Back-contact cell and manufacturing method therefor

Abstract

The present application relates to the technical field of semiconductors, and discloses a back-contact cell and a manufacturing method therefor, for use in preventing electric leakage and improving the electrical stability of the back-contact cell. The back-contact cell comprises a cell substrate, and a first electrode and a second electrode which are formed on a non-illuminated surface of the cell substrate. The non-illuminated surface of the cell substrate comprises first areas and second areas which are alternately distributed. The first areas and the second areas have opposite conductivity types. The projection of at least part of the first electrode on the non-illuminated surface is located in the first areas. The projection of the second electrode on the non-illuminated surface is located in the second areas. Each of the first electrode and the second electrode comprises a plurality of current collector electrodes and a plurality of busbar electrodes. In a second direction, the distance between the end of each current collector electrode segment in the first electrode and an adjacent busbar electrode comprised in the second electrode is a first distance. In the second direction, the distance between the end of each current collector electrode segment in the second electrode and an adjacent busbar electrode comprised in the first electrode is a second distance. The first distance is different from the second distance.

Description

Back contact battery and manufacturing method thereof Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a semiconductor device and a method for manufacturing the same. Background Art

[0002] Back-contact cells are solar cells in which both the positive and negative electrodes are located on the backside of the cell, with no metal electrodes blocking the light-facing side. Compared to solar cells with blocked light-facing sides, back-contact cells offer higher short-circuit current and photoelectric conversion efficiency, and are currently one of the technological advancements in achieving high-efficiency crystalline silicon cells.

[0003] However, after the first electrode and the second electrode of opposite conductivity types are formed on the backlight side of the battery substrate included in the existing back-contact battery, it is easy for the end of the collector electrode segment included in the first electrode along the second direction to overlap with the second area or the end of the collector electrode segment included in the second electrode along the second direction to overlap with the first area, resulting in leakage, which is not conducive to improving the electrical stability of the back-contact battery.

[0004] Summary of the Invention

[0005] The purpose of the present application is to provide a back-contact battery and a method for manufacturing the same, which is used to prevent leakage caused by the end of the collecting electrode segment in the first electrode along the second direction overlapping the second area or the end of the collecting electrode segment in the second electrode along the second direction overlapping the first area after forming a first electrode and a second electrode with opposite conductivity types on the backlight surface of the battery substrate, thereby improving the electrical stability of the back-contact battery.

[0006] In order to achieve the above-mentioned objectives, in a first aspect, the present application provides a back-contact battery, which includes: a battery substrate, and a first electrode and a second electrode formed on the backlight surface of the battery substrate. The backlight surface of the battery substrate has a first region and a second region that are alternately distributed. The conductivity types of the first region and the second region are opposite. At least part of the projection of the first electrode on the backlight surface is located in the first region. The projection of the second electrode on the backlight surface is located in the second region. The first electrode and the second electrode each include a plurality of collecting electrodes and a plurality of bus electrodes. The bus electrodes included in the first electrode and the bus electrodes included in the second electrode both extend along a first direction and are alternately spaced along a second direction, and the first direction is different from the second direction. The collecting electrode included in the first electrode is in ohmic contact with the first region, and the collecting electrode included in the second electrode is in ohmic contact with the second region. The collecting electrodes included in the first electrode and the collecting electrodes included in the second electrode both extend along the second direction and are alternately spaced along the first direction. Each collecting electrode is connected to a bus electrode of the same polarity as itself, and each collecting electrode includes multiple collecting electrode segments spaced apart along a second direction. The spacing between two adjacent collecting electrode segments in the same collecting electrode is used to isolate the bus electrode of opposite polarity from itself. Along the second direction, the spacing between the end of each collecting electrode segment in the first electrode and the adjacent bus electrode in the second electrode is a first distance. Along the second direction, the spacing between the end of each collecting electrode segment in the second electrode and the adjacent bus electrode in the first electrode is a second distance. The first distance is different from the second distance.

[0007] The first electrode includes a collector electrode that is in ohmic contact with the first region and is used to collect carriers of the corresponding conductivity type in the first region and conduct them to the bus electrode included in the first electrode. The second electrode includes a collector electrode that is in ohmic contact with the second region and is used to collect carriers of the corresponding conductivity type in the second region and conduct them to the bus electrode included in the second electrode. Based on this, because the first and second regions alternately distributed on the backlight side of the battery substrate have opposite conductivity types, the conductivity types of the first and second electrodes are also opposite. In this case, the gap between two adjacent collector electrode segments included in the same collector electrode in the first and second electrodes is used to isolate the bus electrode of opposite polarity to itself, thereby suppressing leakage.

[0008] Along the second direction, the end of each collecting electrode segment in the first electrode is spaced apart from the adjacent bus electrode included in the second electrode by a first distance. Along the second direction, the end of each collecting electrode segment in the second electrode is spaced apart from the adjacent bus electrode included in the first electrode by a second distance. The first distance is different from the second distance. In one embodiment, when the projection of the first electrode on the backlight surface is located within the first region, the first distance is greater than the second distance. In this case, the end of each collecting electrode segment in the first electrode can be separated from the adjacent bus electrode included in the second electrode by the longer first distance, ensuring that the end of each collecting electrode segment in the first electrode along the second direction does not overlap with the second region of opposite conductivity type or the adjacent bus electrode included in the second electrode, thereby preventing leakage. Furthermore, while ensuring that the end of each collecting electrode segment in the second electrode along the second direction does not overlap with the first region of opposite conductivity type or the adjacent bus electrode included in the first electrode, the spacing between the end of each collecting electrode segment in the second electrode along the second direction and the first region is significantly reduced, thereby improving the carrier collection capability of each collecting electrode segment in the second electrode. In other words, the back-contact battery provided in the present application can separately adjust the distance between the end of each collecting electrode segment in the positive electrode and the adjacent bus electrode included in the negative electrode, and the distance between the end of each collecting electrode segment in the negative electrode and the adjacent bus electrode included in the positive electrode according to the actual application scenario. In this way, while preventing leakage and improving the electrical stability of the back-contact battery, the collecting electrode segment can have a relatively strong carrier collection ability, which is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0009] As a possible implementation scheme, along the second direction, the distance between the end of each collecting electrode segment in the first electrode and the edge of the second region is a third distance. Along the second direction, the minimum distance between the edge of each bus electrode in the first electrode and the edge of the second region is a fourth distance. The third distance is greater than the fourth distance. In this case, it can be ensured that the third distance, which is longer in length, prevents the end of each collecting electrode segment in the first electrode from overlapping the second region with the opposite conductivity type to itself along the second direction, thereby avoiding leakage. At the same time, there is no need to increase the distance between the edge of each bus electrode in the first electrode and the edge of the second region along the second direction due to the processing width error and offset error of the bus electrode included in the first electrode, thereby ensuring that the first region and the second region located on the backlight side both have a suitable range, reducing the carrier recombination rate on the backlight side, and helping to improve the photoelectric conversion efficiency of the back contact battery.

[0010] As a possible implementation, along the second direction, the minimum distance between the edge of the first region and the edge of the bus electrode in the second electrode is a fifth distance. Along the second direction, the distance between the edge of the first region and the end of the collector electrode segment in the second electrode is a sixth distance. The ratio of the fifth distance to the sixth distance is greater than or equal to 0.8 and less than or equal to 1.2.

[0011] The fifth distance and the sixth distance are respectively the distances between the edge of the bus electrode and the end of the collector electrode segment in the second electrode and the edge of the first region of opposite conductivity type to the first region along the second direction. Based on this, in the actual manufacturing process, the fifth distance and the sixth distance need to take into account the processing errors of the bus electrode and the collector electrode segment in the second electrode, respectively, so as to reserve corresponding distances to prevent the edge of the bus electrode and the end of the collector electrode segment in the second electrode from overlapping the first region of opposite conductivity type to the first region. The processing errors of the bus electrode and the collector electrode segment included in the second electrode manufactured by the processing machine are roughly the same. Therefore, when the ratio of the fifth distance to the sixth distance is greater than or equal to 0.8 and less than or equal to 1.2, the two are roughly equal. Under the premise of preventing the edge of the bus electrode and the end of the collector electrode segment in the second electrode from leaking to the first region respectively, it is possible to prevent some carriers in the second region from being unable to be promptly extracted due to the setting of one of the fifth distance and the sixth distance being larger, thereby ensuring that the back contact battery has a high photoelectric conversion efficiency.

[0012] As a possible implementation, along the second direction, the distance between the end of each collector electrode segment in the first electrode and the edge of the second region is a third distance greater than or equal to 0.15 mm and less than or equal to 0.3 mm.

[0013] When the above technical solution is employed, if the third distance is within the above range, this can prevent the poor leakage protection between the end of each collector electrode segment in the first electrode along the second direction and the edge of the second region, which would otherwise be caused by a small third distance, thereby ensuring the back-contact cell has high electrical stability. Furthermore, this can also prevent the end of each collector electrode segment in the first electrode along the second direction from having difficulty collecting carriers of the corresponding conductivity type generated near the edge of the first region, which would otherwise be caused by a large third distance. This ensures that each collector electrode segment in the first electrode has a high carrier collection capability, thereby ensuring that the back-contact cell has high photoelectric conversion efficiency.

[0014] As a possible implementation, along the second direction, the minimum distance between the edge of each bus electrode in the first electrode and the edge of the second region is a fourth distance, which is greater than or equal to 0.07 mm and less than 0.15 mm.

[0015] When the above technical solution is adopted, the fourth distance is within the above range, which can prevent the part of the bus electrode included in the actually formed first electrode from being located above the second area due to the small processing allowance reserved due to the small fourth distance, ensuring that the bus electrode included in the first electrode can be prevented from overlapping and leaking. At the same time, it can also prevent the strict requirements on the manufacturing accuracy of the bus electrode in the first electrode to avoid leakage, thereby reducing the difficulty of manufacturing the bus electrode in the first electrode. In addition, it can also prevent the second area located on the side of the backlight surface together with the first area from being smaller due to the large fourth distance, which is beneficial to reducing the carrier recombination rate on the side of the backlight surface and improving the photoelectric conversion efficiency of the back-contact battery.

[0016] As a possible implementation, along the second direction, the distance between the end of each collector electrode segment in the first electrode and the edge of the second region is a third distance. Along the second direction, the minimum distance between the edge of each bus electrode in the first electrode and the edge of the second region is a fourth distance. The ratio of the third distance to the fourth distance is greater than 1 and less than or equal to 2. The beneficial effects of this case are similar to those described above for the third distance being greater than or equal to 0.15 mm and less than or equal to 0.3 mm, and for the fourth distance being greater than or equal to 0.07 mm and less than 0.15 mm, and are not further described here.

[0017] As a possible implementation scheme, each bus electrode included in the first electrode does not directly contact the first region. In this case, to prevent leakage, it is not necessary to include the leakage factor between the edge of the bus electrode included in the first electrode and the edge of the second region when considering the setting size of the second distance. However, when considering the setting size of the first distance, it is still necessary to include the leakage factor between the end of the collector electrode segment included in the first electrode along the second direction and the edge of the second region. Therefore, setting the first distance to be greater than the second distance can not only prevent overlap leakage at the end of each collector electrode segment in the first electrode along the second direction, but also improve the carrier collection capacity of each collector electrode segment in the second electrode.

[0018] As a possible implementation solution, each bus electrode included in the second electrode is not in direct contact with the second region.

[0019] When employing the above technical solution, with other factors remaining the same, the contact area between the second electrode and the second region is smaller when the bus electrode included in the second electrode is not in direct contact with the second region, compared to when the bus electrode included in the second electrode is also in direct contact with the second region. In this case, when the back-contact cell further includes a passivation layer disposed on the backlight side of the cell substrate, if the contact area between the second electrode and the second region is smaller, the contact area between the passivation layer and the second region is larger, thereby enhancing the passivation effect of the passivation layer on the backlight side of the cell substrate, thereby improving the operating performance of the back-contact cell.

[0020] As one possible implementation, the battery substrate includes a semiconductor substrate and a doped semiconductor layer formed on a portion of the backlight surface of the semiconductor substrate. In this case, the backlight surface of the semiconductor substrate and the backlight surface of the battery substrate are on the same side. The doped semiconductor layer and the semiconductor substrate have opposite conductivity types. The area of ​​the backlight surface of the semiconductor substrate exposed outside the doped semiconductor layer is a first area, and the area of ​​the doped semiconductor layer facing away from the semiconductor substrate is a second area.

[0021] When the above-mentioned technical solution is adopted, in the actual process of manufacturing the battery base, it is only necessary to form an entire doped semiconductor layer covering the backlight surface of the semiconductor substrate and remove the portion of the doped semiconductor layer covering the first area. Then, a first area and a second area with opposite conductivity types can be formed on the backlight side, thereby solving the problem of the complicated back-contact battery manufacturing process caused by the need to dope the backlight surface twice with opposite conductivity types.

[0022] As a possible implementation solution, the semiconductor substrate is a P-type semiconductor substrate, the doped semiconductor layer is an N-type doped semiconductor layer, and the battery base further includes a tunneling passivation layer located between the P-type semiconductor substrate and the N-type doped semiconductor layer.

[0023] When the above technical solution is adopted, the tunneling passivation layer and the N-type doped semiconductor layer can form a tunneling passivation contact structure. This tunneling passivation contact structure has excellent interface passivation effect and selective collection of carriers, which can further improve the photoelectric conversion efficiency of the back contact cell.

[0024] On the second aspect, the present application also provides a back contact cell and a method for manufacturing the same, which is used to improve the carrier collection ability of the non-burn-through electrode when the back contact cell has a back passivation layer and the collector electrode included in the first electrode is a non-burn-through electrode, thereby helping to improve the photoelectric conversion efficiency of the back contact cell, taking into account the following problems: forming a back passivation layer on the backlight side of the cell substrate included in the back contact cell can reduce the carrier recombination rate on the backlight side of the cell substrate, thereby improving the working performance of the back contact cell; however, in the existing back contact cell with a back passivation layer, the carrier collection ability of the non-burn-through collector electrode included in the first electrode is poor, which is not conducive to improving the photoelectric conversion efficiency of the back contact cell.

[0025] As a possible implementation scheme, in addition to the battery substrate, first electrode and second electrode included in the back-contact battery of the first aspect, the back-contact battery also includes a surface passivation layer covering the backlight side, wherein a conductive window is provided in the surface passivation layer, and the bottom exposed portion of the conductive window is the first region; the collector electrode included in the first electrode is a non-burn-through electrode, and is in ohmic contact with the first region through the conductive window; the collector electrode included in the second electrode is a burn-through electrode, and burns through part of the surface passivation layer and is in ohmic contact with the second region; wherein the portion in the first region that is in ohmic contact with each collector electrode segment in the first electrode is the contact region; along the second direction, the minimum spacing between the end of each contact region and the edge of the second region is the seventh distance; along the second direction, the spacing between the end of each collector electrode segment in the second electrode and the edge of the first region is the sixth distance; the seventh distance is smaller than the sixth distance.

[0026] The battery substrate can be a semiconductor substrate. The first electrode includes a collector electrode that forms ohmic contact with the first region through a conductive window within the surface passivation layer. It is used to collect carriers of the corresponding conductivity type within the first region and conduct them to the bus electrode within the first electrode. The second electrode includes a collector electrode that burns through a portion of the surface passivation layer and forms ohmic contact with the second region. It is used to collect carriers of the corresponding conductivity type within the second region and conduct them to the bus electrode within the second electrode. Therefore, because the first and second regions, which are alternately distributed on the backlight side of the battery substrate, have opposite conductivity types, the first and second electrodes also have opposite conductivity types. Furthermore, the portion of the first region that forms ohmic contact with each collector electrode segment in the first electrode constitutes a contact region. In this case, along the second direction, the minimum spacing between the end of each contact region and the edge of the second region (i.e., the seventh distance) serves to isolate the first electrode of opposite conductivity type from the second region. Furthermore, the spacing between the end of each collector electrode segment in the second electrode and the edge of the first region (i.e., the sixth distance) serves to isolate the second electrode of opposite conductivity type from the first region, preventing leakage and ensuring high electrical stability for the back-contact battery.

[0027] Secondly, because each collector electrode included in the first electrode is a non-burn-through electrode and the surface passivation layer is a non-conductive insulating material layer, the conductive window provided in the surface passivation layer determines the contact range between each collector electrode in the first electrode and the first region. In other words, in the actual process of manufacturing the back-contact battery provided in the present application, after forming the surface passivation layer provided with a conductive window, when each collector electrode included in the first electrode is manufactured by using a non-burn-through electrode paste, the non-burn-through electrode paste can only contact part of the first region through the conductive window, and it cannot penetrate the part of the surface passivation layer where the conductive window is not provided. Each collector electrode included in the second electrode is a burn-through electrode, and burns through part of the surface passivation layer and is in ohmic contact with the second region. In other words, in the actual process of manufacturing the back-contact battery provided in the present application, the burn-through electrode used to manufacture each collector electrode included in the second electrode can penetrate the surface passivation layer, thereby achieving electrical coupling with the region of the semiconductor substrate located below the burned-through portion of the surface passivation layer. In the above case, it is necessary to set the distance between the end of each collector electrode segment in the second electrode and the edge of the first region along the second direction to a relatively large sixth distance to prevent the end of each collector electrode segment in the second electrode from overlapping the first region along the second direction and causing leakage. However, because the surface passivation layer is a non-conductive film layer, the minimum distance between the end of the contact area of ​​each collector electrode segment in the first electrode and the edge of the second region in ohmic contact with the first region and the edge of the second region can be set to a relatively small seventh distance, which can reduce the clearance distance between the end of the contact area along the second direction and the edge of the second region, thereby improving the carrier collection capacity of each collector electrode segment included in the first electrode, thereby solving the problem that the seventh distance is set to be equal to the sixth distance in the prior art, which makes it difficult for each collector electrode segment in the first electrode to promptly extract carriers of the corresponding conductive type at the above-mentioned clearance distance, resulting in a large carrier recombination rate, and is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0028] As a possible implementation, along the second direction, the end of each collector electrode segment in the first electrode is flush with the end of the corresponding contact region. In this case, along the second direction, the actual manufactured length of each collector electrode segment in the first electrode is roughly the same as the effective carrier collection length (i.e., the distance between the two ends of the corresponding contact region along the second direction). This can reduce the amount of consumables used in each collector electrode segment in the first electrode, which is conducive to reducing the manufacturing cost of the back-contact battery.

[0029] As a possible implementation scheme, along the second direction, the end of each collector electrode segment in the first electrode is located between the end of the contact area and the edge of the second area or above the second area. In this case, along the second direction, the actual manufacturing length of each collector electrode segment in the first electrode can be greater than the effective carrier collection length. At this time, even if the end of each collector electrode segment in the first electrode along the second direction crosses the boundary between the first area and the second area and is located above the second area of ​​opposite conductivity type to itself, the two can be separated by the surface passivation layer. There is no need to strictly require high manufacturing precision for each collector electrode segment included in the first electrode in order to manufacture the end flush with the end of the corresponding contact area, thereby reducing the manufacturing difficulty of the back contact battery.

[0030] As described above, along the second direction, the distance between the end of each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode is a first distance. As a possible implementation, along the second direction, the distance between the end of each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode is a second distance, where the first distance is smaller than the second distance.

[0031] When the above technical solution is adopted, it can be understood that the spacing between the two adjacent collecting electrode segments included in the same collecting electrode in the first electrode and the second electrode is used to isolate the bus electrode with the opposite polarity to itself, thereby suppressing leakage. Based on this, when the first distance is less than the second distance, the end of each collecting electrode segment in the second electrode can be isolated from the adjacent bus electrode included in the first electrode by the second distance with a larger length, ensuring that the end of each collecting electrode segment in the second electrode along the second direction will not overlap with the first region with the opposite conductivity type to itself, and the adjacent bus electrode included in the first electrode, thereby preventing leakage. At the same time, while ensuring that the end of each collecting electrode segment in the first electrode along the second direction will not overlap with the second region with the opposite conductivity type to itself, and the adjacent bus electrode included in the second electrode, the spacing between the end of each collecting electrode segment in the first electrode along the second direction and the second region is greatly reduced, thereby improving the carrier collection capacity of each collecting electrode segment in the first electrode. In other words, the back-contact battery provided in the present application can separately adjust the distance between the end of each collecting electrode segment in the positive electrode and the adjacent bus electrode included in the negative electrode, and the distance between the end of each collecting electrode segment in the negative electrode and the adjacent bus electrode included in the positive electrode according to the actual application scenario. In this way, while preventing leakage and improving the electrical stability of the back-contact battery, the collecting electrode segment can have a relatively strong carrier collection ability, which is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0032] As one possible implementation, each busbar electrode included in the first electrode does not directly contact the first region. In this case, all other factors being equal, the contact area between the first electrode and the first region is smaller when the busbar electrodes included in the first electrode do not directly contact the first region, compared to when the busbar electrodes included in the first electrode also directly contact the first region. In this case, the contact area between the surface passivation layer and the first region is larger, which can enhance the passivation effect of the surface passivation layer on the backlight side of the battery substrate, thereby improving the performance of back-contact batteries.

[0033] As one possible implementation, each busbar electrode included in the second electrode does not directly contact the second region. In this case, all other factors being equal, the contact area between the second electrode and the second region is smaller when the busbar electrodes included in the second electrode do not directly contact the second region, compared to when the busbar electrodes included in the second electrode also directly contact the second region. In this case, the contact area between the surface passivation layer and the second region is larger, which can enhance the passivation effect of the surface passivation layer on the backlight side of the battery substrate, thereby improving the performance of back-contact batteries.

[0034] As one possible implementation, the battery substrate includes a semiconductor substrate and a doped semiconductor layer formed on a portion of the backlight surface of the semiconductor substrate. In this case, the backlight surface of the semiconductor substrate and the backlight surface of the battery substrate are on the same side. The doped semiconductor layer and the semiconductor substrate have opposite conductivity types. The area of ​​the backlight surface of the semiconductor substrate exposed outside the doped semiconductor layer is a first area, and the area of ​​the doped semiconductor layer facing away from the semiconductor substrate is a second area.

[0035] When the above technical solution is adopted, the beneficial effects of the relevant implementation methods of the first aspect can be achieved in the actual process of manufacturing the battery substrate, which will not be described in detail here.

[0036] As a possible implementation solution, the semiconductor substrate is a P-type semiconductor substrate, the doped semiconductor layer is an N-type doped semiconductor layer, and the battery base further includes a tunneling passivation layer located between the P-type semiconductor substrate and the N-type doped semiconductor layer.

[0037] When the above technical solution is adopted, the tunneling passivation layer and the N-type doped semiconductor layer can form a tunneling passivation contact structure. The tunneling passivation contact structure has the beneficial effects of the related implementation of the first aspect, which will not be described in detail here.

[0038] In a third aspect, the present application also provides a method for manufacturing a back-contact battery according to the first aspect or the second aspect.

[0039] In a fourth aspect, the present application also provides a method for manufacturing a back-contact battery, comprising: first, forming a battery substrate. The backlight surface of the battery substrate has a first region and a second region that are alternately distributed. Next, obtaining a regional pattern of the first region, design structure-related parameters corresponding to the first and second electrodes of the back-contact battery, a first performance adjustment-related parameter corresponding to the first electrode, and a second performance adjustment-related parameter corresponding to the second electrode. The first performance adjustment-related parameter is different from the second performance adjustment-related parameter. Furthermore, the first electrode and the second electrode each include a plurality of collecting electrodes and a plurality of bus electrodes. The bus electrodes included in the first electrode and the bus electrodes included in the second electrode each extend along a first direction and are alternately spaced along a second direction, the first direction being different from the second direction. The collecting electrodes included in the first electrode and the collecting electrodes included in the second electrode each extend along the second direction and are alternately spaced along the first direction. Each collecting electrode is connected to a bus electrode of the same polarity, and each collecting electrode includes a plurality of collecting electrode segments spaced along the second direction. The spacing between two adjacent collecting electrode segments in the same collecting electrode is used to isolate bus electrodes of opposite polarity from the collecting electrode. Next, based on the regional pattern, the design structure associated parameters, and the first performance adjustment associated parameters, the spacing between each collector electrode segment in the first electrode and the adjacent bus electrode included in the second electrode is adjusted to a first distance, and the design structure associated parameters are updated. Next, based on the regional pattern, the design structure associated parameters, and the second performance adjustment associated parameters, the spacing between each collector electrode segment in the second electrode and the adjacent bus electrode included in the first electrode is adjusted to a second distance, and the design structure associated parameters are updated. Then, according to the updated design structure associated parameters, the first electrode and the second electrode are formed on the backlight surface. The projection of the first electrode on the backlight surface is located within the first region. The projection of the second electrode on the backlight surface is located within the second region.

[0040] Under the above-mentioned technical scheme, the manufacturing method of the back-contact battery provided in the present application can separately adjust the spacing between each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode, and the spacing between each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode according to different first performance adjustment associated parameters and second performance adjustment associated parameters after obtaining the regional pattern of the first region, the design structure associated parameters corresponding to the first electrode and the second electrode included in the back-contact battery, thereby preventing leakage from occurring due to the end of each collecting electrode segment included in the first electrode and the second electrode being overlapped with the bus electrode with opposite polarity to itself, thereby improving the electrical stability of the back-contact battery and making the collecting electrode segment in the second electrode have a relatively strong carrier collection ability, which is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0041] As a possible implementation scheme, the first performance adjustment associated parameters include a first minimum anti-leakage distance and a first maximum collection distance. The first distance is greater than or equal to the first minimum anti-leakage distance and less than or equal to the first maximum collection distance. In this case, the distance between each collector electrode segment in the first electrode and the adjacent bus electrode included in the second electrode is set within the minimum distance to prevent leakage and the maximum distance that can effectively collect the corresponding conductive type carriers. This can avoid leakage at the end of each collector electrode segment in the first electrode while ensuring that each collector electrode segment in the first electrode can effectively collect the corresponding conductive type carriers generated in each part of the first region, reduce the carrier recombination rate, and help improve the photoelectric conversion efficiency of the back contact battery.

[0042] As a possible implementation scheme, the second performance adjustment associated parameter includes a second minimum anti-leakage distance and a second maximum collection distance. The second distance is greater than or equal to the second minimum anti-leakage distance and less than or equal to the second maximum collection distance. The beneficial effects in this case can be referred to the beneficial effects analysis described above in which the first performance adjustment associated parameter includes the first minimum anti-leakage distance and the first maximum collection distance, and the first distance is greater than or equal to the first minimum anti-leakage distance and less than or equal to the first maximum collection distance, and will not be repeated here.

[0043] As one possible implementation, forming a battery substrate includes forming a fully layered doped semiconductor layer on the backlight surface of a semiconductor substrate. Next, using a laser etching process, the portion of the doped semiconductor layer located above the first region is removed to form the battery substrate. The battery substrate includes the semiconductor substrate and the remaining doped semiconductor layer.

[0044] As a possible implementation scheme, a laser etching process is used to remove the portion of the doped semiconductor layer located on the first region, including: obtaining laser etching associated parameters, first processing error associated parameters corresponding to the bus electrode included in the second electrode, and second processing error associated parameters corresponding to the bus electrode included in the first electrode. Then, based on the design structure associated parameters and the laser etching associated parameters, a laser spot pattern is determined. Next, based on the design structure associated parameters and the first processing error associated parameters, the spacing between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction is adjusted. And based on the design structure associated parameters and the second processing error associated parameters, the spacing between the edge of the laser spot pattern and the bus electrode in the first electrode along the second direction is adjusted. Then, a laser etching process is used, and the doped semiconductor layer is etched according to the adjusted laser spot pattern.

[0045] When the above technical solution is adopted, based on the design structure associated parameters and the laser etching associated parameters, the laser spot pattern under theoretical conditions can be determined (the laser spot pattern is consistent with the pattern of the first area subsequently formed based on the laser etching process). However, during the actual processing of the first electrode and the second electrode, processing errors often occur due to factors such as machine accuracy or electrode slurry state. The existence of processing errors may cause the actual width and actual formation position of the bus electrode included in the actual processing of the second electrode to change, thereby causing the distance between the bus electrode included in the second electrode and the edge of the laser spot pattern in the theoretical situation along the second direction to no longer meet the working requirements; similarly, the existence of processing errors may cause the actual width and actual formation position of the bus electrode included in the actual processing of the first electrode to change, thereby causing the distance between the bus electrode included in the first electrode and the edge of the laser spot pattern in the theoretical situation along the second direction to no longer meet the working requirements. Therefore, after determining the laser spot pattern in the theoretical situation, the distance between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction, and the distance between the edge of the laser spot pattern and the bus electrode in the first electrode along the second direction are adjusted according to the first processing error associated parameters and the second processing error associated parameters, respectively, which can prevent the bus electrode from overlapping and short-circuiting, and improve the yield of the manufactured back-contact battery.

[0046] As a possible implementation scheme, the laser etching associated parameters include: laser spot size, the overlap distance between adjacent laser spots, the designed spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction, and the designed spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction. In this case, the range corresponding to the setting of a corresponding number of laser spots can be determined by combining the laser spot size and the overlap distance between adjacent laser spots. Furthermore, the designed spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction, and the designed spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction, define the boundaries of the laser spot pattern to be determined. Based on this, when the laser etching associated parameters include the laser spot size, the overlap distance between adjacent laser spots, the designed spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction, and the designed spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction, the laser spot pattern can be accurately determined based on the design structure associated parameters and the laser etching associated parameters, thereby improving the accuracy of determining the laser spot pattern.

[0047] As a possible implementation, the first processing error-related parameters include processing width errors and offset errors corresponding to the busbar electrodes included in the second electrode. In this case, the first processing error-related parameters can be used to infer changes in the morphology and position of the busbar electrodes included in the second electrode due to machine accuracy and slurry state during actual manufacturing of the busbar electrodes included in the second electrode. This allows the spacing between the edge of the laser spot pattern and the busbar electrodes included in the second electrode along the second direction to be effectively adjusted based on the first processing error-related parameters to avoid leakage.

[0048] As a possible implementation, the second machining error-related parameter includes a machining width error and an offset error corresponding to the busbar electrode included in the first electrode. The beneficial effects of this scenario can be referenced in the aforementioned analysis of the beneficial effects of the first machining error-related parameter including the machining width error and the offset error corresponding to the busbar electrode included in the second electrode, and will not be further elaborated here.

[0049] As a possible implementation scheme, the design spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction is greater than 0 and less than 0.4 mm. In this case, the design spacing is within the above range, which can prevent the poor leakage prevention effect between the end of each collector electrode segment in the first electrode along the second direction and the edge of the second region due to the small design spacing, thereby ensuring that the back contact battery has high electrical stability. In addition, it can also prevent the difficulty of the end of each collector electrode segment in the first electrode along the second direction to collect carriers of the corresponding conductive type generated near the edge of the first region due to the large design spacing, thereby ensuring that each collector electrode segment in the first electrode has a high carrier collection ability, thereby ensuring that the back contact battery has a high photoelectric conversion efficiency.

[0050] As a possible implementation solution, a designed spacing along the second direction between an edge of the laser spot pattern and a bus electrode included in the first electrode is equal to half of a difference between a laser spot size and an overlapping distance between adjacent laser spots.

[0051] When the above technical solution is adopted, since the number of laser spots included in the laser spot pattern can only be an integer greater than or equal to 1, leakage is likely to occur when the edge of the laser spot pattern coincides with the bus electrode included in the first electrode. Therefore, at this time, the width of a laser spot is added to reserve corresponding processing allowances for both sides of the bus electrode included in the first electrode along the second direction. At this time, the design spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction is equal to half of the difference between the laser spot size and the overlapping distance of adjacent laser spots. This can prevent leakage while avoiding energy waste or a smaller range of the second area due to setting more spots, thereby ensuring that the manufactured back-contact battery has higher working performance.

[0052] As a possible implementation, the distance between the edge of the adjusted laser spot pattern and the busbar electrode included in the second electrode along the second direction is greater than or equal to M1 and less than N1. M1 is the sum of the processing width error and offset error corresponding to the busbar electrode included in the second electrode, and N1 is the sum of the difference between the laser spot size and the overlap distance between adjacent laser spots and M1. In this case, while preventing leakage, it can avoid energy waste caused by setting too many spots or a smaller first area, thereby ensuring that the manufactured back-contact cell has high operating performance.

[0053] As a possible implementation, the distance between the edge of the adjusted laser spot pattern and the busbar electrode included in the first electrode along the second direction is greater than or equal to M2 and less than N2. M2 is half the difference between the laser spot size and the overlap distance between adjacent laser spots, and N2 is the sum of the processing width error and offset error corresponding to the busbar electrode included in the first electrode, as well as M2. In this case, while preventing leakage, it avoids energy waste caused by setting too many spots or a smaller first area, ensuring high performance of the manufactured back-contact cell.

[0054] As described above, along the second direction, the distance between the end of each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode is a first distance; along the second direction, the distance between the end of each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode is a second distance. As a possible implementation, the first distance is different from the second distance. In one embodiment, the first distance is greater than the second distance.

[0055] In a fifth aspect, the present application also provides a method for manufacturing a back-contact battery, which comprises: first, forming a battery substrate. The backlight surface of the battery substrate has a first region and a second region that are alternately distributed. The first region and the second region have opposite conductivity types. Next, a surface passivation layer covering the backlight surface is formed. A conductive window is provided in the surface passivation layer, and the bottom of the conductive window exposes a portion of the first region. Next, a first electrode and a second electrode are formed on one side of the backlight surface. At least a portion of the projection of the first electrode on the backlight surface is located within the first region. The projection of the second electrode on the backlight surface is located within the second region. The first electrode and the second electrode both include a plurality of collector electrodes and a plurality of bus electrodes. The bus electrodes included in the first electrode and the bus electrodes included in the second electrode both extend along the first direction and are alternately spaced along the second direction, and the first direction is different from the second direction. The first electrode includes a collector electrode that passes through the surface passivation layer through a conductive window and is in ohmic contact with the first region. The second electrode includes a collector electrode that burns through a portion of the surface passivation layer and is in ohmic contact with the second region. The collector electrodes included in the first electrode and the collector electrodes included in the second electrode both extend along the second direction and are alternately spaced along the first direction. Each collector electrode is connected to a bus electrode with the same polarity as itself, and each collector electrode includes a plurality of collector electrode segments spaced along the second direction. The spacing between two adjacent collector electrode segments in the same collector electrode is used to isolate the bus electrode with the opposite polarity from itself. The portion in the first region that is in ohmic contact with each collector electrode segment in the first electrode is the contact region. Along the second direction, the distance between the end of each contact region and the edge of the first region is the seventh distance. Along the second direction, the distance between the end of each collector electrode segment in the second electrode and the edge of the first region is the sixth distance. The seventh distance is smaller than the sixth distance.

[0056] As a possible implementation, along the second direction, the distance between the end of each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode is a first distance; along the second direction, the distance between the end of each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode is a second distance; the first distance is different from the second distance. In one embodiment, the first distance is less than the second distance.

[0057] The beneficial effects of the fourth and fifth aspects of this application can be respectively analyzed by referring to the beneficial effects of the first aspect and its related implementation methods and the second aspect and its related implementation methods, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0059] FIG1 is a schematic diagram illustrating the distribution positions of a first electrode and a second electrode included in a back-contact battery in the related art for illustrating the first embodiment of the present application, and an enlarged schematic diagram of the corresponding positions of the first electrode and the second electrode;

[0060] FIG2 is a schematic diagram of the distribution positions of the first electrode and the second electrode included in the back-contact battery provided in the first embodiment of the present application, and an enlarged schematic diagram of the corresponding positions of the first electrode and the second electrode;

[0061] FIG3 is a schematic longitudinal cross-sectional view of a portion of the structure of the second electrode included in the back-contact battery provided in the first embodiment of the present application;

[0062] FIG4 is a schematic longitudinal cross-sectional view of a portion of the structure of the first electrode included in the back-contact battery provided in the first embodiment of the present application.

[0063] 5 is a schematic diagram illustrating the distribution positions of the first electrode and the second electrode included in a back-contact battery in the related art according to the second embodiment of the present application;

[0064] 6 is a schematic diagram of the distribution positions of the first electrode and the second electrode included in the back-contact battery provided in the second embodiment of the present application, and an enlarged schematic diagram of the corresponding positions of the first electrode and the second electrode;

[0065] 7 is a schematic longitudinal cross-sectional view of a portion of the structure of a back-contact battery at the second electrode according to a second embodiment of the present application;

[0066] FIG8 is a schematic longitudinal cross-sectional view of a portion of the structure of a back-contact battery at the first electrode provided in the second embodiment of the present application.

[0067] Figure numerals: 11 is the first area, 12 is the second area, 13 is the first electrode, 14 is the second electrode, 15 is the collecting electrode, 16 is the bus electrode, 17 is the collecting electrode segment, 18 is the conductive window, L1 is the first distance, L2 is the second distance, L3 is the third distance, L4 is the fourth distance, L5 is the fifth distance, L6 is the sixth distance, L7 is the seventh distance, and L8 is the eighth distance. DETAILED DESCRIPTION

[0068] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present disclosure. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0069] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments of the present disclosure. These figures are not drawn to scale, and for the purpose of clarity, certain details are exaggerated and certain details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0070] In the context of this disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intervening layer / element between them. Furthermore, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element. To make the technical problems, technical solutions, and beneficial effects to be solved by this application more clearly understood, the application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain this application and are not intended to limit this application.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0072] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0073] Solar cells are increasingly being used as a new energy alternative. Photovoltaic solar cells are devices that convert sunlight into electricity. Specifically, they use the principle of photovoltaics to generate charge carriers, which are then extracted using electrodes, facilitating efficient use of the electrical energy.

[0074] Among them, when the positive and negative electrodes included in the solar cell are both located on the backlight side of the solar cell, the solar cell is a back-contact cell. The light-facing side of the back-contact cell is not affected by the obstruction of the metal electrode. Therefore, compared with solar cells with obstructed light-facing sides, back-contact cells have higher short-circuit current and photoelectric conversion efficiency, and are one of the current technical directions for achieving high-efficiency crystalline silicon cells. In addition, forming a back passivation layer on the backlight side of the cell substrate included in the back-contact cell can reduce the carrier recombination rate on the backlight side of the cell substrate, thereby improving the working performance of the back-contact cell. In the present application, the cell substrate can be a semiconductor substrate.

[0075] First embodiment

[0076] Specifically, as shown in FIG1 , the back-contact battery includes a first electrode 13 and a second electrode 14 of opposite conductivity types, both of which are formed on the backlight side of the battery substrate. Based on this, in the actual manufacturing process, a doped semiconductor layer is usually formed in its entirety on the backlight side of the semiconductor substrate, and a portion of the doped semiconductor layer is removed by laser etching or other methods to form a battery substrate having first regions 11 and second regions 12 (the first regions 11 and the second regions 12 have opposite conductivity types) alternately distributed on the backlight side. Then, the first electrode 13 and the second electrode 14 are formed on the backlight side of the battery substrate. The first electrode 13 and the second electrode 14 each include a plurality of collector electrodes 15 and a plurality of bus electrodes 16. The bus electrodes 16 included in the first electrode 13 and the bus electrodes 16 included in the second electrode 14 each extend along a first direction and are alternately spaced along a second direction (the second direction is different from the first direction). The collector electrode 15 included in the first electrode 13 is in ohmic contact with the first region 11, and the collector electrode 15 included in the second electrode 14 is in ohmic contact with the second region 12. The collector electrodes 15 included in the first electrode 13 and the collector electrodes 15 included in the second electrode 14 both extend along the second direction and are alternately spaced along the first direction. Each collector electrode 15 is connected to a bus electrode 16 of the same polarity as itself. Each collector electrode 15 includes multiple collector electrode segments 17 spaced along the second direction. The spacing between adjacent collector electrode segments 17 in the same collector electrode 15 is used to isolate the bus electrode 16 of opposite polarity from itself to prevent leakage.

[0077] Among them, along the second direction, the distance between the end of each collector electrode segment included in the first electrode and the adjacent bus electrode included in the second electrode is a first distance. Along the second direction, the distance between the end of each collector electrode segment in the second electrode and the adjacent bus electrode included in the first electrode is a second distance. As shown in Figure 1, in the existing back-contact battery, the first distance L1 is equal to the second distance L2. At this time, it is impossible to set the first distance L1 and the second distance L2 separately according to the morphology of the first region 11 and the second region 12 obtained after patterning the doped semiconductor layer using processes such as laser etching. It is easy to cause leakage due to the end of the collector electrode segment 17 included in the first electrode 13 along the second direction overlapping the second region 12, which is not conducive to improving the electrical stability of the back-contact battery.

[0078] In order to solve the above technical problems, in the first aspect, an embodiment of the present application provides a back-contact battery. As shown in Figure 2, the back-contact battery includes: a battery substrate, and a first electrode 13 and a second electrode 14 formed on the backlight surface of the battery substrate. The backlight surface of the battery substrate has a first area 11 and a second area 12 that are alternately distributed. The first area 11 and the second area 12 have opposite conductivity types. The projection of the first electrode 13 on the backlight surface is located within the first area 11. The projection of the second electrode 14 on the backlight surface is located within the second area 12. The first electrode 13 and the second electrode 14 each include a plurality of collecting electrodes 15 and a plurality of bus electrodes 16. The bus electrodes 16 included in the first electrode 13 and the bus electrodes 16 included in the second electrode 14 both extend along the first direction and are alternately spaced along the second direction, and the first direction is different from the second direction. The collecting electrode 15 included in the first electrode 13 is in ohmic contact with the first region 11, and the collecting electrode 15 included in the second electrode 14 is in ohmic contact with the second region 12. The collecting electrodes 15 included in the first electrode 13 and the collecting electrodes 15 included in the second electrode 14 both extend along the second direction and are alternately spaced along the first direction. Each collecting electrode 15 is connected to a bus electrode 16 of the same polarity as itself. Each collecting electrode 15 includes multiple collecting electrode segments 17 spaced along the second direction. The spacing between adjacent collecting electrode segments 17 in the same collecting electrode 15 is used to isolate the bus electrode 16 of opposite polarity from itself. Along the second direction, the distance between the end of each collecting electrode segment 17 in the first electrode 13 and the adjacent bus electrode 16 in the second electrode 14 is a first distance L1. Along the second direction, the distance between the end of each collecting electrode segment 17 in the second electrode 14 and the adjacent bus electrode 16 in the first electrode 13 is a second distance L2. The first distance L1 is greater than the second distance L2.

[0079] Specifically, the embodiments of the present application do not impose any specific restrictions on the structure and material of the battery substrate, and the conductivity types of the first region and the second region, as long as they can be applied to the back-contact battery provided in the embodiments of the present application.

[0080] Exemplarily, the battery substrate may include: a semiconductor substrate, and a doped semiconductor layer formed on a portion of the backlight surface of the semiconductor substrate. The region of the backlight surface of the semiconductor substrate exposed outside the doped semiconductor layer is the first region, and the region of the doped semiconductor layer facing away from the semiconductor substrate is the second region. Furthermore, the doped semiconductor layer and the semiconductor substrate may have the same conductivity type. In this case, the battery substrate further includes a second doped semiconductor layer having a conductivity type opposite to that of the semiconductor substrate and formed on a portion of the surface of the semiconductor substrate corresponding to the first region. Alternatively, the doped semiconductor layer may have a conductivity type opposite to that of the semiconductor substrate. It is worth noting that when the doped semiconductor layer and the semiconductor substrate have opposite conductivity types, in the actual manufacturing process of the battery substrate, it is only necessary to form an entire doped semiconductor layer covering the backlight surface of the semiconductor substrate and remove a portion of the doped semiconductor layer. This allows the formation of the first and second regions of opposite conductivity types on the backlight side, thereby resolving the problem of requiring the backlight surface to be doped twice with opposite conductivity types, which complicates the manufacturing process of back-contact batteries.

[0081] Specifically, in terms of conductivity type, the semiconductor substrate may be an N-type semiconductor substrate. In this case, if the doped semiconductor layer and the N-type semiconductor substrate have the same conductivity type, the doped semiconductor layer is an N-type doped semiconductor layer, the first region is a P-type region, and the second region is an N-type region. If the doped semiconductor layer and the N-type semiconductor substrate have opposite conductivity types, the doped semiconductor layer is a P-type doped semiconductor layer, the first region is an N-type region, and the second region is a P-type region.

[0082] Alternatively, the semiconductor substrate may be a P-type semiconductor substrate. In this case, if the conductivity type of the doped semiconductor layer is the same as that of the N-type semiconductor substrate, the doped semiconductor layer is a P-type doped semiconductor layer, the first region is an N-type region, and the second region is a P-type region. If the conductivity type of the doped semiconductor layer is opposite to that of the P-type semiconductor substrate, the doped semiconductor layer is an N-type doped semiconductor layer, the first region is a P-type region, and the second region is an N-type region.

[0083] In terms of materials, the semiconductor substrate can be made of any semiconductor material, such as silicon, silicon germanium, germanium, or gallium arsenide. As for the doped semiconductor layer, the doped semiconductor layer can be made of any semiconductor material, such as silicon, silicon germanium, germanium, silicon carbide, or gallium arsenide. In terms of the internal arrangement of the material, the doped semiconductor layer can be amorphous, microcrystalline, single crystal, nanocrystalline, or polycrystalline.

[0084] In some cases, the battery substrate may further include a passivation layer located between the semiconductor substrate and the doped semiconductor layer. This passivation layer can passivate at least the portion of the surface where the semiconductor substrate contacts the doped semiconductor layer, reducing the rate at which carriers recombine at the point of contact between the two. Furthermore, the doped semiconductor layer formed on the passivation layer can selectively collect carriers of the corresponding conductivity type within the semiconductor substrate, thereby further improving the photoelectric conversion efficiency of the back-contact battery provided in the embodiments of the present application. Specifically, the material of the passivation layer can be determined based on the material of the doped semiconductor layer.

[0085] For example, when the doped semiconductor layer is a doped amorphous silicon layer, a doped microcrystalline silicon layer, or a mixed layer of doped amorphous silicon and microcrystalline silicon, the passivation layer can be an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, or a mixed layer of intrinsic amorphous silicon and microcrystalline silicon. In this case, the doped semiconductor layer and the passivation layer can form a heterogeneous contact structure.

[0086] For another example, when the doped semiconductor layer is a doped polysilicon layer, the passivation layer is a tunneling passivation layer. In this case, the doped semiconductor layer and the passivation layer can form a tunneling passivation contact structure. Furthermore, the material of the tunneling passivation layer can include any dielectric material having a tunneling passivation effect. For example, the material of the tunneling passivation layer can include one or more of silicon oxide, aluminum oxide, titanium oxide, hafnium dioxide, gallium oxide, tantalum pentoxide, niobium pentoxide, silicon nitride, silicon carbonitride, aluminum nitride, titanium nitride, and titanium nitride carbide.

[0087] Among them, when the semiconductor substrate included in the battery base is a P-type semiconductor substrate, the doped semiconductor layer is an N-type doped polysilicon layer, and a tunneling passivation layer is formed between the P-type semiconductor substrate and the N-type doped polysilicon layer, the back contact battery provided in the embodiment of the present application is a HPBC (composite passivated back contact) battery.

[0088] Regarding the first electrode and the second electrode, in terms of materials, the material of the first electrode or the second electrode may include conductive materials such as silver, aluminum, copper, titanium or nickel, etc. The materials of the first electrode and the second electrode may be the same or different.

[0089] In terms of polarity, since the collector electrode included in the first electrode is in ohmic contact with the first region, and the collector electrode included in the second electrode is in ohmic contact with the second region, the polarities of the first electrode and the second electrode can be determined according to the conductivity types of the first region and the second region, respectively.

[0090] For example, when the first region is an N-type region and the second region is a P-type region, the first electrode is a negative electrode and the second electrode is a positive electrode.

[0091] For another example, when the first region is a P-type region and the second region is an N-type region, the first electrode is a positive electrode and the second electrode is a negative electrode.

[0092] It is understandable that a collector electrode included in the positive electrode has a polarity opposite to that of a collector electrode included in the negative electrode (or a bus electrode included in the negative electrode), and has the same polarity as another collector electrode included in the positive electrode (or a bus electrode included in the positive electrode). Similarly, a bus electrode included in the positive electrode has a polarity opposite to that of a collector electrode included in the negative electrode (or a bus electrode included in the negative electrode), and has the same polarity as another bus electrode included in the positive electrode (or a collector electrode included in the positive electrode). Accordingly, the situations of electrodes with the same or opposite polarity corresponding to the collector electrode and bus electrode included in the negative electrode can be referred to the previous text and will not be repeated here.

[0093] In terms of morphology, the bus electrodes included in the first and second electrodes can be straight bus electrodes, wavy bus electrodes, or zigzag bus electrodes. The specific shape of the bus electrodes included in the first and second electrodes can be set according to the actual application scenario and is not specifically limited here. In addition, the collector electrodes included in the first and second electrodes can be straight collector electrodes, wavy collector electrodes, or zigzag collector electrodes. The specific shape of the collector electrodes included in the first and second electrodes can be set according to the actual application scenario and is not specifically limited here.

[0094] As for the first direction and the second direction, they can be any two directions that are parallel to the backlight surface and different from each other. Preferably, the first direction is orthogonal to the second direction.

[0095] In terms of quantity and size, the number and specifications of the collecting electrodes and bus electrodes included in the first electrode and the second electrode respectively, the gaps between the collecting electrodes included in the first electrode and the adjacent collecting electrodes included in the second electrode along the first direction, and the size of the gaps between the bus electrodes included in the first electrode and the adjacent bus electrodes included in the second electrode along the second direction can be set according to the actual application scenario, as long as they can be applied to the back-contact battery provided in the embodiment of the present application. Secondly, in actual applications, the number of bus electrodes included in the first electrode and the second electrode can be the same or different. The number of collecting electrodes included in the first electrode and the second electrode can be the same or different. In addition, in the first electrode, the number of collecting electrode segments included in each collecting electrode can be determined according to the number of bus electrodes included in the second electrode. In the second electrode, the number of collecting electrode segments included in each collecting electrode can be determined according to the number of bus electrodes included in the first electrode.

[0096] As for the size of the spacing between the end of each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode (i.e., the first distance), and the size of the spacing between the end of each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode (i.e., the second distance) along the second direction, they can be determined according to actual needs, as long as the first distance is greater than the second distance and can be applied to the back contact battery provided in the embodiment of the present application.

[0097] When the above technical solution is adopted, the collector electrode included in the first electrode is in ohmic contact with the first region, and is used to collect carriers of the corresponding conductivity type in the first region and conduct them to the bus electrode included in the first electrode. The collector electrode included in the second electrode is in ohmic contact with the second region, and is used to collect carriers of the corresponding conductivity type in the second region and conduct them to the bus electrode included in the second electrode. Based on this, since the first and second regions alternately distributed on the backlight side of the battery substrate have opposite conductivity types, the conductivity types of the first electrode and the second electrode are also opposite. In the above case, as shown in Figure 2, in the first electrode 13 and the second electrode 14, the gap between the two adjacent collector electrode segments 17 included in the same collector electrode 15 is used to isolate the bus electrode 16 with the opposite polarity to itself, thereby suppressing leakage.

[0098] Furthermore, as shown in Figures 2 to 4 , along the second direction, the distance between the end of each collecting electrode segment 17 in the first electrode 13 and the adjacent bus electrode 16 included in the second electrode 14 is a first distance L1. Along the second direction, the distance between the end of each collecting electrode segment 17 in the second electrode 14 and the adjacent bus electrode 16 included in the first electrode 13 is a second distance L2. The first distance L1 is greater than the second distance L2. At this time, the end of each collecting electrode segment 17 in the first electrode 13 can be separated from the adjacent bus electrode 16 included in the second electrode 14 by a first distance L1 with a larger length, ensuring that the end of each collecting electrode segment 17 in the first electrode 13 along the second direction will not overlap the second region 12 with a conductivity type opposite to its own, and the adjacent bus electrode 16 included in the second electrode 14, thereby preventing leakage. At the same time, while ensuring that the end of each collecting electrode segment 17 in the second electrode 14 along the second direction will not overlap the first region 11 with a conductivity type opposite to its own, and the adjacent bus electrode 16 included in the first electrode 13, the distance between the end of each collecting electrode segment 17 in the second electrode 14 along the second direction and the first region 11 is greatly reduced, thereby improving the carrier collection ability of each collecting electrode segment 17 in the second electrode 14. In other words, the back-contact battery provided in the embodiment of the present application can separately adjust the distance between the end of each collecting electrode segment 17 in the positive electrode and the adjacent bus electrode 16 included in the negative electrode, and the distance between the end of each collecting electrode segment 17 in the negative electrode and the adjacent bus electrode 16 included in the positive electrode according to the actual application scenario. In this way, while preventing leakage and improving the electrical stability of the back-contact battery, the collecting electrode segment 17 has a relatively strong carrier collection ability, which is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0099] In actual applications, as shown in Figures 2 and 3, the first distance L1 is equal to the sum of the third distance L3 and the fifth distance L5. Specifically, along the second direction, the distance between the end of each collector electrode segment 17 in the first electrode 13 and the edge of the second region 12 is the third distance L3. Because each collector electrode 15 included in the first electrode 13 is in ohmic contact with the first region 11, and the conductivity type of the second region 12 is opposite to that of the first region 11, the size of the third distance L3 affects whether leakage occurs between the end of each collector electrode segment 17 in the first electrode 13 and the edge of the second region 12 along the second direction, and affects the carrier collection of each collector electrode segment 17 in the first electrode 13 from the corresponding portion of the first region 11. In addition, along the second direction, the minimum distance between the edge of the first region 11 and the edge of the bus electrode 16 in the second electrode 14 is the fifth distance L5. In the actual manufacturing process, the slurry state of the second electrode 14 will affect the width of the bus electrode 16 included in the formed second electrode 14, and the machine accuracy of the second electrode 14 will affect the position offset of the bus electrode 16 included in the formed second electrode 14. Therefore, the fifth distance L5 also affects whether the bus electrode 16 included in the second electrode 14 is overlapped.

[0100] As for the second distance, as shown in Figures 2 to 4, the second distance L2 is equal to the sum of the fourth distance L4 and the sixth distance L6. Specifically, along the second direction, the minimum distance between the edge of each busbar electrode 16 in the first electrode 13 and the edge of the second region 12 is the fourth distance L4. Because the size of the fourth distance L4 affects the range of the first region 11, and the first region 11 and the second region 12 are both located on the backlight side, the fourth distance L4 affects the range of the PN junction on the backlight side, thereby affecting carrier collection. Furthermore, during the actual manufacturing process, the slurry state used to manufacture the first electrode 13 affects the width of the busbar electrode 16 included in the formed first electrode 13, and the precision of the machine used to manufacture the first electrode 13 affects the positional offset of the busbar electrode 16 included in the formed first electrode 13. Therefore, the fourth distance L4 also affects whether the busbar electrodes 16 included in the first electrode 13 overlap. Furthermore, along the second direction, the distance between the edge of the first region 11 and the end of the collector electrode segment 17 in the second electrode 14 is the sixth distance L6. Because each collector electrode 15 included in the second electrode 14 is in ohmic contact with the second region 12, and the conductivity type of the first region 11 is opposite to the conductivity type of the second region 12, the size of the sixth distance L6 affects whether leakage occurs between the end of each collector electrode segment 17 in the second electrode 14 along the second direction and the edge of the first region 11, and affects the carrier collection of the corresponding part of the second region 12 by each collector electrode segment 17 in the second electrode 14.

[0101] In the case of the above content, the third distance and the fifth distance included in the first distance, and the fourth distance and the sixth distance included in the second distance can be determined based on the contact situation between the bus electrode in the first electrode and the first area, the contact situation between the bus electrode in the second electrode and the second area, the anti-leakage requirements between the first electrode and the second electrode and the second area and the first area respectively in actual application scenarios, and the collection requirements of the first electrode and the second electrode for the carriers generated in the first area and the second area respectively in actual application scenarios. No specific limitation is made here.

[0102] During actual application, each bus electrode included in the first electrode can be in direct contact with the first region. At this time, the contact area between the first electrode and the first region is large, which is conducive to reducing the contact resistance between the first electrode and the first region. Alternatively, each bus electrode included in the first electrode may not be in direct contact with the first region. In this case, the battery substrate may also include an insulating material layer located at least on the first region (the insulating material layer may be a passivation anti-reflection layer located on the backlight side, etc.), the collector electrode included in the first electrode passes through the insulating material layer and contacts the first region, and the bus electrode included in the first electrode is isolated from the first region by the insulating material layer. At this time, each bus electrode included in the first electrode is electrically coupled to the first region through the corresponding collector electrode segment included in the first electrode. In the above case, in order to prevent leakage, when considering the setting size of the second distance, it is not necessary to include the leakage factor between the edge of the bus electrode included in the first electrode and the edge of the second region. When considering the setting size of the first distance, it is still necessary to take into account the leakage factor between the end of the collecting electrode segment included in the first electrode along the second direction and the edge of the second region. Therefore, setting the first distance to be greater than the second distance can not only prevent overlapping leakage at the end of each collecting electrode segment in the first electrode along the second direction, but also improve the carrier collection ability of each collecting electrode segment in the second electrode.

[0103] As for the second electrode, each bus electrode included in the second electrode can be in direct contact with the second region. In this case, the contact area between the second electrode and the second region is larger, which is conducive to reducing the contact resistance between the second electrode and the second region. Alternatively, each bus electrode included in the second electrode may not be in direct contact with the second region. In this case, the battery substrate may also include an insulating material layer located at least on the second region, the collecting electrode included in the second electrode passes through the insulating material layer and contacts the second region, and the bus electrode included in the second electrode is isolated from the second region by the insulating material layer. In this case, each bus electrode included in the second electrode is electrically coupled to the second region through the corresponding collecting electrode segment included in the second electrode. In the above case, when other factors are the same, the contact area between the second electrode and the second region is smaller when the bus electrode included in the second electrode is not in direct contact with the second region, compared with when the bus electrode included in the second electrode is also in direct contact with the second region. In this case, when the back-contact battery also includes an insulating material layer with a passivation effect arranged on the backlight side of the battery substrate, if the contact area between the second electrode and the second region is small, the contact area between the insulating material layer with a passivation effect and the second region is larger, which can improve the passivation effect of the insulating material layer with a passivation effect on the backlight side of the battery substrate, which is beneficial to improving the working performance of the back-contact battery.

[0104] For example, as shown in Figures 2 to 4, the third distance L3 is greater than the fourth distance L4. In this case, the third distance L3 having a greater length can prevent the end of each collector electrode segment 17 in the first electrode 13 from overlapping the second region 12 of the opposite conductivity type along the second direction, thereby preventing leakage. Furthermore, there is no need to increase the spacing between the edge of each bus electrode 16 in the first electrode 13 and the edge of the second region 12 along the second direction due to processing width errors and offset errors in forming the bus electrode 16 included in the first electrode 13. This ensures that the first region 11 and the second region 12, which are located on the backlight side, both have appropriate ranges, reduce the carrier recombination rate on the backlight side, and help improve the photoelectric conversion efficiency of the back-contact cell.

[0105] Exemplarily, the third distance may be greater than or equal to 0.15 mm and less than or equal to 0.3 mm. For example, the third distance may be 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm or 0.3 mm, etc. In this case, the third distance is within the above range, which can prevent the poor anti-leakage effect between the end of each collecting electrode segment in the first electrode along the second direction and the edge of the second region due to the small third distance, thereby ensuring that the back contact battery has higher electrical stability. In addition, it can also prevent the end of each collecting electrode segment in the first electrode along the second direction from being difficult to collect carriers of the corresponding conductive type generated near the edge of the first region due to the large third distance, thereby ensuring that each collecting electrode segment in the first electrode has a higher carrier collection ability, thereby ensuring that the back contact battery has a higher photoelectric conversion efficiency.

[0106] Exemplarily, the fourth distance can be greater than or equal to 0.07mm and less than 0.15mm. For example, the fourth distance can be 0.07mm, 0.09mm, 0.11mm, 0.13mm or 0.14mm, etc. In this case, the fourth distance is within the above range, which can prevent the part of the bus electrode included in the actually formed first electrode from being located above the second area due to the smaller processing allowance reserved due to the smaller fourth distance, and ensure that the bus electrode included in the first electrode can be prevented from overlapping and leaking. At the same time, it can also prevent the manufacturing accuracy of the bus electrode in the first electrode from being strictly required to avoid leakage, thereby reducing the manufacturing difficulty of the bus electrode in the first electrode. In addition, it can also prevent the second area located on the side of the backlight surface together with the first area from being smaller due to the larger fourth distance, which is beneficial to reducing the carrier recombination rate on the side of the backlight surface and improving the photoelectric conversion efficiency of the back contact battery.

[0107] For example, as shown in Figures 2 to 4 , the ratio of the third distance L3 to the fourth distance L4 is greater than 1 and less than or equal to 2. For example, the ratio of the third distance L3 to the fourth distance L4 can be 1.3, 1.5, 1.8, or 2. The beneficial effects in this case are similar to those described above when the third distance L3 is greater than or equal to 0.15 mm and less than or equal to 0.3 mm, and the fourth distance L4 is greater than or equal to 0.07 mm and less than 0.15 mm, and are not further described here.

[0108] For example, as shown in Figures 2 to 4, the ratio of the fifth distance L5 to the sixth distance L6 is greater than or equal to 0.8 and less than or equal to 1.2. For example, the ratio of the fifth distance L5 to the sixth distance L6 can be 0.8, 0.9, 1, 1.1, or 1.2. In this case, the fifth distance L5 and the sixth distance L6 are respectively the distances between the edge of the bus electrode 16 and the end of the collector electrode segment 17 in the second electrode 14 along the second direction and the edge of the first region 11 of the opposite conductivity type. Based on this, in the actual manufacturing process, the fifth distance L5 and the sixth distance L6 need to take into account the processing errors of the bus electrode 16 and the collector electrode segment 17 in the second electrode 14, respectively, so as to reserve corresponding spacing to prevent the edge of the bus electrode 16 and the end of the collector electrode segment 17 in the second electrode 14 from overlapping the first region 11 of the opposite conductivity type. The processing errors of the bus electrode 16 and the collector electrode segment 17 included in the second electrode 14 manufactured by the processing machine are roughly the same. Therefore, when the ratio of the fifth distance L5 to the sixth distance L6 is greater than or equal to 0.8 and less than or equal to 1.2, the two are roughly equal. Under the premise of preventing the edge of the bus electrode 16 and the end of the collector electrode segment 17 in the second electrode 14 from leaking to the first area 11 respectively, it can prevent some carriers in the second area 12 from being unable to be extracted in time due to one of the fifth distance L5 and the sixth distance L6 being set larger, thereby ensuring that the back-contact battery has a higher photoelectric conversion efficiency.

[0109] It is understood that when the specifications of the battery substrate included in the back-contact battery vary, the requirements for leakage protection and carrier collection capabilities of the first and second electrodes may also vary. Furthermore, the precision of the first and second electrodes manufactured using different equipment or slurry in different states may also vary. Therefore, the values ​​of the fifth and sixth distances can be determined based on the specifications of the battery substrate in the actual application scenario and the actual manufacturing process.

[0110] For example, the absolute value of the difference between the fifth distance and the sixth distance may be greater than or equal to 0 and less than or equal to 300 μm.

[0111] For example, the fifth distance may be greater than 0 and less than or equal to 3 mm. The sixth distance may be greater than 0 and less than or equal to 3 mm.

[0112] In a fourth aspect, an embodiment of the present application further provides a method for manufacturing a back-contact battery, the method comprising:

[0113] First, a battery substrate is formed. The backlight surface of the battery substrate has a first area and a second area that are alternately distributed. Next, the regional pattern of the first area, the design structure associated parameters corresponding to the first electrode and the second electrode included in the back contact battery, the first performance adjustment associated parameters corresponding to the first electrode, and the second performance adjustment associated parameters corresponding to the second electrode are obtained. The first performance adjustment associated parameters are different from the second performance adjustment associated parameters. And as shown in Figure 2, the first electrode 13 and the second electrode 14 both include a plurality of collecting electrodes 15 and a plurality of bus electrodes 16. The bus electrodes 16 included in the first electrode 13 and the bus electrodes 16 included in the second electrode 14 both extend along the first direction and are alternately spaced along the second direction, and the first direction is different from the second direction. The collecting electrodes 15 included in the first electrode 13 and the collecting electrodes 15 included in the second electrode 14 both extend along the second direction and are alternately spaced along the first direction. Each collecting electrode 15 is connected to a bus electrode 16 of the same polarity as itself, and each collecting electrode 15 includes multiple collecting electrode segments 17 spaced apart along the second direction. The spacing between adjacent collecting electrode segments 17 in the same collecting electrode 15 is designed to isolate bus electrodes 16 of opposite polarity from its own. Next, based on the regional pattern, design structure-related parameters, and first performance adjustment-related parameters, the spacing between each collecting electrode segment 17 in the first electrode 13 and the adjacent bus electrode 16 in the second electrode 14 is adjusted to a first distance L1, and the design structure-related parameters are updated. Next, based on the regional pattern, design structure-related parameters, and second performance adjustment-related parameters, the spacing between each collecting electrode segment 17 in the second electrode 14 and the adjacent bus electrode 16 in the first electrode 13 is adjusted to a second distance L2, and the design structure-related parameters are updated. Then, according to the updated design structure-related parameters, the first and second electrodes 13 and 14 are formed on the backlight surface. As shown in Figure 2, the projection of the first electrode 13 on the backlight surface is located within the first region 11. The projection of the second electrode 14 on the backlight surface is located within the second region 12 .

[0114] The specific structure and material of the battery substrate, as well as the polarity and size of the first electrode and the second electrode, can be found in the previous text and will not be described in detail here.

[0115] In addition, the regional pattern of the first region refers to the pattern corresponding to the formation range of the first region on the backlight side of the battery substrate. The design structure-related parameters corresponding to the first electrode and the second electrode may include any parameters related to the dimensions of the structures of the first and second electrodes. For example, the design structure-related parameters may include the design length and design width of each bus electrode included in the first and second electrodes, the design spacing between different bus electrodes, the design length of the collector electrode segment, the design spacing between different collector electrodes, the design spacing between the end of the collector electrode segment included in the first electrode and the adjacent bus electrode included in the second electrode along the second direction, and the design spacing between the end of the collector electrode segment included in the second electrode and the adjacent bus electrode included in the first electrode along the second direction. Among them, the design spacing between the end of the collector electrode segment included in the first electrode and the adjacent bus electrode included in the second electrode along the second direction, and the design spacing between the end of the collector electrode segment included in the second electrode and the adjacent bus electrode included in the first electrode along the second direction, may be equal or unequal.

[0116] In actual applications, the length and width of the bus electrodes included in the first and second electrodes significantly affect the amount of electrode slurry used and the transfer resistance. Therefore, the dimensions of the bus electrodes included in the first and second electrodes are typically designed dimensions and are not optimized. The collector electrodes included in the first and second electrodes primarily affect battery leakage and carrier collection. In embodiments of the present application, the spacing between each collector electrode segment in the first electrode and the adjacent bus electrodes included in the second electrode, as well as the spacing between each collector electrode segment in the second electrode and the adjacent bus electrodes included in the first electrode, are adjusted based on first and second performance adjustment parameters. Based on this, the first performance adjustment parameters may include parameters related to battery leakage and carrier collection for the first electrode. The second performance adjustment parameters may include parameters related to battery leakage and carrier collection for the second electrode. Specifically, embodiments of the present application do not impose specific restrictions on the regional pattern of the first region, the design structure-related parameters corresponding to the first and second electrodes included in the back-contact battery, the first performance adjustment parameters corresponding to the first electrode, and the second performance adjustment parameters corresponding to the second electrode, or the order in which these parameters are acquired. Any parameters can be applied to the manufacturing methods provided in embodiments of the present application.

[0117] Under the above-mentioned technical scheme, the manufacturing method of the back-contact battery provided in the embodiment of the present application can separately adjust the spacing between each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode, and the spacing between each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode according to different first performance adjustment associated parameters and second performance adjustment associated parameters after obtaining the regional pattern of the first region, the design structure associated parameters corresponding to the first electrode and the second electrode included in the back-contact battery, thereby preventing leakage from occurring due to the end of each collecting electrode segment included in the first electrode and the second electrode being overlapped with the bus electrode with opposite polarity to itself, thereby improving the electrical stability of the back-contact battery and making the collecting electrode segment in the second electrode have a relatively strong carrier collection ability, which is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0118] In the actual manufacturing process, the specific process of manufacturing the battery substrate can be determined according to the specific structure of the battery substrate.

[0119] Exemplarily, forming a battery substrate may include the steps of: forming a fully layered doped semiconductor layer on the backlight surface of a semiconductor substrate; then, using a laser etching process, removing the portion of the doped semiconductor layer located on the first region to form the battery substrate. The battery substrate includes the semiconductor substrate and the remaining doped semiconductor layer.

[0120] Specifically, a doped semiconductor layer can be formed by processes such as chemical vapor deposition. The material of the doped semiconductor layer can be referred to above and will not be described in detail here. In addition, the conductivity type of the doped semiconductor layer can be the same as or different from the conductivity type of the semiconductor substrate. Among them, when the conductivity type of the doped semiconductor layer is opposite to the conductivity type of the semiconductor substrate, it is only necessary to form an entire layer of doped semiconductor layer covering the backlight surface of the semiconductor substrate and remove the portion of the doped semiconductor layer covering the first region. Then, a first region and a second region of opposite conductivity types can be formed on the backlight side, thereby solving the problem of the need to dope the backlight surface twice with opposite conductivity types, which leads to a complicated back contact battery manufacturing process.

[0121] After forming the entire doped semiconductor layer disposed on the backlight side, a laser etching process can be used to remove the portion of the doped semiconductor layer located on the first region to obtain the battery substrate. Of course, dry etching or wet etching can also be used under the masking effect of a corresponding mask layer to remove the portion of the doped semiconductor layer located on the first region.

[0122] It should be noted that if the battery base also includes a passivation layer located between the semiconductor substrate and the doped semiconductor layer, before forming the doped semiconductor layer as a whole layer on the backlight side of the semiconductor substrate, it is necessary to use a process such as chemical vapor deposition to form the passivation layer as a whole layer on the backlight side of the semiconductor substrate. Then, after removing the portion of the doped semiconductor layer located on the first region, it is also necessary to remove the portion of the passivation layer located on the first region to obtain the battery base.

[0123] Specifically, when a laser etching process is used to remove at least the portion of the doped semiconductor layer located on the first region, after forming a complete doped semiconductor layer on the backlight surface of the semiconductor substrate, design structure-related parameters corresponding to the first and second electrodes and laser etching-related parameters can be obtained. Subsequently, a laser spot pattern can be determined based on the design structure-related parameters and the laser etching-related parameters. Then, a laser etching process is used to etch the doped semiconductor layer according to the laser spot pattern to obtain a battery substrate.

[0124] Among them, the laser etching associated parameters may include any parameters associated with laser etching. Exemplarily, the laser etching associated parameters may include: laser spot size, overlapping distance between adjacent laser spots, the designed spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction, and the designed spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction. In this case, the range corresponding to the setting of the corresponding number of laser spots can be determined by combining the laser spot size and the overlapping distance between adjacent laser spots. In addition, the designed spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction, and the designed spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction define the boundary of the laser spot pattern to be determined. Based on this, when the laser etching associated parameters include the laser spot size, the overlapping distance of adjacent laser spots, the designed spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction, and the designed spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction, the laser spot pattern can be accurately determined according to the design structure associated parameters and the laser etching associated parameters, thereby improving the determination accuracy of the laser spot pattern.

[0125] Specifically, the designed spacing between the edge of the laser spot pattern and the end of each collecting electrode segment in the first electrode along the second direction affects the spacing between the end of each collecting electrode segment in the first electrode and the edge of the second area along the second direction, thereby affecting the battery leakage and the carrier collection ability of each collecting electrode segment in the first electrode for the corresponding part of the first area. Therefore, the size of the above-mentioned designed spacing can be determined according to the requirements for the leakage prevention and carrier collection ability of the first electrode in the actual application scenario.

[0126] Exemplarily, the design spacing between the edge of the laser spot pattern and the end of each collector electrode segment in the first electrode along the second direction is greater than 0 and less than 0.4 mm. In this case, the design spacing is within the above range, which can prevent the poor leakage prevention effect between the end of each collector electrode segment in the first electrode along the second direction and the edge of the second region due to the small design spacing, thereby ensuring that the back contact battery has high electrical stability. In addition, it can also prevent the difficulty of the end of each collector electrode segment in the first electrode along the second direction to collect carriers of the corresponding conductive type generated near the edge of the first region due to the large design spacing, thereby ensuring that each collector electrode segment in the first electrode has a high carrier collection ability, thereby ensuring that the back contact battery has a high photoelectric conversion efficiency.

[0127] As for the design spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction, it affects the spacing between the bus electrode included in the first electrode and the edge of the second area along the second direction, and thus affects the battery leakage. Therefore, the size of the above-mentioned design spacing can be determined based on the anti-leakage requirements for the first electrode in the actual application scenario and the actual situation of the laser spot.

[0128] Exemplarily, the designed spacing along the second direction between the edge of the laser spot pattern and the bus electrode included in the first electrode is equal to half the difference between the laser spot size and the overlapping distance between adjacent laser spots. For example, when the laser spot size is 0.2 mm to 0.3 mm and the overlapping distance between adjacent laser spots is approximately 0.05 mm, the designed spacing along the second direction between the edge of the laser spot pattern and the bus electrode included in the first electrode can be 0.075 mm to 0.125 mm. In this case, since the number of laser spots included in the laser spot pattern can only be an integer greater than or equal to 1, leakage is likely to occur when the edge of the laser spot pattern coincides with the bus electrode included in the first electrode. Therefore, at this time, the width of a laser spot is added to reserve corresponding processing allowances for both sides of the bus electrode included in the first electrode along the second direction. At this time, the design spacing between the edge of the laser spot pattern and the bus electrode included in the first electrode along the second direction is equal to half of the difference between the laser spot size and the overlapping distance of adjacent laser spots. This can prevent leakage while avoiding energy waste or a smaller range of the second area due to setting more spots, thereby ensuring that the manufactured back-contact battery has higher working performance.

[0129] Alternatively, using a laser etching process to remove the portion of the doped semiconductor layer located on the first region may also include the steps of: obtaining laser etching associated parameters, first processing error associated parameters corresponding to the bus electrode included in the second electrode, and second processing error associated parameters corresponding to the bus electrode included in the first electrode. Then, based on the design structure associated parameters and the laser etching associated parameters, a laser spot pattern is determined. Next, based on the design structure associated parameters and the first processing error associated parameters, the spacing between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction is adjusted; and based on the design structure associated parameters and the second processing error associated parameters, the spacing between the edge of the laser spot pattern and the bus electrode in the first electrode along the second direction is adjusted. Then, a laser etching process is used to etch the doped semiconductor layer according to the adjusted laser spot pattern. In this case, based on the design structure associated parameters and the laser etching associated parameters, a theoretical laser spot pattern can be determined (the laser spot pattern is consistent with the pattern of the first region subsequently formed based on the laser etching process). However, during the actual processing of the first electrode and the second electrode, processing errors often occur due to factors such as machine accuracy or electrode slurry state. The existence of processing errors may cause the actual width and actual formation position of the bus electrode included in the actual processing of the second electrode to change, thereby causing the distance between the bus electrode included in the second electrode and the edge of the laser spot pattern in the theoretical situation along the second direction to no longer meet the working requirements; similarly, the existence of processing errors may cause the actual width and actual formation position of the bus electrode included in the actual processing of the first electrode to change, thereby causing the distance between the bus electrode included in the first electrode and the edge of the laser spot pattern in the theoretical situation along the second direction to no longer meet the working requirements. Therefore, after determining the laser spot pattern in the theoretical situation, the distance between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction, and the distance between the edge of the laser spot pattern and the bus electrode in the first electrode along the second direction are adjusted according to the first processing error associated parameters and the second processing error associated parameters. Specifically, when it is judged based on the design structure associated parameters and the laser spot pattern that the distance between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction is less than the adjustment distance range corresponding to the first processing error associated parameters, one or more laser spots are reduced for the part of the laser spot pattern close to the bus electrode included in the second electrode; if it is judged based on the design structure associated parameters and the laser spot pattern that the distance between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction is greater than the adjustment distance range corresponding to the first processing error associated parameters, one or more laser spots are added to the part of the laser spot pattern close to the bus electrode included in the second electrode until the distance between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction is equal to the adjustment distance range corresponding to the first processing error associated parameters.Similarly, based on the design structure-related parameters and the second processing error-related parameters, the method of adjusting the distance between the edge of the laser spot pattern and the bus electrode in the first electrode along the second direction can refer to the previous text to prevent the bus electrode from overlapping and short-circuiting, thereby improving the yield of the manufactured back-contact battery.

[0130] Specifically, the laser etching-related parameters can be referred to above. The first processing error-related parameters can include parameters indicating processing errors in the busbar electrodes included in any pair of second electrodes during the actual manufacturing process. The second processing error-related parameters can include parameters indicating processing errors in the busbar electrodes included in any pair of first electrodes during the actual manufacturing process.

[0131] Exemplarily, the first processing error associated parameters may include a processing width error and an offset error corresponding to the bus electrode included in the second electrode. In this case, the embodiment of the present application does not specifically limit the size of the processing width error and the offset error corresponding to the bus electrode included in the second electrode, and can be determined according to the actual application scenario. In this case, the changes in the morphology and position of the bus electrode included in the second electrode caused by the machine accuracy and the slurry state during the actual manufacture of the bus electrode included in the second electrode can be inferred based on the first processing error associated parameters, so that the distance between the edge of the laser spot pattern and the bus electrode included in the second electrode along the second direction can be effectively adjusted according to the first processing error associated parameters to avoid leakage.

[0132] Exemplarily, the second processing error-associated parameter includes a processing width error and an offset error corresponding to the busbar electrode included in the first electrode. The embodiment of the present application does not specifically limit the magnitude of the processing width error and the offset error corresponding to the busbar electrode included in the first electrode, and can be determined based on the actual application scenario. The beneficial effects in this case can be referenced in the analysis of the beneficial effects of the first processing error-associated parameter including the processing width error and the offset error corresponding to the busbar electrode included in the second electrode, as described above, and will not be repeated here.

[0133] As for the spacing between the edge of the adjusted laser spot pattern and the bus electrode included in the second electrode along the second direction, and the spacing between the edge of the adjusted laser spot pattern and the bus electrode included in the first electrode along the second direction, they can be determined based on the laser spot size, the overlapping distance between adjacent laser spots, and the processing width error and offset error corresponding to the bus electrode included in the first electrode and the second electrode, and no specific limitation is made here.

[0134] For example, as shown in Figure 2, the distance between the edge of the adjusted laser spot pattern and the busbar electrode 16 included in the second electrode 14 along the second direction is greater than or equal to M1 and less than N1. M1 is the sum of the processing width error and offset error corresponding to the busbar electrode 16 included in the second electrode 14, and N1 is the sum of the difference between the laser spot size and the overlapping distance between adjacent laser spots and M1. In this case, while preventing leakage, it is possible to avoid energy waste caused by setting too many spots or a smaller area of ​​the first region 11, thereby ensuring that the manufactured back-contact cell has high operating performance.

[0135] For example, as shown in Figure 2, the distance between the edge of the adjusted laser spot pattern and the busbar electrode 16 included in the first electrode 13 along the second direction is greater than or equal to M2 and less than N2. M2 is half the difference between the laser spot size and the overlap distance between adjacent laser spots, and N2 is the sum of the machining width error and offset error corresponding to the busbar electrode 16 included in the first electrode 13, as well as M2. In this case, while preventing leakage, it is possible to avoid energy waste caused by setting too many spots or a smaller first region 11, thereby ensuring high performance of the manufactured back-contact cell.

[0136] In the actual manufacturing process, after obtaining the battery substrate, the actual range of the first area and the second area located on the backlight side of the battery substrate is determined. However, the obtained design structure associated parameters of the first electrode and the second electrode are used to characterize the distance between each collector electrode segment in the first electrode and the adjacent bus electrodes included in the second electrode, and the distance between each collector electrode segment in the second electrode and the adjacent bus electrodes included in the first electrode. The parameter size may not meet the actual working requirements. Based on this, before forming the first electrode, it is also necessary to adjust the distance between each collector electrode segment in the first electrode and the adjacent bus electrodes included in the second electrode to the first distance based on the regional pattern, the design structure associated parameters, and the first performance adjustment associated parameters, and update the design structure associated parameters. In the above case, the first performance adjustment associated parameters may include any parameter that affects the operation of the first electrode in the actual application scenario.

[0137] Exemplarily, the first performance adjustment associated parameters include a first minimum anti-leakage distance and a first maximum collection distance. The first distance is greater than or equal to the first minimum anti-leakage distance and less than or equal to the first maximum collection distance. In this case, the distance between each collector electrode segment in the first electrode and the adjacent bus electrode included in the second electrode is set within the minimum distance to prevent leakage and the maximum distance that can effectively collect the corresponding conductive type carriers. This can avoid leakage at the end of each collector electrode segment in the first electrode while ensuring that each collector electrode segment in the first electrode can effectively collect the corresponding conductive type carriers generated in each part of the first region, reduce the carrier recombination rate, and help improve the photoelectric conversion efficiency of the back contact battery.

[0138] As for the second electrode, before forming the second electrode, it is necessary to adjust the spacing between each collector electrode segment in the second electrode and the adjacent bus electrode included in the first electrode to a second distance based on the regional pattern, the design structure-related parameters, and the second performance adjustment-related parameters, and update the design structure-related parameters. In this case, the second performance adjustment-related parameters may include any parameters that affect the operation of the second electrode in actual application scenarios.

[0139] Exemplarily, the second performance adjustment associated parameters include a second minimum anti-leakage distance and a second maximum collection distance. The second distance is greater than or equal to the second minimum anti-leakage distance and less than or equal to the second maximum collection distance. The beneficial effects in this case can be referred to the beneficial effects analysis described above in which the first performance adjustment associated parameters include the first minimum anti-leakage distance and the first maximum collection distance, and the first distance is greater than or equal to the first minimum anti-leakage distance and less than or equal to the first maximum collection distance, and will not be repeated here.

[0140] Among them, the embodiment of the present application does not specifically limit the size of the first performance adjustment associated parameters including the first minimum anti-leakage distance and the first maximum collection distance, and the second performance adjustment associated parameters including the second minimum anti-leakage distance and the second maximum collection distance, which can be determined according to actual needs.

[0141] In the above situation, the spacing between each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode, as well as the spacing between each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode, are adjusted respectively, and the design structure associated parameters are updated. Then, the first electrode and the second electrode are formed on the backlight surface according to the updated design structure associated parameters. At this time, along the second direction, the spacing between the end of each collecting electrode segment in the first electrode and the adjacent bus electrode included in the second electrode, as well as the spacing between the end of each collecting electrode segment in the second electrode and the adjacent bus electrode included in the first electrode, can be equal or unequal, as long as the above corresponding conditions are met.

[0142] Second embodiment

[0143] Specifically, Figure 5 shows a schematic diagram of the distribution of the first and second electrodes included in a back-contact battery in the related art. As shown in Figure 5, the first and second electrodes 13, 14 of opposite conductivity types included in the back-contact battery are both formed on the backlight side of the battery substrate, which is a semiconductor substrate. Based on this, in the actual manufacturing process, a doped semiconductor layer is usually formed in its entirety on the backlight side of the semiconductor substrate, and a portion of the doped semiconductor layer is removed by laser etching or other methods to form a battery substrate with first regions 11 and second regions 12 (of opposite conductivity types) alternating on the backlight side. Then, a surface passivation layer with conductive windows is formed on the backlight side of the battery substrate. Next, as shown in Figure 5, the first and second electrodes 13, 14 are formed on the backlight side using a process such as screen printing. The first and second electrodes 13, 14 each include multiple collector electrodes 15 and multiple bus electrodes 16. The bus electrodes 16 included in the first electrode 13 and the bus electrodes 16 included in the second electrode 14 extend along a first direction and are alternately spaced along a second direction (the second direction is different from the first direction). The first electrode 13 includes a collector electrode 15 fabricated from a non-burn-through electrode paste and in ohmic contact with the first region 11 through a conductive window (not shown). The second electrode 14 includes a collector electrode 15 fabricated from a burn-through electrode paste and in ohmic contact with the second region 12 by burning through a portion of the surface passivation layer (not shown). The collector electrodes 15 of the first electrode 13 and the collector electrodes 15 of the second electrode 14 extend along the second direction and are alternately spaced along the first direction. Each collector electrode 15 is connected to a bus electrode 16 of the same polarity as itself, and each collector electrode 15 includes multiple collector electrode segments 17 spaced apart along the second direction. The spacing between adjacent collector electrode segments 17 in the same collector electrode 15 is used to isolate the bus electrode 16 of opposite polarity from itself to prevent leakage.

[0144] Among them, along the second direction, the distance between the end of each collector electrode segment in the first electrode and the edge of the second region is the third distance. Along the second direction, the distance between the end of each collector electrode segment in the second electrode and the edge of the first region is the sixth distance. As shown in Figure 5, the third distance L3 in the existing back-contact battery is equal to the sixth distance L6. It can be understood that the portion of the first region 11 that is in ohmic contact with each collector electrode segment 17 in the first electrode 13 is the contact area. Along the second direction, the end of each collector electrode segment 17 in the first electrode 13 is flush with the end of the contact area, or the end of each collector electrode segment 17 in the first electrode 13 is closer to the second region 12 than the end of the contact area. Based on this, when the third distance L3 is equal to the sixth distance L6, the minimum distance (seventh distance) between the end of each contact area and the edge of the second region 12 is greater than or equal to the sixth distance L6. In this case, since the collecting electrode 15 in the first electrode 13 is a non-burn-through electrode, the conductive window limits the contact range between the non-burn-through electrode and the first region 11, so that the collecting electrode 15 in the first electrode 13 will not contact the portion of the backlight side of the battery substrate that is not exposed in the conductive window, and the sixth distance L6 is a safe distance between the burn-through electrode and the oppositely doped region to prevent leakage. Therefore, when the seventh distance is greater than or equal to the sixth distance L6, the gap between the end of the contact area along the second direction and the edge of the second region 12 is large, resulting in poor carrier collection ability of each collecting electrode segment 17 included in the first electrode 13, and then resulting in a large carrier recombination rate, which is not conducive to improving the photoelectric conversion efficiency of the back-contact battery.

[0145] To address the above technical issues, in a second aspect, embodiments of the present application provide a back-contact battery. The back-contact battery comprises a battery substrate, a surface passivation layer, a first electrode, and a second electrode. As shown in FIG6 , the backlight side of the battery substrate has alternating first and second regions 11 and 12. The first and second regions 11 and 12 have opposite conductivity types. The surface passivation layer covers the backlight side. A conductive window 18 is provided within the surface passivation layer, with the bottom of the conductive window 18 partially exposing the first region 11. First and second electrodes 13 and 14 are formed on the backlight side. At least a portion of the projection of the first electrode 13 on the backlight side is located within the first region 11. The projection of the second electrode 14 on the backlight side is located within the second region 12. The first and second electrodes 13 and 14 each include a plurality of collector electrodes 15 and a plurality of bus electrodes 16. The bus electrodes 16 included in the first electrode 13 and the bus electrodes 16 included in the second electrode 14 extend along a first direction and are alternately spaced along a second direction, where the first direction is different from the second direction. The first electrode 13 includes a collector electrode 15 that is a non-burn-through electrode and makes ohmic contact with the first region 11 through a conductive window 18. The second electrode 14 includes a collector electrode 15 that is a burn-through electrode and burns through a portion of the surface passivation layer to make ohmic contact with the second region 12. The collector electrodes 15 of the first electrode 13 and the collector electrodes 15 of the second electrode 14 both extend along the second direction and are alternately spaced along the first direction. Each collector electrode 15 is connected to a bus electrode 16 of the same polarity as itself. Each collector electrode 15 includes multiple collector electrode segments 17 spaced along the second direction. The spacing between adjacent collector electrode segments 17 in the same collector electrode 15 is used to isolate the bus electrode 16 of opposite polarity. The portion of the first region 11 that makes ohmic contact with each collector electrode segment 17 in the first electrode 13 constitutes the contact region. Along the second direction, the minimum spacing between the end of each contact region and the edge of the second region 12 is a seventh distance L7. Along the second direction, the distance between the end of each collector electrode segment 17 in the second electrode 14 and the edge of the first region 11 is a sixth distance L6. The seventh distance L7 is smaller than the sixth distance L6.

[0146] It should be noted that Figure 6 is only for the convenience of showing the relative positional relationship between the first region and the second region and the first electrode and the second electrode, as well as the specific range of the conductive window. The corresponding structure is shown in a perspective manner. In actual applications, the first region, the second region and the conductive window cannot be directly observed from this perspective.

[0147] Specifically, the embodiments of the present application do not impose any specific restrictions on the structure and material of the battery substrate, and the conductivity types of the first region and the second region, as long as they can be applied to the back-contact battery provided in the embodiments of the present application.

[0148] Similar to the description above regarding the first embodiment, the battery substrate may illustratively include: a semiconductor substrate; and a doped semiconductor layer formed on a portion of the backlight surface of the semiconductor substrate. In this case, the backlight surface of the semiconductor substrate and the backlight surface of the battery substrate are on the same side. The area of ​​the backlight surface of the semiconductor substrate exposed outside the doped semiconductor layer is the first region, and the area of ​​the doped semiconductor layer facing away from the semiconductor substrate is the second region. Furthermore, the doped semiconductor layer and the semiconductor substrate may have the same conductivity type. In this case, the battery substrate also includes a second doped semiconductor layer of opposite conductivity type to that of the semiconductor substrate and formed on a portion of the semiconductor substrate corresponding to the first region. Alternatively, the doped semiconductor layer may have an opposite conductivity type to that of the semiconductor substrate. It is worth noting that when the doped semiconductor layer and the semiconductor substrate have opposite conductivity types, during the actual manufacturing process of the battery substrate, it is only necessary to form the entire doped semiconductor layer covering the backlight surface of the semiconductor substrate and remove a portion of the doped semiconductor layer to form the first and second regions of opposite conductivity types on the backlight side. This solves the problem of requiring the backlight surface to be doped twice with opposite conductivity types, which complicates the back-contact battery manufacturing process.

[0149] In addition, the conductivity types of the semiconductor substrate, the doped semiconductor layer, the first region, and the second region may be similar to those described above with respect to the first embodiment, and are not described in detail here.

[0150] It is worth noting that aluminum material is a commonly used material for manufacturing positive electrodes in back-contact batteries, so as to form an alloy layer by aluminum and corresponding semiconductor materials to reduce contact resistance. In addition, most electrode pastes containing aluminum are non-burn-through electrode pastes. Silver material is a commonly used material for manufacturing negative electrodes in back-contact batteries, and some electrode pastes containing silver are burn-through electrode pastes. Based on this, when the conductivity type of the first region is P-type and the conductivity type of the second region is N-type, at least the collector electrode included in the first electrode can be manufactured using aluminum material, and at least the collector electrode included in the second electrode can be manufactured using silver material. While reducing the difficulty of manufacturing the first electrode and the second electrode, the scope of application of the back-contact battery provided in the embodiment of the present application can also be expanded.

[0151] In terms of materials, the materials of the semiconductor substrate and the doped semiconductor layer can be similar to those described above with respect to the first embodiment, and will not be repeated here. In terms of the internal arrangement of the materials, the doped semiconductor layer can be similar to those described above with respect to the first embodiment, and will not be repeated here.

[0152] In some cases, the battery substrate may further include a passivation layer similar to that described above with respect to the first embodiment, which will not be described in detail here.

[0153] Among them, when the semiconductor substrate included in the battery base is a P-type semiconductor substrate, the doped semiconductor layer is an N-type doped polysilicon layer, and a tunneling passivation layer is formed between the P-type semiconductor substrate and the N-type doped polysilicon layer, the back contact battery provided by the embodiment of the present application is a HPBC (composite passivated back contact) battery. The tunneling passivation layer and the N-type doped polysilicon layer constitute an N-type tunneling passivation contact structure. The N-type tunneling passivation contact structure can be formed on a partial area of ​​the backlight surface of the P-type semiconductor substrate. At this time, the area of ​​the backlight surface of the P-type semiconductor substrate exposed outside the N-type tunneling passivation contact structure can be considered as the first area, and the area on the side of the N-type tunneling passivation contact structure away from the P-type semiconductor substrate is the second area.

[0154] The material and thickness of the surface passivation layer can be determined based on actual needs, as long as it can be applied to the back-contact battery provided in the embodiments of the present application. For example, the material of the surface passivation layer can include at least one of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, and silicon carbide.

[0155] Regarding the first and second electrodes, the materials of the first and second electrodes may include conductive materials such as silver, aluminum, copper, titanium, or nickel, as long as the collector electrode included in the first electrode is a non-burn-through electrode and the collector electrode included in the second electrode is a burn-through electrode. The materials of the first and second electrodes may be the same or different.

[0156] It is worth noting that aluminum and silver are commonly used electrode materials for back-contact batteries. When the material of the collector electrode included in the first electrode includes aluminum, and the material of the collector electrode included in the second electrode includes silver, the manufacturing difficulty of the first and second electrodes can be reduced while also expanding the scope of application of the back-contact batteries provided by the embodiments of the present application.

[0157] Regarding the polarity of the first region, the second region, and the collecting electrode and the bus electrode respectively included in the first electrode and the second electrode, regarding the morphology of the collecting electrode and the bus electrode respectively included in the first electrode and the second electrode, as well as regarding the first direction and the second direction, please refer to the description of the first embodiment above and will not be repeated here.

[0158] From the perspective of electrical coupling, each region of each collector electrode segment in the first electrode along the second direction may be in direct contact with the first region. Alternatively, as shown in Figures 6 and 7 , a portion of each collector electrode segment 17 in the first electrode 13 along the second direction may be in direct contact with the first region 11.

[0159] It is worth noting that, under the same conditions as other factors, when each region of each collecting electrode segment in the first electrode along the second direction is in direct contact with the first region, the contact area between each collecting electrode segment in the first electrode and the first region is larger, compared with the direct contact between a portion of each collecting electrode segment in the first electrode along the second direction and the first region, which is conducive to reducing the contact resistance between each collecting electrode segment in the first electrode and the first region. Compared with the direct contact between each region of each collecting electrode segment in the first electrode along the second direction and the first region, when each region of each collecting electrode segment in the first electrode along the second direction is in direct contact with the first region, the contact area between each collecting electrode segment in the first electrode and the first region is smaller, so that the area in which the surface passivation layer contacts the first region is larger, which can improve the passivation effect of the surface passivation layer on the first region. In the above case, the contact range of each collecting electrode segment in the first electrode and the first region can be determined based on the requirements of the actual application scenario for the passivation effect of the surface passivation layer and the contact resistance of the first electrode.

[0160] It should be noted that when a portion of each collector electrode segment in the first electrode along the second direction is in direct contact with the first region, the end of each collector electrode segment in the first electrode can be flush with the end of the corresponding contact region along the second direction. In this case, along the second direction, the actual manufacturing length of each collector electrode segment in the first electrode is roughly the same as the effective carrier collection length (i.e., the distance between the two ends of the corresponding contact region along the second direction), which can reduce the amount of consumables used in each collector electrode segment in the first electrode, thereby reducing the manufacturing cost of the back-contact battery.

[0161] Alternatively, in the case where a portion of the area of ​​each collector electrode segment in the first electrode along the second direction is in direct contact with the first area, it may also be that along the second direction, the end of each collector electrode segment in the first electrode is located between the end of the corresponding contact area and the edge of the second area or above the second area. In this case, along the second direction, the actual manufacturing length of each collector electrode segment in the first electrode can be greater than the length for effectively collecting carriers. At this time, even if the end of each collector electrode segment in the first electrode along the second direction crosses the boundary between the first area and the second area and is located above the second area of ​​opposite conductivity type to itself, the two can be separated by a surface passivation layer, and there is no need to strictly require high manufacturing precision for each collector electrode segment included in the first electrode in order to manufacture an end that is flush with the end of the corresponding contact area, thereby reducing the manufacturing difficulty of the back contact battery. Specifically, in this case, the specific length of the end of each collector electrode segment in the first electrode along the second direction extending relative to the end of the corresponding contact area can be determined according to the actual application scenario and is not specifically limited here.

[0162] When each region of each collector electrode segment in the first electrode along the second direction is in direct contact with the first region, an end of each collector electrode segment in the first electrode is flush with an end of the corresponding contact region along the second direction.

[0163] It can be understood that when, along the second direction, the end of each collecting electrode segment in the first electrode is flush with the end of the corresponding contact region, or the end of each collecting electrode segment in the first electrode is located between the end of the corresponding contact region and the edge of the second region, the projections of all parts of the first electrode are located within the first region. Furthermore, when, along the second direction, the end of each collecting electrode segment in the first electrode is located above the second region, the projection of the end of each collecting electrode segment in the first electrode along the second direction is located within the second region, and the projections of the remaining parts of the first electrode are located within the first region.

[0164] As for the collector electrode included in the second electrode, since the collector electrode included in the second electrode is a burn-through electrode, each region of the collector electrode included in the second electrode along the second direction is in direct contact with the first region.

[0165] As for the bus electrodes included in the first electrode and the bus electrodes included in the second electrode, each bus electrode included in the first electrode can be in direct contact with the first region. At this time, the contact area between the first electrode and the first region is large, which is conducive to reducing the contact resistance between the first electrode and the first region. Alternatively, each bus electrode included in the first electrode may not be in direct contact with the first region. In this case, the bus electrodes included in the first electrode are isolated from the first region by the surface passivation layer, and each bus electrode included in the first electrode is electrically coupled to the first region through the corresponding collector electrode segment included in the first electrode. At this time, the contact area between the surface passivation layer and the first region is large, which is conducive to improving the passivation effect of the surface passivation layer on the first region.

[0166] In addition, each bus electrode included in the second electrode can be in direct contact with the second region. In this case, the contact area between the second electrode and the second region is larger, which is conducive to reducing the contact resistance between the second electrode and the second region. Alternatively, each bus electrode included in the second electrode may not be in direct contact with the second region. In this case, the bus electrodes included in the second electrode are isolated from the second region by the surface passivation layer, and each bus electrode included in the second electrode is electrically coupled to the second region through the corresponding collector electrode segment included in the second electrode. In the above case, when other factors are the same, compared with the case where the bus electrodes included in the second electrode are also in direct contact with the second region, when the bus electrodes included in the second electrode are not in direct contact with the second region, the contact area between the second electrode and the second region is smaller, while the contact area between the surface passivation layer and the second region is larger, which can improve the passivation effect of the surface passivation layer on the backlight side of the battery substrate, which is conducive to improving the working performance of the back-contact battery.

[0167] Regarding the number and specifications of the collecting electrodes and bus electrodes respectively included in the first electrode and the second electrode, as well as the size of the gaps between the collecting electrodes included in the first electrode and the adjacent collecting electrodes included in the second electrode along the first direction, and the size of the gaps between the bus electrodes included in the first electrode and the adjacent bus electrodes included in the second electrode along the second direction, please refer to the description of the first embodiment above and will not be repeated here.

[0168] Along the second direction, the size of the minimum distance between the end of each contact area and the edge of the second area (the seventh distance), and the size of the distance between the end of each collecting electrode segment in the second electrode and the edge of the first area (i.e., the sixth distance) can be determined according to actual needs, as long as the seventh distance is smaller than the sixth distance and can be applied to the back-contact battery provided in the embodiments of the present application.

[0169] When using the above technical solution, the collector electrode included in the first electrode is in ohmic contact with the first region through a conductive window provided in the surface passivation layer. It is used to collect carriers of the corresponding conductivity type in the first region and conduct them to the bus electrode included in the first electrode. The collector electrode included in the second electrode burns through a portion of the surface passivation layer and is in ohmic contact with the second region. It is used to collect carriers of the corresponding conductivity type in the second region and conduct them to the bus electrode included in the second electrode. Based on this, because the first and second regions alternately distributed on the backlight side of the battery substrate have opposite conductivity types, the conductivity types of the first and second electrodes are also opposite. At the same time, the portion of the first region that is in ohmic contact with each collector electrode segment in the first electrode is the contact area. In the above case, as shown in Figures 6 to 8, along the second direction, the minimum distance between the end of each contact area and the edge of the second area 12 (i.e., the seventh distance L7) is used to isolate the first electrode 13 of opposite conductivity type from the second area 12, and the distance between the end of each collecting electrode segment 17 in the second electrode 14 and the edge of the first area 11 (i.e., the sixth distance L6) is used to isolate the second electrode 14 of opposite conductivity type from the first area 11 to prevent leakage and ensure that the back-contact battery has higher electrical stability.

[0170] Secondly, as shown in Figures 6 and 7, because each collector electrode 15 included in the first electrode 13 is a non-burn-through electrode and the surface passivation layer is a non-conductive insulating material layer, the conductive window 18 provided in the surface passivation layer determines the contact range between each collector electrode 15 in the first electrode 13 and the first region 11. In other words, in the actual process of manufacturing the back-contact battery provided by the embodiment of the present application, after forming the surface passivation layer provided with the conductive window 18, when each collector electrode 15 included in the first electrode 13 is manufactured using the non-burn-through electrode paste, the non-burn-through electrode paste can only contact a portion of the first region 11 through the conductive window 18, and cannot penetrate the portion of the surface passivation layer where the conductive window 18 is not provided. In contrast, each collector electrode 15 included in the second electrode 14 is a burn-through electrode, and burns through a portion of the surface passivation layer and is in ohmic contact with the second region 12. In other words, during the actual manufacturing process of the back-contact battery provided by the embodiments of the present application, the burn-through electrode used to manufacture each collector electrode included in the second electrode 14 can penetrate the surface passivation layer, thereby achieving electrical coupling with the region of the semiconductor substrate located below the burned-through portion of the surface passivation layer. In this case, it is necessary to set the distance between the end of each collector electrode segment 17 in the second electrode 14 and the edge of the first region 11 along the second direction to a relatively large sixth distance L6 to prevent the end of each collector electrode segment 17 in the second electrode 14 from overlapping the first region 11 along the second direction, thereby generating leakage. However, since the surface passivation layer is a non-conductive film layer, the minimum spacing between the end of the contact area in which each collecting electrode segment 17 in the first electrode 13 is in ohmic contact with the first region 11 and the edge of the second region 12 can be set to a relatively small seventh distance L7. This can reduce the clearance distance between the end of the contact area along the second direction and the edge of the second region 12, thereby improving the carrier collection ability of each collecting electrode segment 17 included in the first electrode 13. This can solve the problem that in the prior art, the seventh distance L7 is set equal to the sixth distance L6, resulting in difficulty for each collecting electrode segment 17 in the first electrode 13 to promptly extract carriers of the corresponding conductive type at the above-mentioned clearance distance, resulting in a high carrier recombination rate. This is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0171] In actual applications, as shown in Figures 6 to 8 , along the second direction, the minimum spacing between the edge of the bus electrode 16 in the second electrode 14 and the edge of the first region 11 is the fifth distance L5. Along the second direction, the spacing between the end of each collecting electrode segment 17 in the first electrode 13 and the adjacent bus electrode 16 included in the second electrode 14 is the first distance L1. Along the second direction, the spacing between the end of each collecting electrode segment 17 in the second electrode 14 and the adjacent bus electrode 16 included in the first electrode 13 is the second distance L2. Along the second direction, the minimum spacing between the edge of the bus electrode 16 in the first electrode 13 and the edge of the first region 11 is the eighth distance L8. It will be appreciated that the first distance L1 is equal to the sum of the seventh distance L7 and the fifth distance L5, and the second distance L2 is equal to the sum of the sixth distance L6 and the eighth distance L8.

[0172] As shown in Figures 6 and 8 , since each collector electrode 15 included in the second electrode 14 is in ohmic contact with the second region 12, and the conductivity type of the first region 11 is opposite to that of the second region 12, the size of the sixth distance L6 affects whether leakage occurs between the end of each collector electrode segment 17 in the second electrode 14 along the second direction and the edge of the first region 11, and also affects the carrier collection of each collector electrode segment 17 in the second electrode 14 from the corresponding portion of the second region 12. Based on this, the size of the sixth distance L6 can be determined based on the requirements for leakage prevention and carrier collection capabilities of each collector electrode 15 included in the second electrode 14 as a burn-through electrode in actual application scenarios.

[0173] Exemplarily, the sixth distance can be greater than 0 and less than 0.4 mm. For example, the sixth distance can be 0.1 mm, 0.2 mm, 0.3 mm or 0.4 mm, etc. In this case, the sixth distance is within the above range, which can prevent the poor leakage prevention effect between the end of each collecting electrode segment in the second electrode along the second direction and the edge of the first region due to the smaller sixth distance, thereby ensuring that the back contact battery has higher electrical stability. In addition, it can also prevent the end of each collecting electrode segment in the second electrode along the second direction from being difficult to collect carriers of the corresponding conductive type generated near the edge of the second region due to the larger sixth distance, thereby ensuring that each collecting electrode segment in the second electrode also has a higher carrier collection ability, thereby ensuring that the back contact battery has a higher photoelectric conversion efficiency.

[0174] As for the seventh distance, it can be any value greater than or equal to 0 and less than the sixth distance. For example, when the sixth distance is equal to 0.3 mm, the seventh distance can be greater than or equal to 0 and less than 0.3 mm.

[0175] Preferably, the seventh distance is 0. In this case, along the second direction, the end of the corresponding contact area corresponding to each collector electrode segment in the first electrode is aligned with the edge of the second region. In other words, the clearance distance between the end of the contact area along the second direction and the edge of the second region is 0. At this time, the effective carrier collection length corresponding to each collector electrode segment in the first electrode can be maximized, ensuring that the corresponding conductive type carriers generated by the portion of the first region corresponding to each collector electrode segment in the first electrode can be collected and exported in a timely manner, further reducing the carrier recombination rate and improving the photoelectric conversion efficiency of the back-contact battery.

[0176] As for the fifth distance, during the actual manufacturing process, the slurry state used to manufacture the second electrode will affect the width of the busbar electrode included in the formed second electrode, and the precision of the machine used to manufacture the second electrode will affect the positional offset of the busbar electrode included in the formed second electrode. Therefore, the fifth distance also affects whether the busbar electrode included in the second electrode overlaps. Based on this, the size of the fifth distance can be determined based on the actual manufacturing process and is not specifically limited here.

[0177] Exemplarily, the ratio of the fifth distance to the sixth distance is greater than or equal to 0.8 and less than or equal to 1.2. In this case, the sixth distance and the fifth distance are the distances between the end of the collector electrode segment and the edge of the bus electrode in the second electrode and the edge of the first region of opposite conductivity type, respectively, along the second direction. Based on this, in the actual manufacturing process, the sixth distance and the fifth distance need to take into account the processing errors of the bus electrode and the collector electrode segment in the second electrode, respectively, to reserve corresponding spacing to prevent the edge of the bus electrode and the end of the collector electrode segment in the second electrode from overlapping the first region of opposite conductivity type. The processing errors of the bus electrode and the collector electrode segment included in the second electrode manufactured by the processing machine are roughly the same. Therefore, when the ratio of the sixth distance to the fifth distance is greater than or equal to 0.8 and less than or equal to 1.2, the two are roughly equal. Under the premise of preventing leakage from the edge of the bus electrode and the end of the collector electrode segment in the second electrode to the first region, it is possible to prevent some carriers in the second region from being unable to be promptly extracted due to a larger setting of the sixth distance or the fifth distance, thereby ensuring that the back contact cell has a high photoelectric conversion efficiency.

[0178] It is understood that when the specifications of the battery substrate included in the back-contact battery vary, the requirements for leakage protection and carrier collection capabilities of the first and second electrodes may also vary. Furthermore, the precision of the first and second electrodes manufactured using different equipment or slurry in different states may also vary. Therefore, the size of the fifth distance can be determined based on the specifications of the battery substrate in the actual application scenario and the actual manufacturing process.

[0179] For example, the absolute value of the difference between the sixth distance and the fifth distance may be greater than or equal to 0 and less than or equal to 300 μm.

[0180] For example, the fifth distance may be greater than 0 and less than or equal to 3 mm.

[0181] Secondly, it is understood that the spacing between adjacent collector electrode segments within the same collector electrode in the first and second electrodes is used to isolate the bus electrode of opposite polarity from the collector electrode itself, thereby suppressing leakage. Based on this, the first and second distances can be determined based on the leakage prevention requirements between the collector electrode and the bus electrode of opposite polarity in actual application scenarios.

[0182] Exemplarily, the first distance is smaller than the second distance. In this case, the end of each collecting electrode segment in the second electrode can be isolated from the adjacent bus electrode included in the first electrode by the second distance having a larger length, ensuring that the end of each collecting electrode segment in the second electrode along the second direction will not overlap the first region of opposite conductivity type to the first electrode segment itself, and the adjacent bus electrode included in the first electrode, thereby preventing leakage. While ensuring that the end of each collecting electrode segment in the first electrode along the second direction will not overlap the second region of opposite conductivity type to the first electrode segment itself, and the adjacent bus electrode included in the second electrode, the spacing between the end of each collecting electrode segment in the first electrode along the second direction and the second region can be greatly reduced, thereby improving the carrier collection capacity of each collecting electrode segment in the first electrode. In other words, the back-contact battery provided in the embodiment of the present application can separately adjust the distance between the end of each collecting electrode segment in the positive electrode and the adjacent bus electrode included in the negative electrode, and the distance between the end of each collecting electrode segment in the negative electrode and the adjacent bus electrode included in the positive electrode according to the actual application scenario. In this way, while preventing leakage and improving the electrical stability of the back-contact battery, the collecting electrode segment can have a relatively strong carrier collection ability, which is beneficial to improving the photoelectric conversion efficiency of the back-contact battery.

[0183] As for the eighth distance, it can be determined based on the size of the second distance and the sixth distance. Exemplarily, the eighth distance can be greater than or equal to 0.07mm and less than 0.15mm. For example, the eighth distance can be 0.07mm, 0.09mm, 0.11mm, 0.13mm or 0.14mm, etc. In this case, if the eighth distance is within the above range, it can prevent the part of the bus electrode included in the actually formed first electrode from being located above the second area due to the smaller processing allowance reserved due to the smaller eighth distance, thereby ensuring that the bus electrode included in the first electrode can be prevented from overlapping and leaking. At the same time, it can also prevent the manufacturing accuracy of the bus electrode in the first electrode from being strictly required to avoid leakage, thereby reducing the manufacturing difficulty of the bus electrode in the first electrode. In addition, it can also prevent the second area located on the backlight side of the first area from being smaller due to the larger eighth distance, which is beneficial to reducing the carrier recombination rate on the backlight side and improving the photoelectric conversion efficiency of the back contact battery.

[0184] In a fifth aspect, an embodiment of the present application further provides a method for manufacturing a back-contact battery, the method for manufacturing a back-contact battery comprising the following steps:

[0185] First, a battery substrate is formed. The backlight surface of the battery substrate has first and second regions that are alternately distributed. The first and second regions have opposite conductivity types.

[0186] Specifically, the specific structure and materials of the battery substrate can be referred to above and will not be described in detail here. As for the formation process of the battery substrate, it can be determined according to the specific structure of the battery substrate.

[0187] For example, when the battery substrate includes a P-type semiconductor substrate, and a tunneling passivation layer and an N-type doped polysilicon layer stacked on a portion of the backlight side of the P-type semiconductor substrate, a process such as chemical vapor deposition can be used to form the tunneling passivation layer and the N-type doped polysilicon layer entirely covering the backlight side of the P-type semiconductor substrate. Subsequently, a process such as laser etching is used to remove the portion of the stacked tunneling passivation layer and the N-type doped polysilicon layer located on the first region of the P-type semiconductor substrate, thereby obtaining the battery substrate.

[0188] Then, a surface passivation layer is formed to cover the backlight surface. A conductive window is provided in the surface passivation layer, and a portion of the first area is exposed at the bottom of the conductive window.

[0189] Specifically, the material and thickness of the surface passivation layer can be referred to above and will not be described here. In the actual manufacturing process, a process such as chemical vapor deposition can be used to form a surface passivation layer covering the entire backlight side of the battery substrate, and then a process such as laser etching can be used to form a conductive window that penetrates the surface passivation layer. Alternatively, a process such as photolithography can be used to form a mask layer at a position corresponding to the conductive window. Then, a process such as chemical vapor deposition is used to directly form a surface passivation layer with a conductive window. Next, the mask layer is removed.

[0190] Next, a first electrode and a second electrode are formed on the backlight side. As shown in Figures 6 to 8, at least a portion of the projection of the first electrode 13 on the backlight surface is located within the first region 11. The projection of the second electrode 14 on the backlight surface is located within the second region 12. The first electrode 13 and the second electrode 14 each include a plurality of collector electrodes 15 and a plurality of bus electrodes 16. The bus electrodes 16 included in the first electrode 13 and the bus electrodes 16 included in the second electrode 14 both extend along a first direction and are alternately spaced along a second direction, where the first direction is different from the second direction. The collector electrode 15 included in the first electrode 13 penetrates the surface passivation layer through the conductive window 18 and is in ohmic contact with the first region 11. The collector electrode 15 included in the second electrode 14 burns through a portion of the surface passivation layer and is in ohmic contact with the second region 12. The collector electrodes 15 included in the first electrode 13 and the collector electrodes 15 included in the second electrode 14 both extend along the second direction and are alternately spaced along the first direction. Each collecting electrode 15 is connected to a bus electrode 16 of the same polarity as itself, and each collecting electrode 15 includes multiple collecting electrode segments 17 spaced apart along the second direction. The spacing between two adjacent collecting electrode segments 17 in the same collecting electrode 15 serves to isolate the bus electrode 16 of opposite polarity. The portion of the first region 11 that is in ohmic contact with each collecting electrode segment 17 in the first electrode 13 constitutes the contact area. Along the second direction, the distance between the end of each contact area and the edge of the first region 11 is a seventh distance L7. Along the second direction, the distance between the end of each collecting electrode segment 17 in the second electrode 14 and the edge of the first region 11 is a sixth distance L6. The seventh distance L7 is less than the sixth distance L6.

[0191] Specifically, the specific structures of the first electrode and the second electrode, as well as the sizes of the seventh distance and the sixth distance, can be referred to above and will not be repeated here. Secondly, in the actual manufacturing process, the first electrode and the second electrode can be formed using a process such as screen printing. The collector electrode included in the first electrode is manufactured using a non-burn-through electrode paste, and the collector electrode included in the second electrode is manufactured using a burn-through electrode paste.

[0192] The beneficial effects of the fifth aspect in the embodiments of the present application can be analyzed by referring to the beneficial effects in the second aspect and its various implementation methods, and will not be repeated here.

[0193] While the above description does not provide detailed technical details regarding patterning and etching of each layer, those skilled in the art will appreciate that various technical means can be employed to form layers, regions, and the like in desired shapes. Furthermore, those skilled in the art may devise methods that differ from those described above to form the same structure. Furthermore, while each embodiment has been described separately, this does not mean that the measures in each embodiment cannot be advantageously combined.

[0194] The above describes the embodiments of the present disclosure. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which are intended to fall within the scope of the present disclosure.

Claims

1. A back-contact battery, comprising: A battery substrate, a first electrode and a second electrode formed on a backlight surface of the battery substrate; The backlight surface of the battery substrate has alternately distributed first regions and second regions; the conduction types of the first regions and the second regions are opposite; At least a part of the projection of the first electrode on the backlight surface is located in the first region; the projection of the second electrode on the backlight surface is located in the second region; both the first electrode and the second electrode include a plurality of current collecting electrodes and a plurality of bus bars; the bus bars included in the first electrode and the bus bars included in the second electrode both extend along a first direction and are alternately spaced along a second direction, the first direction being different from the second direction; the current collecting electrodes included in the first electrode are in ohmic contact with the first region, the current collecting electrodes included in the second electrode are in ohmic contact with the second region, the current collecting electrodes included in the first electrode and the current collecting electrodes included in the second electrode both extend along the second direction and are alternately spaced along the first direction; each current collecting electrode is connected to the bus bar having the same polarity as itself, and each current collecting electrode includes a plurality of current collecting electrode segments spaced along the second direction, and the gap between two adjacent current collecting electrode segments in the same current collecting electrode is used to isolate the bus bar having the opposite polarity to itself; wherein, Along the second direction, the distance between the end of each current collecting electrode segment in the first electrode and the adjacent bus bar included in the second electrode is a first distance; along the second direction, the distance between the end of each current collecting electrode segment in the second electrode and the adjacent bus bar included in the first electrode is a second distance; the first distance is different from the second distance.

2. The back-contact battery according to claim 1, wherein, The projection of the first electrode on the backlight surface is located in the first region, and the first distance is greater than the second distance.

3. The back-contact battery according to claim 2, wherein, Along the second direction, the distance between the end of each current collecting electrode segment in the first electrode and the edge of the second region is a third distance; along the second direction, the minimum distance between the edge of each bus bar in the first electrode and the edge of the second region is a fourth distance; the third distance is greater than the fourth distance; and / or Along the second direction, the minimum distance between the edge of the first region and the edge of the bus bar in the second electrode is a fifth distance; along the second direction, the distance between the edge of the first region and the end of the current collecting electrode segment in the second electrode is a sixth distance; the ratio of the fifth distance to the sixth distance is greater than or equal to 0.8 and less than or equal to 1.

2.

4. The back contact battery according to claim 2, wherein, Along the second direction, the distance between the end of each current collecting electrode segment in the first electrode and the edge of the second region is a third distance; the third distance is greater than or equal to 0.15 mm and less than or equal to 0.3 mm; and / or Along the second direction, the minimum distance between the edge of each bus bar in the first electrode and the edge of the second region is a fourth distance; the fourth distance is greater than or equal to 0.07 mm and less than 0.15 mm; and / or Along the second direction, the distance between the end of each collecting electrode segment in the first electrode and the edge of the second region is a third distance; along the second direction, the minimum distance between the edge of each bus electrode in the first electrode and the edge of the second region is a fourth distance; the ratio of the third distance to the fourth distance is greater than 1 and less than or equal to 2.

5. The back contact battery according to claim 1, wherein, The battery substrate is a semiconductor substrate, and the back-contact battery further includes a surface passivation layer covering the backlight side, wherein a conductive window is provided in the surface passivation layer, and the bottom exposed portion of the conductive window is the first region; the collector electrode included in the first electrode is a non-burn-through electrode, and is in ohmic contact with the first region through the conductive window; the collector electrode included in the second electrode is a burn-through electrode, and burns through part of the surface passivation layer and is in ohmic contact with the second region; wherein, The portion of the first region that is in ohmic contact with each collector electrode segment in the first electrode is the contact region; along the second direction, the minimum spacing between the end of each contact region and the edge of the second region is the seventh distance; along the second direction, the spacing between the end of each collector electrode segment in the second electrode and the edge of the first region is the sixth distance; the seventh distance is smaller than the sixth distance.

6. The back-contact battery according to claim 5, wherein, Along the second direction, an end of each collector electrode segment in the first electrode is flush with an end of the corresponding contact region; or, Along the second direction, an end of each of the collector electrode segments in the first electrode is located between an end of the corresponding contact region and an edge of the second region; or, Along the second direction, an end portion of each of the collecting electrode segments in the first electrode is located above the second region.

7. The back contact battery according to claim 5 or 6, wherein, The first distance is smaller than the second distance.

8. The back-contact battery according to any one of claims 1 to 6, wherein, Each bus electrode included in the first electrode is not in direct contact with the first area; and / or, Each bus electrode included in the second electrode does not directly contact the second region.

9. The back-contact battery according to any one of claims 1 to 6, wherein, The battery substrate comprises: a semiconductor substrate, and a doped semiconductor layer formed on a partial area of a backlight surface of the semiconductor substrate; the backlight surface of the semiconductor substrate and the backlight surface of the battery substrate are on the same side; the doped semiconductor layer and the semiconductor substrate have opposite conductivity types; The area of the backlight surface of the semiconductor substrate exposed outside the doped semiconductor layer is the first area, and the area of the doped semiconductor layer on one side away from the semiconductor substrate is the second area.

10. The back-contact battery according to claim 9, wherein, The semiconductor substrate is a P-type semiconductor substrate, and the doped semiconductor layer is an N-type doped semiconductor layer; The battery substrate further includes a tunnel passivation layer located between the P-type semiconductor substrate and the N-type doped semiconductor layer. 11 . The method for producing a back contact cell according to claim 1 .

12. A method for manufacturing a back contact battery, comprising: forming a battery substrate; The backlight surface of the battery substrate has a first area and a second area that are alternately distributed; Obtain the regional pattern of the first region, the design structure correlation parameters corresponding to the first electrode and the second electrode included in the back-contact battery, the first performance adjustment correlation parameters corresponding to the first electrode, and the second performance adjustment correlation parameters corresponding to the second electrode; the first performance adjustment correlation parameters are different from the second performance adjustment correlation parameters; both the first electrode and the second electrode include a plurality of current collecting electrodes and a plurality of bus bars; the bus bars included in the first electrode and the bus bars included in the second electrode both extend along a first direction and are alternately spaced along a second direction, the first direction being different from the second direction; the current collecting electrodes included in the first electrode and the current collecting electrodes included in the second electrode both extend along the second direction and are alternately spaced along the first direction; each current collecting electrode is connected to the bus bar with the same polarity as itself, and each current collecting electrode includes a plurality of current collecting electrode segments spaced along the second direction, and the gap between two adjacent current collecting electrode segments in the same current collecting electrode is used to isolate the bus bar with the opposite polarity to itself; Based on the regional pattern, the design structure correlation parameters, and the first performance adjustment correlation parameters, adjust the distance between each current collecting electrode segment in the first electrode and the adjacent bus bar included in the second electrode to a first distance, and update the design structure correlation parameters; Based on the regional pattern, the design structure correlation parameters, and the second performance adjustment correlation parameters, adjust the distance between each current collecting electrode segment in the second electrode and the adjacent bus bar included in the first electrode to a second distance, and update the design structure correlation parameters; Form the first electrode and the second electrode on the backlight surface according to the updated design structure correlation parameters; The projection of the first electrode on the backlight surface is located within the first region; the projection of the second electrode on the backlight surface is located within the second region.

13. The manufacturing method of the back-contact battery according to claim 12, wherein, The first performance adjustment correlation parameters include a first minimum anti-leakage distance and a first maximum collection distance; the first distance is greater than or equal to the first minimum anti-leakage distance and less than or equal to the first maximum collection distance; and / or The second performance adjustment correlation parameters include a second minimum anti-leakage distance and a second maximum collection distance; the second distance is greater than or equal to the second minimum anti-leakage distance and less than or equal to the second maximum collection distance.

14. The manufacturing method of the back-contact battery according to claim 12 or 13, wherein, The forming of a battery substrate includes: Form a doped semiconductor layer provided as a whole layer on the backlight surface of the semiconductor substrate; Adopt a laser etching process to remove the part of the doped semiconductor layer located on the first region to form the battery substrate; the battery substrate includes the semiconductor substrate and the remaining doped semiconductor layer.

15. The manufacturing method of the back-contact battery according to claim 14, wherein, The adopting of the laser etching process to remove the part of the doped semiconductor layer located on the first region includes: Obtain the laser etching correlation parameters, the first processing error correlation parameters corresponding to the bus bars included in the second electrode, and the second processing error correlation parameters corresponding to the bus bars included in the first electrode; Determine a laser spot pattern based on the design structure correlation parameters and the laser etching correlation parameters; Based on the design structure correlation parameters and the first processing error correlation parameters, adjust the distance between the edge of the laser spot pattern and the current collecting electrode included in the second electrode along the second direction; and based on the design structure correlation parameters and the second processing error correlation parameters, adjust the distance between the edge of the laser spot pattern and the current collecting electrode in the first electrode along the second direction; Adopt the laser etching process and etch the doped semiconductor layer according to the adjusted laser spot pattern.

16. The manufacturing method of the back contact battery according to claim 15, wherein, The laser etching correlation parameters include: laser spot size, overlapping distance between adjacent laser spots, designed distance between the edge of the laser spot pattern and the end of each current collecting electrode segment in the first electrode along the second direction, and designed distance between the edge of the laser spot pattern and the current collecting electrode included in the first electrode along the second direction; and / or The first processing error correlation parameters include the processing width error and offset error corresponding to the current collecting electrode included in the second electrode; and / or The second processing error correlation parameters include the processing width error and offset error corresponding to the current collecting electrode included in the first electrode.

17. The manufacturing method of the back contact battery according to claim 16, wherein, The designed distance between the edge of the laser spot pattern and the end of each current collecting electrode segment in the first electrode along the second direction is greater than 0 and less than 0.4 mm; and / or The designed distance between the edge of the laser spot pattern and the current collecting electrode included in the first electrode along the second direction is equal to one half of the difference between the laser spot size and the overlapping distance between adjacent laser spots.

18. The manufacturing method of the back-contact battery according to claim 16, wherein, The distance between the edge of the adjusted laser spot pattern and the current collecting electrode included in the second electrode along the second direction is greater than or equal to M1 and less than N1; where M1 is the sum of the processing width error and offset error corresponding to the current collecting electrode included in the second electrode, and N1 is the sum of the difference between the laser spot size and the overlapping distance between adjacent laser spots and M1; and / or The distance between the edge of the adjusted laser spot pattern and the current collecting electrode included in the first electrode along the second direction is greater than or equal to M2 and less than N2; where M2 is one half of the difference between the laser spot size and the overlapping distance between adjacent laser spots, and N2 is the sum of the processing width error and offset error corresponding to the current collecting electrode included in the first electrode and M2.

19. A manufacturing method of a back contact battery, comprising: Form a battery substrate; The backlight surface of the battery substrate has alternately distributed first regions and second regions; The first regions and the second regions have opposite conduction types; Form a surface passivation layer covering the backlight surface; a conductive window is provided in the surface passivation layer, and a part of the first region is exposed at the bottom of the conductive window; A first electrode and a second electrode are formed on one side of the backlight surface; at least a part of the projection of the first electrode on the backlight surface is located within the first region; the projection of the second electrode on the backlight surface is located within the second region; both the first electrode and the second electrode include a plurality of current collecting electrodes and a plurality of bus electrodes; the bus electrodes included in the first electrode and the bus electrodes included in the second electrode both extend along a first direction and are alternately spaced along a second direction, the first direction being different from the second direction; the current collecting electrodes included in the first electrode penetrate through the surface passivation layer through the conductive window and are in ohmic contact with the first region, the current collecting electrodes included in the second electrode burn through a part of the surface passivation layer and are in ohmic contact with the second region, the current collecting electrodes included in the first electrode and the current collecting electrodes included in the second electrode both extend along the second direction and are alternately spaced along the first direction; each current collecting electrode is connected to the bus electrode with the same polarity as itself, and each current collecting electrode includes a plurality of current collecting electrode segments spaced along the second direction, and the gap between two adjacent current collecting electrode segments in the same current collecting electrode is used to isolate the bus electrode with the opposite polarity to itself; wherein, the part in the first region that is in ohmic contact with each current collecting electrode segment in the first electrode is the contact region; along the second direction, the distance between the end of each contact region and the edge of the first region is the seventh distance; Along the second direction, the distance between the end of each current collecting electrode segment in the second electrode and the edge of the first region is the sixth distance; the seventh distance is less than the sixth distance.

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