Solar cell, photovoltaic module, and photovoltaic system

Abstract

The application relates to the photovoltaic technical field, in particular to a solar cell, a photovoltaic module and a photovoltaic system. A doped layer of the solar cell is arranged on the surface of a silicon substrate layer, and a passivation layer is arranged on the doped layer. The passivation layer is provided with a plurality of conductive windows penetrating along a first direction, the conductive windows are used for exposing the doped layer, the conductive windows form a plurality of rows along a second direction, and each row of the conductive windows is arranged at intervals along a third direction. Each row of adjacent conductive windows has a center spacing, the length l1 of at least one of the center spacings in a first length interval L1 of each row of the conductive windows is smaller than the length l2 of at least one of the center spacings in a second length interval L2, and an electrode sequentially passes through each row of the conductive windows along the third direction to form an ohmic contact with the doped layer. The conductive windows in the edge region are arranged more densely, the transmission distance of the carriers in the edge region is shortened, and the resistance loss in the carrier transmission process is reduced. A larger number of the conductive windows effectively reduces the contact resistance between the electrode and the doped layer.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a solar cell, photovoltaic module and photovoltaic system. Background Technology

[0002] In crystalline silicon solar cell applications, the emitter is responsible for collecting photogenerated carriers and conducting them to the metal electrode. The contact interface between the emitter and the metal electrode is the critical path for current transport. However, a high contact resistance between the metal electrode and the cell emitter results in significant resistive losses, causing the photogenerated energy to be dissipated as heat, reducing the photoelectric conversion efficiency of the solar cell, and affecting the improvement of the solar cell's photoelectric performance. Summary of the Invention

[0003] Therefore, it is necessary to provide a solar cell, photovoltaic module, and photovoltaic system to address the problem of high contact resistance between the metal electrodes and emitters of solar cells, which leads to significant resistance loss.

[0004] In a first aspect, a solar cell includes:

[0005] Silicon substrate;

[0006] A doped layer is stacked on the surface of the silicon substrate layer along a first direction, which is the thickness direction of the solar cell;

[0007] A passivation layer is stacked along the first direction on the surface of the doped layer away from the silicon substrate. The passivation layer has a plurality of conductive windows extending through it along the first direction. The conductive windows are used to expose the doped layer. The conductive windows are arranged in multiple rows along the second direction. Each row of conductive windows is spaced apart along a third direction. The third direction intersects the first direction and the second direction in pairs and the three directions are not coplanar.

[0008] Each row of adjacent conductive windows has a center-to-center spacing. Each row of conductive windows forms two connected first length intervals L1 and second length intervals L2 along the third direction upwards. The first length interval L1 includes a portion of the center-to-center spacing near the edge of the solar cell, and the second length interval L2 includes another portion of the center-to-center spacing near the center of the solar cell. The length l1 of at least one center-to-center spacing within the first length interval L1 of each row of conductive windows is less than the length l2 of at least one center-to-center spacing within the second length interval L2.

[0009] The electrodes, along the third direction, sequentially pass through each row of conductive windows to form ohmic contacts with the doped layer.

[0010] In one embodiment, the length l1 of the center-to-center spacing within the first length interval L1 of each row of conductive windows increases sequentially along the third direction from the edge of the solar cell to the center of the solar cell.

[0011] And / or, the length l2 of the center spacing within the second length interval L2 of each row of conductive windows is the same;

[0012] And / or, the length of the first length interval L1 in each row of the conductive windows is H, satisfying: 30μm < H < 20mm;

[0013] And / or, in each row of the conductive windows, the ratio of the length l1 of any center spacing in the first length interval L1 to the length l2 of any center spacing in the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9;

[0014] And / or, in each row of the conductive windows, the length l2 of any of the center-to-center spacings within the second length interval L2 is less than the distance d1 between the conductive window located at the end along the third direction and the edge of the solar cell;

[0015] And / or, the length of any center spacing within the first length interval L1 in each row of conductive windows is l1, satisfying: 20μm≤l1≤300μm;

[0016] And / or, the length of any of the center-to-center spacings within the second length interval L2 in each row of the conductive windows is l2, satisfying: 25μm≤l2≤350μm.

[0017] In one embodiment, the doped layer is provided with multiple rows of first doped regions and multiple rows of second doped regions alternately spaced along the second direction, with the conductive windows of some rows located in the first doped regions of the corresponding rows, and the conductive windows of other rows located in the second doped regions of the corresponding rows.

[0018] Each row of adjacent conductive windows has a center-to-center spacing. Each row of conductive windows forms two connected first length intervals L1 and second length intervals L2 along the third direction upwards. The first length interval L1 includes a portion of the center-to-center spacing near the edge of the solar cell, and the second length interval L2 includes another portion of the center-to-center spacing near the center of the solar cell. The length l1 of any center-to-center spacing within the first length interval L1 of each row of conductive windows is less than the length l2 of any center-to-center spacing within the second length interval L2.

[0019] The electrode includes a first fine gate and a second fine gate. The first fine gate forms an ohmic contact with the first doped region through each row of conductive windows along the third direction. The second fine gate forms an ohmic contact with the second doped region through each row of conductive windows along the third direction.

[0020] In one embodiment, the doping concentration of the first doped region is less than that of the second doped region, the sheet resistance of the first doped region is greater than that of the second doped region, and the length l1 of a center-to-center distance at the third end of the first doped region is less than the length l1 of a center-to-center distance at the third end of the second doped region.

[0021] In one embodiment, the first doped region includes a first region connected to each other and multiple rows of second regions, and the second doped region includes a third region connected to each other and multiple rows of fourth regions. The first region and the third region are respectively disposed on both sides of the silicon substrate along the third direction. All the second regions and all the fourth regions are alternately spaced along the second direction. The conductive windows of some rows are located in the second region of the corresponding row, and the conductive windows of other rows are located in the fourth region of the corresponding row.

[0022] The first fine gate forms an ohmic contact with the second region through each row of conductive windows along the third direction, and the second fine gate forms an ohmic contact with the fourth region through each row of conductive windows along the third direction;

[0023] The electrode further includes a first main gate and a second main gate, the first main gate being located in the first region and extending along the second direction to be electrically connected to the first fine gate, and the second main gate being located in the third region and extending along the third direction to be electrically connected to the second fine gate;

[0024] The distance d2 between a conductive window located at one end of the first region along the third direction and close to the first main grid and the edge of the solar cell on the same side therewith, and the distance d3 between a conductive window located away from the first main grid and the edge of the solar cell on the same side therewith, satisfying d2 < d3.

[0025] And / or, the distance d4 between a conductive window on one side of the second region along the third direction and close to the edge of the solar cell on the same side as the second main grid, and the distance d5 between a conductive window on the other side of the second main grid and the edge of the solar cell on the same side as the second main grid, satisfies d4 < d5.

[0026] In one embodiment, the length of any of the center-to-center spacings located in the first doped region and within the first length interval L1 is l1, satisfying: 20μm≤l1≤300μm;

[0027] And / or, the length of any of the center-to-center spacings located in the first doped region and within the second length interval L2 is l2, satisfying: 25μm≤l2≤350μm;

[0028] And / or, the length of any of the center-to-center spacings located in the second doped region and within the first length interval L1 is l1, satisfying: 25μm≤l1≤305μm;

[0029] And / or, the length of any of the center-to-center spacings located in the second doped region and within the second length interval L2 is l2, satisfying: 30μm≤l2≤310μm.

[0030] In one embodiment, the length l1 of the center-to-center spacing located in the first doped region and within the first length interval L1 increases sequentially along the third direction from the edge of the solar cell to the center of the solar cell.

[0031] And / or, the length l1 of the center spacing located in the second doped region and within the first length interval L1 increases sequentially along the third direction from the edge of the solar cell to the center of the solar cell;

[0032] And / or, the length l2 of the center spacing located in the first doped region and within the second length interval L2 is the same;

[0033] And / or, the length l2 of the center spacing located in the second doped region and within the second length interval L2 is the same;

[0034] And / or, the length of the first length interval L1 located in the first doped region is H, satisfying: 30μm < H < 20mm;

[0035] And / or, the length of the second doped region located in the first length interval L1 is H, satisfying: 30μm < H < 20mm;

[0036] And / or, in the first doped region, the ratio of the length l1 of any of the center spacings located within the first length interval L1 to the length l2 of any of the center spacings located within the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9;

[0037] And / or, in the second doped region, the ratio of the length l1 of any of the center spacings located within the first length interval L1 to the length l2 of any of the center spacings located within the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9;

[0038] And / or, the length l2 of any of the center-to-center spacings located in the first doped region and within the second length interval L2 is less than the distances d2 and d3 between a conductive window located at the end of the first doped region and the edge of the solar cell along the third direction upwards;

[0039] And / or, the length l2 of any of the center-to-center spacings located in the second doped region and within the second length interval L2 is less than the distances d4 and d5 between a conductive window located at the end of the second doped region along the third direction and the edge of the solar cell.

[0040] In one embodiment, the outline dimension of the conductive window along the third direction is smaller than the lengths l1 and l2 of the center-to-center spacing it has.

[0041] In a second aspect, a photovoltaic module comprising a solar cell as described in the first aspect.

[0042] Thirdly, a photovoltaic system comprising photovoltaic modules as described in the second aspect.

[0043] The first length interval L1 of the aforementioned solar cell corresponds to the edge region of the solar cell. A smaller center-to-center spacing l1 within the first length interval L1 means a denser arrangement of conductive windows in the edge region. For the same length of edge region, a greater number of conductive windows can be arranged. On one hand, this brings the conductive windows closer to the edge of the solar cell, significantly shortening the carrier transport distance and reducing resistance loss during carrier transport. On the other hand, a larger number of conductive windows increases the contact area between the electrodes and the doped layer, effectively reducing the contact resistance between them. These two aspects together reduce the overall resistance of the solar cell's edge region, decrease the overall resistance loss of the solar cell, and improve the photoelectric conversion efficiency and operational stability of the solar cell. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the disclosed drawings without creative effort.

[0045] Figure 1 This is a planar schematic diagram of a solar cell provided in an embodiment of this application.

[0046] Figure 2 for Figure 1 A cross-sectional view along the RR direction.

[0047] Figure 3 This is a planar schematic diagram of another solar cell provided in an embodiment of this application.

[0048] Explanation of reference numerals in the attached figures: 100, solar cell; 1, silicon substrate; 2, doped layer; 21, first doped region; 211, first region; 212, second region; 22, second doped region; 221, third region; 222, fourth region; 3, passivation layer; 31, conductive window; 4, electrode. Detailed Implementation

[0049] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0050] Please see Figures 1 to 3 , Figure 1 This is a plan view of a solar cell 100 provided in an embodiment of this application. Figure 2 for Figure 1 A cross-sectional view along the RR direction. Figure 3 A plan view of another solar cell 100 provided in an embodiment of this application.

[0051] Please see Figure 2 The solar cell 100 includes a silicon substrate layer 1, a doped layer 2, a passivation layer 3, and an electrode 4. In this embodiment, the first direction is the thickness direction of the solar cell 100, that is, the direction in which the silicon substrate layer 1, the doped layer 2, and the passivation layer 3 are stacked. Figures 1 to 3 The first direction is shown as direction A. The second direction is the width direction of the solar cell 100, that is... Figures 1 to 3 The direction shown is B. The third direction is the length direction of the solar cell 100, that is... Figures 1 to 3 The direction C is shown. The first direction, the second direction, and the third direction intersect each other and are not coplanar. The three directions together form a spatial rectangular coordinate system.

[0052] The silicon substrate 1 is the substrate of the solar cell 100, providing the basis for the formation of the PN junction; it can also be called the silicon substrate layer or the base layer. The doped layer 2 is a doped semiconductor layer stacked on the surface of the silicon substrate 1, used to form a PN junction with the silicon substrate 1; it can also be called the emitter or base layer. The passivation layer 3 is an insulating passivation film covering the surface of the doped layer 2, used to passivate surface defects of the doped layer 2. The conductive window 31 is an opening structure penetrating the passivation layer 3 along a first direction, used to expose the doped layer 2, allowing the electrode 4 to form electrical contact with the doped layer 2; it can also be called a contact opening or an electrode window. The electrode 4 is a metallic conductive structure used to collect the current generated by the solar cell 100; it can also be called a collecting electrode or a metal electrode.

[0053] Please see Figure 2 In some embodiments, the doped layer 2 is stacked on the surface of the silicon substrate 1 along a first direction, which is the thickness direction of the solar cell 100; the passivation layer 3 is stacked on the surface of the doped layer 2 away from the silicon substrate 1 along the first direction, and the passivation layer 3 has a plurality of conductive windows 31 extending through it along the first direction. The conductive windows 31 are used to expose the doped layer 2. Please refer to [link to relevant documentation]. Figure 1 The conductive windows 31 are arranged in multiple rows along the second direction, and each row of conductive windows 31 is arranged at intervals along the third direction. The third direction intersects the first direction and the second direction in pairs and the three directions are not coplanar. Each row of adjacent conductive windows 31 has a center-to-center distance. Each row of conductive windows 31 forms two connected first length intervals L1 and second length intervals L2 along the third direction. The first length interval L1 includes a part of the center-to-center distance near the edge of the solar cell 100, and the second length interval L2 includes another part of the center-to-center distance near the center of the solar cell 100. The length l1 of at least one center-to-center distance in the first length interval L1 of each row of conductive windows 31 is less than the length l2 of at least one center-to-center distance in the second length interval. The electrode 4 forms an ohmic contact with the doped layer 2 by passing through each row of conductive windows 31 along the third direction.

[0054] It is understandable that the center-to-center spacing is the straight-line distance between the geometric centers of two adjacent conductive windows 31 within the same row. The first length interval L1 is a portion of the conductive windows 31 in the same row extending upwards along a third direction, near the edge of the solar cell 100. This interval includes a portion of the center-to-center spacing of adjacent conductive windows 31, which is l1. The second length interval L2 is a portion of the conductive windows 31 in the same row extending upwards along a third direction, near the center of the solar cell 100. This interval includes the remaining portion of the center-to-center spacing of adjacent conductive windows 31, which is l2.

[0055] When the solar cell 100 is operating, photons are absorbed upon impact with the silicon substrate 1, generating electron-hole pairs. Under the influence of the built-in electric field, these pairs separate, and charge carriers of different polarities migrate to their respective electrodes 4, where they are ultimately collected to output current. The doped layer 2 acts as the emitter, forming a PN junction with the silicon substrate 1. A passivation layer 3 on the doped layer 2 effectively passivates surface defects and suppresses carrier recombination, while also providing anti-reflection and insulation protection against leakage, thus improving the photoelectric conversion efficiency and operational stability of the solar cell 100. A conductive window 31 is formed on the passivation layer 3, through which the electrode 4 forms an ohmic contact with the doped layer 2, thereby conducting current.

[0056] The first length interval L1 corresponds to the edge region of the solar cell 100. A smaller center-to-center spacing l1 within the first length interval L1 means that the conductive windows 31 in the edge region are more densely arranged. For the same length of edge region, a greater number of conductive windows 31 can be arranged. On one hand, this brings the conductive windows 31 closer to the edge of the solar cell 100, significantly shortening the carrier transport distance in the edge region and reducing resistance loss during carrier transport. On the other hand, a greater number of conductive windows 31 increases the contact area between the electrode 4 and the doped layer 2, effectively reducing the contact resistance between the electrode 4 and the doped layer 2. These two aspects together reduce the overall resistance of the edge region of the solar cell 100, reduce the overall resistance loss of the solar cell 100, and improve the photoelectric conversion efficiency and operational stability of the solar cell 100.

[0057] The embodiments of this application do not limit the outline shape of the conductive window 31. The outline shape of the conductive window 31 can be circular, square, elliptical, etc.

[0058] In some embodiments, the outline dimension of the conductive window 31 along the third direction is smaller than the lengths l1 and l2 of its center-to-center spacing. If the outline dimension of the conductive window 31 along the third direction is greater than or equal to the lengths l1 and l2 of its center-to-center spacing, adjacent conductive windows 31 will overlap, resulting in a large area of ​​exposed doped layer 2, a significant reduction in the area of ​​passivation layer 3, and a significant increase in surface recombination loss. Making the outline dimension of the conductive window 31 along the third direction smaller than the length of its center-to-center spacing ensures that adjacent conductive windows 31 are separated from each other, retains a sufficient area of ​​passivation layer 3, reduces unnecessary recombination loss, and balances the contact performance and recombination performance of the conductive window 31.

[0059] In this embodiment, the silicon substrate 1 can be an N-type silicon substrate or a P-type silicon substrate. The doped layer 2 can be N-type doped or P-type doped. The doping polarity of the doped layer 2 is the same as or opposite to that of the silicon substrate 1. When the doping polarity of the doped layer 2 and the silicon substrate 1 is the same, they form a high-low junction. When the doping polarity of the doped layer 2 and the silicon substrate 1 is opposite, they form a PN junction. The doped layer 2 can be doped polycrystalline silicon, doped microcrystalline silicon, doped nanocrystalline silicon, doped monocrystalline silicon, doped amorphous silicon, etc.

[0060] The passivation layer 3 in this embodiment can be a single-layer structure or a multi-layer structure, both of which can achieve the functions of passivation and insulation. The passivation layer 3 can be made of alumina, silicon oxide, silicon nitride, or a composite material of alumina and silicon nitride.

[0061] The silicon substrate 1 in this embodiment includes a light-incident surface and a back-light surface disposed opposite to each other. The doped layer 2, the passivation layer 3, and the electrode 4 may be disposed on the light-incident surface of the silicon substrate 1, or on the back-light surface of the silicon substrate 1, or simultaneously on both the light-incident surface and the back-light surface of the silicon substrate 1.

[0062] In this embodiment, electrode 4 can be a silver paste sintered electrode, a copper electroplated electrode, or a vacuum-deposited aluminum electrode, all of which can form a stable ohmic contact. Electrode 4 can be connected to the doped layer 2 by sintering or by pressing, achieving a low-resistance contact.

[0063] The solar cell 100 in this application embodiment can be a TOPCon (Tunnel Oxide Passivated Contact) solar cell or a BC (Back Contact Cell) solar cell, etc., both of which can achieve the effect of reducing resistance loss.

[0064] Please see Figure 1In some embodiments, the length l1 of the center-to-center spacing within the first length region L1 of each row of conductive windows 31 increases sequentially along a third direction from the edge of the solar cell 100 towards the center of the solar cell 100. The conductive windows 31 are processed using a laser etching process. The laser moves along a third direction from one edge of the solar cell 100 towards the center, and then from the center towards the other edge. During processing, the laser speed gradually increases to its maximum and then remains constant, before gradually decreasing. As the laser speed gradually increases, the processing interval between two adjacent conductive windows 31 gradually increases, forming the first length region L1 where the center-to-center spacing increases sequentially from the edge to the center. This arrangement matches the laser etching process, requiring only continuous adjustment of the laser speed during processing. It eliminates the need for frequent laser start-ups and stops, and avoids the need for pre-designing complex unequal spacing coordinates. This reduces processing difficulty and increases processing efficiency, significantly lowering the processing cost of the solar cell 100.

[0065] The length l1 of the center-to-center spacing within the first length interval L1 of each row of conductive windows 31 can be increased sequentially along a third direction from the edge of the solar cell 100 to the center of the solar cell 100. This can be either an equal increase, meaning that the value of the center-to-center spacing l1 increases by the same amount for each window, or an unequal increase, meaning that the value of the center-to-center spacing l1 increases by different amounts for each window.

[0066] Please see Figure 1 In some embodiments, the center-to-center spacing length l2 within the second length interval L2 of each row of conductive windows 31 is the same. During laser etching, the laser moving speed remains constant after reaching a preset maximum value, thus the center-to-center spacing length of adjacent conductive windows 31 obtained by etching is the same, forming the second length interval L2. The carrier transport distance in the central region of the solar cell 100 is inherently shorter, resulting in lower resistance loss. The processing difficulty of equally spaced arrangement is the lowest, while ensuring that a sufficient area of ​​passivation layer 3 is retained in the central region, reducing carrier recombination loss in the central region, and balancing resistance loss and recombination loss.

[0067] Please see Figure 1In some embodiments, the length of the first length interval L1 in each row of conductive windows 31 is H, satisfying: 30μm < H < 20mm. If the length of H is less than or equal to 30μm, it indicates that the length of the first length interval L1 is too small, resulting in a small number of densely packed conductive windows 31 that can be arranged in the edge region, and the effect of reducing edge resistance is not significant. If the length of H is greater than or equal to 20mm, it indicates that the length of the first length interval L1 is too large, and if densely packed conductive windows 31 are arranged in an excessively large area, the total area of ​​the conductive windows 31 will be too large, the area ratio of the passivation layer 3 will be insufficient, the surface recombination loss will increase significantly, and the light-shielding area of ​​the electrode 4 will also increase, which will reduce the photoelectric conversion efficiency of the solar cell 100. Controlling the first length interval L1 within the above range can balance resistance loss and recombination loss and improve photoelectric conversion efficiency.

[0068] The length H of the first length interval L1 in each row of conductive windows 31 can be any value within the above range, such as 30μm, 40μm, 50μm, 60μm, 10mm, 15mm, etc.

[0069] Please see Figure 1 In some embodiments, the ratio of the length l1 of any center-to-center spacing within the first length interval L1 to the length l2 of any center-to-center spacing within the second length interval L2 in each row of conductive windows 31 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9. If X is less than or equal to 0.1, it indicates that the length l1 of the center-to-center spacing within the first length interval L1 is too small, resulting in overly dense conductive windows 31, which leads to a significant increase in recombination loss, offsetting the benefits of reduced resistance. If X is greater than or equal to 0.9, it indicates that the difference between the length l1 of the center-to-center spacing within the first length interval L1 and the length l2 of the center-to-center spacing within the second length interval L2 is too small, the effect of dense arrangement is not obvious, and it cannot effectively reduce the overall resistance of the edge region. Controlling X within the above range can ensure the density of the edge conductive windows 31 without causing excessive recombination loss, balancing the resistance loss and recombination loss in the edge region.

[0070] The ratio X of the length l1 of any center-to-center distance within the first length interval L1 to the length l2 of any center-to-center distance within the second length interval L2 can be any value within the above range, such as 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0071] Please see Figure 1In some embodiments, the length l2 of any center-to-center spacing within the second length interval L2 of each row of conductive windows 31 is less than the distance d1 between the end conductive window 31 and the edge of the solar cell 100 along a third upward direction. When the length l2 of the center-to-center spacing within the second length interval L2 is greater than the distance d1 between the end conductive window 31 and the edge of the solar cell 100, the circuit transmission path will be increased, resulting in increased resistance loss and affecting electrical performance.

[0072] Please see Figure 1 In some embodiments, the length of any center-to-center distance within the first length interval L1 in each row of conductive windows 31 is l1, satisfying: 20μm≤l1≤300μm. If l1 is less than 20μm, the conductive windows 31 in the first length interval are too dense, resulting in excessive recombination loss; if l1 is greater than 300μm, the conductive windows 31 are too sparse, resulting in insufficient contact resistance reduction.

[0073] The center spacing l1 within the first length interval L1 can be any value within the above range, such as 20μm, 40μm, 60μm, 80μm, 100μm, 200μm, 300μm, etc.

[0074] Please see Figure 1 In some embodiments, the length of any center-to-center spacing within the second length interval L2 of each row of conductive windows 31 is l2, satisfying: 25μm≤l2≤350μm. If l2 is less than 25μm, the conductive windows 31 in the central region are too dense, resulting in excessive recombination loss; if l2 is greater than 350μm, the contact resistance in the central region is too high.

[0075] The center spacing l2 within the second length interval L2 can be any value within the above range, such as 25μm, 40μm, 60μm, 80μm, 100μm, 200μm, 300μm, 350μm, etc.

[0076] This application also provides a solar cell 100, which is a back-contact solar cell.

[0077] Please see Figure 3In some embodiments, the doped layer 2 is provided with multiple rows of first doped regions 21 and multiple rows of second doped regions 22 alternately spaced along the second direction. The conductive windows 31 of some rows are located in the first doped regions 21 of the corresponding row, and the conductive windows 31 of other rows are located in the second doped regions 22 of the corresponding row. Each row of adjacent conductive windows 31 has a center-to-center spacing. Each row of conductive windows 31 forms two connected first length intervals L1 and second length intervals L2 along the third direction. The first length interval L1 includes a portion of the center-to-center spacing near the edge of the solar cell 100, and the second length interval L2 includes another portion of the center-to-center spacing near the center of the solar cell 100. The length l1 of any center-to-center spacing in the first length interval L1 of each row of conductive windows 31 is less than the length l2 of any center-to-center spacing in the second length interval L2. The electrode 4 includes a first fine gate and a second fine gate. The first fine gate forms an ohmic contact with the first doped region 21 through each row of conductive windows 31 along the third direction, and the second fine gate forms an ohmic contact with the second doped region 22 through each row of conductive windows 31 along the third direction.

[0078] Understandably, the first doped region 21 is a doped region of the first polarity in the solar cell 100, used to collect first polarity charge carriers, and can also be called an N-type doped region or a P-type doped region; the second doped region 22 is a doped region of the second polarity in the back contact solar cell 100, used to collect second polarity charge carriers, and can also be called a P-type doped region or an N-type doped region. When the first doped region 21 is an N-type doped region, the second doped region 22 is a P-type doped region. When the first doped region 21 is a P-type doped region, the second doped region 22 is an N-type doped region.

[0079] When the silicon substrate 1 of the solar cell 100 is an N-type silicon substrate, the first doped region 21 can be N-type doped and the second doped region 22 can be P-type doped. The first doped region 21 forms a high-low junction with the N-type silicon substrate 1, and the second doped region 22 forms a PN junction with the N-type silicon substrate 1. Alternatively, when the silicon substrate 1 of the solar cell 100 is an N-type silicon substrate, the first doped region 21 can be P-type doped and the second doped region 22 can be N-type doped. The first doped region 21 forms a PN junction with the N-type silicon substrate 1, and the second doped region 22 forms a high-low junction with the N-type silicon substrate 1. Alternatively, when the silicon substrate 1 of the solar cell 100 is a P-type silicon substrate, the first doped region 21 can be P-type doped and the second doped region 22 can be N-type doped. The first doped region 21 forms a high-low junction with the N-type silicon substrate 1, and the second doped region 22 forms a PN junction with the N-type silicon substrate 1. Alternatively, when the silicon substrate 1 of the solar cell 100 is a P-type silicon substrate, the first doped region 21 can be N-type doped and the second doped region 22 can be P-type doped. The first doped region 21 forms a PN junction with the N-type silicon substrate 1, and the second doped region 22 forms a high-low junction with the N-type silicon substrate 1.

[0080] The PN junction and all electrodes 4 of the back-contact solar cell 100 are located on the back side of the cell, with no electrode structure on the front side. This significantly increases the front-side light-receiving area and achieves higher current output. In this embodiment, the structure of densely arranged conductive windows 31 at the edges is applied to each row of the first doped region 21 and the second doped region 22 of the back-contact solar cell 100. Each row of the first doped region 21 and the second doped region 22 can achieve the effect of reducing the overall edge resistance, which is consistent with the effect of non-back-contact solar cells 100. This effectively reduces the overall resistance loss of the back-contact solar cell 100 and improves the photoelectric conversion efficiency of the back-contact solar cell 100.

[0081] Please see Figure 3 In some embodiments, the doping concentration of the first doped region 21 is lower than that of the second doped region 22, the sheet resistance of the first doped region 21 is greater than that of the second doped region 22, and the length l1 of a center-to-center distance at one end of the first doped region 21 along a third direction is less than the length l1 of a center-to-center distance at the same end of the second doped region 22. The lower doping concentration and higher sheet resistance of the first doped region 21 allow it to carry a higher current density. This higher current results in greater Joule resistance loss, thus requiring a lower contact resistance to match the current demand. Setting the center-to-center distance at the ends of the first doped region 21 to be less than the center-to-center distance at the same end of the second doped region 22 makes the edge conductive windows 31 of the first doped region 21 more densely packed, resulting in a larger contact area and lower contact resistance. This matches the high current demand of the first doped region 21, further reducing overall resistance loss and improving the conversion efficiency of the solar cell 100.

[0082] Please see Figure 3In some embodiments, the first doped region 21 includes a first region 211 connected to each other and multiple rows of second regions 212, and the second doped region 22 includes a third region 221 connected to each other and multiple rows of fourth regions 222. The first region 211 and the third region 221 are respectively disposed on both sides of the silicon substrate 1 along a third direction; all the second regions 212 and all the fourth regions 222 are alternately spaced along a second direction; the conductive windows 31 of some rows are located in the second regions 212 of the corresponding row, and the conductive windows 31 of other rows are located in the fourth regions 222 of the corresponding row; the first fine gate forms an ohmic contact with the second region 212 along a third direction through each row of conductive windows 31, and the second fine gate forms an ohmic contact with the second region 212 along a third direction. The third direction forms an ohmic contact with the fourth region 222 through each row of conductive windows 31; the electrode 4 also includes a first main grid and a second main grid, the first main grid being located in the first region 211 and extending along the second direction to be electrically connected to all the first fine grids, and the second main grid being located in the third region 221 and extending along the second direction to be electrically connected to all the second fine grids; the distance d2 between a conductive window 31 located at one end of each row of the second region 212 along the third direction and close to the edge of the solar cell 100 on the same side, and the distance d3 between a conductive window 31 located at the other end of each row of the second region 212 away from the first main grid and the edge of the solar cell 100 on the same side, satisfies d2 < d3. The distance d4 between a conductive window 31 located at one end of each row of the second region 212 along the third direction and close to the edge of the second main grid and the edge of the solar cell 100 on the same side, and the distance d5 between a conductive window 31 located at the other end of each row of the second region 212 away from the second main grid and the edge of the solar cell 100 on the same side, satisfies d4 < d5.

[0083] Understandably, the first region 211 is the area of ​​the first doped region 21 located at the edge of the solar cell 100 for setting the first main gate. The second region 212 is the area of ​​the first doped region 21 for extending and setting the first fine gate. The third region 221 is the area of ​​the second doped region 22 located at the other edge of the solar cell 100 for setting the second main gate. The fourth region 222 is the area of ​​the second doped region 22 for extending and setting the second fine gate. The first main gate collects all the current from the first fine gate, and the second main gate collects all the current from the second fine gate. The conductive window 31 near the first or second main gate is closer to the edge of the corresponding solar cell 100, which shortens the path of carrier transport to the first or second main gate, effectively reducing resistance loss during transport and improving current collection efficiency.

[0084] Please see Figure 3In some embodiments, the length of any center-to-center spacing located in the first doped region 21 and within the first length interval L1 is l1, satisfying: 20μm≤l1≤300μm. If l1 is less than 20μm, the conductive window 31 in the first length interval L1 is too dense, resulting in excessive recombination loss; if l1 is greater than 300μm, the conductive window 31 is too sparse, resulting in insufficient contact resistance reduction.

[0085] The center spacing l1 located in the first doped region 21 and within the first length interval L1 can be any value within the above range, such as 20μm, 40μm, 60μm, 80μm, 100μm, 200μm, 300μm, etc.

[0086] Please see Figure 3 In some embodiments, the length of any center-to-center spacing located in the first doped region 21 and within the second length interval L2 is l2, satisfying: 25μm≤l2≤350μm. If l2 is less than 25μm, the conductive window 31 in the central region is too dense, resulting in excessive recombination loss; if l2 is greater than 350μm, the contact resistance in the central region is too high.

[0087] The center spacing l2 within the second length interval L2 can be any value within the above range, such as 25μm, 40μm, 60μm, 80μm, 100μm, 200μm, 300μm, 350μm, etc.

[0088] Please see Figure 3 In some embodiments, the length of any center-to-center spacing located in the second doped region 22 and within the first length interval L1 is l1, satisfying: 25μm≤l1≤305μm. If l1 is less than 25μm, the conductive window 31 in the central region is too dense, resulting in excessive recombination loss; if l1 is greater than 305μm, the contact resistance in the central region is too high.

[0089] The center spacing l1 located in the second doped region 22 and within the first length interval L1 can be any value within the above range, such as 25μm, 40μm, 60μm, 80μm, 100μm, 200μm, 300μm, 305μm, etc.

[0090] In some embodiments, the length of any center-to-center spacing located in the second doped region 22 and within the second length interval L2 is l2, satisfying: 30μm≤l2≤310μm. If l2 is less than 30μm, the conductive window 31 in the central region is too dense, resulting in excessive recombination loss; if l2 is greater than 310μm, the contact resistance in the central region is too high.

[0091] The center spacing l2 located in the second doped region 22 and within the second length interval L2 can be any value within the above range, such as 30μm, 40μm, 60μm, 80μm, 100μm, 200μm, 300μm, 310μm, etc.

[0092] Please see Figure 3 In some embodiments, the length l1 of the center-to-center spacing located in the first doped region 21 and within the first length interval L1 increases sequentially from the edge of the solar cell 100 toward the center of the solar cell 100 along a third direction. In some embodiments, the length l1 of the center-to-center spacing located in the second doped region 22 and within the first length interval L1 increases sequentially from the edge of the solar cell 100 toward the center of the solar cell 100 along a third direction.

[0093] Similarly, the conductive window 31 of the back contact solar cell 100 is also processed using laser etching. The laser moves along a third direction from one edge of the solar cell 100 towards the center, and then from the center towards the other edge. During processing, the laser speed gradually increases to a maximum and then remains constant, before gradually decreasing. As the laser speed increases, the processing interval between two adjacent conductive windows 31 gradually increases, with the center-to-center spacing increasing sequentially from the edge to the center over a first length interval L1. This arrangement matches the laser etching process, requiring only continuous adjustment of the laser speed during processing. It eliminates the need for frequent laser start-ups and stops, and avoids the need for pre-designing complex unequal spacing coordinates. This reduces processing difficulty and increases processing efficiency, significantly lowering the processing cost of the solar cell 100.

[0094] Please see Figure 3 In some embodiments, the center-to-center spacing length l2 within the first doped region 21 and the second length interval L2 is the same. In some embodiments, the center-to-center spacing length l2 within the second doped region 22 and the second length interval L2 is the same. During laser etching, the laser moving speed remains constant after reaching a preset maximum value, thus the center-to-center spacing length of adjacent conductive windows 31 obtained by etching is the same, forming the second length interval L2. The carrier transport distance in the central region of the solar cell 100 is shorter, the resistance loss is smaller, and the processing difficulty of equidistant arrangement is the lowest. At the same time, it can ensure that the central region retains a sufficient area of ​​passivation layer 3, reduce the carrier recombination loss in the central region, balance the resistance loss and recombination loss, and obtain the optimal overall performance.

[0095] In some embodiments, the length of the first doped region 21 within the first length interval L1 is H, satisfying: 30μm < H < 20mm. In some embodiments, the length of the second doped region 22 within the first length interval L1 is H, satisfying: 30μm < H < 20mm. If the length of H is less than or equal to 30μm, it indicates that the length of the first length interval L1 is too small, resulting in too few densely packed conductive windows 31 that can be arranged in the edge region, and the effect of reducing edge resistance is not significant. If the length of H is greater than or equal to 20mm, it indicates that the length of the first length interval L1 is too large, and the densely packed conductive windows 31 in the large region will lead to an excessively large total area of ​​conductive windows 31, insufficient area ratio of the passivation layer 3, a significant increase in surface recombination loss, and an increase in the light-shielding area of ​​the electrode 4, which will actually reduce the photoelectric conversion efficiency of the solar cell 100. Controlling the first length interval within the above range can balance resistance loss and recombination loss, thereby improving photoelectric conversion efficiency.

[0096] The length H of the first doped region 21 located within the first length interval L1 can be any value within the aforementioned range, such as 30μm, 40μm, 50μm, 60μm, 10mm, 15mm, etc. The length H of the second doped region 22 located within the second length interval L2 can also be any value within the aforementioned range, such as 30μm, 40μm, 50μm, 60μm, 10mm, 15mm, etc.

[0097] In some embodiments, in the first doped region 21, the ratio of the length l1 of any center-to-center spacing within the first length interval L1 to the length l2 of any center-to-center spacing within the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9. In some embodiments, in the second doped region 22, the ratio of the length l1 of any center-to-center spacing within the first length interval L1 to the length l2 of any center-to-center spacing within the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9. If X is less than or equal to 0.1, it indicates that the length l1 of the center-to-center spacing in the first length interval L1 is too small, and the conductive windows 31 are too dense, leading to a significant increase in recombination loss, offsetting the benefits of reduced resistance. If X is greater than or equal to 0.9, it indicates that the difference between the length l1 of the center-to-center spacing in the first length interval L1 and the length l2 of the center-to-center spacing in the second length interval L2 is too small, the effect of dense arrangement is not obvious, and it cannot effectively reduce the overall resistance of the edge region. By controlling X within the above range, the density of the edge conductive window 31 can be guaranteed without causing excessive recombination loss, thus balancing the resistance loss and recombination loss in the edge region.

[0098] In the first doped region 21, the ratio X of the length l1 of any center spacing in the first length interval L1 to the length l2 of any center spacing in the second length interval L2 can be any value within the above range, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0099] In the second doped region 22, the ratio X of the length l1 of any center spacing in the first length interval L1 to the length l2 of any center spacing in the second length interval L2 can be any value within the above range, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0100] In some embodiments, the length l2 of any center-to-center spacing located in the first doped region 21 and within the second length interval L2 is less than the distances d2 and d3 between a conductive window 31 located at the end of the first doped region 21 and the edge of the solar cell 100 along a third direction upward. In some embodiments, the length l2 of any center-to-center spacing located in the second doped region 22 and within the second length interval L2 is less than the distances d4 and d5 between a conductive window 31 located at the end of the second doped region 22 and the edge of the solar cell 100 along a third direction upward. Conversely, this would increase the circuit transmission path, thereby increasing resistance loss and affecting electrical performance.

[0101] Secondly, embodiments of this application provide a photovoltaic module, which includes the solar cell 100 as described in the first aspect. Because the solar cell 100 of this application has lower resistance loss and higher photoelectric conversion efficiency, the photovoltaic module including the solar cell 100 also has higher output power and conversion efficiency, while having a longer lifespan and better power generation stability. The photovoltaic module can be a conventional full-cell monocrystalline photovoltaic module, a half-cell cut photovoltaic module, a shingled photovoltaic module, or a bifacial double-glass photovoltaic module. Different types of photovoltaic modules can utilize the solar cell 100 of this application to obtain higher output power.

[0102] Thirdly, embodiments of this application also provide a photovoltaic system, which includes photovoltaic modules as described in the second aspect. Because the photovoltaic modules have higher conversion efficiency and output power, the overall photovoltaic system has higher power generation efficiency, lower cost, and better operational stability. The photovoltaic system can be a residential distributed photovoltaic system, a large-scale ground-mounted power station photovoltaic system, a photovoltaic energy storage integrated system, or a portable mobile photovoltaic power supply system. Different types of photovoltaic systems can utilize the photovoltaic modules of this application to achieve better power generation performance.

[0103] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0104] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0105] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0106] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0107] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0108] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0109] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A solar cell, characterized in that, include: Silicon substrate; A doped layer is stacked on the surface of the silicon substrate layer along a first direction, which is the thickness direction of the solar cell; A passivation layer is stacked along the first direction on the surface of the doped layer away from the silicon substrate. The passivation layer has a plurality of conductive windows extending through it along the first direction. The conductive windows are used to expose the doped layer. The conductive windows are arranged in multiple rows along the second direction. Each row of conductive windows is spaced apart along a third direction. The third direction intersects the first direction and the second direction in pairs and the three directions are not coplanar. Each row of adjacent conductive windows has a center-to-center spacing. Each row of conductive windows forms two connected first length intervals L1 and second length intervals L2 along the third direction upwards. The first length interval L1 includes a portion of the center-to-center spacing near the edge of the solar cell, and the second length interval L2 includes another portion of the center-to-center spacing near the center of the solar cell. The length l1 of at least one center-to-center spacing within the first length interval L1 of each row of conductive windows is less than the length l2 of at least one center-to-center spacing within the second length interval L2. The electrodes, along the third direction, sequentially pass through each row of conductive windows to form ohmic contacts with the doped layer.

2. The solar cell according to claim 1, characterized in that, The length l1 of the center spacing within the first length interval L1 of each row of conductive windows increases sequentially along the third direction from the edge of the solar cell to the center of the solar cell. And / or, the length l2 of the center spacing within the second length interval L2 of each row of conductive windows is the same; And / or, the length of the first length interval L1 in each row of the conductive windows is H, satisfying: 30μm < H < 20mm; And / or, in each row of the conductive windows, the ratio of the length l1 of any center spacing in the first length interval L1 to the length l2 of any center spacing in the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9; And / or, in each row of the conductive windows, the length l2 of any of the center-to-center spacings within the second length interval L2 is less than the distance d1 between the conductive window located at the end along the third direction and the edge of the solar cell; And / or, the length of any center spacing within the first length interval L1 in each row of conductive windows is l1, satisfying: 20μm≤l1≤300μm; And / or, the length of any of the center-to-center spacings within the second length interval L2 in each row of the conductive windows is l2, satisfying: 25μm≤l2≤350μm.

3. The solar cell according to claim 1, characterized in that, The doped layer is provided with multiple rows of first doped regions and multiple rows of second doped regions alternately spaced along the second direction. The conductive windows of some rows are located in the first doped regions of the corresponding rows, and the conductive windows of other rows are located in the second doped regions of the corresponding rows. Each row of adjacent conductive windows has a center-to-center spacing. Each row of conductive windows forms two connected first length intervals L1 and second length intervals L2 along the third direction upwards. The first length interval L1 includes a portion of the center-to-center spacing near the edge of the solar cell, and the second length interval L2 includes another portion of the center-to-center spacing near the center of the solar cell. The length l1 of any center-to-center spacing within the first length interval L1 of each row of conductive windows is less than the length l2 of any center-to-center spacing within the second length interval L2. The electrode includes a first fine gate and a second fine gate. The first fine gate forms an ohmic contact with the first doped region through each row of conductive windows along the third direction. The second fine gate forms an ohmic contact with the second doped region through each row of conductive windows along the third direction.

4. The solar cell according to claim 3, characterized in that, The doping concentration of the first doped region is less than that of the second doped region, the sheet resistance of the first doped region is greater than that of the second doped region, and the length l1 of a center-to-center distance at the third end of the first doped region is less than the length l1 of a center-to-center distance at the third end of the second doped region.

5. The solar cell according to claim 3, characterized in that, The first doped region includes a first region connected to each other and multiple rows of second regions. The second doped region includes a third region connected to each other and multiple rows of fourth regions. The first region and the third region are respectively disposed on both sides of the silicon substrate along the third direction. All the second regions and all the fourth regions are alternately spaced along the second direction. The conductive windows of some rows are located in the second region of the corresponding row, and the conductive windows of other rows are located in the fourth region of the corresponding row. The first fine gate forms an ohmic contact with the second region through each row of conductive windows along the third direction, and the second fine gate forms an ohmic contact with the fourth region through each row of conductive windows along the third direction; The electrode further includes a first main gate and a second main gate, the first main gate being located in the first region and extending along the second direction to be electrically connected to the first fine gate, and the second main gate being located in the third region and extending along the third direction to be electrically connected to the second fine gate; The distance d2 between a conductive window located at one end of the first region along the third direction and close to the first main grid and the edge of the solar cell on the same side therewith, and the distance d3 between a conductive window located away from the first main grid and the edge of the solar cell on the same side therewith, satisfying d2 < d3. And / or, the distance d4 between a conductive window on one side of the second region along the third direction and close to the edge of the solar cell on the same side as the second main grid, and the distance d5 between a conductive window on the other side of the second main grid and the edge of the solar cell on the same side as the second main grid, satisfies d4 < d5.

6. The solar cell according to claim 3, characterized in that, The length of any one of the center-to-center spacings located in the first doped region and within the first length interval L1 is l1, satisfying: 20μm≤l1≤300μm; And / or, the length of any of the center-to-center spacings located in the first doped region and within the second length interval L2 is l2, satisfying: 25μm≤l2≤350μm; And / or, the length of any of the center-to-center spacings located in the second doped region and within the first length interval L1 is l1, satisfying: 25μm≤l1≤305μm; And / or, the length of any of the center-to-center spacings located in the second doped region and within the second length interval L2 is l2, satisfying: 30μm≤l2≤310μm.

7. The solar cell according to claim 3, characterized in that, The length l1 of the center-to-center spacing located in the first doped region and within the first length interval L1 increases sequentially along the third direction from the edge of the solar cell to the center of the solar cell. And / or, the length l1 of the center spacing located in the second doped region and within the first length interval L1 increases sequentially along the third direction from the edge of the solar cell to the center of the solar cell; And / or, the length l2 of the center spacing located in the first doped region and within the second length interval L2 is the same; And / or, the length l2 of the center spacing located in the second doped region and within the second length interval L2 is the same; And / or, the length of the first length interval L1 located in the first doped region is H, satisfying: 30μm < H < 20mm; And / or, the length of the second doped region located in the first length interval L1 is H, satisfying: 30μm < H < 20mm; And / or, in the first doped region, the ratio of the length l1 of any of the center spacings located within the first length interval L1 to the length l2 of any of the center spacings located within the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9; And / or, in the second doped region, the ratio of the length l1 of any of the center spacings located within the first length interval L1 to the length l2 of any of the center spacings located within the second length interval L2 is X, satisfying: X = l1 / l2, and 0.1 < X < 0.9; And / or, the length l2 of any of the center-to-center spacings located in the first doped region and within the second length interval L2 is less than the distances d2 and d3 between a conductive window located at the end of the first doped region and the edge of the solar cell along the third direction upwards; And / or, the length l2 of any of the center-to-center spacings located in the second doped region and within the second length interval L2 is less than the distances d4 and d5 between a conductive window located at the end of the second doped region along the third direction and the edge of the solar cell.

8. The solar cell according to any one of claims 1 to 7, characterized in that, The outline dimension of the conductive window along the third direction is smaller than the lengths l1 and l2 of its center-to-center spacing.

9. A photovoltaic module, characterized in that, The photovoltaic module includes a solar cell as described in any one of claims 1 to 8.

10. A photovoltaic system, characterized in that, The photovoltaic system includes the photovoltaic module as described in claim 9.

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