrical connection. That is, the bending segment is a discontinuous structure at the electrical connection. When the materials of the bending segment and the electrical connection differ, the bending segment and the electrical connection may experience inconsistent stress deformation, leading to poor contact. Therefore, discontinuing the bending segment at the electrical connection allows it to better adapt to the deformation of the electrical connection, reducing the likelihood of poor contact between the bending segment and the electrical connection.

[0022] In some possible implementations, in the first direction, the ratio of the distance at which the bent segment breaks at the electrical junction to the length of the electrical junction is less than or equal to 2 / 3. If the proportion of the break distance is greater than 2 / 3, the length of the bent segment at the electrical junction is too small, which is not conducive to the current collection and transmission below the bent segment, nor to the bonding ability between the bent segment and the electrical junction. Therefore, considering the current collection and transmission capability of the first collector grid line and its bonding capability with the electrical junction, the proportion of the break distance is chosen to be less than or equal to 2 / 3.

[0023] In some possible implementations, along the first direction, the third distance from the end of the bent segment that breaks at the electrical junction to the edge of the electrical junction is greater than the first distance the bent segment extends beyond the edge of the electrical junction. This ensures that the first distance the bent segment extends is not too large, and the third distance between the bent segment and the electrical junction is not too small, thereby improving the current collection and transmission capability of the first collector grid line and its connection capability with the electrical junction.

[0024] In some possible implementations, the ratio of the first distance to the third distance is 0 to 1:3. If the ratio is less than 1:3, the third distance is too small, which is not conducive to the current collection and transmission of the bending section below, nor to the bonding ability of the bending section with the electrical junction. Therefore, considering the current collection and transmission capability of the first collector grid line and its bonding capability with the electrical junction, the ratio of the first distance to the third distance is selected to be 0 to 1:3.

[0025] In some possible implementations, the same first collector wire includes multiple alternating straight segments and bent segments, with electrical connections overlapping one-to-one with the bent segments. The number and position of the bent segments of the first collector wire are set according to the number and arrangement of the electrical connections, thereby increasing the overall contact area between the first collector wire and the electrical connections and improving the current collection capability.

[0026] In some possible implementations, the two straight segments at both ends of the same bend are located on the same straight line. This facilitates the setting of the spacing between two adjacent first collector grid lines, facilitates the arrangement of the first collector grid lines corresponding to the battery carrier collection area, and improves the uniformity of current collection.

[0027] In some possible implementations, multiple straight segments of the same first collector grid line lie on the same straight line. This facilitates the setting of the spacing between two adjacent first collector grid lines, makes it easier to arrange the first collector grid lines corresponding to the battery carrier collection area, and improves the uniformity of current collection.

[0028] In some possible implementations, in the second direction, the extension of the straight segment passes through the middle of the bent segment, and the first direction is perpendicular to the second direction. This arrangement, with the bent segment symmetrically arranged relative to the straight segment in the second direction, allows the first collector grid line to be positioned entirely in the central region of the battery's charge carrier collection area, corresponding to the center of the electrical junction, further improving the balance of charge carrier and current collection.

[0029] In some possible implementations, the electrical joint can be rectangular, circular, rhomboid, H-shaped, Type II, or Type III. The key is to achieve a good connection between the electrical joint and the bending section, ensuring efficient current transmission and minimizing electrode paste usage.

[0030] In some possible implementations, the electrode includes a plurality of first collector grid lines and a plurality of second collector grid lines, the first collector grid lines and the second collector grid lines having opposite polarities; The electrical connection includes multiple first electrical connections and multiple second electrical connections. The first electrical connections and the second electrical connections have opposite polarities. The bent section of the first collector grid line overlaps with the first electrical connection. The first direction is perpendicular to the second direction. The second collector wire has a straight structure; And / or, the second collector grid line includes connected bent sections and straight sections, the bent sections of the second collector grid line overlap with the second electrical junction, and the bent sections of the second collector grid line include at least one bent structure that bends laterally toward the first direction.

[0031] By employing the above technical solution, the combination of the bent first and second collector wires allows for the selection of different wire shapes to meet varying needs, achieving optimized configuration. The second collector wire can be a straight structure, or it can also have a bent section; some second collector wires can be straight, while others can have bent sections.

[0032] In some possible implementations, in the second direction, the width of the second electrical connection is smaller than the width of the first electrical connection, and / or, in the direction perpendicular to the substrate surface, the thickness of the second electrical connection is greater than the thickness of the first electrical connection.

[0033] In the above technical solution, a bent section is provided on the first collector grid line at the first electrical junction, making it wider than at other locations. To achieve good contact between the bent section of the first collector grid line and the first electrical junction, increase the contact area, enhance the current collection capacity of the first electrical junction, and improve the bonding strength between the first collector grid line and the first electrical junction, the width of the first electrical junction is set to be wider. The width of the second electrical junction can be set relatively smaller, reducing material consumption and light shading. The thickness of the first electrical junction is less than the thickness of the second electrical junction. The smaller thickness of the first electrical junction reduces light shading and stress effects. Furthermore, by providing the bent section of the first collector grid line, the contact area with the first electrical junction can be increased, reducing contact resistance and mitigating the impact of increased resistance due to the reduced thickness of the first electrical junction on current transmission. Especially when the second collector grid line has a straight structure, its current collection capacity is weaker than that of the bent grid line, which can be matched with the narrower second electrical junction. The second electrical junction is thicker, resulting in lower resistance. When the second collector grid line has a straight structure, electrical losses can be avoided.

[0034] In some possible implementations, the substrate includes opposing first and second surfaces; The first surface is the light-receiving surface, the first collector grid line is disposed on the first surface, and the second collector grid line is disposed on the second surface.

[0035] In the case of the above technical solution, the solar cell is a bifacial cell. The first side typically has a textured surface, and the first current collector grid line disposed on the first side has a bent section. Due to the uneven textured surface, the bent section can increase the connection reliability between the first current collector grid line and the electrical junction, and better improve the bonding performance between the first current collector grid line and the electrical junction. When the first current collector grid line is located between the textured surface and the electrical junction, the bonding performance between the first current collector grid line and the textured surface can also be improved.

[0036] In some possible implementations, when the second collector grid line is a straight line structure, the number of the second collector grid line is greater than the number of the first collector grid line; In some possible implementations, when the second collector grid line is a straight structure, the width of the first collector grid line is greater than the width of the second collector grid line.

[0037] With the above technical solution, the second collector grid line is located on the second side, i.e., the back side. Since the first side is the light-receiving surface, it needs to minimize shading. Therefore, the number of second collector grid lines on the second side is greater than the number of first collector grid lines on the first side. When the second collector grid line has a straight structure, its arrangement on the second side can be denser. Because the first collector grid line has a bend, it requires more space, and the distance between adjacent first collector grid lines is greater. Therefore, the number of first collector grid lines is less than that of the second collector grid lines, resulting in a sparser density. In addition, the greater distance between adjacent first collector grid lines allows for a wider range of widths for the first collector grid lines. Therefore, the width of the first collector grid line can be greater than that of the second collector grid line. Wider grid lines have stronger carrier collection capabilities, and the presence of bends allows the collected carriers to flow into the electrical junction through more reliable contact. Therefore, these two features complement each other.

[0038] In some possible implementations, a tunneling passivation contact structure layer is provided between the second collector line and the substrate, the second collector line is disposed on the side of the tunneling passivation contact structure layer away from the substrate, and the tunneling passivation contact structure layer between the second collector lines has a hollow structure.

[0039] With this configuration, for bifacial cells, a tunneling passivation contact structure layer is provided on the first and / or second sides. This tunneling passivation contact structure layer has the characteristics of efficient passivation and selective carrier transport, which is beneficial to improving the conversion efficiency of the solar cell. The tunneling passivation contact structure layer between the second collector grid lines has a hollow structure, that is, the tunneling passivation contact structure is not provided in some areas between the electrodes, which can reduce parasitic absorption.

[0040] In some embodiments, the substrate includes a first side and a second side facing each other, the first side being the light-receiving side, and electrodes disposed on the second side of the substrate. First and second collector grid lines are arranged alternately along a second direction. The electrodes are disposed only on the back side of the solar cell, with no electrodes obstructing the front side, thus improving the light incident rate and increasing the short-circuit current and photoelectric conversion efficiency of the solar cell.

[0041] Secondly, this utility model also provides a photovoltaic module, comprising: A battery string is formed by electrically connecting several solar cells as described in any of the above. Interconnectors are electrically connected to the solar cells; And an encapsulation layer that covers the surface of the battery string.

[0042] Since photovoltaic modules include solar cells as described in the second aspect, they have the same beneficial effects as the first and second aspects, which will not be elaborated further. Attached Figure Description

[0043] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the first electrode of the solar cell provided in an embodiment of the present invention; Figure 2 A schematic diagram of the graphic structure of electrode screen printing provided for an embodiment of this utility model; Figure 3 This is a schematic diagram of the structure of the second electrode provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the third electrode provided in an embodiment of the present utility model; Figure 5 This is a schematic diagram of the structure of the fourth electrode provided in an embodiment of the present utility model; Figure 6 This is a schematic diagram of the structure of the fifth electrode provided in an embodiment of the present utility model; Figure 7 This is a schematic diagram of the structure of the sixth electrode provided in an embodiment of the present utility model; Figure 8 This is a schematic diagram of the structure of the seventh electrode provided in an embodiment of the present utility model; Figure 9 This is a schematic diagram of the structure of the eighth electrode provided in the embodiment of this utility model; Figure 10 A schematic diagram of the structure of the ninth electrode provided in this embodiment of the present utility model; Figure 11 This is a schematic diagram of the structure of the tenth electrode provided in an embodiment of the present utility model; Figure 12 A schematic diagram of the structure of the eleventh electrode provided in this embodiment of the present utility model; Figure 13 This is a schematic diagram of the structure of the twelfth type of electrode provided in the embodiment of this utility model; Figure 14 This is a schematic diagram of the thirteenth electrode provided in this embodiment of the utility model; Figure 15 This is a schematic diagram of the structure of the fourteenth electrode provided in this embodiment of the utility model; Figure 16 This is a schematic diagram of the structure of the fifteenth type of electrode provided in this embodiment of the utility model; Figure 17 A schematic diagram of the structure of the sixteenth type of electrode provided in this embodiment of the present utility model; Figure 18A schematic diagram of the structure of the seventeenth type of electrode provided in this embodiment of the present utility model; Figure 19 A schematic diagram of the structure of the eighteenth type of electrode provided in this embodiment of the present utility model; Figure 20 This is a schematic diagram of the structure of the nineteenth type of electrode provided in this embodiment of the utility model; Figure 21 This is a schematic diagram of the twentieth type of electrode provided in this embodiment of the utility model; Figure 22 This is a schematic diagram of the structure of the twenty-first electrode provided in this embodiment of the present utility model; Figure 23 A schematic diagram of the electrode arrangement on the first side (light-receiving side) of a bifacial solar cell provided for an embodiment of this utility model; Figure 24 A schematic diagram of the electrode arrangement on the second side (back side) of a bifacial battery provided for an embodiment of this utility model; Figure 25 This is a schematic diagram of the back electrode arrangement of a back contact battery provided for an embodiment of the present invention.

[0044] Reference numerals: 1 for electrical connection, 11 for connection, 12 for edge, 101 for first electrical connection, 102 for second electrical connection, 2 for first collector wire, 202 for second collector wire, 21 for bent section, 211 for bent structure, 212 for first segment, 213 for second segment, 22 for straight segment, 3 for wire mesh, 31 for knot. Detailed Implementation

[0045] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0046] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0048] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0049] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0050] Screen printing is a core process in photovoltaic manufacturing for electrode preparation. Its effectiveness directly impacts the cell's current collection capacity, series resistance, optical losses, and electrical losses, ultimately determining the cell's efficiency. Screen-printed patterns typically consist of pad patterns and grid lines. Generally, pads are printed first, followed by grid lines, with some grid lines penetrating the pads. Electrodes obtained through screen printing usually include pads and fine grids. The fine grids penetrate the pads and are straight lines. If the fine grids shift during printing, there is a risk of misalignment and overlap between the fine grids and the pads. Due to cost reduction requirements, the fine grids are becoming increasingly fine, increasing the risk of misalignment and overlap. Furthermore, printing fine grids in straight lines is prone to grid breakage.

[0051] Firstly, such as Figures 1-22As shown, this embodiment of the present invention provides a solar cell, including a substrate and electrodes. The substrate has two opposing sides, and the electrodes are disposed on at least one side of the substrate, i.e., only one side (the back side) of the substrate. The electrodes on the back side include a positive electrode and a negative electrode, or they can be disposed on both sides of the substrate, with a positive electrode on one side and a negative electrode on the other. It should be noted that the substrate may include a semiconductor substrate and various functional layers such as doped layers and passivation layers disposed on the semiconductor substrate. The electrodes are conductively connected to their corresponding conductive regions. The electrode includes an electrical junction 1 and a first current collector line 2. The first current collector line 2 extends along a first direction. The electrical junction 1 can be rectangular, square, circular, elliptical, or other shapes. The first current collector line 2 includes a connected bent segment 21 and a straight segment 22. The bent segment 21 is correspondingly arranged with the electrical junction 1. Specifically, in the longitudinal space parallel to the thickness direction of the solar cell, the bent segment 21 is located above and / or below and / or inside the electrical junction 1. In the projection plane parallel to the light-receiving surface (or backlight surface) of the solar cell, the bent segment 21 is correspondingly arranged with the electrical junction 1. The projection of the bent segment 21 on the projection plane overlaps at least partially (partially or completely) with the projection of the electrical junction 1 on the projection plane. That is, at least a partial structure (partial structure or complete structure) of the bent segment 21 and the electrical junction 1 are stacked. Overall, the segment on the first collector wire 2 corresponding to the electrical connection 1 is a bent segment 21, and the segment not corresponding to the electrical connection 1 is a straight segment 22. The bent segment 21 is different from the straight segment 22. The entire segment of the straight segment 22 is a straight line extending along the first direction, while the bent segment 21 is not entirely parallel to the first direction or not parallel to the first direction at all. The bent segment 21 includes at least one bent structure 211 that bends laterally towards the first direction. The bent structure 211 is the smallest unit that makes up the bent segment 21. The lines of the bent structure 211 itself are not parallel to the first direction and can be short straight lines or short curves. That is, the direction in which the bent structure 211 bends relative to the straight segment 22 is different from the first direction. In addition to the bent structure 211, the bent segment 21 may also contain a straight section parallel to the first direction (not the straight segment 22). The starting position and ending position of the bent segment 21 are the point where the bent structure 211 at the end begins to bend relative to the straight segment 22.

[0052] It should be noted that the first collector grid line 2, also known as the fine grid, is used to collect the current generated by the photovoltaic power generation of the solar cell. The electrical connection portion 1 is used for conductive connection with the interconnect of the photovoltaic module, transmitting the current collected by the first collector grid line 2 to the interconnect through the electrical connection portion 1. The electrical connection portion 1 can be a pad or a thickened section of the collector grid line. In the case of a bus grid line (also known as a main grid), the electrical connection portion 1 can also be a thickened section set on the bus grid line. The electrode includes multiple electrical connection portions 1 and multiple first collector grid lines 2. Each first collector grid line 2 can be provided with multiple bends 21 for conductive connection with multiple electrical connection portions 1 arranged on the same straight line.

[0053] In the case of the above technical solution, the first collector grid line 2 includes a connected straight segment 22 and a bent segment 21. The straight segment 22 extends along a first direction, and the bent segment 21 includes a bent structure 211 that bends laterally toward the extension direction (first direction) of the first collector grid line 2. That is, the bent segment 21 is not a straight line. The first collector grid line 2 overlaps with the electrical connection part 1 (such as a pad, a thickened section of the grid line, etc.) through the bent segment 21. Compared with the existing structure where a straight collector grid line overlaps with a pad, the bent segment 21 in this application bends laterally toward the extension direction (first direction) of the first collector grid line 2. The lateral bending structure 211 in the first direction increases the area occupied by the overlap between the first collector grid line 2 and the electrical connection portion 1 in the direction perpendicular to the first direction (i.e., the second direction). Therefore, even if the first collector grid line 2 experiences a certain offset during printing, compared to existing straight collector grid lines, the bent segment 21 can still maintain the overlap with the electrical connection portion 1 when the offset is less than the distance of the area occupied by the bent segment 21 in the second direction, reducing the risk of the first collector grid line 2 detaching from the electrical connection portion 1. Furthermore, with the same dimensions of the electrical connection portion 1 in the first direction, the bent segment 21 increases the actual line length of the first collector grid line 2, i.e., the contact area between the first collector grid line 2 and the electrical connection portion 1 increases, thereby enhancing the current collection capability of the electrical connection portion 1 and improving the bonding capability between the first collector grid line 2 and the electrical connection portion 1. During probe testing, the increased contact area between the bent segment 21 and the test probe improves the accuracy and stability of the probe test. Furthermore, during the screen printing process, the first collector wire 2 with the bent section 21, compared to a straight collector wire, can bypass the mesh 31 of the screen 3 by bending the structure 211 of the bent section 21, such as... Figure 2 As shown, this reduces the impact of the mesh 31 on the printing quality of the first collector line 2 and reduces the risk of grid breakage.

[0054] like Figures 1-15As shown, in some embodiments, the bent segment 21 extends through the electrical connection portion 1 along a first direction. That is, in the first direction, the extension length of the bent segment 21 is not much different from the extension length of the electrical connection portion 1, and the bent structure 211 at the end of the bent segment 21 is provided close to both sides of the electrical connection portion 1. This allows the overlap length between the bent segment 21 and the electrical connection portion 1 to be maximized, thereby increasing the contact area between the first collector grid line 2 and the electrical connection portion 1, thus enhancing the current collection capability of the electrical connection portion 1 and improving the bonding capability between the first collector grid line 2 and the electrical connection portion 1, while maintaining the same dimensions in the first direction.

[0055] like Figure 1 As shown, in some embodiments, the line width of the bent segment 21 is greater than the line width of the straight segment 22. By increasing the line width of the bent segment 21, the contact area between the bent segment 21 and the electrical junction 1 is further increased, improving the current collection capability, and the wider bent segment 21 can reduce the risk of grid breakage during printing.

[0056] Furthermore, in this embodiment, the ratio of the linewidth of the bent segment 21 to the linewidth of the straight segment 22 is 1.1 to 4. Specifically, the ratio can be 1.1, 1.3, 1.5, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.5, 3.8, 4, etc. If the ratio is less than 1.1, the linewidth of the bent segment 21 is only slightly thicker than that of the straight segment 22, and the increase in the contact area between the bent segment 21 and the electrical junction 1 is limited, thus limiting the improvement in current collection capability. If the ratio is greater than 4, the linewidth of the bent segment 21 increases too much relative to that of the straight segment 22, resulting in a waste of electrode material. Therefore, considering the contact area between the bent segment 21 and the electrical junction 1, the current collection capability, the risk of grid breakage, and the material cost, the ratio is selected to be 1.1 to 4.

[0057] In some embodiments, in the first direction, the end of the bent segment 21 extends or retracts relative to the edge of the electrical connection portion 1, for example, as shown in... Figure 4 As shown, one end of the bent section 21 can extend out relative to the edge of the electrical connection portion 1, and the other end can retract inward relative to the edge of the electrical connection portion 1; or, as... Figure 3 and Figure 7 As shown, both ends of the bent section 21 extend or retract relative to the edge of the electrical connection portion 1. The first distance d between the end of the bent section 21 and the edge of the electrical connection portion 1 is 0~0.3mm. That is, the end of the bent section 21 can extend beyond the edge of the electrical connection portion 1, and the first distance d is 0~0.3mm, specifically 0mm, 0.01mm, 0.02mm, 0.03mm, 0.05mm, 0.06mm, 0.08mm, 0.1mm, 0.2mm, 0.3mm, etc. When it is 0mm, the end of the bent section 21 is flush with the edge of the electrical connection portion 1, such as... Figure 1, Figure 6 , Figure 10 , Figure 14 , Figure 15 , Figures 18-20 As shown; or, as Figure 4 As shown, one end of the bent section 21 does not extend beyond the edge of the electrical connection portion 1, and the first distance d between the end of the bent section 21 that does not extend beyond the edge of the electrical connection portion 1 and the edge of the electrical connection portion 1 is 0~0.3mm, specifically 0.01mm, 0.02mm, 0.03mm, 0.05mm, 0.06mm, 0.08mm, 0.1mm, 0.2mm, 0.3mm, etc.

[0058] If the first distance d from the end of the bent segment 21 beyond the edge of the electrical connection 1 is greater than 0.3 mm, the extension length of the bent segment 21 in the first direction is too long, resulting in an excessively long actual line length. This increases the current transmission path of the first collector grid line 2, which is detrimental to improving transmission efficiency. If the first distance d from the end of the bent segment 21 to the edge of the electrical connection 1 is greater than 0.3 mm, the actual line length of the bent segment 21 is too short, and the contact area between the bent segment 21 and the electrical connection 1 is too small. This is detrimental to improving current collection capability and the bonding capability between the bent segment 21 and the electrical connection 1. Therefore, considering the current transmission efficiency, current collection capability, and bonding capability between the bent segment 21 and the electrical connection 1 of the first collector grid line 2, the first distance d from the end to the edge is selected to be 0~0.3 mm.

[0059] In some embodiments, in the first direction, at least one bent structure 211 partially extends out of the electrical connection portion 1 and is partially located within the electrical connection portion 1. A first current collector line 2 includes one or more bent structures 211. The bent structure 211 may be completely located within the electrical connection portion 1, partially extend out of the electrical connection portion 1, or both of these forms may exist. The partial extension and partial location of the bent structure 211 within the electrical connection portion 1 can improve the overlap reliability between the first current collector line 2 and the edge of the electrical connection portion 1, resulting in a significant improvement in contact and effectively improving battery efficiency.

[0060] In some embodiments, the proportion of the portion of the bent structure 211 located inside the electrical connection 1 is greater than the proportion located outside the electrical connection 1 in the first direction. That is, along the first direction, a portion of the bent structure 211 is located outside the electrical connection 1. Specifically, one end of the bent segment 21 may be located outside the electrical connection 1, or both ends may be located outside the electrical connection 1. The proportion of the bent structure 211 located inside the electrical connection 1 is greater than the proportion located outside the electrical connection 1. The larger proportion located inside the electrical connection 1 can increase the contact area between the first collector grid line 2 and the electrical connection 1, thereby enhancing the current collection capability of the electrical connection 1 and improving the bonding capability between the first collector grid line 2 and the electrical connection 1.

[0061] like Figures 1-22 As shown, in some embodiments, in the second direction, the bent segment 21 does not extend beyond the edge of the electrical connection portion 1, and the first and second directions are perpendicular. Thus, the bent segment 21 is entirely located within the electrical connection portion 1 in the second direction, enabling the entire area of ​​the bent segment 21 in the second direction to collect the current from the electrical connection portion 1. This avoids the current collection capacity of the bent segment 21 being insufficient if it extends beyond the edge of the electrical connection portion 1 in the second direction, thereby improving the current collection capacity of the bent segment 21 for the electrical connection portion 1.

[0062] like Figure 1 and Figure 6 As shown, in some embodiments, taking the shape of the electrical connection 1 as a rectangle as an example, two opposite sides of the rectangular electrical connection 1 are parallel to the first direction, and the other two opposite sides are parallel to the second direction. The second distance b between the two farthest points of the bent segment 21 in the second direction is 10% to 90% of the width c of the electrical connection 1 in the second direction, specifically 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc. If the proportion of the area occupied by the bent segment 21 in the second direction of the electrical connection 1 is less than 10%, then the proportion of the area occupied by the bent segment 21 in the second direction is too small. On the one hand, it is not conducive to improving the current collection capability of the bent segment 21 for the electrical connection 1. On the other hand, it is not conducive to the bonding stability between the bent segment 21 and the electrical connection 1. Furthermore, if there is a printing offset when printing the first collector grid line 2, it is not conducive to reducing the risk of the bent segment 21 and the electrical connection 1 detaching and overlapping. If the proportion of the area occupied by the bent segment 21 in the second direction of the electrical connection 1 is greater than 90%, then the proportion of the area occupied by the bent segment 21 in the second direction is too large, resulting in an excessively long actual current transmission path for the bent segment 21, which is not conducive to improving current transmission efficiency. Therefore, considering the current collection capability of the bent segment 21, the connection stability with the electrical connection 1, and the current transmission efficiency, the proportion of the area occupied by the bent segment 21 in the second direction of the electrical connection 1 is selected to be 10%~90%.

[0063] Furthermore, the second distance b between the two furthest points of the bent segment 21 in the second direction is 25% to 50% of the width c of the electrical connection 1 in the second direction, specifically it can be 25%, 30%, 35%, 40%, 45%, 50%, etc. This further integrates the current collection capability of the bent segment 21, the connection stability with the electrical connection 1, and the current transmission efficiency.

[0064] For example, the second distance b can be 0.01mm to 0.3mm, and the width of the electrical connection portion 1 in the second direction is 0.1mm to 0.35mm. Specifically, the second distance b can be 0.01mm, 0.02mm, 0.05mm, 0.08mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, etc., and the width of the electrical connection portion 1 can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.24mm, 0.26mm, 0.28mm, 0.3mm, 0.32mm, 0.34mm, 0.35mm, etc. Furthermore, if the second distance is less than 0.01 mm, the bending distance of the bent segment in the second direction is too small. This is detrimental to improving the current collection capacity of the bent segment for the electrical junction, and also to the stability of the connection between the bent segment and the electrical junction. Additionally, if there is printing misalignment during the printing of the first collector grid line, it is difficult to reduce the risk of detachment and overlap between the bent segment and the electrical junction. If the second distance is greater than 0.3 mm, the bending distance of the bent segment in the second direction is too large, resulting in an excessively long current transmission path, which is detrimental to improving current transmission efficiency. If the width of the electrical junction is less than 0.1 mm, the width of the electrical junction is too small, which is detrimental to the electrical junction collecting current from the solar cell. If the width of the electrical junction is greater than 0.35 mm, the width of the electrical junction is too large, which may encroach on the position of adjacent collector grid lines with opposite polarities, which is detrimental to insulation isolation. By arbitrarily selecting the combination of the second distance b and the width of the electrical junction 1 within the above numerical range, it is preferable to select a proportion of the area occupied by the bent segment 21 in the second direction of the electrical junction 1 to be 10% to 90%.

[0065] In some embodiments, in the second direction, the bent segment 21 is located at the middle position of the electrical connection portion 1, and the distances on both sides of the bent segment 21 to the two side edges of the electrical connection portion 1 are equal. This ensures that the current transmission paths of the bent segment 21 and the electrical connection portion 1 are equal in the second direction, resulting in balanced current transmission time and improved transmission efficiency. Of course, the bent segment 21 can also be disposed biased towards one edge of the electrical connection portion 1 in the second direction, as long as the bent segment 21 overlaps with the electrical connection portion 1.

[0066] like Figures 1-22 As shown, in some embodiments, the bending structure 211 at the end of the bending segment 21 bends relative to the straight segment 22 to the same side or different sides. This is as long as it enhances the overlap between the bending segment 21 and the electrical connection portion 1. For example, with... Figures 1-4 , Figure 6 , Figure 7 , Figure 9 , Figure 15 , Figure 16 and Figure 21 The orientation shown illustrates that the two bending structures 211 at the left and right ends of the bending segment 21 both bend upwards relative to the straight segment 22; alternatively, they could both bend downwards relative to the straight segment. For example, using... Figure 5 , Figure 8 , Figure 10 , Figure 11 , Figure 14 , Figures 17-20 and Figure 22 The orientation is explained as follows: at the left end of the bent segment 21, one bent structure 211 bends upward relative to the straight segment 22, and at the right end of the bent segment 21, another bent structure 211 bends downward relative to the straight segment 22. Regardless of which side the bent structures 211 at both ends of the bent segment 21 bend relative to the straight segment 22, the overlap performance between the bent segment 21 and the electrical junction 1 can be improved, thereby enhancing the current collection capacity and reducing the risk of the collector grid line 2 detaching from the electrical junction 1 during printing. The position of the mesh knot 31 can be reasonably selected according to the actual screen printing position to avoid the mesh knot 31 position, improve printing quality, and avoid grid breakage.

[0067] In some embodiments, the bending structure 211 is a broken line structure or a curved structure; that is, a bending structure 211 is either a broken line or a curve, and can be bent relative to the straight line segment 22. The broken line structure is a short straight line, and the curved structure is a short curve, serving as the smallest unit constituting the bending segment 21. For example... Figure 14 As shown, the bent segment 21 can have only one broken line structure; or, as... Figure 15 As shown, the bent segment 21 has only two directly connected broken line structures; or, as... Figures 1-5 As shown, the bent segment 21 includes two broken line structures. The two broken line structures at both ends have an angle with the first direction. The two broken line structures are connected by a straight section parallel to the first direction located in the middle. There is an inflection point between the two broken line structures and the middle straight section; or, as shown... Figures 6-13 As shown, the bent segment 21 is composed of multiple broken line structures and / or curved structures forming a wavy shape. For example, as... Figures 1-8 and Figure 12 As shown, when the bent segment 21 is composed of multiple broken line structures, it forms a serrated structure that bends back and forth in the second direction. The serrated structure can be triangular, trapezoidal, or rectangular. Figures 1-4 As shown, when there are two broken line structures and the relative straight line segments 22 bend toward the same side, the two broken line structures are close to the edge of the electrical connection part 1. The two broken line structures are connected by a straight line part parallel to the first direction to form a trapezoidal sawtooth structure.

[0068] For example, such as Figures 9-11 As shown, when the bending segment 21 is composed of multiple continuous curved structures, it forms an S-shaped structure that bends back and forth in the second direction.

[0069] For example, such as Figure 13 As shown, the bent segment 21 can also be composed of multiple broken line structures and multiple curved structures in a continuous combination, forming a wave shape that is not a single cycle. The broken line structures and curved structures can be arranged alternately, or one segment can consist entirely of broken line structures and the other segment can consist entirely of curved structures.

[0070] With the above technical solution, the bend 21 is wavy, which makes the bend 21 evenly distributed in the second direction, and the current transmission path of the bend 21 is balanced in the second direction, which can evenly collect the current on the electrical joint 1 and improve the current collection capability. Moreover, the wavy bend 21 can improve the uniformity of the connection with the electrical joint 1, the connection force is more balanced, and the connection reliability is improved.

[0071] like Figure 2 and Figure 5 As shown, in some embodiments, the bending structure 211 located at both ends of the bending segment 21 is a broken line structure, and the angle α between the broken line structure and the connected straight line segment 22 is greater than or equal to 90° and less than or equal to 170°, specifically 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, etc.

[0072] like Figure 11 As shown, the bending structure 211 at the end of the bending segment 21 is a curved structure. The angle between the tangent of the arc at the intersection of the curved structure and the straight segment 22 and the straight segment 22 is greater than or equal to 90° and less than or equal to 170°. Specifically, it can be 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, etc.

[0073] The angle between the bending structure at the end of the bent segment 21 connected to the straight segment 22 and the straight segment 22, or the angle between the tangent of the arc at the intersection and the straight segment 22, can be selected according to the position of the mesh knot 31 in the actual screen printing process to avoid the mesh knot 31, so that the quality of the printed bent segment is better and the grid breakage is less likely to occur.

[0074] like Figure 7 and Figure 8 As shown, in some embodiments, when the bent segment is composed of multiple broken line structures forming a wave shape, the bending angle β between two adjacent broken line structures is 20°~160°, specifically 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, etc. The bending angle β between different broken line structures can be the same or different. The size of the bending angle β between two adjacent broken line structures is related to the density of the wave structure; the smaller the bending angle β, the denser the wave structure, and the larger the bending angle β, the sparser the wave structure. If the bending angle β is less than 20°, the broken line structures of the bent segment 21 are arranged too densely in the first direction, increasing the amount of electrode material used, increasing the cost, and the actual line length of the bent segment 21 is too long, resulting in an excessively long current transmission path, which is not conducive to improving the current transmission efficiency of the first collector grid line 2. If the bending angle β is greater than 160°, the broken line structure of the bending segment 21 is too sparsely distributed in the first direction, which is not conducive to increasing the contact area between the first collector grid line 2 and the electrical junction 1, and is not conducive to improving the current collection capability and the bonding capability. Therefore, considering the current transmission efficiency, current collection capability and bonding capability, the bending angle β is selected to be 20°~160°.

[0075] like Figure 16 , Figure 17 and Figure 19As shown, in some embodiments, the bent segment 21 is broken at the electrical connection portion 1, forming a first segment 212 and a second segment 213 that are disconnected. The two ends of the first segment 212 and the second segment 213 that are close to each other are staggered in a first direction, and the ends of the first segment 212 and the second segment 213 that are far apart from each other are respectively connected to the straight segments 22 at both ends of the bent segment 21. Both the first segment 212 and the second segment 213 include at least one bent structure 211. The structures of the first segment 212 and the second segment 213 may be the same or different, and the dimensions of the first segment 212 and the second segment 213 in the first direction or the second direction may be the same or different. By making the bent segment 21 into two discontinuous segments at the electrical connection 1, when there is a difference in the material of the bent segment 21 and the electrical connection 1, the bent segment 21 and the electrical connection 1 may have inconsistent stress deformation, resulting in poor contact between the bent segment 21 and the electrical connection 1. Therefore, the bent segment 21 is broken at the electrical connection 1. The broken bent segment 21 can better adapt to the deformation of the electrical connection 1 and reduce the occurrence of poor contact between the bent segment 21 and the electrical connection 1.

[0076] like Figure 16 and Figure 17 As shown, in some embodiments, in the first direction, the ratio of the distance f at which the bent segment 21 breaks at the electrical junction 1 to the length of the electrical junction 1 is less than or equal to 2 / 3. That is, the proportion of the offset distance f between the two adjacent ends of the first segment 212 and the second segment 213 in the first direction relative to the length of the electrical junction 1 is less than or equal to 2 / 3. Specifically, the proportion can be 0, 1 / 10, 1 / 8, 1 / 6, 1 / 4, 1 / 2, 2 / 3, etc. If the proportion of the breakage distance f is greater than 2 / 3, the length of the bent segment 21 at the electrical junction 1 is too small, which is not conducive to the current collection and transmission of the bent segment 21 below and the bonding ability of the bent segment 21 with the electrical junction 1. Therefore, considering the current collection and transmission capability of the first collector grid line 2 and the bonding capability with the electrical junction 1, the proportion of the breakage distance f is chosen to be less than or equal to 2 / 3.

[0077] like Figure 16As shown, in some embodiments, along the first direction, the third distance e from the endpoint of the bent segment 21 that breaks off at the electrical connection 1 to the edge of the adjacent electrical connection 1 is greater than the first distance d from the bent segment 21 extending beyond the edge of the electrical connection 1. It should be noted that the bent segment 21 can be either one of the two ends or both ends extending beyond the edge of the adjacent electrical connection 1; it does not specifically refer to which end extends beyond the edge of the electrical connection 1. Similarly, the endpoint of the bent segment 21 that breaks off is not specifically one of the two endpoints, but all satisfy the above relationship. For example, if the first segment 212 extends beyond the edge of the electrical connection 1, while the second segment 213 does not extend beyond the edge of the adjacent electrical connection 1, then in the first direction, the third distance e from the endpoint of the first segment 212 that breaks off to the edge of the electrical connection adjacent to the first segment 212 is greater than the first distance d from the edge of the electrical connection adjacent to the first segment 212. At the same time, the third distance e from the endpoint of the second segment 213 that breaks off to the edge of the electrical connection adjacent to the second segment 213 is also greater than the first distance d from the edge of the electrical connection adjacent to the first segment 212. In this way, the first distance d of the bent section 21 will not be too large, and the length of the bent section 21 connected with the electrical junction 1 will not be too small, thereby improving the current collection and transmission capability of the first collector grid line 2 and its connection capability with the electrical junction 1.

[0078] For example, the ratio of the first distance d extending from the edge of the bent segment 21 to the third distance e is 0 to 1:3, specifically 0, 1:1, 1:2, 1:3, etc. If the ratio is less than 1:3, the third distance e is too small, which is not conducive to the current collection and transmission of the bent segment 21 below, nor to the bonding ability of the bent segment 21 with the electrical junction 1. Therefore, considering the current collection and transmission capability of the first collector grid line 2 and its bonding capability with the electrical junction 1, the ratio of the first distance d to the third distance e is selected to be 0 to 1:3.

[0079] In some embodiments, the same first collector grid line 2 includes multiple alternating straight segments 22 and bent segments 21, with the electrical connection portion 1 overlapping the bent segments 21 one-to-one. The number and position of the bent segments 21 of the first collector grid line 2 are set according to the number and arrangement of the electrical connection portions 1, thereby increasing the overall contact area between the first collector grid line 2 and the electrical connection portion 1 and improving the current collection capability.

[0080] like Figures 1-4 , Figure 6 , Figure 7 , Figures 9-13 as well as Figure 15 , Figure 16 , Figure 18 , Figures 20-22As shown, in some embodiments, the two straight segments 22 located at both ends of the same bend 21 are on the same straight line. This facilitates the setting of the spacing between two adjacent collector grid lines, facilitates the arrangement of the collector grid lines corresponding to the battery carrier collection area, and improves the uniformity of current collection.

[0081] Furthermore, in some embodiments, when the same first collector grid line 2 includes multiple straight segments 22, the multiple straight segments 22 of the same first collector grid line 2 are located on the same straight line. In this way, the spacing between two adjacent first collector grid lines 2 can be equal to the spacing between the straight segments 22 of the two first collector grid lines 2, facilitating the setting of the spacing between two adjacent first collector grid lines 2, facilitating the arrangement of the first collector grid lines 2 corresponding to the battery carrier collection region, and improving the uniformity of current collection. Of course, as... Figure 5 , Figure 8 , Figure 17 and Figure 19 As shown, multiple straight segments 22 of the same first collector grid line 2 can also be located on different straight lines. The arrangement of multiple straight segments 22 of the same first collector grid line 2 is determined according to the layout pattern of the battery carrier collection area and the position of the screen-printed mesh.

[0082] In some embodiments, in the second direction, the extension of the straight segment 22 on the same first collector grid line 2 passes through the middle of the bent segment 21. This arrangement, with the bent segment 21 symmetrically arranged relative to the straight segment 22 in the second direction, allows the first collector grid line 2 to be positioned entirely in the central region of the battery carrier collection area, corresponding to the center position of the electrical junction 1, further improving the balance of carrier and current collection.

[0083] In some embodiments, the electrical connection 1 is rectangular, circular, rhomboid, H-shaped, type II, or type III. For example... Figures 1-17 As shown, when the electrical connection 1 is rectangular, the rectangle can include a rectangle or a square. For example... Figure 18 As shown, the electrical connection 1 is H-shaped, comprising a connecting portion 11 in the middle and side portions 12 at both ends of the connecting portion 11. The connecting portion 11 connects the middle position of the two side portions 12, and a bent section 21 is correspondingly provided on the connecting portion 11. Figure 19 As shown, the electrical connection 1 has a type II shape, comprising two parallel and spaced-apart connecting portions 11 in the middle and side portions 12 at both ends of the connecting portions 11. The two connecting portions 11 are connected at the middle position of the two side portions 12. A bent segment 21 is correspondingly provided on the connecting portion 11. When the bent segment 21 is a continuous structure, the continuous bent segment 21 is provided on only one of the connecting portions 11. When the bent segment 21 is a discontinuous structure, the first segment 212 and the second segment 213 are respectively provided on the two connecting portions 11. Figure 20As shown, the electrical connection 1 has a type III shape, comprising three parallel and spaced-apart connecting portions 11 in the middle and side portions 12 at both ends of the connecting portions 11. The three connecting portions 11 are connected to the middle position of the two side portions 12. A bent segment 21 is correspondingly provided on the connecting portion 11. When the bent segment 21 is a continuous structure, the continuous bent segment 21 is only provided on one of the three connecting portions 11, either on one of the two side connecting portions 11 or on the middle connecting portion 11. When the bent segment 21 is a discontinuous structure, the first segment 212 and the second segment 213 are respectively provided on any two of the three connecting portions 11. Figure 21 As shown, the electrical connection 1 is rhomboid in shape, and the bent section 21 is arranged along one diagonal of the rhombus. Figure 22 As shown, the electrical connection portion 1 is circular in shape, which can be either a perfect circle or an ellipse. Of course, the electrical connection portion 1 can also be other shapes, and is not limited to the shapes listed in this embodiment.

[0084] like Figures 23-25 As shown, in some embodiments, the electrode includes a plurality of first collector grid lines 2 and a plurality of second collector grid lines 202, the first collector grid lines 2 and the second collector grid lines 202 having opposite polarities; the electrical connection portion 1 includes a plurality of first electrical connection portions 101 and a plurality of second electrical connection portions 102, the first electrical connection portions 101 and the second electrical connection portions 102 having opposite polarities, the bent segment 21 of the first collector grid line 2 overlapping with the first electrical connection portion 101, the first direction being perpendicular to the second direction; the second collector grid line 202 having a straight structure; and / or, the second collector grid line 202 includes connected bent segments 21 and straight segments 22, the bent segment 21 of the second collector grid line 202 overlapping with the second electrical connection portion 102, the bent segment 21 of the second collector grid line 202 including at least one bent structure 211 bending laterally toward the first direction. When the second collector grid line 202 also has a bent section 21 and a straight section 22, the arrangement of the second collector grid line 202 can refer to the arrangement of the first collector grid line 2. It should be noted that the shape of the bent section 21 of the second collector grid line 202 and the bent section 21 of the first collector grid line 2 can be the same or different, and the degree of bending, size, etc., can be the same or different. The second collector grid line 202 is a straight structure, which means it is printed along a straight direction. The second collector grid line 202 does not have the bent section 21 described in this application, but the slight deformation caused by the printing process during straight printing also belongs to a straight structure. By combining the bent first collector grid line 2 and the second collector grid line, different grid line shapes can be selected according to different needs to achieve optimized settings. The second collector grid line 202 can be a straight structure, or it can also have a bent section 21, or some second collector grid lines 202 are straight structures and some have bent sections.

[0085] like Figure 23 and Figure 24 As shown, in some embodiments, for a bifacial solar cell, the substrate includes a first side and a second side opposite to each other, the first side being the light-receiving side and the second side being the back side; a first collector grid line 2 and a first electrical junction 101 are disposed on the first side, and a second collector grid line 202 and a second electrical junction 102 are disposed on the second side; the first collector grid line 2 includes a bent section 21 and a straight section 22; the second collector grid line 202 has a straight structure, and / or, the second collector grid line 202 includes a connected bent section 21 and a straight section 22, the bent section 21 of the second collector grid line 202 overlaps with the second electrical junction 102, and the bent section 21 of the second collector grid line 202 includes at least one bent structure 211 that bends laterally in a first direction.

[0086] When the above technical solution is adopted, the solar cell is a bifacial cell. The first collector grid line 2 described in any of the above embodiments is disposed on the first side, and the second collector grid line 202 is disposed on the second side. The first side usually has a textured surface, and the first collector grid line 2 disposed on the first side has a bent section. Because the textured surface structure is uneven, the bent section 21 can increase the connection reliability between the first collector grid line 2 and the electrical connection part 1, and better improve the bonding performance between the first collector grid line 2 and the electrical connection part 1. When the first collector grid line 2 is located between the textured surface and the electrical connection part 1, it can also improve the bonding performance between the first collector grid line 2 and the textured surface.

[0087] In some embodiments, for a bifacial battery, when the second collector grid line 202 is a straight structure, the number of the second collector grid lines 202 is greater than the number of the first collector grid lines 2; the width of the first collector grid line 2 is greater than the width of the second collector grid line 202.

[0088] With the above technical solution, the second collector grid line 202 is disposed on the second surface, i.e., the back surface. Since the first surface is the light-receiving surface, it is necessary to reduce shading. Therefore, the number of second collector grid lines 202 on the second surface is greater than the number of first collector grid lines 2 on the first surface. When the second collector grid line 202 has a straight structure, the arrangement of the second collector grid lines 202 on the second surface can be more dense. Because the first collector grid line 2 has a bent section 21, it requires more space, and the distance between adjacent first collector grid lines 2 is greater. Therefore, the number of first collector grid lines 2 is less than that of the second collector grid lines 202, and the density is sparser. Furthermore, the greater distance between adjacent first collector grid lines 2 allows for a wider range of widths for the first collector grid lines 2. Therefore, the width of the first collector grid line 2 can be greater than the width of the second collector grid line 202. Wider grid lines have a stronger carrier collection effect, and the presence of the bend section allows the collected carriers to flow into the electrical junction through more reliable contact. Thus, these two features complement each other.

[0089] Of course, for bifacial batteries, if the number of current collector grid lines on the first and second sides are basically the same, or the arrangement density is not too high, current collector grid lines including bent sections are provided on both the first and second sides.

[0090] In some embodiments, for bifacial cells, a tunneling passivation contact structure layer is provided between the second current collector line 202 on the second side (i.e., the back side) and the substrate. The second current collector line 202 is located on the side of the tunneling passivation contact structure layer away from the substrate, and the tunneling passivation contact structure layer between the second current collector lines 202 has a hollow structure. With this configuration, for bifacial cells, the first and / or second sides have a tunneling passivation contact structure layer, which features efficient passivation and selective carrier transport, thus improving the conversion efficiency of the solar cell. The tunneling passivation contact structure layer can be provided entirely on the first and / or second sides, or it can be provided partially on the first and / or second sides. Alternatively, the tunneling passivation contact structure can be provided only in the area below the second current collector line 202, meaning that the tunneling passivation contact structure layer between two adjacent second current collector lines 202 has a hollow structure, i.e., the tunneling passivation contact structure is not provided locally between the electrodes, which can reduce parasitic absorption. Alternatively, a tunneling passivation contact structure can be provided only in the region below the first collector grid line 2, with a perforated structure between adjacent first collector grid lines 2. This means that a tunneling passivation contact structure is not provided locally between the electrodes, which reduces parasitic absorption. For example, the tunneling passivation contact structure layer can be a structure composed of multiple strips or a cross-shaped structure, provided only below the corresponding electrode to reduce light shading, lower parasitic absorption, and improve battery performance. Of course, a tunneling passivation contact structure layer can also be provided locally in the interval region between adjacent electrodes, which facilitates lateral carrier transport and improves transport and collection speeds.

[0091] In some embodiments, in the second direction, the width of the second electrical bonding portion 102 is smaller than the width of the first electrical bonding portion 101, and / or, in the direction perpendicular to the substrate surface, the thickness of the second electrical bonding portion 102 is greater than the thickness of the first electrical bonding portion 101.

[0092] In the above technical solution, a bent section 21 is provided on the first collector wire 2 at the first electrical connection portion 101, which is wider than other positions. To achieve good contact between the first collector wire 2 with the bent section 21 and the first electrical connection portion 101, increase the contact area with the first electrical connection portion 101, enhance the current collection capability of the first electrical connection portion 101, and improve the bonding capability between the first collector wire 2 and the first electrical connection portion 101, the width of the first electrical connection portion 101 is set to be wider. The width of the second electrical connection portion 102 can be set to be relatively smaller, reducing material consumption and light shading. The thickness of the first electrical connection portion 101 is less than the thickness of the second electrical connection portion 102. The smaller thickness of the first electrical connection portion 101 can reduce light shading and stress effects. Furthermore, by providing the bent section 21 on the first collector wire 2, the contact area with the first electrical connection portion 101 can be increased, reducing contact resistance and mitigating the impact of increased resistance due to the reduced thickness of the first electrical connection portion 101 on current transmission. Especially when the second collector grid line 202 has a straight structure, its current collection capability is weaker than that of a grid line with bends, which can be matched with the narrower second electrical junction 102. The second electrical junction 102 is thicker and has lower resistance, which can avoid electrical losses when the second collector grid line 202 has a straight structure.

[0093] For example, for a back-contact battery, the second side, i.e. the back side, has a first doped region and a second doped region with alternating strip structures extending along a first direction. The first doped region can be an N-type doped region and the second doped region can be a P-type doped region, or the first doped region is a P-type doped region and the second doped region is an N-type doped region. When the widths of the first doped region and the second doped region are different, a wider first electrical junction 101 can be provided on the wider first doped region. Therefore, the first collector grid line 2 provided on the first doped region may include a bent section. By increasing the bonding area with the first electrical junction 101 through the bent section, the current collection capability of the first electrical junction 101 is enhanced, and the bonding capability between the first collector grid line 2 and the first electrical junction 101 is improved. On the narrower second doped region, a narrower second electrical junction 102 is provided. Since the width of the second electrical junction 102 is small, in order to achieve good contact between the second electrical junction 102 and the second collector grid line 202, reduce material consumption and light blocking, the second collector grid line may not have a bent section and has a straight structure.

[0094] like Figure 25As shown, in some embodiments, the substrate includes a first surface and a second surface opposite to each other. The first surface can be a light-receiving surface, and the second surface is a back surface. The second surface includes a first doped region and a second doped region, which are alternately arranged along a second direction. The first doped region and the second doped region have different conductivity types. An electrode is disposed on the second surface of the substrate. The electrode includes a plurality of first collector gate lines 2 and a plurality of second collector gate lines 202. The first collector gate lines 2 and the second collector gate lines 202 have opposite polarities and are alternately arranged along the second direction. An electrical connection portion 1 includes a plurality of first electrical connection portions 101 and a plurality of second electrical connection portions 102. The first electrical connection portions 101 and the second electrical connection portions 102 have opposite polarities. The bent section 21 of the first collector gate line 2 overlaps with the first electrical connection portion 101. The first direction is perpendicular to the second direction. For example, the first collector gate line 2 and the first electrical connection portion 101 are disposed in the first doped region, and the second collector gate line 202 and the second electrical connection portion 102 are disposed in the second doped region. The second collector grid line 202 is a straight structure, and / or the second collector grid line 202 includes a connected bent section 21 and a straight section 22. The bent section 21 of the second collector grid line 202 overlaps with the second electrical connection portion 102. The bent section 21 of the second collector grid line 202 includes at least one bent structure 211 that bends laterally in the first direction. When the second collector grid line 202 also has a bent section 21 and a straight section 22, the arrangement of the second collector grid line 202 can refer to the arrangement of the first collector grid line 2. It should be noted that the shape of the bent section 21 of the second collector grid line 202 and the bent section of the first collector grid line 2 can be the same or different. The degree of bending, size, etc. can be the same or different.

[0095] With the above technical solution, the electrodes are only located on the back side of the solar cell, forming a back-contact cell. There are no electrodes blocking the front side, which improves the light incident rate and increases the short-circuit current and photoelectric conversion efficiency of the solar cell. The second collector grid line located on the back side can be a straight structure, or it can also have a bent section; some second collector grid lines can be straight, while others have bent sections.

[0096] It should be noted that the electrodes may also include bus electrodes, also known as main grids. The bus electrodes extend along the second direction and are connected to multiple electrical junctions. The bus electrodes and current collectors form a U-shaped structure. The bus electrodes can be a continuous structure or a discontinuous structure, such as connecting some like-pair current collector grid lines and electrical junctions through local connecting lines to achieve current collection. Of course, the electrodes may also not include bus electrodes, forming a gridless cell.

[0097] In some possible implementations, for back-contact solar cells, the second side, i.e., the back side, includes a tunneling passivation contact structure layer, with the electrodes disposed on the side of the tunneling passivation contact structure layer away from the substrate. The tunneling passivation contact structure layer includes a tunneling oxide layer and a doped polycrystalline silicon layer stacked on the substrate, with the tunneling oxide layer disposed closer to the substrate. For back-contact solar cells, the tunneling passivation contact structure layer can be disposed in at least one doped region on the back side, i.e., only one doped region, or two doped regions. This configuration allows the tunneling passivation contact structure layer to exhibit efficient passivation and selective carrier transport, which is beneficial for improving the conversion efficiency of the solar cell.

[0098] Secondly, this utility model embodiment also provides a photovoltaic module, including a battery string, interconnecting elements, and an encapsulation layer; wherein, the battery string is formed by electrically connecting a plurality of solar cells as described in any of the above embodiments; the interconnecting elements are electrically connected to the solar cells; and the encapsulation layer covers the surface of the battery string. The interconnecting elements can be solder strips or conductive backsheets.

[0099] Since the photovoltaic module uses the solar cell of the first aspect, i.e., any of the above embodiments, it has the same beneficial effects as the first aspect and any of the embodiments, and will not be described again.

[0100] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0101] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A solar cell, characterized in that, The device includes a substrate and an electrode, the electrode being disposed on at least one side of the substrate, the electrode including an electrical junction portion and a first collector grid line, the first collector grid line extending along a first direction, the first collector grid line including a connected bent segment and a straight segment, the bent segment being disposed corresponding to the electrical junction portion; the bent segment including at least one bent structure bending laterally toward the first direction.

2. The solar cell according to claim 1, characterized in that, The bent section extends through the electrical junction along the first direction.

3. The solar cell according to claim 1, characterized in that, The width of the bent segment is greater than the width of the straight segment.

4. The solar cell according to claim 1, characterized in that, In the first direction, at least one of the bending structures partially extends out of the electrical connection portion and is partially located within the electrical connection portion.

5. The solar cell according to claim 1, characterized in that, In the first direction, the end of the bent section extends or retracts relative to the edge of the electrical connection portion, and the first distance of extension or retraction is 0~0.3mm.

6. The solar cell according to claim 1, characterized in that, The portion of the bent structure located inside the electrical joint is larger than the portion located outside the electrical joint when projected in the first direction.

7. The solar cell according to claim 1, characterized in that, In the second direction, the bent section does not extend beyond the edge of the electrical connection portion, and the first direction and the second direction are perpendicular; And / or, in the second direction, the second distance between the two furthest points on the bent segment accounts for 10% to 90% of the width of the electrical connection, and the first direction and the second direction are perpendicular.

8. The solar cell according to claim 1, characterized in that, In the second direction, the second distance between the two points furthest apart on the bent segment is 0.01mm to 0.3mm, and the first direction and the second direction are perpendicular.

9. The solar cell according to claim 1, characterized in that, The two bending structures located at both ends of the bending segment bend relative to the straight segment to the same side or different sides.

10. The solar cell according to claim 1, characterized in that, The bending structure is a broken line structure or a curved structure.

11. The solar cell according to claim 10, characterized in that, The bending structure located at the end of the bending segment is a broken line structure, and the angle between the broken line structure and the connected straight line segment is greater than or equal to 90° and less than or equal to 170°. And / or, the bending structure at the end of the bending segment is a curved structure, and the angle between the tangent of the arc at the intersection of the curved structure and the straight segment and the straight segment is greater than or equal to 90° and less than or equal to 170°.

12. The solar cell according to claim 10, characterized in that, The bent segment is composed of multiple broken line structures forming a wave shape, and the bending angle between two adjacent broken line structures is 20°~160°.

13. The solar cell according to claim 1, characterized in that, The bent section breaks off at the electrical junction.

14. The solar cell according to claim 13, characterized in that, In the first direction, the ratio of the distance at which the bent segment breaks at the electrical joint to the length of the electrical joint is less than or equal to 2 / 3.

15. The solar cell according to claim 13, characterized in that, Along the first direction, the third distance from the end point where the bent segment breaks at the electrical junction to the edge of the electrical junction is greater than the first distance by which the bent segment extends beyond the edge of the electrical junction.

16. The solar cell according to claim 1, characterized in that, The same first collector wire includes multiple alternating straight segments and bent segments, and the electrical connection portion overlaps with each of the bent segments in a one-to-one correspondence.

17. The solar cell according to claim 16, characterized in that, The two straight segments located at both ends of the same bend are on the same straight line.

18. The solar cell according to claim 16, characterized in that, Multiple straight segments of the same first collector grid line are located on the same straight line.

19. The solar cell according to claim 18, characterized in that, In the second direction, the extension of the straight segment passes through the middle of the bent segment, and the first direction is perpendicular to the second direction.

20. The solar cell according to claim 1, characterized in that, The electrical junction can be rectangular, circular, rhomboid, H-shaped, type II, or type III.

21. The solar cell according to any one of claims 1-20, characterized in that, The electrode includes a plurality of first collector grid lines and a plurality of second collector grid lines, wherein the first collector grid lines and the second collector grid lines have opposite polarities; The electrical connection includes a plurality of first electrical connections and a plurality of second electrical connections, the first electrical connections and the second electrical connections having opposite polarities, the bent section of the first collector grid line overlapping with the first electrical connection, and the first direction being perpendicular to the second direction; The second collector grid line has a straight structure; And / or, the second collector grid line includes connected bent sections and straight sections, the bent sections of the second collector grid line overlap with the second electrical junction, and the bent sections of the second collector grid line include at least one bent structure that bends laterally toward the first direction.

22. The solar cell according to claim 21, characterized in that, In the second direction, the width of the second electrical connection is less than the width of the first electrical connection, and / or, in the direction perpendicular to the substrate surface, the thickness of the second electrical connection is greater than the thickness of the first electrical connection.

23. The solar cell according to claim 21, characterized in that, The substrate includes a first surface and a second surface opposite to each other, wherein the first surface is the light-receiving surface. The first collector grid line is disposed on the first surface, and the second collector grid line is disposed on the second surface.

24. The solar cell according to claim 23, characterized in that, When the second collector grid line is a straight structure, the number of the second collector grid lines is greater than the number of the first collector grid lines; And / or, when the second collector grid line is a straight structure, the width of the first collector grid line is greater than the width of the second collector grid line.

25. The solar cell according to claim 24, characterized in that, A tunneling passivation contact structure layer is provided between the second collector gate line and the substrate. The second collector gate line is disposed on the side of the tunneling passivation contact structure layer away from the substrate. The tunneling passivation contact structure layer between the second collector gate lines has a hollow structure.

26. The solar cell according to claim 21, characterized in that, The substrate includes a first surface and a second surface opposite to each other. The first surface is the light-receiving surface. The electrode is disposed on the second surface of the substrate. The first collector grid line and the second collector grid line are arranged alternately at intervals along a second direction.

27. 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 1-26; Interconnector, electrically connected to the solar cell; And an encapsulation layer that covers the surface of the battery string.

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