Solar cell and photovoltaic module
By setting auxiliary gate lines on the edge area of the main gateless solar cell and passing through the interrupted area of the thin gate lines, the problems of easy shedding of welding tape and increased silver consumption in traditional designs are solved, and the effect of reducing costs and improving efficiency is achieved.
Patent Information
- Application Number
- CN202411646972.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-02-28
AI Technical Summary
The welding tapes of traditional main gateless solar cells in the edge areas are easily raised and fall off, affecting battery efficiency, and the increase in the number of main gate lines will lead to an increase in silver consumption and increase costs.
The design of setting auxiliary gate lines in the edge area is adopted, and the auxiliary gate lines are arranged in the interrupted area of the thin gate lines and connected to the corresponding thin gate lines to reduce battery costs and improve battery efficiency.
While ensuring the welding tension requirements, the battery cost is reduced, the battery efficiency is improved, and the problem of welding tape falling off in the edge area is avoided.
Smart Images
Figure CN119545974A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Art
[0002] Solar cells are clean and environmentally friendly, so they are widely used. The grid lines of back contact (BC) solar cells are all located on the back of the cell (i.e., the backlight side), and there are no grid lines on the front of the cell (i.e., the light-facing side). Therefore, BC solar cells are highly sought after by the market for their characteristics of no grid line blocking the front, increased light-receiving area, and high cell efficiency.
[0003] BC solar cells include IBC (Interdigitated back contact), TBC (Tunneling oxide passivated contact Back Contact), HBC (Heterojunction Back Contact) and other solar cells. The grid lines of traditional BC solar cells are mainly composed of busbars (BB) and finger lines (also known as finger lines). The busbars mainly collect the current of the finger lines and connect them in series, while the finger lines are used to collect photogenerated carriers.
[0004] The grid lines of solar cells are usually made of screen-printed conductive silver paste. The use of a large amount of silver paste increases the cost of solar cells. Busbar-less (0BB) solar cells have been widely used due to their low cost. The thin grid lines in busbar-less (0BB) solar cells are directly connected to the welding ribbon through solder joints, which has low reliability. Summary of the invention
[0005] In order to alleviate, mitigate or eliminate the above-mentioned technical problems, the present application provides a solar cell and a photovoltaic module to improve the cell efficiency.
[0006] In a first aspect, the present application provides a solar cell, comprising a semiconductor substrate and an electrode structure disposed on the semiconductor substrate, wherein the electrode structure comprises:
[0007] Fine grid lines extending along a first direction and distributed in a first region and a second region, the fine grid lines comprising first fine grid lines and second fine grid lines alternately arranged in a second direction, the first fine grid lines and the second fine grid lines in the first region are continuously distributed along the first direction, and at least part of the first fine grid lines and the second fine grid lines in the second region are discontinuously distributed along the first direction, wherein the first region and the second region are distributed side by side along the second direction, and the first region is a middle region, and the second region is an edge region;
[0008] Auxiliary gate lines extend along the second direction and are distributed in the second area. The auxiliary gate lines include first auxiliary gate lines and second auxiliary gate lines alternately arranged in the first direction. The first auxiliary gate lines pass through the discontinuous areas of the second fine gate lines and are connected to the first fine gate lines. The second auxiliary gate lines pass through the discontinuous areas of the first fine gate lines and are connected to the second fine gate lines.
[0009] In a second aspect, the present application provides a photovoltaic assembly, comprising the solar cell described in the first aspect, wherein a plurality of the solar cells are electrically connected into a cell string.
[0010] Compared with the prior art, this application has the following advantages:
[0011] The electrode structure in the solar cell of the present application includes fine grid lines and auxiliary grid lines, the fine grid lines extend along a first direction and are distributed in the middle area and the edge area along a second direction, and include first fine grid lines and second fine grid lines alternately arranged in the second direction, the fine grid lines in the middle area are continuously distributed along the first direction, at least part of the fine grid lines in the edge area are intermittently distributed along the first direction, the auxiliary grid lines extend along the second direction and are distributed in the edge area, and include first auxiliary grid lines and second auxiliary grid lines alternately arranged in the first direction, the first auxiliary grid lines are arranged in the intermittent area of the second fine grid lines and connected to the first fine grid lines, and the second auxiliary grid lines are arranged in the intermittent area of the first fine grid lines and connected to the second fine grid lines. The present application reduces the battery cost and improves the battery efficiency while ensuring the welding tension requirements by arranging auxiliary grid lines in the edge area and passing through the intermittent area of the fine grid lines to connect with the corresponding fine grid lines.
[0012] The photovoltaic module of the present application includes the above-mentioned solar cell and thus has the same effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:
[0014] Figure 1is a partial cross-sectional schematic diagram of a solar cell provided in an embodiment of the present application;
[0015] Figure 2 is a schematic diagram of the back side of a solar cell provided in an embodiment of the present application;
[0016] Figure 3 is a schematic diagram of an electrode structure provided in an embodiment of the present application;
[0017] Figure 4 is a schematic diagram of another electrode structure provided in an embodiment of the present application;
[0018] Figure 5 This is a schematic diagram of another electrode structure provided in an embodiment of the present application. DETAILED DESCRIPTION
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.
[0020] As shown in this application, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not specifically refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate that the elements that have been clearly identified are included, and these elements do not constitute an exclusive list, and the device may also include other elements.
[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts set forth in these embodiments do not limit the scope of the present application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.
[0022] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application.
[0023] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0024] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.
[0025] It should be understood that when a component is referred to as being “on another component,” “connected to another component,” “coupled to another component,” or “contacting another component,” it can be directly on, connected to, coupled to, or contacting the other component, or intervening components may be present. In contrast, when a component is referred to as being “directly on another component,” “directly connected to,” “directly coupled to,” or “directly contacting” another component, there are no intervening components present.
[0026] Figure 1 is a partial cross-sectional schematic diagram of a solar cell provided in an embodiment of the present application. Figure 1 As shown, the solar cell 100 includes a semiconductor substrate 101, which has a front side and a back side in the thickness direction. When the solar cell is working, the front side faces the sun. A plurality of solar cells 100 can be electrically connected into a cell string to form a photovoltaic module.
[0027] The semiconductor substrate 101 has an anti-reflection layer 102 formed on the front side, and a first region 110 and a second region 120 formed on the back side. The first region 110 includes a first doping layer 111, a first passivation layer 112, and a first electrode 113 from the inside to the outside, and the first electrode 113 penetrates the first passivation layer 112 and contacts the first doping layer 111. The second region 120 includes a second doping layer 121, a second passivation layer 122, and a second electrode 123 from the inside to the outside, and the second electrode 123 penetrates the second passivation layer 122 and contacts the second doping layer 121.
[0028] The semiconductor substrate 101 is doped with a first type of doping impurity, the first doping layer 111 is doped with the first type of doping impurity, and the second doping layer 121 is doped with a second type of doping impurity, wherein the first type and the second type are opposite. By way of example, the semiconductor substrate 101 is doped with an N type of doping impurity, the first doping layer 111 is doped with an N type of doping impurity, and the second doping layer 121 is doped with a P type of doping impurity. In some embodiments, the doping concentration of the first type of doping impurity in the first doping layer 111 is greater than the doping concentration of the first type of doping impurity in the semiconductor substrate 101. As an example, the P type doping impurity is, for example, boron, and the N type doping impurity is, for example, phosphorus.
[0029] Please refer to Figure 2 The back side of the semiconductor substrate 101 includes a plurality of first regions 110 and second regions 120 arranged alternately. The first region 110 is provided with a first fine gate line 213, and the second region 120 is provided with a second fine gate line 223. The first fine gate line 213 contacts the first doping layer 111 of the first region 110 to form a first electrode 113. The second fine gate line 223 contacts the second doping layer 121 of the second region 120 to form a second electrode 123.
[0030] In order to reduce production costs, the size specifications of existing solar cells have reached 182mm*182mm or more. In the case of large-area solar cells, in order to improve battery efficiency and reduce series resistance, the number of main grid lines is generally greater than 16. The increase in the number of main grid lines will lead to an increase in silver consumption, which will increase costs. The thin grid lines in the main grid-free solar cell are directly connected to the welding ribbon through the welding point, and the reliability is low. The inventors of this application have noticed that the welding ribbon in the edge area of the solar cell is prone to warping and falling off, affecting the battery efficiency.
[0031] Please refer to Figure 3-Figure 5The electrode structure provided in the embodiment of the present application includes a first region 301 and a second region 302 arranged side by side along a second direction B (horizontal direction in the figure), wherein the first region 301 is a middle region, such as the region in the small dashed line frame in the figure, and the second region 302 is an edge region. The first region 301 and the second region 302 are both provided with a plurality of fine gate lines extending along a first direction A (vertical direction in the figure), and the fine gate lines include a first fine gate line 213 and a second fine gate line 223 alternately arranged in the second direction B. The second region 302 is also provided with a plurality of auxiliary gate lines extending along the second direction B, and the auxiliary gate lines include a first auxiliary gate line 313 and a second auxiliary gate line 323 alternately arranged in the first direction A, the first auxiliary gate line 313 is used to connect the first fine gate line 213, and is only connected to the first fine gate line 213, and the second auxiliary gate line 323 is used to connect the second fine gate line 223, and is only connected to the second fine gate line 223.
[0032] The embodiment of the present application adopts a main grid-free design and adds auxiliary grid lines in the edge area to reduce battery cost and improve battery efficiency while ensuring welding tension requirements.
[0033] In some embodiments, the first fine gate lines 213 and the second fine gate lines 223 in the first region 301 are continuously distributed along the first direction A, and at least part of the first fine gate lines 213 and the second fine gate lines 223 in the second region 302 are discontinuously distributed along the first direction A, so that the first auxiliary gate lines 313 pass through the discontinuous areas of the second fine gate lines 223 and are connected to the first fine gate lines 213, and the second auxiliary gate lines 323 pass through the discontinuous areas of the first fine gate lines 213 and are connected to the second fine gate lines 223.
[0034] Furthermore, the fine grid lines in the second region 302 that are closest to the first region 301, such as the fine grid line 2231 in the figure, are continuously distributed along the first direction A. The fine grid lines in the second region 302 that are farthest from the first region 301, such as the first fine grid line 2131 in the figure, are discontinuously distributed along the first direction A. The continuous distribution of the fine grid lines close to the first region 301 can improve the battery efficiency, while the discontinuous distribution of the fine grid lines far from the first region 301 can facilitate the passage of the welding strip through these discontinuous areas, thereby improving the smoothness of the welding strip laying, reducing edge cold solder joints, and further improving the battery efficiency. It should be noted that although Figure 3-Figure 5 In the embodiment, the number of the fine gate lines in the second region 302 is an even number. However, in some other embodiments, the number of the fine gate lines in the second region 302 may also be an odd number.
[0035] In some embodiments, a plurality of spaced welding points are further provided on the fine grid lines in the first region 301, such as a plurality of first welding points 315 are provided on the first fine grid line 213, a plurality of second welding points 325 are provided on the second fine grid line 223, and the connection line of the first welding points 315 is parallel to the connection line of the second welding points 325. The auxiliary grid lines in the second region 302 pass through these welding points along the extension line of the second direction B, such as the first welding point 315 is present at the intersection of the extension line of the first auxiliary grid line 313 along the second direction B and the first fine grid line 213 of the first region 301, and the second welding point 325 is present at the intersection of the extension line of the second auxiliary grid line 323 along the second direction B and the second fine grid line 223 of the first region 301, so as to facilitate welding and improve welding tension.
[0036] The fine grid lines in the second region 302 may also be provided with a plurality of spaced-apart welding spots, such as a plurality of first welding spots 315 on the first fine grid line 213, and a plurality of second welding spots 325 on the second fine grid line 223. The connection point between the first auxiliary grid line 313 and the first fine grid line 213 is the first welding spot 315 on the first fine grid line 213, and the connection point between the second auxiliary grid line 323 and the second fine grid line 223 is the second welding spot 325 on the second fine grid line 223, so as to further improve the welding tension.
[0037] In some embodiments, please refer to Figure 3 and Figure 4 , the fine grid line includes an end discontinuous fine grid line 2232 located closest to the end and discontinuous in the second region, and the auxiliary grid line includes an end auxiliary grid line 331 located in the end region of the second region in the first direction A, and the end auxiliary grid line 331 connects the end discontinuous fine grid line 2232 with an adjacent continuous fine grid line of the same polarity, so that the carriers collected by the end discontinuous fine grid line 2232 are conducted out through the continuous fine grid line, thereby improving battery efficiency. The continuous fine grid line includes an end intersection 3252 that intersects with the end auxiliary grid line 331 and is adjacent to the end region, and is divided into a middle grid line segment and an end grid line segment by the end intersection 3252. The width of the end auxiliary grid line 331 and the end grid line segment is greater than the width of the middle grid line segment, thereby preventing grid breakage and improving battery efficiency. In some embodiments, there is an end welding point 3251 at the end intersection 3252, such as Figure 3 shown.
[0038] In some embodiments, the length of the welding spot in the first direction is greater than the length of the auxiliary grid line in the first direction, and the length of the welding spot in the second direction is less than the distance between two adjacent thin grid lines, so as to increase the welding tension and prevent string welding. For example, the length of the auxiliary grid line in the first direction is about 0.2-2mm, such as the length of the auxiliary grid line in the first direction can be 0.2mm, 0.5mm, 1mm, 1.5mm or 2mm, and the length of the welding spot in the first direction is about 0.2-2mm, such as the length of the auxiliary grid line in the first direction can be 0.2mm, 0.6mm, 1.2mm, 1.6mm or 2mm, which can avoid the auxiliary grid line or welding spot being too small to cause insufficient welding tension, and can also prevent the auxiliary grid line or welding spot from being too large to cause the discontinuity area of the thin grid line to be too large, thereby affecting the battery efficiency.
[0039] The length of the weld point in the second area 302 may be 0.1-1.5mm larger than the length of the weld point in the first area 301 in the second direction. For example, the length of the weld point in the second area 302 may be 0.1mm, 0.5mm, 0.7mm, 1mm or 1.5mm larger than the length of the weld point in the first area 301 in the second direction. This can reduce the cold solder joints in the edge area and avoid the weld point being connected in series with the first thin grid line and the second thin grid line, thereby affecting the battery efficiency.
[0040] In some embodiments, please refer to Figure 4 , an end grid line 410 is also provided in the end area of the first region 301 in the first direction A, and the end grid line 410 extends along the second direction B. The width of the end grid line 410 may be greater than the width of the fine grid line. The first welding point 315 of the first fine grid line 213 in the first region 301 includes a first end area welding point 3151 adjacent to the end area, and the second welding point 325 on the second fine grid line 223 in the first region 301 includes a second end area welding point 3251 adjacent to the end area, wherein the first end area welding point 3151 is closer to the end area than the second end area welding point 3251. The end grid line 410 is connected to the second fine grid line 223 where the second end area welding point 3251 is relatively farther away from the end area, to prevent the carriers collected by the fine grid lines at both ends from being unable to be conducted out due to broken gates, thereby improving battery efficiency.
[0041] In some other embodiments, the first end region welding point 3151 on the first fine gate line 213 may be further away from the end region than the second end region welding point 3251 on the second fine gate line 223 , and the first fine gate lines 213 are connected via the end gate lines 410 .
[0042] In some embodiments, please refer to Figure 5, the electrode structure also includes an end grid line 410 extending along the second direction B and located in the end area on the first direction A. The width of the end grid line 410 may be greater than the width of the fine grid line. The first welding point 315 of the first fine grid line 213 includes a first end area welding point 3151 adjacent to the end area, and the second welding point 325 on the second fine grid line 223 of the first area 301 includes a second end area welding point 3251 adjacent to the end area, wherein the first end area welding point 3151 is closer to the end area than the second end area welding point 3251. The end grid line 410 is connected to the second fine grid line 223 where the second end area welding point 3251 is relatively farther away from the end area, to prevent the carriers collected by the fine grid lines at both ends from being unable to be conducted out due to broken gates, thereby improving battery efficiency.
[0043] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.
[0044] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.
[0045] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of the present application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the subject of the present application requires more features than the features mentioned. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.
[0046] In some embodiments, numbers describing the quantity of attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values is as accurate as possible within the feasible range.
[0047] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the present application.
Claims
1. A solar cell, characterized in that: The invention comprises a semiconductor substrate and an electrode structure arranged on the semiconductor substrate, wherein the electrode structure comprises: Fine grid lines extending along a first direction and distributed in a first region and a second region, the fine grid lines comprising first fine grid lines and second fine grid lines alternately arranged in a second direction, the first fine grid lines and the second fine grid lines in the first region are continuously distributed along the first direction, and at least part of the first fine grid lines and the second fine grid lines in the second region are discontinuously distributed along the first direction, wherein the first region and the second region are distributed side by side along the second direction, and the first region is a middle region, and the second region is an edge region; Auxiliary gate lines extend along the second direction and are distributed in the second area. The auxiliary gate lines include first auxiliary gate lines and second auxiliary gate lines alternately arranged in the first direction. The first auxiliary gate lines pass through the discontinuous areas of the second fine gate lines and are connected to the first fine gate lines. The second auxiliary gate lines pass through the discontinuous areas of the first fine gate lines and are connected to the second fine gate lines.
2. The solar cell according to claim 1, wherein: The thin gate lines in the second region that are closest to the first region are continuously distributed along the first direction.
3. The solar cell according to claim 1 or 2, characterized in that: The thin gate lines in the second region that are farthest from the first region are distributed discontinuously along the first direction.
4. The solar cell according to claim 1, wherein: Also includes: Welding points, including a first welding point located on the first thin grid line in the first region and a second welding point located on the second thin grid line in the first region; The first welding spot exists at the intersection of the first auxiliary gate line extended along the second direction and the first thin gate line in the first area, and the second welding spot exists at the intersection of the second auxiliary gate line extended along the second direction and the second thin gate line in the first area.
5. The solar cell according to claim 4, characterized in that The welding points further include a first welding point located on at least part of the first fine grid lines in the second region and a second welding point located on at least part of the second fine grid lines in the second region; The connection point between the first auxiliary gate line and the first fine gate line is a first welding point on the first fine gate line; and / or The connection point between the second auxiliary gate line and the second thin gate line is a second welding point on the second thin gate line.
6. The solar cell according to claim 5, characterized in that The length of the welding spot in the second area is 0.1-1.5 mm greater than the length of the welding spot in the first area in the second direction.
7. The solar cell according to any one of claims 4 to 6, characterized in that: The length of the welding spot in the first direction is greater than the length of the auxiliary gate line in the first direction, and the length of the welding spot in the second direction is less than the distance between two adjacent thin gate lines.
8. The solar cell according to claim 7, wherein: The length of the auxiliary gate line in the first direction is 0.2-2 mm, and / or The length of the welding spot in the first direction is 0.2-2 mm.
9. The solar cell according to claim 4, characterized in that: Also includes: an end gate line extending along the second direction and located in an end region in the first direction, The first welding point on the first fine grid line in the first region includes a first end area welding point adjacent to the end area, the second welding point on the second fine grid line in the first region includes a second end area welding point adjacent to the end area, the first end area welding point is closer to the end area than the second end welding point, and the end grid line is connected to the second fine grid line.
10. The solar cell according to claim 9, characterized in that The width of the end gate line is greater than the width of the thin gate line.
11. The solar cell according to claim 4 or 9, characterized in that: The fine gate lines include end discontinuous fine gate lines that are closest to the ends and are discontinuous in the second region, and the auxiliary gate lines include end auxiliary gate lines located in the end region of the second region in the first direction, and the end auxiliary gate lines connect the end discontinuous fine gate lines with adjacent continuous fine gate lines with the same polarity.
12. The solar cell according to claim 11, wherein: The continuous fine gate line includes an end intersection point intersecting with the end auxiliary gate line and adjacent to the end region, and is divided into a middle gate line segment and an end gate line segment by the end intersection point, and the width of the end auxiliary gate line and the end gate line segment is greater than the width of the middle gate line segment.
13. The solar cell according to claim 5, characterized in that Also includes: an end gate line extending along the second direction and located in an end region in the first direction, The first welding point on the first fine gate line includes a first end area welding point adjacent to the end area, the second welding point on the second fine gate line includes a second end area welding point adjacent to the end area, the first end area welding point is closer to the end area than the second end welding point, and the end gate line is connected to the second fine gate line.
14. A solar cell according to claim 1, characterized in that: The semiconductor substrate is doped with a first type of dopant impurities, the back side of the semiconductor substrate has a first region and a second region, the first region includes a first doping layer, the second region includes a second doping layer, the first doping layer is doped with the first type of dopant impurities, the second doping layer is doped with a second type of dopant impurities, and the first type and the second type are opposite; The first thin gate line is located in the first region and contacts the first doped layer, and the second thin gate line is located in the second region and contacts the second doped layer.
15. The solar cell according to claim 14, wherein: The doping concentration of the first type doping impurities in the first doping layer is greater than the doping concentration of the first type doping impurities in the semiconductor substrate.
16. A photovoltaic module, characterized in that: The solar cell comprises the solar cell according to any one of claims 1 to 15, wherein a plurality of the solar cells are electrically connected into a cell string.