Solar cell and manufacturing method thereof, cell module and photovoltaic system

Abstract

The invention provides a solar cell, a manufacturing method thereof, a cell module and a photovoltaic system. The solar cell comprises a substrate having a first surface and a second surface opposite to each other; the first doped region and the second doped region are arranged on the first surface along a first direction parallel to the first surface, and the doping type of the first doped region is different from that of the second doped region; the isolation region is arranged between the first doped region and the second doped region along the first direction and is used for separating the first doped region from the second doped region; wherein the isolation area comprises a plurality of isolation subareas arranged along a first direction; and in a second direction perpendicular to the first surface, adjacent isolation subareas of the substrate in the plurality of isolation subareas have different heights.

Description

Technical Field

[0001] This disclosure relates to the field of solar cell technology, and in particular to a solar cell, a method for manufacturing the same, a cell module, and a photovoltaic system. Background Technology

[0002] In the field of solar cell technology, the main structure of a back contact (BC) cell is to form P-type doped regions (P-regions) and N-type doped regions (N-regions) that are isolated from each other on the back of the cell by an isolation region. Therefore, the isolation region is directly related to the overall performance of the BC cell.

[0003] In related technologies, the isolation region of BC (Polymer Carbon) cells is processed using a one-step process. This process mainly includes the following steps: First, a laser is used to create an isolation trench in a specific area on the back of the cell. Then, during the post-texturing process, the laser-drilled area is treated using the chemical etching effect of the texturing solution. This process removes highly doped layers (such as phosphorus or boron doped layers) formed by the high-temperature diffusion process within the isolation region through chemical etching, thereby achieving isolation between the P-region and the N-region. However, the laser etching process often suffers from uneven energy distribution, resulting in local differences in the morphology, depth, and width of the drilled area. In particular, in areas with lower laser energy, some highly doped layers may remain due to insufficient etching. During the subsequent chemical etching process, these residual highly doped layers are difficult to completely remove through the chemical etching effect of the texturing solution, resulting in incompletely removed doped material remaining in the isolation region. These problems lead to a significantly lower parallel resistance in BC cells compared to other cell structures using localized contacts, such as tunnel oxide passivated contact (TOPCon) cells. Specifically, a lower parallel resistance will cause a significant decrease in the conversion efficiency of BC cells under low light intensity, affecting the low-irradiance power generation performance of BC cells. Summary of the Invention

[0004] There is a need in the art to solve the problem of residual doped layers in the isolation region of BC cells caused by uneven laser energy and insufficient etching by texturing solution. To solve the above problems, this disclosure provides a solar cell, a method for manufacturing the same, a cell module, and a photovoltaic system.

[0005] In a first aspect, this disclosure provides a solar cell, comprising:

[0006] The substrate has a first surface and a second surface that are opposite to each other;

[0007] The first doped region and the second doped region are disposed on the first surface along a first direction parallel to the first surface, and the doping type of the first doped region is different from that of the second doped region.

[0008] An isolation region is disposed along the first direction between the first doped region and the second doped region, serving to separate the first doped region and the second doped region;

[0009] The isolation region includes a plurality of isolation partitions disposed along the first direction; and in a second direction perpendicular to the first surface, adjacent isolation partitions of the substrate have different heights.

[0010] In some embodiments, in the first direction, for any two adjacent isolation partitions, the height of the substrate in the isolation partition closer to the first doped region is greater than the height of the substrate in the isolation partition closer to the second doped region.

[0011] In some embodiments, in the first direction, the plurality of isolation partitions include a first isolation partition near the first doped region and a second isolation partition near the second doped region, and the height difference between the substrate at the height of the first isolation partition and the height of the second isolation partition is in the range of 1 to 4 μm.

[0012] In some embodiments, in the first direction, the ratio of the width of the first isolation partition to the width of the second isolation partition is in the range of 1 to 15.

[0013] In some embodiments, in the first direction, the width of the first isolation partition is in the range of 50 to 150 μm, and the width of the second isolation partition is in the range of 10 to 50 μm.

[0014] In some embodiments, in the first direction, the ratio of the width of the first doped region to the width of the first isolation partition is in the range of 1 to 9.

[0015] In some embodiments, in the first direction, the ratio of the width of the second doped region to the width of the second isolation partition is in the range of 4 to 50.

[0016] In some embodiments, in the first direction from the first doped region to the second doped region, the plurality of isolation partitions include a first isolation partition, a second isolation partition, and a third isolation partition arranged sequentially, and the total height difference of the substrate in the plurality of isolation partitions is in the range of 2 to 8 μm.

[0017] In some embodiments, the height difference between the substrate in the first isolation partition and the height in the second isolation partition, and the height difference between the substrate in the second isolation partition and the height in the third isolation partition, are in the range of 1 to 4 μm.

[0018] In some embodiments, in the first direction, the ratio of the sum of the widths of the second isolation partition and the third isolation partition to the width of the first isolation partition is in the range of 0.5 to 7.5.

[0019] In some embodiments, in the first direction, the width of the first isolation partition, the width of the second isolation partition, and the width of the third isolation partition are the same.

[0020] In some embodiments, in the first direction, the width of the second isolation partition is the same as the width of the third isolation partition and is smaller than the width of the first isolation partition.

[0021] In some embodiments, in the first direction, the width of the first isolation partition is in the range of 50 to 150 μm, the width of the second isolation partition is in the range of 10 to 50 μm, and the width of the third isolation partition is in the range of 10 to 50 μm.

[0022] In some embodiments, in the first direction, the ratio of the width of the first doped region to the width of the first isolation partition is in the range of 1 to 9.

[0023] In some embodiments, in the first direction, the ratio of the width of the second doped region to the width of the third isolation partition is in the range of 4 to 50.

[0024] In some embodiments, the plurality of isolation partitions includes at least three isolation partitions, and in the first direction, the height of one of the isolation partitions in which the substrate is located between the other isolation partitions is greater than the height of the substrate in any of the other isolation partitions.

[0025] In some embodiments, in the first direction from the first doped region to the second doped region, the plurality of isolation partitions include a first isolation partition, a second isolation partition, and a third isolation partition arranged sequentially, and the total height difference of the substrate in the plurality of isolation partitions is in the range of 1 to 4 μm.

[0026] In some embodiments, the height difference between the substrate in the first isolation partition and the height in the second isolation partition, and the height difference between the substrate in the second isolation partition and the height in the third isolation partition, are in the range of 1 to 4 μm.

[0027] In some embodiments, in the first direction, the ratio of the sum of the widths of the first isolation partition and the third isolation partition to the width of the second isolation partition is in the range of 0.5 to 7.5.

[0028] In some embodiments, in the first direction, the width of the first isolation partition, the width of the second isolation partition, and the width of the third isolation partition are the same.

[0029] In some embodiments, in the first direction, the width of the first isolation partition is the same as the width of the third isolation partition and is smaller than the width of the second isolation partition.

[0030] In some embodiments, in the first direction, the width of the first isolation partition is in the range of 10 to 50 μm, the width of the second isolation partition is in the range of 50 to 150 μm, and the width of the third isolation partition is in the range of 10 to 50 μm.

[0031] In some embodiments, in the first direction, the ratio of the width of the first doped region to the width of the first isolation partition is in the range of 3 to 45.

[0032] In some embodiments, in the first direction, the ratio of the width of the second doped region to the width of the third isolation partition is in the range of 4 to 50.

[0033] In some embodiments, in the first direction from the first doped region to the second doped region, the plurality of isolation partitions include a first isolation partition, a second isolation partition, a third isolation partition, and a fourth isolation partition arranged sequentially, wherein the height of the substrate in the second isolation partition is greater than the height of the substrate in any other isolation partition, and the total height difference of the substrate in the plurality of isolation partitions is in the range of 2 to 8 μm.

[0034] In some embodiments, the height difference between the substrate at the first isolation partition and at the second isolation partition is in the range of 1 to 4 μm.

[0035] In some embodiments, the height difference between the substrate in the second isolation partition and the height in the third isolation partition is in the range of 0.5 to 2 μm, and the height difference between the substrate in the third isolation partition and the height in the fourth isolation partition is in the range of 0.5 to 2 μm.

[0036] In some embodiments, in the first direction, the ratio of the sum of the widths of the first isolation partition and the second isolation partition to the sum of the widths of the third isolation partition and the fourth isolation partition is in the range of 0.5 to 7.5.

[0037] In some embodiments, in the first direction, the widths of the first isolation partition, the second isolation partition, the third isolation partition, and the fourth isolation partition are the same.

[0038] In some embodiments, in the first direction, the width of the first isolation partition is in the range of 10 to 50 μm, the width of the second isolation partition is in the range of 40 to 140 μm, the width of the third isolation partition is in the range of 5 to 25 μm, and the width of the fourth isolation partition is in the range of 5 to 25 μm.

[0039] In some embodiments, in the first direction, the ratio of the width of the first doped region to the width of the first isolation partition is in the range of 3 to 45.

[0040] In some embodiments, in the first direction, the ratio of the width of the second doped region to the sum of the widths of the third isolation partition and the fourth isolation partition is in the range of 4 to 50, and the ratio of the width of the third isolation partition to the width of the fourth isolation partition is in the range of 2 to 50.

[0041] In some embodiments, at least one of the plurality of isolation partitions is a velvety surface, and / or at least one of the plurality of isolation partitions is a polished surface.

[0042] In some embodiments, the first doped region is formed with a first doped layer, and the second doped region is formed with a second doped layer, wherein the height of the second doped layer is greater than the height of the first doped layer.

[0043] In some embodiments, the dopant ions in the first doped layer include phosphorus ions, and the dopant ions in the second doped layer include boron ions.

[0044] In some embodiments, the substrate has a transition surface connecting adjacent isolation partitions in a plurality of isolation partitions.

[0045] In some embodiments, the transition surface is a plane.

[0046] In some embodiments, the angle between the transition surface and the substrate in the adjacent isolation partition is in the range of 45° to 65°.

[0047] In some embodiments, the transition surface is formed with a scaly texture.

[0048] Secondly, this disclosure provides a battery assembly including the aforementioned solar cell.

[0049] Thirdly, this disclosure provides a photovoltaic system including the aforementioned battery module.

[0050] Fourthly, this disclosure provides a method for manufacturing a solar cell, used to manufacture the aforementioned solar cell, comprising:

[0051] At least two laser processing and wet etching are used to form the substrate in which adjacent isolation partitions in a plurality of isolation partitions have different heights.

[0052] The embodiments provided in this disclosure include a solar cell comprising: a substrate having a first surface and a second surface opposite to each other; a first doped region and a second doped region disposed on the first surface along a first direction parallel to the first surface, wherein the doping type of the first doped region is different from that of the second doped region; and an isolation region disposed between the first doped region and the second doped region along the first direction for separating the first doped region and the second doped region. The isolation region includes a plurality of isolation partitions disposed along the first direction; and in a second direction perpendicular to the first surface, adjacent isolation partitions of the substrate have different heights. Therefore, by forming a plurality of planes with height differences within the isolation region, the embodiments of this disclosure can more thoroughly remove highly doped materials of different depths in segments, strengthen the isolation effect between the first doped region and the second doped region, thereby significantly improving the parallel resistance of the cell, suppressing the leakage current of the cell, and improving the conversion efficiency of the cell under low light intensity.

[0053] The embodiments provided in this disclosure describe a method for manufacturing solar cells that includes at least two laser processing steps and wet etching to form a substrate in which adjacent isolation zones have different heights. Therefore, the manufacturing method of this disclosure, through the alternating cycle of at least two laser processing steps and wet etching, can specifically remove residual dopant material in specific areas within the isolation zone, solving the problem of dopant material residue caused by uneven energy in a single laser processing step. Furthermore, this method can be based on existing solar cell processing equipment without introducing new process equipment, has a minimal impact on overall production costs, and possesses good process compatibility and industrialization feasibility.

[0054] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0055] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the embodiments of the present disclosure to explain the disclosure and do not constitute a limitation thereof. The above and other features and advantages will become more apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0056] Figure 1A solar cell provided in this disclosure has two isolation zones with decreasing heights between the isolation zones;

[0057] Figure 2 A solar cell provided in this disclosure has three isolation zones with decreasing heights.

[0058] Figure 3 A solar cell provided in this disclosure has three isolation zones, the height of which first increases and then decreases.

[0059] Figure 4 A solar cell provided in this disclosure has four isolation zones with the height of the isolation zones increasing first and then decreasing.

[0060] Figure 5 A solar cell provided in this disclosure has two isolation zones with increasing isolation zone heights.

[0061] Figure label:

[0062] 1. Substrate; 10. First doped region; 20. Second doped region; 30. Isolation region;

[0063] 110. First isolation partition; 120. Second isolation partition;

[0064] 210, First Isolation Zone; 220, Second Isolation Zone; 230, Third Isolation Zone;

[0065] 310, First Isolation Zone; 320, Second Isolation Zone; 330, Third Isolation Zone;

[0066] 410, First Isolation Partition; 420, Second Isolation Partition; 430, Third Isolation Partition; 440, Fourth Isolation Partition;

[0067] 510, First Isolation Partition; 520, Second Isolation Partition. Detailed Implementation

[0068] To enable those skilled in the art to better understand the technical solutions of this disclosure, exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments of this disclosure to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0069] Where there is no conflict, the various embodiments of this disclosure and the features thereof in the embodiments may be combined with each other.

[0070] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0071] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Words such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0072] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning, unless expressly so defined herein.

[0073] Firstly, such as Figures 1 to 5 As shown, this disclosure provides a solar cell including a substrate 1. The substrate 1 has a first surface and a second surface facing each other. The solar cell also includes a first doped region 10, a second doped region 20, and an isolation region 30. The first doped region 10 and the second doped region 20 are disposed on the first surface along a first direction X parallel to the first surface, and the doping type of the first doped region 10 is different from that of the second doped region 20. The isolation region 30 is disposed between the first doped region 10 and the second doped region 20 along the first direction X, serving to separate the first doped region 10 and the second doped region 20. The isolation region 30 includes a plurality of isolation partitions disposed along the first direction X. In a second direction Y perpendicular to the first surface, adjacent isolation partitions of the substrate 1 have different heights. Thus, the solar cell of this disclosure, by forming a plurality of planes with height differences within the isolation region, can more thoroughly remove highly doped materials of different depths in segments, strengthen the isolation effect between the first doped region and the second doped region, thereby significantly improving the parallel resistance of the cell, suppressing the leakage current of the cell, and improving the conversion efficiency of the cell under low light intensity.

[0074] The term "height" as used herein can be understood as the dimension of the corresponding structure or material in the second direction Y. In specific embodiments, this dimension can be characterized by parameters such as the size difference between isolation partitions, doped regions, etc., and is used to describe the morphological features of isolation partitions or doped regions and their relative positional relationships in the second direction.

[0075] In some embodiments, such as Figures 1 to 2 and Figure 5 As shown, in the first direction X, for any two adjacent isolation partitions, the height of substrate 1 in the isolation partition closer to the first doped region 10 is greater than the height of substrate 1 in the isolation partition closer to the second doped region 20. For example, in the first direction X from the first doped region 10 to the second doped region 20 (i.e., the direction from left to right in the illustration), the height of substrate 1 in multiple isolation partitions can decrease. For example, in some embodiments, such as Figure 1 As shown, in the first direction X, the multiple isolation partitions may include a first isolation partition 110 near the first doped region 10 and a second isolation partition 120 near the second doped region 20. The inventors have discovered that the doping depth of isolation partitions near different doped regions varies; for example, the doping depth of the first isolation partition 110 differs from that of the second isolation partition 120. Taking the case where the second isolation partition 120 has a higher doping depth as an example, the second isolation partition 120 needs further removal of doped material to achieve effective isolation. Therefore, the solar cell of this embodiment, by making the substrate 1 decrease in height towards the multiple isolation partitions of the second doped region 20, can selectively remove doped material from isolation partitions with higher doping depths (e.g., the second isolation partition 120). Furthermore, the solar cell of this embodiment, by setting this structure with height differences, facilitates the guidance of texturing solution to converge and act on the isolation partitions with higher doping depths during chemical etching, thereby improving etching efficiency and uniformity, and further ensuring the effective removal of residual doped layers in this area.

[0076] In some embodiments, the height difference between the first isolation partition 110 and the second isolation partition of the substrate 1 can be in the range of 1 to 4 μm. Therefore, the solar cell of this disclosure, by setting the above-mentioned height difference range, can effectively remove doped materials in the isolation partitions while avoiding insufficient structural strength due to excessive height differences between the isolation partitions.

[0077] In some embodiments, the height difference between the first isolation partition 110 and the first doped region 10 can be in the range of 1.5 to 5 μm, and the height difference between the second isolation partition 120 and the first doped region 10 can be in the range of 2.5 to 9 μm. Therefore, by setting the above-mentioned height difference range, the solar cell of this disclosure embodiment can effectively avoid insufficient structural strength due to an excessively large height difference between the isolation partition and the doped region.

[0078] In some embodiments, the ratio of the width of the first isolation partition 110 to the width of the second isolation partition 120 in the first direction X can be in the range of 1 to 15. In some embodiments, the width of the first isolation partition 110 in the first direction X can be in the range of 50 to 150 μm, and the width of the second isolation partition 120 can be in the range of 10 to 50 μm. The inventors have discovered that the doping depth distribution of isolation partitions near different doped regions in the isolation region is related to the height of the corresponding doped region (the doped layer therein). For example, because the first doped region 10 and the second doped region 20 differ in height, the distribution width of the doped material in the first isolation partition 110 also differs from that in the second isolation partition 120. Taking the case where the second doped region 20 is higher than the first doped region 10 as an example, the distribution width of the doped material in the first isolation partition 110 is greater than that in the second isolation partition 120. Therefore, the solar cell of this disclosure, by setting the above-mentioned width ratio and / or range, can accurately divide the isolation region into multiple isolation partitions with appropriate widths according to the height difference between the first doped region and the second doped region (e.g., the height difference between the first doped layer and the second doped layer), so as to effectively remove the doped material in each partition while reducing the amount of material removed to improve the cell performance.

[0079] In some embodiments, the ratio of the width of the first doped region 10 to the width of the first isolation partition 110 in the first direction X can be in the range of 1 to 9. In some embodiments, the ratio of the width of the second doped region 20 to the width of the second isolation partition 120 in the first direction X can be in the range of 4 to 50. Thus, the solar cell of this disclosure embodiment, by setting the above-mentioned width ratios and / or ranges, can effectively adjust the width of the corresponding isolation partition according to the width of the doped region, and accurately divide it into multiple isolation partitions with suitable widths. Furthermore, the above-mentioned ratios and / or ranges of the width of the doped region to the width of the isolation partition can be combined with the above-mentioned ratios and / or ranges of the widths between the isolation partitions to further accurately divide it into multiple isolation partitions with suitable widths.

[0080] In some embodiments, such as Figure 2As shown, in a first direction X from the first doped region 10 to the second doped region 20, multiple isolation partitions may include a first isolation partition 210, a second isolation partition 220, and a third isolation partition 230 arranged sequentially. The height of the substrate 1 in the first isolation partition 210 may be greater than its height in the second isolation partition 220. The height of the substrate 1 in the second isolation partition 220 may be greater than its height in the third isolation partition 230. In some embodiments, the total height difference of the substrate 1 in the multiple isolation partitions may be in the range of 2 to 8 μm. Thus, the solar cell of this embodiment, by setting three isolation partitions, allows the middle second isolation partition 220 to serve as a transition partition, providing a buffer transition between the first isolation partition 210 and the third isolation partition 230, and avoiding excessive height difference.

[0081] In some embodiments, the height difference between the substrate 1 in the first isolation partition 210 and the height in the second isolation partition 220 can be in the range of 1 to 4 μm. In some embodiments, the height difference between the substrate 1 in the second isolation partition 220 and the height in the third isolation partition 230 can be in the range of 1 to 4 μm. Therefore, the solar cell of the present disclosure, by setting the above-mentioned height difference range, can effectively avoid insufficient structural strength due to excessive height difference between isolation partitions.

[0082] In some embodiments, in the first direction X, the ratio of the sum of the widths of the second isolation partition 220 and the third isolation partition 230 to the width of the first isolation partition 210 can be in the range of 0.5 to 7.5. In some embodiments, in the first direction X, the width of the first isolation partition 210 is in the range of 50 to 150 μm, the width of the second isolation partition 220 is in the range of 10 to 50 μm, and the width of the third isolation partition 230 is in the range of 10 to 50 μm. In some embodiments, in the first direction X, the widths of the first isolation partition 210 and the third isolation partition 230 are the same and smaller than the width of the second isolation partition 220. Based on the aforementioned correlation between the isolation partition width and the corresponding doped region height, the solar cell of the present disclosure embodiment has a wider second isolation partition 220. Furthermore, taking the case where the third isolation partition 230 near the second doped region 20 has a higher doping depth as an example, the inventors have found that the second isolation partition 220 slightly farther away from the second doped region 20 has a relatively lower doping depth compared to the third isolation partition 230 directly adjacent to the second doped region 20. Therefore, by setting the aforementioned width ratio and range, the solar cell of this disclosure can further precisely divide the isolation region into multiple isolation partitions with suitable widths, so as to effectively remove doped materials in each partition while reducing the amount of material removed to improve cell performance.

[0083] In some embodiments, the widths of the first isolation partition 210, the second isolation partition 220, and the third isolation partition 230 may be the same in the first direction X. Therefore, the solar cells of this disclosure embodiment can reduce the complexity of the manufacturing process.

[0084] In some embodiments, the height difference between the first isolation partition 210 and the first doped region 10 can be in the range of 1.5 to 5 μm, and the height difference between the third isolation partition 230 and the first doped region 10 can be in the range of 3.5 to 13 μm. Therefore, by setting the above-mentioned height difference range, the solar cell of this disclosure embodiment can effectively avoid insufficient structural strength due to an excessively large height difference between the isolation partition and the doped region.

[0085] In some embodiments, the ratio of the width of the first doped region 10 to the width of the first isolation partition 210 in the first direction X can be in the range of 1 to 9. In some embodiments, the ratio of the width of the second doped region 20 to the width of the third isolation partition 230 in the first direction X can be in the range of 4 to 50. Based on the aforementioned correlation between the width of the isolation partition and the width of the corresponding doped region, the solar cells of the embodiments of this disclosure are provided with the above-mentioned width ratios and / or ranges.

[0086] In some embodiments, such as Figure 3 As shown, the multiple isolation partitions may include at least three isolation partitions. In the first direction X, the height of one of the at least three isolation partitions, located between the other isolation partitions, is greater than the height of the substrate 1 in any of the other isolation partitions. In other words, the height of the substrate 1 in the middle isolation partition can be greater than the heights of the isolation partitions on either side of that partition. For example, in the first direction X from the first doped region 10 to the second doped region 20, the height of the substrate 1 in the multiple isolation partitions first increases and then decreases. For example, as... Figure 3As shown, in some embodiments, in a first direction X from the first doped region 10 to the second doped region 20, multiple isolation partitions include a first isolation partition 310, a second isolation partition 320, and a third isolation partition 330 arranged sequentially, wherein the second isolation partition 320 has the highest relative height. The inventors have discovered that the overall doping depth of the second isolation partition 320, located in the middle position, is lower than that of the first isolation partition 310 directly adjacent to the first doped region 10 and the third isolation partition 330 adjacent to the second doped region 20. Therefore, the solar cell of this disclosure, by setting the second isolation partition 320 as a relatively convex structure, can achieve effective isolation without excessive material removal, thereby reducing the amount of material removed and improving cell performance. In some embodiments, the total height difference of the substrate 1 across the multiple isolation partitions is in the range of 1 to 4 μm. Therefore, the solar cell of this disclosure, by setting the above-mentioned height difference range, can effectively avoid insufficient structural strength due to an excessively large height difference between the isolation partitions and the doped regions.

[0087] In some embodiments, the height difference between the substrate 1 in the first isolation partition 310 and the height in the second isolation partition 320 can be in the range of 1 to 4 μm. The height difference between the substrate 1 in the second isolation partition 320 and the height in the third isolation partition 330 can also be in the range of 1 to 4 μm. Therefore, the solar cell of this embodiment, by setting the above-mentioned height difference range, can effectively avoid insufficient structural strength due to excessive height differences between the isolation partitions.

[0088] In some embodiments, in the first direction X, the ratio of the sum of the widths of the first isolation partition 310 and the third isolation partition 330 to the width of the second isolation partition 320 can be in the range of 0.5 to 7.5. In some embodiments, in the first direction X, the width of the first isolation partition 310 is in the range of 10 to 50 μm, the width of the second isolation partition 320 is in the range of 50 to 150 μm, and the width of the third isolation partition 330 is in the range of 10 to 50 μm. In some embodiments, in the first direction X, the widths of the first isolation partition 310 and the third isolation partition 330 can be the same and smaller than the width of the second isolation partition 320. Based on the foregoing description of the doping depth variation of the isolation partitions, the solar cells of the embodiments of this disclosure are configured with the above-mentioned width ratios and / or ranges.

[0089] In some embodiments, the widths of the first isolation partition 310, the second isolation partition 320, and the third isolation partition 330 may be the same in the first direction X. Therefore, the solar cells of this disclosure embodiment can reduce the complexity of the manufacturing process.

[0090] In some embodiments, in the first direction X, the ratio of the width of the first doped region 10 to the width of the first isolation partition 310 can be in the range of 3 to 45. In some embodiments, in the first direction X, the ratio of the width of the second doped region 20 to the width of the third isolation partition 330 can be in the range of 4 to 50. Based on the aforementioned correlation between the width of the isolation partition and the width of the corresponding doped region, the solar cells of the embodiments of this disclosure are provided with the above-mentioned width ratios and / or ranges.

[0091] In some embodiments, such as Figure 4 As shown, in a first direction X from the first doped region 10 to the second doped region 20, multiple isolation partitions may include a first isolation partition 410, a second isolation partition 420, a third isolation partition 430, and a fourth isolation partition 440 arranged sequentially. The height of the substrate 1 in the second isolation partition 420 is greater than the height of the substrate 1 in any other isolation partition. In other words, the height of the second isolation partition 420 is greater than the height of any one of the first isolation partition 410, the third isolation partition 430, and the fourth isolation partition 440. In some embodiments, the total height difference of the substrate 1 in the multiple isolation partitions can be in the range of 2 to 8 μm. Based on the aforementioned description of the doping depth variation of the isolation partitions, the solar cell of this disclosure embodiment, by setting four isolation partitions, such that the second isolation partition 420 is set as a relatively convex structure, can achieve effective isolation without excessive material removal, thereby reducing the amount of material removed to improve cell performance, and makes the third isolation partition 430 serve as a transition partition to provide a buffer transition between the second isolation partition 420 and the fourth isolation partition 440, avoiding excessive height difference.

[0092] In some embodiments, the height difference between the first isolation partition 410 and the second isolation partition 420 of the substrate 1 can be in the range of 1 to 4 μm. In some embodiments, the height difference between the second isolation partition 420 and the third isolation partition 430 of the substrate 1 can be in the range of 0.5 to 2 μm, and the height difference between the third isolation partition 430 and the fourth isolation partition 440 of the substrate 1 can be in the range of 0.5 to 2 μm. Therefore, the solar cell of the present disclosure, by setting the above-mentioned height difference range, can effectively avoid insufficient structural strength due to an excessive height difference between the isolation partition and the doped region.

[0093] In some embodiments, in the first direction X, the ratio of the sum of the widths of the first isolation partition 410, the third isolation partition 430, and the fourth isolation partition 440 to the width of the second isolation partition 420 can be in the range of 0.5 to 7.5. In some embodiments, in the first direction X, the width of the first isolation partition 410 can be in the range of 10 to 50 μm, the width of the second isolation partition 420 can be in the range of 40 to 140 μm, the width of the third isolation partition 430 can be in the range of 5 to 25 μm, and the width of the fourth isolation partition 440 can be in the range of 5 to 25 μm. Based on the foregoing description of the doping depth variation of the isolation partitions, the solar cells of the embodiments of this disclosure are configured with the above-mentioned width ratios and / or ranges.

[0094] In some embodiments, in the first direction X, the ratio of the width of the first doped region 10 to the width of the first isolation partition 410 can be in the range of 3 to 45. In some embodiments, in the first direction X, the ratio of the width of the second doped region 20 to the sum of the widths of the third isolation partition 430 and the fourth isolation partition 440 can be in the range of 4 to 50, and the ratio of the width of the third isolation partition 431 to the width of the fourth isolation partition 440 is in the range of 2 to 50. Based on the aforementioned correlation between the width of the isolation partition and the width of the corresponding doped region, the solar cells of the embodiments of this disclosure are provided with the above-mentioned width ratios and / or ranges.

[0095] In some embodiments, the widths of the first isolation partition 410, the second isolation partition 420, the third isolation partition 430, and the fourth isolation partition 440 may be the same in the first direction X. Therefore, the solar cells of this disclosure embodiment can reduce the complexity of the manufacturing process.

[0096] In some embodiments, at least one of the plurality of isolation partitions may be a textured surface. In some embodiments, at least one of the plurality of isolation partitions may be a polished surface.

[0097] In some embodiments, the first doped region 10 can be an N-type doped region, and the second doped region 20 can be a P-type doped region. It should be noted that in some embodiments, the first doped region 10 can be a P-type doped region, and the second doped region 20 can be an N-type doped region. In some embodiments, the height of the substrate 1 in the first doped region 10 can be lower than its height in the second doped region 20. It should be noted that in some embodiments, the height of the substrate 1 in the first doped region 10 can be higher than its height in the second doped region 20.

[0098] In some embodiments, the first doped region 10 may have a first doped layer, and the second doped region 20 may have a second doped layer. In some embodiments, the height of the second doped layer may be greater than the height of the first doped layer. In some embodiments, the dopant ions in the first doped layer may include phosphorus ions, and the dopant ions in the second doped layer may include boron ions. Since the etching rate of the second doped layer containing boron ions is slower than that of the first doped layer containing phosphorus ions, the doping depth of the isolation zone near the second doped region is higher. Therefore, the solar cell of the present disclosure embodiment can effectively remove residual material near the second doped layer in the isolation zone through the above-described decreasing and / or increasing-then-decreasing isolation zone variation structure. It should be noted that the solar cell of the present disclosure embodiment can also remove residual material near the second doped layer in the isolation zone to a certain extent through the increasing (equivalent to decreasing in another direction) isolation zone variation structure.

[0099] In some embodiments, the substrate 1 may be connected to adjacent isolation partitions in a plurality of isolation partitions by a transition surface. In some embodiments, the transition surface may be a plane. In some embodiments, the angle between the transition surface and the substrate 1 in adjacent isolation partitions may be in the range of 45° to 65°. In some embodiments, the transition surface may be formed with a scaly texture.

[0100] Example 1

[0101] like Figure 1As shown, this embodiment provides a solar cell including a substrate 1. The substrate 1 has a first surface and a second surface opposite to each other. The solar cell also includes a first doped region 10, a second doped region 20, and an isolation region 30. The first doped region 10 and the second doped region 20 are disposed on the first surface along a first direction X. The first doped region 10 is an N-type doped region and has a first doped layer including phosphorus ions. The second doped region 20 is a P-type doped region and has a second doped layer including boron ions. The height of the second doped layer is higher than the height of the first doped layer. The width of the first doped region 10 is in the range of 150 to 450 μm, and the width of the second doped region 20 is in the range of 200 to 500 μm. The isolation region 30 includes a first isolation partition 110 near the first doped region 10 and a second isolation partition 120 near the second doped region 20. The height of the substrate 1 in the first isolation partition 110 is higher than the height of the substrate 1 in the second isolation partition 120. The height difference between the height of the substrate 1 in the first isolation partition 110 and the height in the second isolation partition is in the range of 1 to 4 μm. The height difference between the first isolation partition 110 and the first doped region 10 can be in the range of 1.5 to 5 μm, and the height difference between the second isolation partition 120 and the first doped region 10 can be in the range of 2.5 to 9 μm. The width of the first isolation partition 110 is in the range of 50 to 150 μm, and the width of the second isolation partition 120 is in the range of 10 to 50 μm. At least one of the multiple isolation partitions is textured, and / or at least one of the multiple isolation partitions is polished.

[0102] Example 2

[0103] The difference from Example 1 is that, as Figure 2 As shown, the isolation region 30 of Embodiment 2 includes a first isolation partition 210, a second isolation partition 220, and a third isolation partition 230 arranged sequentially, with the heights of the first isolation partition 210, the second isolation partition 220, and the third isolation partition 230 decreasing progressively. The total height difference of the substrate 1 across the multiple isolation partitions is in the range of 2 to 8 μm. The height difference between the substrate 1 in the first isolation partition 210 and the second isolation partition 220 is in the range of 1 to 4 μm. The height difference between the substrate 1 in the second isolation partition 220 and the third isolation partition 230 is in the range of 1 to 4 μm. The width of the first isolation partition 210 is in the range of 50 to 150 μm, the width of the second isolation partition 220 is in the range of 10 to 50 μm, and the width of the third isolation partition 230 is in the range of 10 to 50 μm. The height difference between the first isolation partition 210 and the first doped region 10 is in the range of 1.5 to 5 μm, and the height difference between the third isolation partition 230 and the first doped region 10 is in the range of 3.5 to 13 μm.

[0104] Example 3

[0105] The difference from Example 1 is that, as Figure 3 As shown, the isolation region 30 of Embodiment 3 includes a first isolation partition 310, a second isolation partition 320, and a third isolation partition 330 arranged sequentially, wherein the second isolation partition 320 has the highest relative height. The total height difference of the substrate 1 across the multiple isolation partitions is in the range of 1 to 4 μm. The height difference between the substrate 1 in the first isolation partition 310 and the second isolation partition 320 is in the range of 1 to 4 μm. The height difference between the substrate 1 in the second isolation partition 320 and the third isolation partition 330 is in the range of 1 to 4 μm. The width of the first isolation partition 310 is in the range of 10 to 50 μm, the width of the second isolation partition 320 is in the range of 50 to 150 μm, and the width of the third isolation partition 330 is in the range of 10 to 50 μm.

[0106] Example 4

[0107] The difference from Example 3 is that, as Figure 4 As shown, the isolation region 30 of Embodiment 4 includes a first isolation partition 410, a second isolation partition 420, a third isolation partition 430, and a fourth isolation partition 440 arranged sequentially. The height of the substrate 1 in the second isolation partition 420 is greater than the height of the substrate 1 in any of the other isolation partitions. The total height difference of the substrate 1 in the multiple isolation partitions can be in the range of 2 to 8 μm. The height difference between the substrate 1 in the first isolation partition 410 and the height in the second isolation partition 420 can be in the range of 1 to 4 μm. The height difference between the substrate 1 in the second isolation partition 420 and the height in the third isolation partition 430 can be in the range of 0.5 to 2 μm, and the height difference between the substrate 1 in the third isolation partition 430 and the height in the fourth isolation partition 440 can be in the range of 0.5 to 2 μm. The width of the first isolation partition 410 can be in the range of 10 to 50 μm, the width of the second isolation partition 420 can be in the range of 40 to 140 μm, the width of the third isolation partition 430 can be in the range of 5 to 25 μm, and the width of the fourth isolation partition 440 can be in the range of 5 to 25 μm.

[0108] Example 5

[0109] The difference from Example 1 is that, as Figure 5As shown, the height of the substrate 1 in the first isolation partition 510 is lower than the height of the substrate 1 in the second isolation partition 520. The height difference between the first isolation partition 510 and the first doped region 10 is in the range of 2.5 to 9 μm, and the height difference between the second isolation partition 520 and the first doped region 10 is in the range of 1.5 to 5 μm. The width of the first isolation partition 510 is in the range of 10 to 50 μm, and the width of the second isolation partition 520 is in the range of 50 to 150 μm.

[0110] Example 6

[0111] The difference from Embodiment 1 is that the substrate 1 has transition surfaces connecting adjacent isolation zones in a plurality of isolation zones. The transition surfaces are planar. The angle between the transition surfaces and the substrate 1 in adjacent isolation zones is in the range of 45° to 65°. The transition surfaces have a scaly texture.

[0112] In a second aspect, this disclosure provides a battery assembly including the solar cell of the first aspect embodiment.

[0113] Thirdly, this disclosure provides a photovoltaic system including a battery module according to the second aspect embodiment.

[0114] Fourthly, this disclosure provides a method for manufacturing a solar cell, used to manufacture the solar cell of the first aspect embodiment, comprising:

[0115] At least two laser processing and wet etching are used to form the substrate in which adjacent isolation partitions in a plurality of isolation partitions have different heights.

[0116] Therefore, the manufacturing method of this disclosure, through at least two alternating cycles of laser processing and wet etching, can specifically remove residual doped material in specific areas within the isolation zone, solving the problem of doped material residue caused by uneven energy in a single laser processing. Furthermore, this method can be based on existing solar cell processing equipment without introducing new process equipment, has a minimal impact on overall production costs, and possesses good process compatibility and industrialization feasibility.

[0117] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in connection with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of this disclosure as set forth by the appended claims.

Claims

1. A solar cell, characterized by, Comprising: a substrate having opposite first and second faces; a first doped region and a second doped region disposed on the first face in a first direction parallel to the first face, and a doping type of the first doped region being different from a doping type of the second doped region; an isolation region disposed between the first doped region and the second doped region in the first direction for spacing the first doped region and the second doped region; wherein the isolation region comprises a plurality of isolation sub-regions disposed in the first direction; and in a second direction perpendicular to the first face, the substrate has different heights in adjacent isolation sub-regions among the plurality of isolation sub-regions.

2. The solar cell according to claim 1, characterized in that, In the first direction, for any two adjacent isolation sub-regions, a height of the substrate in the isolation sub-region closer to the first doped region is greater than a height of the substrate in the isolation sub-region closer to the second doped region.

3. The solar cell according to claim 2, characterized in that, In the first direction, the plurality of isolation sub-regions comprises a first isolation sub-region closer to the first doped region and a second isolation sub-region closer to the second doped region, and a height difference between the height of the substrate in the first isolation sub-region and the height of the substrate in the second isolation sub-region is in a range of 1 to 4 μm.

4. The solar cell according to claim 3, characterized in that, In the first direction, a ratio of a width of the first isolation sub-region to a width of the second isolation sub-region is in a range of 1 to 15.

5. The solar cell according to claim 3, wherein In the first direction, the width of the first isolation sub-region is in a range of 50 to 150 μm, and the width of the second isolation sub-region is in a range of 10 to 50 μm.

6. The solar cell of claim 3, wherein In the first direction, a ratio of a width of the first doped region to a width of the first isolation sub-region is in a range of 1 to 9.

7. The solar cell of claim 3, wherein In the first direction, a ratio of a width of the second doped region to a width of the second isolation sub-region is in a range of 4 to 50.

8. The solar cell of claim 2, wherein, In the first direction from the first doped region to the second doped region, the plurality of isolation sub-regions comprises a first isolation sub-region, a second isolation sub-region, and a third isolation sub-region disposed in sequence, and a total height difference of the heights of the substrate in the plurality of isolation sub-regions is in a range of 2 to 8 μm.

9. The solar cell of claim 8, wherein, The height difference between the height of the substrate in the first isolation sub-region and the height of the substrate in the second isolation sub-region, and the height difference between the height of the substrate in the second isolation sub-region and the height of the substrate in the third isolation sub-region are in a range of 1 to 4 μm.

10. The solar cell of claim 8, wherein, In the first direction, a ratio of a sum of the width of the second isolation sub-region and the width of the third isolation sub-region to the width of the first isolation sub-region is in a range of 0.5 to 7.

5.

11. The solar cell of claim 10, wherein, In the first direction, the width of the first isolation sub-region, the width of the second isolation sub-region, and the width of the third isolation sub-region are the same.

12. The solar cell of claim 10, wherein, In the first direction, the width of the second isolation sub-region and the width of the third isolation sub-region are the same and smaller than the width of the first isolation sub-region.

13. The solar cell of claim 10, wherein, In the first direction, the width of the first isolation sub-region is in a range of 50 to 150 μm, the width of the second isolation sub-region is in a range of 10 to 50 μm, and the width of the third isolation sub-region is in a range of 10 to 50 μm.

14. The solar cell of claim 8, wherein, In the first direction, a ratio of a width of the first doped region to a width of the first isolation partition is in a range of 1 to 9.

15. The solar cell of claim 8, wherein, In the first direction, a ratio of a width of the second doped region to a width of the third isolation partition is in a range of 4 to 50.

16. The solar cell of claim 1, wherein, The plurality of isolation partitions includes at least three isolation partitions, and in the first direction, a height of the substrate at one of the at least three isolation partitions between other isolation partitions is greater than a height of the substrate at any other isolation partition.

17. The solar cell of claim 16, wherein, In the first direction from the first doped region to the second doped region, the plurality of isolation partitions includes a first isolation partition, a second isolation partition, and a third isolation partition arranged in sequence, and a total height difference of the heights of the substrate at the plurality of isolation partitions is in a range of 1 to 4 μm.

18. The solar cell of claim 17, wherein, A height difference of the height of the substrate at the first isolation partition to the height of the substrate at the second isolation partition, and a height difference of the height of the substrate at the second isolation partition to the height of the substrate at the third isolation partition is in a range of 1 to 4 μm.

19. The solar cell of claim 17, wherein, In the first direction, a ratio of a sum of a width of the first isolation partition and a width of the third isolation partition to a width of the second isolation partition is in a range of 0.5 to 7.

5.

20. The solar cell of claim 19, wherein, In the first direction, widths of the first isolation partition, the second isolation partition, and the third isolation partition are the same.

21. The solar cell of claim 19, wherein, In the first direction, a width of the first isolation partition and a width of the third isolation partition are the same and less than a width of the second isolation partition.

22. The solar cell of claim 19, wherein, In the first direction, a width of the first isolation partition is in a range of 10 to 50 μm, a width of the second isolation partition is in a range of 50 to 150 μm, and a width of the third isolation partition is in a range of 10 to 50 μm.

23. The solar cell of claim 17, wherein, In the first direction, a ratio of a width of the first doped region to a width of the first isolation partition is in a range of 3 to 45.

24. The solar cell of claim 17, wherein, In the first direction, a ratio of a width of the second doped region to a width of the third isolation partition is in a range of 4 to 50.

25. The solar cell of claim 16, wherein, In the first direction from the first doped region to the second doped region, the plurality of isolation partitions includes a first isolation partition, a second isolation partition, a third isolation partition, and a fourth isolation partition arranged in sequence, wherein a height of the substrate at the second isolation partition is greater than a height of the substrate at any other isolation partition, and a total height difference of the heights of the substrate at the plurality of isolation partitions is in a range of 2 to 8 μm.

26. The solar cell of claim 25, wherein, A height difference of the height of the substrate at the first isolation partition to the height of the substrate at the second isolation partition is in a range of 1 to 4 μm.

27. The solar cell of claim 25, wherein, A height difference of the height of the substrate at the second isolation partition to the height of the substrate at the third isolation partition is in a range of 0.5 to 2 μm, and a height difference of the height of the substrate at the third isolation partition to the height of the substrate at the fourth isolation partition is in a range of 0.5 to 2 μm.

28. The solar cell of claim 25, wherein, In the first direction, a ratio of a sum of the width of the first isolation partition and the width of the second isolation partition to a sum of the width of the third isolation partition and the width of the fourth isolation partition is in a range of 0.5 to 7.

5.

29. The solar cell of claim 28, wherein, In the first direction, the width of the first isolation partition, the width of the second isolation partition, the width of the third isolation partition, and the width of the fourth isolation partition are the same.

30. The solar cell of claim 28, wherein, In the first direction, the width of the first isolation partition is in a range of 10 to 50 μm, the width of the second isolation partition is in a range of 40 to 140 μm, the width of the third isolation partition is in a range of 5 to 25 μm, and the width of the fourth isolation partition is in a range of 5 to 25 μm.

31. The solar cell of claim 25, wherein, In the first direction, a ratio of the width of the first doped region to the width of the first isolation partition is in a range of 3 to 45.

32. The solar cell of claim 25, wherein, In the first direction, a ratio of the width of the third isolation partition to the width of the fourth isolation partition is in a range of 2 to 50.

33. The solar cell of claim 1, wherein, At least one of the plurality of isolation partitions is a matte surface, and / or at least one of the plurality of isolation partitions is a polished surface.

34. The solar cell of claim 1, wherein, The first doped region is formed with a first doped layer, and the second doped region is formed with a second doped layer, a height of the second doped layer being higher than a height of the first doped layer.

35. The solar cell of claim 34, wherein, Doped ions in the first doped layer include phosphorus ions, and doped ions of the second doped layer include boron ions.

36. The solar cell of claim 1, wherein, The substrate is connected with a transition surface between adjacent isolation partitions of the plurality of isolation partitions.

37. The solar cell of claim 36, wherein, The transition surface is a flat surface.

38. The solar cell of claim 37, wherein, An angle of the transition surface with the substrate at the adjacent isolation partitions is in a range of 45° to 65°.

39. The solar cell of claim 36, wherein, The transition surface is formed with a scale-like texture.

40. A battery assembly comprising: A solar cell as claimed in any one of claims 1 to 39.

41. A photovoltaic system characterized by, A battery assembly as claimed in claim 40.

42. A method of manufacturing a solar cell, characterized by, A method for manufacturing a solar cell as claimed in any one of claims 1 to 39, comprising: at least twice laser processing and wet etching for forming the substrate with different heights between adjacent isolation partitions of the plurality of isolation partitions.

Images