Back contact solar cells and photovoltaic modules

Abstract

The utility model provides back contact solar cell and photovoltaic module. Back contact solar cell includes first half piece and second half piece, and first half piece includes first intermediate area and first edge area, and the back light surface of first edge area includes first edge P area, first edge N area and first edge isolation area, and first edge P area includes first edge P fine grid area A, first edge P fine grid area B and first edge P vice main grid area, and first edge P fine grid area A is located in the side of first edge P vice main grid area far from first intermediate area, and first edge N area includes first edge N main grid area, first edge N fine grid area and first edge N area welding spot, and first edge N main grid area is located in the side of first edge N fine grid area far from first intermediate area, and first edge N main grid area is located in the side of first edge P fine grid area A close to first intermediate area. Can effectively reduce the horizontal transmission distance of edge area minority carrier hole in the silicon chip in solar cell.

Description

Technical Field

[0001] This utility model relates to the field of solar cell technology, specifically to back-contact solar cells and photovoltaic modules. Background Technology

[0002] In the process of patterning and partitioning the back surface of back-contact solar cells (BC cells), the ideal design is often to have P-regions and N-regions interspersed, filling the entire cell surface. However, due to differences in the actual size of the silicon wafer, the actual size of the gap area (isolation area), and the actual sizes of the P-regions and N-regions, the area near the edge of the cell may not be large enough to accommodate or may exceed a complete N-region or P-region, making it impossible to achieve a perfect overlapping distribution of P-regions and N-regions. To address this, a common design strategy is to make the P-regions near the edges wider than those in the center, in order to reduce the hole-to-electrode transport distance in the edge area (holes have a weaker lateral transport capability than electrons). However, this design strategy is more suitable for strip-shaped PN patterned partitioning. If applied to an interdigitated PN partitioning design, if one half of the cell is designed with a P-region edge, the opposite half needs to be designed with an N-region edge. This results in one half having a wider N-region edge, increasing the hole transport distance in its edge area, which is detrimental to hole collection, leading to increased series resistance, reduced short-circuit current, and decreased cell efficiency. Utility Model Content

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to provide a solar cell that can better transport and collect charge carriers in the edge region of the cell, thus optimizing current collection.

[0004] In one aspect, the present invention provides a back-contact solar cell. According to an embodiment of the present invention, the back-contact solar cell includes a first half-cell and a second half-cell spliced ​​together in a first direction. The first half-cell includes a first intermediate region and first edge regions located on both sides of the first intermediate region in a second direction. The backlight surface of the first edge region includes a first edge P region, a first edge N region, and a first edge isolation region located between the first edge P region and the first edge N region. The first edge P region includes a first edge P fine grid region A extending along the first direction, a first edge P fine grid region B extending along the second direction, and a first edge P sub-main grid region extending along the second direction. The first edge P fine grid region A is located on the side of the first edge P sub-main grid region away from the first intermediate region. The first edge N region includes a first edge N main grid region extending along the first direction, a first edge N fine grid region extending along the second direction, and a plurality of first edge N region solder joints. The first edge N main grid region is located on the side of the first edge N fine grid region away from the first intermediate region, and the first edge N main grid region is located on the side of the first edge P fine grid region A close to the first intermediate region. Therefore, in addition to the N region, the first edge region also includes a first edge P fine grid region A and a first edge P sub-main grid region. This can effectively reduce the lateral transport distance of minority carrier holes in the silicon wafer of the solar cell and effectively optimize current collection.

[0005] According to an embodiment of the present invention, the first edge N main gate region includes a plurality of first sub-edge N main gate regions separated by the first edge P sub-main gate region. The first edge P sub-main gate region at the break point is connected to the first edge P fine gate region A. Each first sub-edge N main gate region is provided with a plurality of first edge N fine gate regions, a plurality of first edge P fine gate regions B and at least one first edge N region solder joint.

[0006] According to an embodiment of the present invention, the first edge N region solder joint is located on the side of the first edge N main gate region close to the first middle region.

[0007] According to an embodiment of the present invention, the backlight surface of the first intermediate region includes a first intermediate P region, a first intermediate N region, and a first intermediate isolation region located between the first intermediate P region and the first intermediate N region. The first intermediate P region includes a first intermediate P main gate region extending along the first direction, a first intermediate P fine gate region extending along the second direction, and a plurality of first intermediate P region solder points, and the solder points of the first intermediate P region are arranged adjacent to the solder points of the first edge N region. The first intermediate N region includes a first intermediate N main gate region extending along the first direction, a first intermediate N fine gate region extending along the second direction, and a plurality of first intermediate N region solder points.

[0008] According to an embodiment of the present invention, the first edge P fine gate region A is connected to the first middle P main gate region through the first edge P sub-main gate region.

[0009] According to an embodiment of the present invention, the first half-piece also satisfies at least one of the following conditions: the width of the first edge N main gate region is less than or equal to the width of the first middle N main gate region; the width of the first edge P fine gate region A is less than or equal to the width of the first middle P fine gate region; the width of the first middle P main gate region is greater than or equal to the width of the first middle N main gate region; and the width of the first middle P fine gate region is greater than or equal to the width of the first middle N fine gate region.

[0010] According to an embodiment of the present invention, the first half-piece further includes: a first non-current collection area, which is located outside the first middle area and the first edge area, and the width of the first non-current collection area located at the chamfer where the first direction and the second direction intersect is greater than the width of the first non-current collection area in the other areas.

[0011] According to an embodiment of the present invention, the second half-piece includes a second intermediate region and a second edge region located on both sides of the second intermediate region in the second direction. The backlight surface of the second edge region includes a second edge P region, a second edge N region, and a second edge isolation region located between the second edge P region and the second edge N region. The second edge P region includes a second edge P main gate region extending along the first direction, a second edge P fine gate region extending along the second direction, and a plurality of second edge P region solder points. The second edge P main gate region is located on the side of the second edge P fine gate region away from the second intermediate region. The second edge N region includes a second edge N fine gate region extending along the second direction.

[0012] According to an embodiment of the present invention, the solder joint of the second edge P region is located on the side of the second edge P main gate region near the second middle region.

[0013] According to an embodiment of the present invention, the backlight surface of the second intermediate region includes a second intermediate P region, a second intermediate N region, and a second intermediate isolation region located between the second intermediate P region and the second intermediate N region. The second intermediate P region includes a second intermediate P main gate region extending along the first direction, a second intermediate P fine gate region extending along the second direction, and a plurality of second intermediate P region solder points. The second intermediate N region includes a second intermediate N main gate region extending along the first direction, a second intermediate N fine gate region extending along the second direction, and a plurality of second intermediate N region solder points. The solder points of the second intermediate N region are arranged adjacent to the solder points of the second edge P region. The second edge N fine gate region is connected to the second intermediate N main gate region.

[0014] According to an embodiment of the present invention, the second half-piece also satisfies at least one of the following conditions: the width of the second intermediate P main gate region is greater than or equal to the width of the second intermediate N main gate region; the width of the second intermediate P fine gate region is greater than or equal to the width of the second intermediate N fine gate region.

[0015] According to an embodiment of the present invention, the second half further includes a second non-current collection area, which is located outside the second middle region and the second edge region, and the width of the second non-current collection area located at the chamfer where the first direction and the second direction intersect is greater than the width of the second non-current collection area in the remaining regions.

[0016] According to an embodiment of the present invention, the first half-piece further includes a first edge P-type fine gate line located in the first edge P fine gate region A, a first edge P-type sub-main gate line located in the first edge P sub-main gate region, a first edge N-type main gate line located in the first edge N main gate region, a first edge N fine gate line located in the first edge N fine gate region, a first edge N-type pad located at the solder joint in the first edge N region, a first intermediate P-type main gate line located in the first intermediate P main gate region, a first intermediate P-type fine gate line located in the first intermediate P fine gate region and a first intermediate P-type pad located at the solder joint in the first intermediate P region, a first intermediate N-type main gate line located in the first intermediate N main gate region, a first intermediate N-type fine gate line located in the first intermediate N fine gate region and a first intermediate N-type pad located at the solder joint in the first intermediate N region;

[0017] The second half-piece includes a second edge P-type main gate line located in the second edge P main gate region, a second edge P-type fine gate line located in the second edge P fine gate region, a second edge P-type pad located in the second edge P region solder joint, a second edge N-type fine gate line located in the second edge N fine gate region, a second intermediate P-type main gate line located in the second intermediate P main gate region, a second intermediate P-type fine gate line located in the second intermediate P fine gate region, a second intermediate P-type pad located in the second intermediate P region solder joint, a second intermediate N-type main gate line located in the second intermediate N main gate region, a second intermediate N-type fine gate line located in the second intermediate N fine gate region, and a second intermediate N-type pad located in the second intermediate N region solder joint.

[0018] In another aspect of this utility model, a photovoltaic module is provided. According to an embodiment of this utility model, the photovoltaic module includes the back-contact solar cell described above. This photovoltaic module has good power generation efficiency. Those skilled in the art will understand that this photovoltaic module has all the structures and features of the back-contact solar cell described above, and will not be described in detail here.

[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 This is a schematic diagram of the structure of a back-contact solar cell in one embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the first half piece in another embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the second half in another embodiment of the present invention;

[0024] Figure 4 This is a partial structural schematic diagram of the first half piece in another embodiment of the present invention;

[0025] Figure 5 This is a partial structural schematic diagram of the second half of the piece in another embodiment of the present invention;

[0026] Figure 6 This is a partial structural schematic diagram of the first half piece in another embodiment of the present invention;

[0027] Figure 7This is a partial structural schematic diagram of the second half of the device in another embodiment of the present invention. Detailed Implementation

[0028] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0029] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0030] In one aspect, this utility model provides a back-contact solar cell. According to an embodiment of this utility model, referring to… Figure 1 , Figure 2 and Figure 3 The back-contact solar cell includes a first half-cell 100 and a second half-cell 200 spliced ​​together in a first direction, as shown in the figure. Figure 2 and 4 The first half-piece 100 includes a first intermediate region 110 and first edge regions 120 located on both sides of the first intermediate region 110 in a second direction. The backlight surface of the first edge region 120 includes a first edge P region 121, a first edge N region 122, and a first edge isolation region 123 located between the first edge P region and the first edge N region.

[0031] Reference Figure 4 The first edge P region 121 includes a first edge P fine gate region A 1211 extending along a first direction, a first edge P fine gate region B 1213 extending along a second direction, and a first edge P sub-main gate region 1212 extending along a second direction. That is, the first edge P sub-main gate region 1212 and the first edge P fine gate region B 1213 are arranged in parallel, and the first edge P fine gate region A 1211 is located on the side of the first edge P sub-main gate region 1212 away from the first intermediate region 110.

[0032] The first edge N region 122 includes a first edge N main gate region 1221 extending along a first direction, a first edge N fine gate region 1222 extending along a second direction, and a plurality of first edge N region solder points 1223. The first edge N main gate region 1221 is located on the side of the first edge N fine gate region 1222 away from the first intermediate region 110, and the first edge N main gate region 1221 is located on the side of the first edge P fine gate region A1211 close to the first intermediate region 110, that is, the first edge N main gate region 1221 is located between the first edge P fine gate region A1211 and the first edge N fine gate region 1222 (or the first edge P sub-main gate region 1212).

[0033] According to the embodiments of this utility model, in the partition design of the P-region and N-region of the backlight surface, in addition to the N-region, the first edge region 120 also has a first edge P fine grid region A and a first edge P sub-main grid region. This can effectively reduce the lateral transport distance of minority carrier holes in the edge region within the silicon wafer of the solar cell, effectively optimize current collection, and reduce recombination.

[0034] It should be noted that the first direction and the second direction intersect, but in some embodiments, the first direction and the second direction are perpendicular to each other. Additionally, the aforementioned backlight surface refers to the backlight surface that contacts the battery, opposite to the light-facing surface.

[0035] According to some embodiments of the present invention, such as Figures 1 to 3 As shown, the N-region and P-region in this solar cell are interdigitated. In the first edge region, the first edge N-grid region 1222, the first edge P-sub-gate region 1212, and the first edge P-grid region B 1213 are also interdigitated. Therefore, in the fabrication process, one of the P-region and the N-region is an etched region, and the other is a non-etched region, which reduces the use of insulating adhesive and lowers costs.

[0036] According to some embodiments of this utility model, refer to Figure 4 The first edge N main gate region 1221 includes multiple first sub-edge N main gate regions 12210 separated by the first edge P sub-main gate region 1212, at the breakpoint ( Figure 4The first edge P sub-main gate region 1212 (marked with an ellipse) is connected to the first edge P fine gate region A1211, while the first edge P fine gate region B1213 is separated from the first edge P fine gate region A1211 by the first edge N main gate region 1221. Each first sub-edge N main gate region 12210 is provided with multiple first edge N fine gate regions 1222, multiple first edge P fine gate regions B1213, and at least one first edge N region solder joint 1223. That is, multiple first edge P fine gate regions B1213 are provided between two adjacent first edge P sub-main gate regions 1212. Thus, the N region current is collected by the independent main gate lines on the segmented first sub-edge N main gate regions 12210. The segmented first sub-edge N main gate regions 12210 extend along the first direction, so that the multiple first edge N fine gate regions 1222 (e.g., ...) in their respective areas are collected by each independent main gate. Figure 4 The fine gate in the dashed box (in the image) finally converges to the pad of the first edge N region solder joint 1223 corresponding to the first sub-edge N main gate region 12210. That is, the collection process of minority carrier holes in the first edge region is: N region - PN junction - gate line on the first edge P fine gate region A - gate line on the first edge P sub-main gate region - pad on the first edge N region solder joint. In this way, the transmission distance of edge holes can be further reduced, which is beneficial to reduce series electrons and improve short-circuit current and battery efficiency.

[0037] According to some embodiments of the present invention, the number of the above-mentioned breakpoints is not limited, and those skilled in the art can flexibly set it according to actual needs; the lengths of the multiple first sub-edge N main gate regions 12210 can be the same or different; the number of first edge N fine gate regions corresponding to the first sub-edge N main gate regions 12210 is also not limited, and those skilled in the art can flexibly choose.

[0038] According to some embodiments of this utility model, refer to Figure 4 The first edge N-region solder joint 1223 is located on the side of the first edge N-main grid region 1221 near the first middle region 110, meaning that the first edge N-region solder joint 1223 and the first edge N-main grid region 1221 are not collinear. This avoids stress concentration during subsequent solar cell connection and soldering processes, thereby preventing cell damage and improving the yield of photovoltaic modules.

[0039] According to some embodiments of this utility model, refer to Figure 4The backlight surface of the first intermediate region 110 includes a first intermediate P region 111, a first intermediate N region 112, and a first intermediate isolation region 113 located between the first intermediate P region 111 and the first intermediate N region 112. In some embodiments, the first intermediate P region 111 includes a first intermediate P main gate region 1111 extending along a first direction, a first intermediate P fine gate region 1112 extending along a second direction, and a plurality of first intermediate P region solder points 1113, wherein the first intermediate P region solder points 1113 are arranged adjacent to the first edge N region solder points 1223; the first intermediate N region 112 includes a first intermediate N main gate region 1121 extending along a first direction, a first intermediate N fine gate region 1122 extending along a second direction, and a plurality of first intermediate N region solder points 1123.

[0040] According to some embodiments of this utility model, refer to Figure 4 The first intermediate P fine gate region 1112 and the first intermediate N fine gate region 1122 are distributed in an interdigitated pattern. The first intermediate P fine gate region 1112 is connected to the first intermediate P main gate region 1111, and the solder joint 1113 of the first intermediate P region is located on the same straight line as the first intermediate P main gate region 1111; the first intermediate N fine gate region 1122 is connected to the first intermediate N main gate region 1121, and the solder joint 1123 of the first intermediate N region is located on the same straight line as the first intermediate N main gate region 1121.

[0041] According to some embodiments of this utility model, refer to Figure 4 The first edge P fine gate region A1211 is connected to the first intermediate P main gate region 1111 via the first edge P sub-main gate region 1212. Thus, the P region of the first edge region and the P region of the first intermediate region become a single unit, facilitating the connection of the component-end solder strips. Furthermore, the first edge P fine gate region B1213 is connected to the first intermediate P main gate region 1111.

[0042] According to some embodiments of this utility model, refer to Figure 4 The width of the first edge N main gate region 1221 is less than or equal to the width of the first intermediate N main gate region 1121. In some embodiments, the width of the first edge N main gate region 1221 is less than the width of the first intermediate N main gate region 1121. As a result, the width of the first edge N main gate region 1221 is smaller, and the area occupied is smaller. This makes it easier to add the first edge P fine gate region A1211 in the first edge region. Moreover, the first edge N main gate region 1221 is only responsible for collecting minority carriers in the first half edge, so the reduction in its size will not have any adverse effect on the collection of carriers.

[0043] In some embodiments, the specific dimensions of the first edge N main gate region 1221 and the first intermediate N main gate region 1121 are not limited, and those skilled in the art can make flexible designs according to the specific arrangement of the P region and N region, the size of the isolation region and the specific size of the battery panel.

[0044] According to some embodiments of this utility model, refer to Figure 4 The width of the first edge P fine gate region A1211 is less than or equal to the width of the first intermediate P fine gate region 1112. Therefore, the smaller first edge P fine gate region A1211 can be better added to the first edge region 120.

[0045] In some embodiments, the specific dimensions of the first edge P-grid region A 1211 and the first intermediate P-grid region 1112 are not limited, and those skilled in the art can flexibly design them according to the specific arrangement of the P-regions and N-regions, the size of the isolation region, and the specific size of the solar panel.

[0046] According to some embodiments of this utility model, refer to Figure 4 The width of the first intermediate P main gate region 1111 is greater than or equal to the width of the first intermediate N main gate region 1121. This is more conducive to hole collection.

[0047] In some embodiments, the specific dimensions of the first intermediate P main gate region 1111 and the first intermediate N main gate region 1121 are not limited, and those skilled in the art can flexibly design them according to the specific arrangement of the P and N regions, the size of the isolation region, and the specific size of the solar panel.

[0048] According to some embodiments of this utility model, refer to Figure 4 The width of the first intermediate P fine gate region 1112 is greater than or equal to the width of the first intermediate N fine gate region 1122. This is more conducive to hole transmission.

[0049] In some embodiments, the specific dimensions of the first intermediate P-grid region 1112 and the first intermediate N-grid region 1122 are not limited, and those skilled in the art can flexibly design them according to the specific arrangement of the P-region and N-region, the size of the isolation region, and the specific size of the solar panel.

[0050] In some embodiments, the specific dimensions of the first intermediate N-grid region 1122 and the first edge N-grid region 1222 are not limited. They can be equal or in a certain proportional relationship. Those skilled in the art can make flexible designs based on the specific arrangement of the P-region and N-region, the size of the isolation region, and the specific size of the solar panel.

[0051] According to some embodiments of this utility model, the first edge N-zone solder joint 1223, the first middle N-zone solder joint, and the first middle P-zone solder joint are all used for connecting the solder strips at the end of the subsequent components. There are no limitations on the number, shape, and size of the three. Those skilled in the art can flexibly set them according to the actual situation.

[0052] According to some embodiments of this utility model, refer to Figures 1 to 4 The first half-cell 100 further includes a first non-current collection area 124, which is located outside the first intermediate region 110 and the first edge region 120. The width of the first non-current collection area 1240 at the chamfer where the first direction and the second direction intersect is greater than the width of the first non-current collection area 124 in other regions. The edge portion of the BC cell (including the edge portion formed by dividing the whole cell into half, i.e., the edge dividing the first half-cell and the second half-cell) has many microcracks and a large potential for defects. It may also have problems such as plating wrapping, resulting in a high risk of leakage. In this application, no grid lines are set in the first non-current collection area (i.e., the sacrificial area or dead area). The first non-current collection area can effectively reduce the risk of leakage, and the larger width of the first non-current collection area 1240 at the chamfer can further reduce the risk of microcracks.

[0053] According to some embodiments of this utility model, refer to Figure 5 The second half 200 includes a second intermediate region 210 and second edge regions 220 located on both sides of the second intermediate region 210 in the second direction. The backlight surface of the second edge region 220 includes a second edge P region 221, a second edge N region 222, and a second edge isolation region (gap region) 223 located between the second edge P region 221 and the second edge N region 222. The second edge P region 221 includes a second edge P main gate region 2211 extending in the first direction, a second edge P fine gate region 2212 extending in the second direction, and a plurality of second edge P region solder points 2213. The second edge P main gate region 2211 is located on the side of the second edge P fine gate region 2212 away from the second intermediate region 210. The second edge N region 222 includes a second edge N fine gate region 2221 extending in the second direction. Therefore, by setting the second edge P region 221 with the above structure in the second edge region 220, the ability of hole lateral transmission can be effectively improved.

[0054] According to some embodiments of this utility model, refer to Figure 5 The second edge N fine gate region 2221 and the second edge P fine gate region 2212 are distributed in an interdigitated pattern.

[0055] According to some embodiments of this utility model, refer to Figure 5The second edge P-region solder joint 2213 is located on the side of the second edge P-main busbar region 2211 near the second intermediate region 210, meaning that the second edge P-region solder joint 2223 and the second edge P-main busbar region 2211 are not collinear. This avoids stress concentration during subsequent solar cell bonding, thus preventing cell damage and improving the yield of photovoltaic modules.

[0056] According to some embodiments of this utility model, refer to Figure 5 The backlight surface of the second intermediate region 210 includes a second intermediate P region 211, a second intermediate N region 212, and a second intermediate isolation region 213 located between the second intermediate P region 211 and the second intermediate N region 212, wherein,

[0057] The second intermediate P region 211 includes a second intermediate P main gate region 2111 extending along a first direction, a second intermediate P fine gate region 2112 extending along a second direction, and a plurality of second intermediate P region solder joints 2113;

[0058] The second intermediate N region 212 includes a second intermediate N main gate region 2121 extending along the first direction, a second intermediate N fine gate region 2122 extending along the second direction, and a plurality of second intermediate N region solder points 2123. The second intermediate N region solder points 2123 are arranged adjacent to the second edge P region solder points 2213. The second edge N fine gate region 2221 is connected to the second intermediate N main gate region 2121.

[0059] According to some embodiments of this utility model, refer to Figure 5 The second intermediate P fine gate region 2112 and the second intermediate N fine gate region 2122 are distributed in an interdigitated manner. In some embodiments, the second intermediate P fine gate region 2112 is connected to the second intermediate P main gate region 2111, and the second intermediate P region solder joint 2113 is located on the same straight line as the second intermediate P main gate region 2111; the second intermediate N fine gate region 2122 is connected to the second intermediate N main gate region 2121, and the second intermediate N region solder joint 2123 is located on the same straight line as the second intermediate N main gate region 2121.

[0060] According to some embodiments of this utility model, refer to Figure 5 The width of the second edge P main gate region 2211 is greater than, equal to, or less than the width of the second middle P main gate region 2111. Therefore, those skilled in the art can flexibly choose a design width that is more conducive to hole collection according to actual needs.

[0061] According to some embodiments of this utility model, refer to Figure 5 The width of the second intermediate P main gate region 2111 is greater than or equal to the width of the second intermediate N main gate region 2121. This is more conducive to hole collection.

[0062] In some embodiments, the specific dimensions of the second intermediate P main gate region 2111 and the second intermediate N main gate region 2121 are not limited, and those skilled in the art can make flexible designs according to the specific arrangement of the P and N regions, the size of the isolation region, and the specific size of the solar panel.

[0063] According to some embodiments of this utility model, refer to Figure 5 The width of the second intermediate P fine gate region 2112 is greater than or equal to the width of the second intermediate N fine gate region 2122.

[0064] In some embodiments, the specific dimensions of the second intermediate P-grid region 2112 and the second intermediate N-grid region 2122 are not limited, and those skilled in the art can flexibly design them according to the specific arrangement of the P-region and N-region, the size of the isolation region, and the specific size of the solar panel.

[0065] In some embodiments, the specific dimensions of the second intermediate P-grid region 2112 and the second edge P-grid region 2212 are not limited. They can be equal or in a certain proportional relationship. Those skilled in the art can make flexible designs based on the specific arrangement of the P-regions and N-regions, the size of the isolation region, and the specific size of the solar panel.

[0066] According to some embodiments of this utility model, the second edge P-area solder joint, the second middle N-area solder joint, and the second middle P-area solder joint are all used for connecting the solder strips at the end of the subsequent components. There are no limitations on the quantity, shape, and size of the three, and those skilled in the art can flexibly set them according to the actual situation.

[0067] According to some embodiments of this utility model, refer to Figure 5 The second half also includes a second non-current collection area 224, which is located outside the second intermediate region 210 and the second edge region 220. The width of the second non-current collection area 2240 located at the chamfer where the first and second directions intersect is greater than the width of the second non-current collection area 224 in other regions. The edge portion of the BC cell (including the edge portion formed by dividing the whole cell into half, i.e., the edge dividing the first and second half) has many microcracks and a large potential for defects. It may also have problems such as plating wrapping, resulting in a high risk of leakage. In this application, no grid lines are set in the second non-current collection area (i.e., the sacrificial area or dead area). The second non-current collection area can effectively reduce the risk of leakage, and the larger width of the second non-current collection area 2240 at the chamfer can further reduce the risk of microcracks.

[0068] According to some embodiments of the utility model, refer to Figure 1The first intermediate P main gate area of ​​the first half 100 and the second intermediate N main gate area of ​​the second half 200 are correspondingly set, that is, the first intermediate P main gate area of ​​the first half 100 and the second intermediate N main gate area of ​​the second half 200 are basically located on the same straight line; the first intermediate N main gate area of ​​the first half 100 and the second intermediate P main gate area of ​​the second half 200 are correspondingly set, that is, the first intermediate N main gate area of ​​the first half 100 and the second intermediate P main gate area of ​​the second half 200 are basically located on the same straight line.

[0069] According to some embodiments of this utility model, refer to Figure 6 The first half-chip 100 also includes a first edge P-type fine gate line 11-1 located in the first edge P fine gate region A 1211 and a first edge P fine gate region B. 11-2 of the first edge P-type fine gate line 1213, 12 of the first edge P-type sub-main gate line 1212, 13 of the first edge N-type main gate line 1221, 14 of the first edge N-type fine gate line 1222, 15 of the first edge N-type pad 1223 of the first edge N-type solder joint, 16 of the first intermediate P-type main gate line 1111, 17 of the first intermediate P-type fine gate line 1112, 18 of the first intermediate P-type pad 1113 of the first intermediate P-type solder joint, 19 of the first intermediate N-type main gate line 1121, 20 of the first intermediate N-type fine gate line 1122 of the first intermediate N-type solder joint, and 21 of the first intermediate N-type pad 1123 of the first intermediate N-type solder joint.

[0070] In some embodiments, refer to Figure 6 The first edge P-type fine gate line 11 and the first edge P-type sub-main gate line 12 are orthogonally connected; the first edge N-type main gate line 13 and the first edge N-type fine gate line 14 are orthogonally connected; the first edge P-type sub-main gate line 12 and the first intermediate P-type main gate line 16 are orthogonally connected; the first intermediate P-type main gate line 16 and the first intermediate P-type fine gate line 17 are orthogonally connected; the first intermediate N-type main gate line 19 and the first intermediate N-type fine gate line 20 are orthogonally connected; the first intermediate P-type pad 18 is located on the first intermediate P-type main gate line 16 and is connected to multiple first intermediate P-type fine gate lines; the first intermediate N-type pad 21 is located on the first intermediate N-type main gate line 19 and is connected to multiple first intermediate N-type fine gate lines 20; the shapes of the first intermediate P-type pad 18 and the first intermediate N-type pad 21 can be at least one of the following: solid rectangle, rectangular frame, solid circle, and annular shape.

[0071] According to some embodiments of this utility model, refer to Figure 7The second half 200 includes a second edge P-type main gate line 22 located in the second edge P main gate region 2211, a second edge P-type fine gate line 23 located in the second edge P fine gate region 2212, a second edge P-type pad 24 located in the second edge P region solder joint 2213, a second edge N-type fine gate line 25 located in the second edge N fine gate region 2221, a second intermediate P-type main gate line 26 located in the second intermediate P main gate region 2111, a second intermediate P-type fine gate line 27 located in the second intermediate P fine gate region 2112, a second intermediate P-type pad 28 located in the second intermediate P region solder joint 2113, a second intermediate N-type main gate line 29 located in the second intermediate N main gate region 2121, a second intermediate N-type fine gate line 30 located in the second intermediate N fine gate region 2122, and a second intermediate N-type pad 31 located in the second intermediate N region solder joint 2123.

[0072] In some embodiments, refer to Figure 7 The second edge P-type main gate line 22 and the second edge P-type fine gate line 23 are orthogonally connected. The second edge N-type fine gate line 25 is orthogonal to the second edge P-type main gate line 22. The second middle P-type main gate line 26 and the second middle P-type fine gate line 27 are orthogonally connected. The second middle N-type main gate line 29 and the second middle N-type fine gate line 30 are orthogonally connected. The second middle P-type pad 28 is located on the second middle P-type main gate line 26 and is connected to multiple second middle P-type fine gate lines. The second middle N-type pad 31 is located on the second middle N-type main gate line 29 and is connected to multiple second middle N-type fine gate lines 30. The shapes of the second middle P-type pad 28 and the second middle N-type pad 31 can be at least one of the following: solid rectangle, rectangular frame, solid circle, and annular shape.

[0073] According to some embodiments of this utility model, the above-mentioned grid structure is adapted to the patterned partitioning of the P-region and N-region, which can better collect, transfer and converge the charge carriers of the P-region and N-region.

[0074] According to some embodiments of this utility model, the materials of all the above-mentioned gate lines and pads include, but are not limited to, one or more conductive metals such as silver, copper, and aluminum, or alloys containing the above-mentioned metals. The methods for preparing the above-mentioned gate lines may include, but are not limited to, at least one of the following processes: screen printing, inkjet printing, stencil printing, laser transfer, and copper electroplating.

[0075] According to some embodiments of this utility model, there are no limitations on the type of back-contact solar cell described above, and it can be applied to HBC, TBC, and other types of cells.

[0076] In another aspect of this utility model, a photovoltaic module is provided. According to an embodiment of this utility model, the photovoltaic module includes the back-contact solar cell described above. This photovoltaic module has good power generation efficiency. Those skilled in the art will understand that this photovoltaic module has all the structures and features of the back-contact solar cell described above, and will not be described in detail here.

[0077] The terms "first" and "second" used in this document are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature marked "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0078] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0079] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A back-contact solar cell, characterized in that, The back-contact solar cell includes a first half and a second half spliced ​​together in a first direction. The first half includes a first intermediate region and first edge regions located on both sides of the first intermediate region in a second direction. The backlight surface of the first edge region includes a first edge P region, a first edge N region, and a first edge isolation region located between the first edge P region and the first edge N region. The first edge P region includes a first edge P fine gate region A extending along the first direction, a first edge P fine gate region B extending along the second direction, and a first edge P sub-main gate region extending along the second direction, wherein the first edge P fine gate region A is located on the side of the first edge P sub-main gate region away from the first intermediate region. The first edge N region includes a first edge N main gate region extending along the first direction, a first edge N fine gate region extending along the second direction, and a plurality of first edge N region solder joints. The first edge N main gate region is located on the side of the first edge N fine gate region away from the first intermediate region, and the first edge N main gate region is located on the side of the first edge P fine gate region A close to the first intermediate region.

2. The back-contact solar cell according to claim 1, characterized in that, The first edge N main gate region includes multiple first sub-edge N main gate regions separated by the first edge P sub-main gate region. The first edge P sub-main gate region at the break point is connected to the first edge P fine gate region A. Each first sub-edge N main gate region is provided with multiple first edge N fine gate regions, multiple first edge P fine gate regions B and at least one first edge N region solder joint.

3. The back-contact solar cell according to claim 1 or 2, characterized in that, The first edge N region solder joint is located on the side of the first edge N main gate region near the first middle region.

4. The back-contact solar cell according to claim 1 or 2, characterized in that, The backlight surface of the first intermediate region includes a first intermediate P region, a first intermediate N region, and a first intermediate isolation region located between the first intermediate P region and the first intermediate N region, wherein, The first intermediate P region includes a first intermediate P main gate region extending along the first direction, a first intermediate P fine gate region extending along the second direction, and a plurality of first intermediate P region solder joints, and the solder joints of the first intermediate P region are arranged adjacent to the solder joints of the first edge N region. The first intermediate N region includes a first intermediate N main gate region extending along the first direction, a first intermediate N fine gate region extending along the second direction, and a plurality of first intermediate N region solder joints.

5. The back-contact solar cell according to claim 4, characterized in that, The first edge P fine gate region A is connected to the first middle P main gate region through the first edge P sub-main gate region.

6. The back-contact solar cell according to claim 4, characterized in that, The first half also satisfies at least one of the following conditions: The width of the first edge N main gate region is less than or equal to the width of the first middle N main gate region; The width of the first edge P fine gate region A is less than or equal to the width of the first middle P fine gate region; The width of the first intermediate P main gate region is greater than or equal to the width of the first intermediate N main gate region; The width of the first intermediate P fine gate region is greater than or equal to the width of the first intermediate N fine gate region.

7. The back-contact solar cell according to claim 1 or 2, characterized in that, The first half-piece further includes: a first non-current collection area, which is located outside the first middle area and the first edge area, and the width of the first non-current collection area located at the chamfer where the first direction and the second direction intersect is greater than the width of the first non-current collection area in the other areas.

8. The back-contact solar cell according to claim 4, characterized in that, The second half includes a second intermediate region and second edge regions located on both sides of the second intermediate region in the second direction. The backlight surface of the second edge region includes a second edge P region, a second edge N region, and a second edge isolation region located between the second edge P region and the second edge N region. The second edge P region includes a second edge P main gate region extending along the first direction, a second edge P fine gate region extending along the second direction, and a plurality of second edge P region solder joints, and the second edge P main gate region is located on the side of the second edge P fine gate region away from the second intermediate region; The second edge N region includes a second edge N fine gate region extending along the second direction.

9. The back-contact solar cell according to claim 8, characterized in that, The second edge P area solder joint is located on the side of the second edge P main gate area near the second middle area.

10. The back-contact solar cell according to claim 8, characterized in that, The backlight surface of the second intermediate region includes a second intermediate P region, a second intermediate N region, and a second intermediate isolation region located between the second intermediate P region and the second intermediate N region, wherein, The second intermediate P region includes a second intermediate P main gate region extending along the first direction, a second intermediate P fine gate region extending along the second direction, and a plurality of second intermediate P region solder joints; The second intermediate N region includes a second intermediate N main gate region extending along the first direction, a second intermediate N fine gate region extending along the second direction, and a plurality of second intermediate N region solder points. The solder points of the second intermediate N region are arranged adjacent to the solder points of the second edge P region. The second edge N fine gate region is connected to the second intermediate N main gate region.

11. The back-contact solar cell according to claim 10, characterized in that, The second half also satisfies at least one of the following conditions: The width of the second intermediate P main gate region is greater than or equal to the width of the second intermediate N main gate region; The width of the second intermediate P fine gate region is greater than or equal to the width of the second intermediate N fine gate region.

12. The back-contact solar cell according to claim 8, characterized in that, The second half also includes a second non-current collection area, which is located outside the second middle region and the second edge region, and the width of the second non-current collection area located at the chamfer where the first direction and the second direction intersect is greater than the width of the second non-current collection area in the remaining regions.

13. The back-contact solar cell according to claim 10, characterized in that, The first half-chip also includes a first edge P-type fine gate line located in the first edge P fine gate region A, a first edge P-type sub-main gate line located in the first edge P sub-main gate region, a first edge N-type main gate line located in the first edge N main gate region, a first edge N fine gate line located in the first edge N fine gate region, a first edge N-type pad located at the solder joint in the first edge N region, a first intermediate P-type main gate line located in the first intermediate P main gate region, a first intermediate P-type fine gate line located in the first intermediate P fine gate region, a first intermediate P-type pad located at the solder joint in the first intermediate P region, a first intermediate N-type main gate line located in the first intermediate N main gate region, a first intermediate N-type fine gate line located in the first intermediate N fine gate region, and a first intermediate N-type pad located at the solder joint in the first intermediate N region. The second half-piece includes a second edge P-type main gate line located in the second edge P main gate region, a second edge P-type fine gate line located in the second edge P fine gate region, a second edge P-type pad located in the second edge P region solder joint, a second edge N-type fine gate line located in the second edge N fine gate region, a second intermediate P-type main gate line located in the second intermediate P main gate region, a second intermediate P-type fine gate line located in the second intermediate P fine gate region, a second intermediate P-type pad located in the second intermediate P region solder joint, a second intermediate N-type main gate line located in the second intermediate N main gate region, a second intermediate N-type fine gate line located in the second intermediate N fine gate region, and a second intermediate N-type pad located in the second intermediate N region solder joint.

14. A photovoltaic module, characterized in that, Includes the back-contact solar cell according to any one of claims 1 to 13.

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