A solar cell, a cell assembly, and a photovoltaic system

Abstract

The application provides a solar cell, a battery assembly and a photovoltaic system. The solar cell comprises: a leakage region between a first region and a second region; the leakage region comprises a first sub-region and a second sub-region; a first doped layer is located in the first region, and a second doped layer is located in the second region; a first leakage doped layer is located in the first sub-region, and a second leakage doped layer is located in the second sub-region; the first leakage doped layer is connected with the first doped layer, and the second leakage doped layer is connected with the second doped layer; the first leakage doped layer is not in contact with a preset region of a side surface of the first leakage doped layer adjacent to a base of the second sub-region; and the second leakage doped layer is not conductive with the first leakage doped layer when the light intensity is less than a set value. The application can improve the weak light response of the solar cell assembly.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and more particularly to a solar cell, a battery module, and a photovoltaic system. Background Technology

[0002] Back-contact solar cells are those where the light-facing side of the cell has no electrodes, and both the positive and negative electrodes are located on the back-facing side. Back-contact cells reduce electrode shading, increase short-circuit current, and improve energy conversion efficiency. Leakage channels are typically artificially created in back-contact cells to prevent hot spots. These channels are generally formed by interconnecting N-type and P-type doped polycrystalline silicon to create a short-circuit structure. However, current leakage channel configurations can lead to poor low-light response in the module. Summary of the Invention

[0003] This invention provides a solar cell, a battery module, and a photovoltaic system to improve the low-light response of a solar cell module.

[0004] According to one aspect of the present invention, a solar cell is provided, comprising: The substrate and a first doped layer, a second doped layer, a first leakage doped layer, a second leakage doped layer, a first tunneling layer and a second tunneling layer disposed on a first surface of the substrate; The first surface of the substrate includes a leakage area and a first region and a second region spaced apart, with the leakage area disposed between a portion of the first region and the second region; the leakage area includes a first sub-region and a second sub-region. The first doped layer is disposed in the first region, and the second doped layer is disposed in the second region; the first leakage doped layer is disposed in the first sub-region, and the second leakage doped layer is disposed in the second sub-region; the first leakage doped layer is connected to the adjacent first doped layer, and the second leakage doped layer is connected to the adjacent second doped layer; the first leakage doped layer and the first doped layer have the same doping type, and the second leakage doped layer and the second doped layer have the same doping type; a first tunneling layer is disposed between the first doped layer and the first leakage doped layer and the substrate, and a second tunneling layer is disposed between the second doped layer and the second leakage doped layer and the substrate; The substrate of the second sub-region includes a side surface adjacent to the first leakage doped layer, wherein the first leakage doped layer is not in contact with a predetermined region of the side surface, and the predetermined region includes the region of the side surface adjacent to the second sub-region; The second leakage doped layer and the first leakage doped layer are not conductive when the light intensity is less than a set value.

[0005] Optionally, a second barrier layer is further disposed between the second leakage doped layer and the substrate, and / or a first barrier layer is further disposed between the first leakage doped layer and the substrate.

[0006] Optionally, the substrate of the second sub-region is adjacent to the side of the first sub-region and may or may not be in contact with the first leakage doped layer.

[0007] Optionally, the substrate further includes a second surface disposed opposite to the first surface, wherein the distance between the surface of the first leakage doped layer away from the substrate and the second surface is less than the distance between the second sub-region of the first surface and the second surface.

[0008] Optionally, when the substrate of the second sub-region is adjacent to the side of the first sub-region and does not contact the first leakage doped layer: the distance between the substrate of the second sub-region adjacent to the side of the first sub-region and the first leakage doped layer adjacent to the side of the second sub-region is greater than or equal to 5 micrometers and less than or equal to 50 micrometers; the height difference between the second sub-region of the first surface and the first sub-region of the first surface is greater than or equal to 1 micrometer and less than or equal to 15 micrometers. When the substrate of the second sub-region is adjacent to the side of the first sub-region and in contact with the first leakage doped layer, the height difference between the surface of the first leakage doped layer away from the substrate and the second sub-region of the first surface is greater than or equal to 1 micrometer and less than or equal to 15 micrometers.

[0009] Optionally, when the substrate of the second sub-region is adjacent to the side of the first sub-region and does not contact the first leakage doped layer, the substrate between the first leakage doped layer and the substrate of the second sub-region is further provided with a trench, and the bottom of the trench is recessed into the substrate relative to the surface of the first sub-region of the first surface other than the trench.

[0010] Optionally, the height difference between the bottom of the trench and the second sub-region of the first surface is greater than or equal to 3 micrometers and less than or equal to 15 micrometers.

[0011] Optionally, the sheet resistance of the first leakage doped layer is less than the sheet resistance of the first doped layer, and / or the sheet resistance of the second leakage doped layer is less than the sheet resistance of the second doped layer.

[0012] Optionally, one of the first leakage doped layer and the second leakage doped layer is an N-type doped layer and the other is a P-type doped layer; the sheet resistance of the N-type doped layer is 50-200 ohms per square, and the sheet resistance of the P-type doped layer is 50-250 ohms per square.

[0013] Optionally, the doping concentration of the surface of the first leakage doped layer away from the substrate is greater than the doping concentration of the surface of the first doped layer away from the substrate, and / or, the doping concentration of the second leakage doped layer is greater than the doping concentration of the second doped layer.

[0014] Optionally, the ratio of the doping concentration of the surface of the first leakage doped layer away from the substrate to the doping concentration of the surface of the first doped layer away from the substrate is greater than 1 and less than or equal to 3. The ratio of the doping concentration of the second leakage doped layer on the surface away from the substrate to the doping concentration of the second doped layer on the surface away from the substrate is greater than 1 and less than or equal to 3.

[0015] Optionally, the second barrier layer may be made of the same or different material as the first tunneling layer; The first barrier layer may be made of the same material as or different from the second tunneling layer.

[0016] Optionally, the material of the second barrier layer includes at least one of silicon oxide, silicon nitride, silicon carbide, and intrinsic polycrystalline silicon; The material of the first barrier layer includes at least one of silicon oxide, silicon nitride, silicon carbide, and intrinsic polycrystalline silicon.

[0017] Optionally, a second barrier layer is disposed between the second leakage doped layer and the substrate, and when a first barrier layer is disposed between the first leakage doped layer and the substrate, the sum of the thicknesses of the second barrier layer and the first barrier layer is greater than or equal to 3 nanometers and less than or equal to 10 nanometers, and the sum of the thicknesses of the first barrier layer, the second barrier layer, the first tunneling layer and the second tunneling layer is greater than or equal to 3 nanometers and less than or equal to 14 nanometers.

[0018] Optionally, the thickness of the second barrier layer is greater than or equal to 0.5 nanometers and less than or equal to 5 nanometers; The thickness of the first barrier layer is greater than or equal to 0.5 nanometers and less than or equal to 5 nanometers; The sum of the thicknesses of the second barrier layer and the second tunneling layer is greater than or equal to 1.5 nanometers and less than or equal to 7 nanometers. The sum of the thicknesses of the first barrier layer and the first tunneling layer is greater than or equal to 1.5 nanometers and less than or equal to 7 nanometers.

[0019] Optionally, an isolation zone is provided between adjacent first and second regions; The first sub-region is located within the isolation zone, and the second sub-region is located within the second zone; or, the first sub-region is located within the first zone, and the second sub-region is located within the isolation zone; or, both the first sub-region and the second sub-region are located within the isolation zone.

[0020] Optionally, when the first sub-region is located within the isolation region and the second sub-region is located within the second region, the dimension of the second barrier layer along the first direction is larger than the dimension of the first leakage doped layer along the first direction; wherein, the first direction is parallel to the edge of the second leakage doped layer adjacent to the first leakage doped layer. When the first sub-region is located within the first region and the second sub-region is located within the isolation region, the dimension of the first barrier layer along the first direction X is greater than the dimension of the second leakage doped layer along the first direction X.

[0021] Optionally, when the first sub-region is located within the isolation region and the second sub-region is located within the second region, the size of the second barrier layer along the first direction is greater than or equal to 30 micrometers and less than or equal to 300 micrometers, and the size of the second barrier layer along the second direction is greater than or equal to 30 micrometers and less than or equal to 300 micrometers; wherein, the second direction is perpendicular to the first direction. When the first sub-region is located within the first region and the second sub-region is located within the isolation region, the size of the first barrier layer along the first direction is greater than or equal to 30 micrometers and less than or equal to 300 micrometers, and the size of the first barrier layer along the second direction Y is greater than or equal to 30 micrometers and less than or equal to 300 micrometers.

[0022] Optionally, the set value is less than or equal to 500W / m 2 .

[0023] According to another aspect of the present invention, a battery assembly is provided, including the solar cell described in any embodiment of the present invention.

[0024] According to another aspect of the present invention, a photovoltaic system is provided, including the battery module described in any embodiment of the present invention.

[0025] In this embodiment of the invention, the substrate of the second sub-region includes a side adjacent to the first leakage doped layer, and the second leakage doped layer is not in contact with at least a predetermined area of ​​the side. This prevents the first and second leakage doped layers from contacting each other, and they are separated by at least one of the first and second tunneling layers and the substrate. This avoids direct conduction between the first and second leakage doped layers, increases the difficulty of conduction between them, and ensures that the first and second leakage doped layers do not conduct when the light intensity is less than a set value. In other words, the leakage channel does not conduct under weak light, thereby improving the photoelectric conversion efficiency of the solar cell under weak light and reducing the weak light response of the battery module.

[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of a solar cell provided in an embodiment of the present invention.

[0029] Figure 2 yes Figure 1 A schematic cross-sectional view of the solar cell along section line AA.

[0030] Figure 3 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0031] Figure 4 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0032] Figure 5 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0033] Figure 6 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0034] Figure 7 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0036] Figure 9 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0037] Figure 10 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] This invention provides a solar cell. Figure 1 This is a schematic diagram of a solar cell provided in an embodiment of the present invention. Figure 2 yes Figure 1 A schematic diagram of the cross-section of the solar cell along section line AA, for reference. Figures 1-2 The solar cells include: The substrate 10 and the first doped layer 20, the second doped layer 30, the first leakage doped layer 40, the second leakage doped layer 50, the first tunneling layer 80 and the second tunneling layer 60 disposed on the first surface 101 of the substrate 10. The first surface 101 of the substrate 10 includes a leakage area 13 and a first region 11 and a second region 12 that are spaced apart, with the leakage area 13 being disposed between a portion of the first region 11 and the second region 12; the leakage area 13 includes a first sub-region 131 and a second sub-region 132. A first doped layer 20 is disposed in a first region 11, and a second doped layer 30 is disposed in a second region 12; a first leakage doped layer 40 is disposed in a first sub-region 131, and a second leakage doped layer 50 is disposed in a second sub-region 132; the first leakage doped layer 40 is connected to the adjacent first doped layer 20, and the second leakage doped layer 50 is connected to the adjacent second doped layer 30; the first leakage doped layer 40 and the first doped layer 20 have the same doping type, and the second leakage doped layer 50 and the second doped layer 30 have the same doping type; a first tunneling layer 80 is disposed between the first doped layer 20 and the first leakage doped layer 40 and the substrate 10, and a second tunneling layer 60 is disposed between the second doped layer 30 and the second leakage doped layer 50 and the substrate 10; The substrate 10 of the second sub-region 132 includes a side 103 adjacent to the first leakage doped layer 40. The first leakage doped layer 40 is not in contact with a preset region of the side 103. The preset region includes the region where the side 103 is adjacent to the second sub-region 132. The second leakage doped layer 50 and the first leakage doped layer 40 are not conductive when the light intensity is less than a set value.

[0041] The solar cell can be a back-contact solar cell. The substrate 10 has a front and a back side. The front side is the side of the solar cell that receives light when operating, and the back side is the side that receives light when operating. The first surface 101 is the back side of the substrate 10, and the second surface 102 is the front side of the substrate. The substrate 10 can be a monocrystalline silicon wafer or a polycrystalline silicon wafer, and can be a P-type silicon wafer or an N-type silicon wafer; the specific type is not limited here. The first doped layer 20 and the second doped layer 30 have different doping types; one of the first doped layer 20 and the other of the second doped layer 30 can be a P-type doped layer and the other an N-type doped layer. The first tunneling layer 80 and the second tunneling layer 60 can be oxide layers, for example, silicon dioxide.

[0042] An isolation zone 14 is also included between the first region 11 and the second region 12. The isolation zone 14 is used to isolate the first region 11 and the second region 12. The isolation zone 14 may include an isolation groove. The bottom surface of the isolation groove is lower than the first region 11 and the second region 12. A leakage current area 13 may be disposed within the isolation zone 14. For example, both the first sub-region 131 and the second sub-region 132 are located within the isolation zone 14. The leakage current area 13 may also be partially located within the isolation zone 14 and partially located within either the first region 11 or the second region 12.

[0043] The substrate 10 of the second sub-region 132 includes a side surface 103 adjacent to the first drain doped layer 40, wherein the second drain doped layer 40 is at least not in contact with a predetermined region of the side surface 103, i.e., reference Figure 2 The first leakage doped layer 40 does not contact the preset area of ​​the side 103, but contacts other areas of the side 103, or the first leakage doped layer 40 does not contact the entire side 103.

[0044] The substrate 10 of the second sub-region 132 includes a side surface 103 adjacent to the first drain doped layer 40. A predetermined region is the area where the side surface 103 connects to the second sub-region 132. The second drain doped layer 40 is at least not in contact with the predetermined region of the side surface 103, so that the first drain doped layer 40 and the second drain doped layer 50 are not in contact. (Refer to...) Figure 2 When the first leakage doped layer 40 does not contact the preset area of ​​the side 103, but contacts other areas of the side 103, the first leakage doped layer 40 and the second leakage doped layer 50 are separated by the second tunneling layer 60 and the substrate 10. Alternatively, when the first leakage doped layer 40 does not contact the entire side 103, the first leakage doped layer 40 and the second leakage doped layer 50 are separated by the first tunneling layer 80, the second tunneling layer 60 and the substrate 10.

[0045] The inventors discovered through research that existing leakage channels are formed by the direct contact and conduction of the P-type and N-type doped layers. Under weak light, the current and voltage generated by the separation of electron-hole pairs under the built-in electric field generated by the PN junction of the solar cell are smaller than under strong light. If a leakage channel exists, some non-equilibrium electron-hole pairs near the leakage channel undergo self-annihilation, resulting in lower photoelectric conversion efficiency of solar cells with leakage channels compared to those without leakage channels, and reduced weak light response of the solar cell module.

[0046] In this embodiment of the invention, the substrate 10 of the second sub-region 132 includes a side 103 adjacent to the first leakage doped layer 40. The second leakage doped layer 40 is not in contact with at least a predetermined area of ​​the side 103, so that the first leakage doped layer 40 and the second leakage doped layer 50 are not in contact. They are separated from the substrate 10 by at least one of the second tunneling layer 60 and the first tunneling layer 80. This can prevent the first leakage doped layer 40 and the second leakage doped layer 50 from being directly connected, increasing the difficulty of the first leakage doped layer 40 and the second leakage doped layer 50 to be connected. This makes it so that the first leakage doped layer 40 and the second leakage doped layer 50 are not connected when the light intensity is less than a set value, that is, the leakage channel is not connected under weak light, thereby improving the photoelectric conversion efficiency of the solar cell under weak light and reducing the weak light response of the battery module.

[0047] Figure 3 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention. Figure 4 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention. Figure 5 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention. Figure 6 This is a cross-sectional schematic diagram of another solar cell provided in an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figures 3-6A second barrier layer 70 is further disposed between the second leakage doped layer 50 and the substrate 10; and / or, a first barrier layer 90 is further disposed between the first leakage doped layer 40 and the substrate 10. This could be: (Refer to...) Figure 3 and Figure 4 The second barrier layer 70 is disposed only between the second leakage dopant 50 and the substrate 10; or refer to Figure 5 The first barrier layer 90 is disposed only between the first leakage doped layer 40 and the substrate 10; or refer to Figure 6 A first barrier layer 90 is provided between the first leakage doped layer 40 and the substrate 10, and a second barrier layer 70 is provided between the second leakage doped layer 50 and the substrate 10.

[0048] The substrate 10 of the second sub-region 132 includes a side surface 103 adjacent to the first leakage doped layer 40. A predetermined region is the area where the side surface 103 connects to the second sub-region 132. The second leakage doped layer 40 is at least not in contact with the predetermined region of the side surface 103, so that the first leakage doped layer 40 and the second leakage doped layer 50 are not in contact. The two are separated by the second barrier layer 70, the second tunneling layer 60, and the substrate 10. Figure 3 Alternatively, they can be separated by a second barrier layer 70, a second tunneling layer 60, a base 10, and a first tunneling layer 80. Figure 4 Alternatively, they can be separated by a base 10, a first tunneling layer 80, a first barrier layer 90, and a second tunneling layer 60. Figure 5 Alternatively, they can be separated by a second barrier layer 70, a second tunneling layer 60, a substrate 10, a first tunneling layer 80, and a first barrier layer 90. Figure 6 Both the second barrier layer 70 and the first barrier layer 90 can be made of silicon oxide, silicon nitride, silicon carbide, intrinsic polycrystalline silicon, or other films with tunneling effects.

[0049] In this embodiment of the invention, the substrate 10 of the second sub-region 132 includes a side 103 adjacent to the first leakage doped layer 40. The second leakage doped layer 40 is not in contact with at least a predetermined area of ​​the side 103, so that the first leakage doped layer 40 and the second leakage doped layer 50 are not in contact. They are separated from the substrate 10 by multiple films among the second barrier layer 70, the second tunneling layer 60, the first barrier layer 90, and the first tunneling layer 80. This can prevent the first leakage doped layer 40 and the second leakage doped layer 50 from directly conducting. Furthermore, the second barrier layer 70 and the first barrier layer 90 can increase the difficulty of carrier tunneling and increase the difficulty of the first leakage doped layer 40 and the second leakage doped layer 50 conducting. This makes the first leakage doped layer 40 and the second leakage doped layer 50 non-conductive when the light intensity is less than a set value. That is, the leakage channel is not conductive under weak light, thereby improving the photoelectric conversion efficiency of the solar cell under weak light and reducing the weak light response of the battery module.

[0050] Based on the above embodiments, optionally, refer to Figures 2-6 The substrate 10 of the second sub-region 132 is adjacent to the side 103 of the first sub-region 131 and may or may not be in contact with the first leakage doped layer 40.

[0051] Specifically, Figure 3 When the substrate 10 of the second sub-region 132 is adjacent to the side 103 of the first sub-region 131 and contacts the first leakage doped layer 40, the first leakage doped layer 40 does not contact a predetermined area of ​​the side 103, thus the second sub-region 132 is higher than the surface of the first leakage doped layer 40 away from the substrate 10. The leakage path consists of the first leakage doped layer 40, a portion of the substrate 10 of the second sub-region 132, the second tunneling layer 60, the second blocking layer 70, and the second leakage doped layer 50. The light intensity corresponding to the conduction of the first leakage doped layer 40 and the second leakage doped layer 50 can be adjusted by adjusting the height difference D1 between the second sub-region 132 and the surface of the first leakage doped layer 40 away from the substrate 10, as well as the material and thickness of the second blocking layer 70, thereby improving the low-light response of the battery module.

[0052] Figures 4-6 The substrate 10 of the second sub-region 132 is adjacent to the side 103 of the first sub-region 131 and does not contact the first leakage doped layer 40. That is, part of the substrate 10 of the first sub-region 131 is exposed. There is a certain distance between the first leakage doped layer 40 and the second sub-region 132, which makes the conduction path between the first leakage doped layer 40 and the second leakage doped layer 50 longer. This can further ensure that the second leakage doped layer 50 and the first leakage doped layer 40 do not conduct when the light intensity is less than a set value, thereby improving the photoelectric conversion efficiency of the solar cell under weak light and enhancing the weak light response of the module.

[0053] refer to Figure 4 The leakage path consists of a first leakage doped layer 40, a first tunneling layer 80, a portion of the substrate 10 of the first sub-region 131, a portion of the substrate 10 of the second sub-region 132, a second tunneling layer 60, a second barrier layer 70, and a second leakage doped layer 50. The light intensity corresponding to the conduction of the first leakage doped layer 40 and the second leakage doped layer 50 can be adjusted by regulating the width D3 of the exposed substrate 10 between the second sub-region 132 and the first sub-region 131, the height difference D2 between the second sub-region 132 and the first sub-region 131, and the material and thickness of the second barrier layer 70, thereby improving the low-light response of the battery module.

[0054] refer to Figure 5The leakage path consists of a first leakage doped layer 40, a first barrier layer 90, a first tunneling layer 80, a portion of the substrate 10 of the first sub-region 131, a portion of the substrate 10 of the second sub-region 132, a second tunneling layer 60, and a second leakage doped layer 50. The light intensity corresponding to the conduction of the first leakage doped layer 40 and the second leakage doped layer 50 can be adjusted by regulating the width D3 of the substrate 10 of the second sub-region 132 and the exposed substrate 10 of the first leakage doped layer 40, the height difference D2 between the second sub-region 132 and the first sub-region 131, and the material and thickness of the first barrier layer 90, thereby improving the low-light response of the battery module.

[0055] refer to Figure 6 The leakage path consists of a first leakage doped layer 40, a first barrier layer 90, a first tunneling layer 80, a portion of the substrate 10 of the first sub-region 131, a portion of the substrate 10 of the second sub-region 132, a second tunneling layer 60, a second barrier layer 70, and a second leakage doped layer 50.

[0056] Based on the above embodiments, optionally, the substrate 10 further includes a second surface 102 disposed opposite to the first surface 101, and the distance between the surface of the first leakage doped layer 40 away from the substrate 10 and the second surface 102 is less than the distance between the second sub-region 132 of the first surface 101 and the second surface 102.

[0057] This configuration allows the first leakage doped layer 40 to be offset from the second leakage doped layer 50 in the thickness direction of the substrate 10, making it less likely for the first leakage doped layer 40 and the second leakage doped layer 50 to come into contact. This allows the first leakage doped layer 40 to be separated from the second leakage doped layer 50, whether it comes into contact with or not with the side 103 of the substrate 10 of the second sub-region 132 adjacent to the first leakage doped layer 40, thus reducing the difficulty of the process.

[0058] It should be noted that when the first leakage doped layer 40 and the substrate 10 of the second sub-region 132 are not in contact with the side 103 of the first leakage doped layer 40, there may or may not be a height difference between the first leakage doped layer 40 and the second sub-region 132, and there may or may not be a height difference between the first sub-region 131 and the second sub-region 132.

[0059] Based on the above embodiments, optionally, refer to Figure 4When the substrate 10 of the second sub-region 132 is adjacent to the side 103 of the first sub-region 131 and is not in contact with the first leakage doped layer 40, the distance D3 between the substrate 10 of the second sub-region 132 adjacent to the side 103 of the first sub-region 131 and the side of the first leakage doped layer 40 adjacent to the second sub-region 132 is greater than or equal to 5 micrometers and less than or equal to 50 micrometers; the height difference D2 between the second sub-region 132 and the first sub-region 131 of the first surface 101 is greater than or equal to 1 micrometer and less than or equal to 15 micrometers. refer to Figure 3 When the substrate 10 of the second sub-region 132 is adjacent to the side of the first sub-region 131 and is in contact with the first leakage doped layer 40, the height difference D1 between the surface of the first leakage doped layer 40 away from the substrate 10 and the second sub-region 132 of the first surface 101 is greater than or equal to 1 micrometer and less than or equal to 15 micrometers.

[0060] For details, please refer to Figure 4 The gap between the first leakage doped layer 40 and the substrate 10 of the second sub-region 132 adjacent to the side 103 of the first sub-region 131 further separates the first leakage doped layer 40 and the second leakage doped layer 50. When the distance D3 (width of the gap) between the side 103 and the first leakage doped layer 40 is too small, the process requirements are high. When the distance D3 between the side 103 and the first leakage doped layer 40 is too large, the gap will occupy too much space in the first sub-region 131, affecting the size of the first leakage doped layer 40 and possibly affecting the conduction of the leakage path under strong light. By setting the distance D3 between the substrate 10 of the second sub-region 132 adjacent to the side 103 of the first sub-region 131 and the first leakage doped layer 40 adjacent to the side of the second sub-region 132 to be greater than or equal to 5 micrometers and less than or equal to 50 micrometers, the process difficulty is reduced while avoiding excessive space occupation of the first sub-region 131 by the gap. This ensures that the first leakage doped layer 40 has a large area and that the leakage path is conductive under strong light intensity, avoiding adverse effects such as hot spots under strong light conditions. For example, the distance D3 between the substrate 10 of the second sub-region 132 adjacent to the side 103 of the first sub-region 131 and the first leakage doped layer 40 adjacent to the side of the second sub-region 132 can be 5 micrometers, 10 micrometers, 20 micrometers, 30 micrometers, 40 micrometers, etc.

[0061] Continue to refer to Figure 4When the height difference D2 between the second sub-region 132 and the first sub-region 131 of the first surface 101 is too small, its effect on increasing the conduction path between the first leakage doped layer 40 and the second leakage doped layer 50 is limited. When the height difference D2 between the second sub-region 132 and the first sub-region 131 is too large, it may affect the conduction of the leakage path under strong light. By setting the height D2 between the second sub-region 132 and the first sub-region 131 to be greater than or equal to 1 micrometer and less than or equal to 15 micrometers, a longer conduction path is ensured between the first leakage doped layer 40 and the second leakage doped layer 50. This ensures that the first leakage doped layer 40 and the second leakage doped layer 50 do not conduct when the light intensity is less than a set value, thereby improving the photoelectric conversion efficiency of the solar cell and the weak light response of the module. It also ensures that the leakage path conducts under strong light, avoiding adverse effects such as hot spots under strong light conditions. For example, the height D2 between the second sub-region 132 and the first sub-region 131 can be 2 micrometers, 3 micrometers, 4 micrometers, 6 micrometers, 8 micrometers, 10 micrometers, 12 micrometers, 13 micrometers, etc.

[0062] refer to Figure 2 and Figure 3 When the height difference D1 between the surface of the first leakage doped layer 40 away from the substrate 10 and the second sub-region 132 of the first surface 101 is too small, the first leakage doped layer 40 and the second leakage doped layer 50 are too close, making them prone to conduction. This affects the photoelectric conversion efficiency of the solar cell under weak light and the weak light response of the module. When the height difference D1 between the surface of the first leakage doped layer 40 away from the substrate 10 and the second sub-region 132 of the first surface 101 is too large, it increases the processing difficulty of the substrate 10 and may affect the conduction of the leakage path under strong light. By setting the height difference D1 between the surface of the first doped layer 40 away from the substrate 10 and the second sub-region 132 of the first surface 101 to be greater than or equal to 1 micrometer and less than or equal to 15 micrometers, the process difficulty can be reduced while ensuring that the second leakage doped layer 50 and the first leakage doped layer 40 do not conduct when the light intensity is less than the set value. This also ensures that the leakage path conducts under strong light and avoids adverse effects such as hot spots under strong light conditions. For example, the height difference D1 between the surface of the first doped layer 40 away from the substrate 10 and the second sub-region 132 of the first surface 101 can be 2 micrometers, 3 micrometers, 4 micrometers, 6 micrometers, 8 micrometers, 10 micrometers, 12 micrometers, 13 micrometers, etc.

[0063] Figure 7 This is a cross-sectional schematic diagram of another type of solar cell provided in an embodiment of the present invention, for reference. Figure 7Based on the above embodiments, optionally, when the substrate 10 of the second sub-region 132 is adjacent to the side 103 of the first sub-region 131 and does not contact the first leakage doped layer 40, the substrate 10 between the first leakage doped layer 40 and the substrate 10 of the second sub-region 132 is further provided with a trench 100; the bottom of the trench 100 is recessed into the substrate 10 relative to the surface of the first sub-region 131 other than the trench 100 in the first surface 101.

[0064] Specifically, the trench 100 further extends the conduction distance between the first leakage doped layer 40 and the second leakage doped layer 50, which can further ensure that the second leakage doped layer 50 and the first leakage doped layer 40 do not conduct when the light intensity is less than a set value, thereby improving the photoelectric conversion efficiency of the solar cell under weak light and enhancing the weak light response of the module.

[0065] Based on the above embodiments, optionally, the height difference between the bottom of the trench 100 and the second sub-region 132 of the first surface 101 is greater than or equal to 3 micrometers and less than or equal to 15 micrometers.

[0066] Specifically, if the height difference between the bottom of the trench 100 and the second sub-region 132 of the first surface 101 is too small, its effect on increasing the conduction path between the first leakage doped layer 40 and the second leakage doped layer 50 is limited. If the height difference between the bottom of the trench 100 and the second sub-region 132 of the first surface 101 is too large, it may affect the conduction of the leakage path under strong light. By setting the height difference between the bottom of the trench 100 and the second sub-region 132 of the first surface 101 to be greater than or equal to 3 micrometers and less than or equal to 15 micrometers, a longer conduction path between the first leakage doped layer 40 and the second leakage doped layer 50 is ensured. This ensures that when the light intensity is less than a set value, the first leakage doped layer 40 and the second leakage doped layer 50 do not conduct, thereby improving the photoelectric conversion efficiency of the solar cell and the weak light response of the module. It also ensures that the leakage path conducts under strong light, avoiding adverse effects such as hot spots under strong light conditions.

[0067] Based on the above embodiments, optionally, the sheet resistance of the first leakage doped layer 40 is less than the sheet resistance of the first doped layer 20, and / or, the sheet resistance of the second leakage doped layer 50 is less than the sheet resistance of the second doped layer 30.

[0068] Specifically, when the doping types of the first leakage doped layer 40 and the substrate 10 are different, a PN junction is formed between the first leakage doped layer 40 and the substrate 10. By setting the sheet resistance of the first leakage doped layer 40 to be less than that of the first doped layer 20, the built-in electric field of the PN junction at the leakage region 13 is stronger and the potential barrier is larger. The leakage channel is less likely to conduct under weak light, thereby improving the photoelectric conversion efficiency of the solar cell under weak light and enhancing the weak light response of the module.

[0069] When the doping types of the second leakage doped layer 50 and the substrate 10 are different, a PN junction is formed between the second leakage doped layer 50 and the substrate 10. By setting the sheet resistance of the second leakage doped layer 50 to be less than that of the second doped layer 30, the built-in electric field of the PN junction at the leakage region 13 is stronger and the potential barrier is larger. The leakage channel is less likely to conduct under weak light, thereby improving the photoelectric conversion efficiency of the solar cell under weak light and enhancing the weak light response of the module.

[0070] Based on the above embodiments, optionally, one of the first leakage doped layer 40 and the second leakage doped layer 50 is an N-type doped layer and the other is a P-type doped layer; the sheet resistance of the N-type doped layer is 50-200 ohms per square, and the sheet resistance of the P-type doped layer is 50-250 ohms per square.

[0071] Specifically, the sheet resistance of the N-type doped layer is set to 50-200 ohms per square, allowing the N-type doped layer to better cooperate with the barrier layer and better control the first leakage doped layer 40 and the second leakage doped layer 50 from conducting when the light intensity is less than a preset value. The sheet resistance of the P-type doped layer is set to 50-250 ohms per square, allowing the P-type doped layer to better cooperate with the barrier layer and better control the first leakage doped layer 40 and the second leakage doped layer 50 from conducting when the light intensity is less than a preset value.

[0072] Based on the above embodiments, optionally, the doping concentration of the surface of the first leakage doped layer 40 away from the substrate 10 is greater than the doping concentration of the surface of the first doped layer 20 away from the substrate 10, and / or, the doping concentration of the surface of the second leakage doped layer 50 away from the substrate 10 is greater than the doping concentration of the surface of the second doped layer 30 away from the substrate 10.

[0073] Specifically, when the doping types of the first leakage doped layer 40 and the substrate 10 are different, a PN junction is formed between the first leakage doped layer 40 and the substrate 10. By setting the doping concentration of the surface of the first leakage doped layer 40 away from the substrate 10 to be greater than the doping concentration of the surface of the first doped layer 20 away from the substrate 10, the built-in electric field of the PN junction at the leakage channel is stronger, the potential barrier is larger, and the leakage channel is less likely to conduct under weak light.

[0074] When the doping types of the second leakage doped layer 50 and the substrate 10 are different, a PN junction is formed between the second leakage doped layer 50 and the substrate 10. By setting the doping concentration of the surface of the second leakage doped layer 50 away from the substrate 10 to be greater than the doping concentration of the surface of the second doped layer 30 away from the substrate 10, the built-in electric field of the PN junction at the leakage channel is stronger and the potential barrier is larger, making it more difficult for the leakage channel to conduct under weak light.

[0075] Based on the above embodiments, optionally, the ratio of the doping concentration of the surface of the first leakage doped layer 40 away from the substrate 10 to the doping concentration of the surface of the first doped layer 20 away from the substrate 10 is greater than 1 and less than or equal to 3. The ratio of the doping concentration of the second leakage doped layer 50 on the surface away from the substrate 10 to the doping concentration of the second doped layer 30 on the surface away from the substrate 10 is greater than 1 and less than or equal to 3.

[0076] Specifically, the ratio of the doping concentration of the surface of the first leakage doped layer 40 away from the substrate 10 to the doping concentration of the surface of the first doped layer 20 away from the substrate 10 is greater than 1 and less than or equal to 3, so that the built-in electric field strength and the potential barrier strength of the PN junction are both within a suitable range, so that the blocking effect of the first leakage doped layer 40 and the barrier layer are matched, ensuring that the first leakage doped layer 40 and the second leakage doped layer 50 are not conductive under weak light.

[0077] The ratio of the doping concentration of the second leakage doped layer 50 on the surface away from the substrate 10 to the doping concentration of the second doped layer 30 on the surface away from the substrate 10 is greater than 1 and less than or equal to 3, so that the built-in electric field strength and the electric barrier strength of the PN junction are both within a suitable range, so that the blocking effect of the second leakage doped layer 50 and the blocking layer are matched, ensuring that the first leakage doped layer 40 and the second leakage doped layer 50 are not conductive under weak light.

[0078] For example, one of the first doped layer and the second doped layer is an N-type doped layer, and the other is a P-type doped layer. The doping concentration of the N-type doped layer on the surface away from the substrate is greater than or equal to 10. 20 atoms / cm 3 And less than or equal to 10×10 20 atoms / cm 3 The doping concentration of the P-type doped layer on the surface furthest from the substrate is greater than or equal to 10. 19 atoms / cm 3 And less than or equal to 10×10 19 atoms / cm 3 .

[0079] Based on the above embodiments, optionally, the second barrier layer 70 and the second tunneling layer 60 may be made of the same or different materials; The first barrier layer 90 may be made of the same or different material as the first tunneling layer 80.

[0080] Based on the above embodiments, optionally, the material of the second barrier layer 70 includes at least one of silicon oxide, silicon nitride, silicon carbide, and intrinsic polycrystalline silicon; The material of the first barrier layer 90 includes at least one of silicon oxide, silicon nitride, silicon carbide, and intrinsic polycrystalline silicon.

[0081] In addition, the first barrier layer 90 and the second barrier layer 70 can also be made of other materials with tunneling effect.

[0082] Based on the above embodiments, optionally, when a second barrier layer 70 is disposed between the second leakage doped layer 50 and the substrate 10, and a first barrier layer 90 is disposed between the first leakage doped layer 40 and the substrate 10, the sum of the thicknesses of the second barrier layer 70 and the first barrier layer 90 is greater than or equal to 1 nanometer and less than or equal to 10 nanometers, and the sum of the thicknesses of the first barrier layer 70, the second barrier layer 90, the first tunneling layer 80 and the second tunneling layer 60 is greater than or equal to 3 nanometers and less than or equal to 14 nanometers.

[0083] Specifically, when the first leakage doped layer 40 and the second leakage doped layer 50 are conducting, the charge carriers need to pass through the second barrier layer 70 and the first barrier layer 90. The sum of the thicknesses of the second barrier layer 70 and the first barrier layer 90 is set to be greater than or equal to 1 nanometer and less than or equal to 10 nanometers. The sum of the thicknesses of the first barrier layer 70, the second barrier layer 90, the first tunneling layer 80, and the second tunneling layer 60 is greater than or equal to 3 nanometers and less than or equal to 14 nanometers. This ensures that when the light intensity is less than a set value, the charge carriers cannot pass through at least one of the second barrier layer 70 and the first barrier layer 90. When the light intensity is less than a set value, the leakage channel is not conducting. However, when the light intensity is strong, the charge carriers can pass through the second barrier layer 70 and the first barrier layer 90, thus avoiding adverse effects such as hot spots under strong light conditions. For example, the sum of the thicknesses of the second barrier layer 70 and the first barrier layer 90 is 2 nanometers, 3 nanometers, 5 nanometers, 8 nanometers, etc.; the sum of the thicknesses of the first barrier layer 70, the second barrier layer 90, the first tunneling layer 80 and the second tunneling layer 60 is 4 nanometers, 5 nanometers, 8 nanometers, 10 nanometers, 13 nanometers, etc.

[0084] Based on the above embodiments, optionally, the thickness of the second barrier layer 70 is 0.5-5 nm; the thickness of the first barrier layer 90 is 0.5-5 nm. The sum of the thicknesses of the second barrier layer 70 and the second tunneling layer 60 is greater than or equal to 1.5 nm and less than or equal to 7 nm; the sum of the thicknesses of the first barrier layer 90 and the first tunneling layer 80 is greater than or equal to 1.5 nm and less than or equal to 7 nm.

[0085] Specifically, if the thickness of the second barrier layer 70 is too small, its blocking effect on charge carriers is weak, and it cannot effectively prevent the first leakage doped layer 40 and the second leakage doped layer 50 from conducting. If the thickness of the second barrier layer 70 is too thick, its blocking effect on charge carriers is strong, which may affect the conduction of the leakage channel when the light intensity is strong. By setting the thickness of the second barrier layer 70 to 0.5-5 nm, and the sum of the thicknesses of the second barrier layer 70 and the second tunneling layer 60 to be greater than or equal to 1.5 nm and less than or equal to 7 nm, the tunneling difficulty of the charge carriers can be appropriately increased by the second barrier layer 70. This ensures that the second leakage doped layer 50 and the first leakage doped layer 40 do not conduct when the light intensity is less than the set value, and conduct when the light intensity is greater than the set value. This can improve the photoelectric conversion efficiency of the battery and the weak light response of the module under weak light, and also avoid adverse effects such as hot spots under strong light.

[0086] When the thickness of the first barrier layer 90 is too small, its blocking effect on charge carriers is weak, failing to effectively prevent the first leakage doped layer 40 and the second leakage doped layer 50 from conducting. When the thickness of the first barrier layer 90 is too large, its blocking effect on charge carriers is strong, potentially affecting the conduction of the leakage channel under strong light intensity. By setting the thickness of the first barrier layer 90 to 0.5-5 nm, and the sum of the thicknesses of the first barrier layer 90 and the first tunneling layer 80 to be greater than or equal to 1.5 nm and less than or equal to 7 nm, the tunneling difficulty of the charge carriers can be appropriately increased by the first barrier layer 90. This ensures that the second leakage doped layer 50 and the first leakage doped layer 40 do not conduct when the light intensity is less than the set value, and conduct when the light intensity is greater than the set value. This improves the photoelectric conversion efficiency of the battery under weak light and the weak light response of the module, while avoiding adverse effects such as hot spots under strong light.

[0087] For example, the first barrier layer is an oxide layer with a thickness of 0.5-2 nm, such as 1 nm or 1.5 nm; when the first barrier layer is intrinsic polysilicon, the thickness is 0.5-5 nm, such as 1 nm, 2 nm, 3 nm or 4 nm. The second barrier layer is an oxide layer with a thickness of 0.5-2 nm, such as 1 nm or 1.5 nm; when the second barrier layer is intrinsic polysilicon, the thickness is 0.5-5 nm, such as 1 nm, 2 nm, 3 nm or 4 nm.

[0088] Figure 8 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention. Figure 9 This is a schematic diagram of yet another type of solar cell provided in an embodiment of the present invention. (See reference) Figure 1 , Figure 8 and Figure 9 Based on the above embodiments, optionally, an isolation zone 14 is provided between adjacent first regions 11 and second regions 12; Sub-area 131 is located within isolation zone 14, and sub-area 132 is located within area 12. Figure 1 ); or, the first sub-region 131 is located within the first region 11, and the second sub-region 132 is located within the isolation zone 14 ( Figure 8 ); or, both sub-region 131 and sub-region 132 are located within isolation zone 14 ( Figure 9 ).

[0089] Specifically, the isolation zone 14 includes an isolation trench. When the first sub-zone 131 is located within the isolation zone 14, the first sub-zone 131 can be flush with the first region 11, and the isolation trench in the isolation zone 14 is located outside the first sub-zone 131, with its bottom lower than the first sub-zone 131. When the second sub-zone 132 is located within the isolation zone 14, the second sub-zone 132 can be flush with the second region 12, and the isolation trench in the isolation zone 14 is located outside the second sub-zone 132, with its bottom lower than the second sub-zone 132. When both the first sub-zone 131 and the second sub-zone 132 are located within the isolation zone 14, the first sub-zone 131 can be flush with the first region 11, the second sub-zone 132 can be flush with the second region 12, and the isolation trench in the isolation zone 14 is located outside both the first and second sub-zones 131 and 132.

[0090] Based on the above embodiments, optionally, refer to Figure 1 When the first sub-region 131 is located within the isolation region 14 and the second sub-region 132 is located within the second region 12, the size L2 of the second barrier layer 70 along the first direction X is greater than the size L3 of the first leakage doped layer 40 along the first direction X; wherein, the first direction X is parallel to the edge of the second leakage doped layer 50 adjacent to the edge of the first leakage doped layer 40.

[0091] This configuration ensures that the first leakage doped layer 40 and the second barrier layer 70 are adjacent in the second direction Y, preventing the first leakage doped layer 40 and the second doped layer 30 from conducting.

[0092] Based on the above embodiments, optionally, refer to Figure 8 When the second sub-region 132 is located within the isolation region 14 and the first sub-region 131 is located within the first region 11, the size of the first barrier layer 90 along the first direction X is larger than the size of the second leakage doped layer 50 along the first direction X.

[0093] This configuration ensures that the second leakage doped layer 50 is adjacent to the first barrier layer 90 in the second direction Y, thus preventing the second leakage doped layer 50 from conducting with the first doped layer 20.

[0094] Based on the above embodiments, optionally, refer to Figure 1When the first sub-region 131 is located within the isolation region 14 and the second sub-region 132 is located within the second region 12, the size L2 of the second barrier layer 70 along the first direction X is greater than or equal to 30 micrometers and less than or equal to 300 micrometers; the size W2 of the second barrier layer 70 along the second direction Y is greater than or equal to 30 micrometers and less than or equal to 300 micrometers; wherein, the second direction Y is perpendicular to the first direction X.

[0095] This configuration ensures that the second barrier layer 70 completely separates the second doped layer 30 from the first leakage doped layer 40, preventing leakage current from being conducted under weak light. Furthermore, it ensures that the second barrier layer 70 does not occupy excessive space in the second region 12 along the second direction Y, thus avoiding interference with carrier transport in the second doped layer 12 and the second tunneling layer 60 within the second region 12.

[0096] Based on the above embodiments, optionally, when the second sub-region 132 is located within the isolation region 14 and the first sub-region 131 is located within the first region 11, the size of the first barrier layer 90 along the first direction X is greater than or equal to 30 micrometers and less than or equal to 300 micrometers, and the size of the first barrier layer 90 along the second direction Y is greater than or equal to 30 micrometers and less than or equal to 300 micrometers.

[0097] This configuration ensures that the first barrier layer 90 completely separates the first doped layer 20 from the second leakage doped layer 50, preventing leakage current from being conducted under weak light. Furthermore, it ensures that the first barrier layer 90 and the first leakage doped layer 40 do not occupy excessive space in the first region 11 along the second direction Y, thus avoiding interference with carrier transport in the first doped layer 11 and the first tunneling layer 80 within the first region 11.

[0098] Based on the above embodiments, optionally, the set value is less than or equal to 500W / m 2 .

[0099] Specifically, the setting value can be 500W / m 2 It can also be 450W / m 2 It can also be 400W / m 2 When the light intensity is less than 500W / m 2 At that time, the PN junction region of the leakage current channel is not conductive, and the light intensity is greater than or equal to 500W / m. 2 At this time, the PN junction region of the non-leakage channel is conductive. This ensures good response in low light and high photoelectric conversion efficiency. Simultaneously, it avoids adverse effects such as hot spots under strong light conditions. The low irradiance coefficient can be improved from 94% to 98%; power generation per watt increases by approximately 6%.

[0100] Figure 10 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention, for reference. Figure 10The solar cell also includes grid lines, which are disposed on the surfaces of the first region 11 and the second region 12. The grid lines include a main grid 111 and a sub-grid 112. The leakage area can be disposed in the region between the sub-grid 112 or in the region between the sub-grid 112 and the main grid 111.

[0101] This invention also provides a battery assembly, including the solar cell described in the above embodiments.

[0102] A battery module may include multiple solar cells, which can be connected in series to form a battery string. The battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current output. For example, the connection between individual cells can be achieved by welding ribbons, or the connection between battery strings can be achieved by busbars.

[0103] The battery module may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film can be filled between the light-facing side of the solar cell and the photovoltaic glass, the back-facing side and the backsheet, and adjacent cells. As a filler, it can be a transparent colloid with good light transmittance and aging resistance; for example, EVA film or POE film can be used, and the choice is based on the specific circumstances and is not limited here. The photovoltaic glass can cover the encapsulating film on the light-facing side of the solar cell. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of ultra-clear glass can reach over 92%, which can protect the solar cell while minimizing the impact on its efficiency. Simultaneously, the encapsulating film can bond the photovoltaic glass and the solar cell together, and its presence provides sealing, insulation, waterproofing, and moisture protection for the solar cell.

[0104] The backsheet can be attached to the encapsulating film on the back side of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulating film, etc., with specific choices depending on the circumstances. The backsheet, solar cell, encapsulating film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0105] The battery module of this invention belongs to the same inventive concept as the solar cell described in the above embodiments of this invention and has corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the solar cell described in any embodiment of this invention.

[0106] This invention also provides a photovoltaic module, including the battery module described in the above embodiments.

[0107] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains grid before being connected to the mains grid to achieve solar power supply.

[0108] The beneficial effects of the photovoltaic system in this embodiment are equivalent to the beneficial effects of the battery module described above, and will not be repeated here.

[0109] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0110] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A solar cell, characterized in that, include: The substrate and a first doped layer, a second doped layer, a first leakage doped layer, a second leakage doped layer, a first tunneling layer and a second tunneling layer disposed on a first surface of the substrate; The first surface of the substrate includes a leakage area and a first region and a second region spaced apart, with the leakage area disposed between a portion of the first region and the second region; the leakage area includes a first sub-region and a second sub-region. The first doped layer is disposed in the first region, and the second doped layer is disposed in the second region; the first leakage doped layer is disposed in the first sub-region, and the second leakage doped layer is disposed in the second sub-region; the first leakage doped layer is connected to the adjacent first doped layer, and the second leakage doped layer is connected to the adjacent second doped layer; the first leakage doped layer and the first doped layer have the same doping type, and the second leakage doped layer and the second doped layer have the same doping type; a first tunneling layer is disposed between the first doped layer and the first leakage doped layer and the substrate, and a second tunneling layer is disposed between the second doped layer and the second leakage doped layer and the substrate; The substrate of the second sub-region includes a side surface adjacent to the first leakage doped layer, wherein the first leakage doped layer is not in contact with a predetermined region of the side surface, and the predetermined region includes the region of the side surface adjacent to the second sub-region; The second leakage doped layer and the first leakage doped layer are not conductive when the light intensity is less than a set value.

2. The solar cell according to claim 1, characterized in that: A second barrier layer is further disposed between the second leakage doped layer and the substrate, and / or a first barrier layer is further disposed between the first leakage doped layer and the substrate.

3. The solar cell according to claim 1, characterized in that: The substrate of the second sub-region is adjacent to the side of the first sub-region and may or may not be in contact with the first leakage doped layer.

4. The solar cell according to claim 1, characterized in that: The substrate further includes a second surface disposed opposite to the first surface, wherein the distance between the surface of the first leakage doped layer away from the substrate and the second surface is less than the distance between the second sub-region of the first surface and the second surface.

5. The solar cell according to claim 4, characterized in that: When the substrate of the second sub-region is adjacent to the side of the first sub-region and is not in contact with the first leakage doped layer: the distance between the substrate of the second sub-region adjacent to the side of the first sub-region and the first leakage doped layer adjacent to the side of the second sub-region is greater than or equal to 5 micrometers and less than or equal to 50 micrometers; the height difference between the second sub-region of the first surface and the first sub-region of the first surface is greater than or equal to 1 micrometer and less than or equal to 15 micrometers. When the substrate of the second sub-region is adjacent to the side of the first sub-region and in contact with the first leakage doped layer, the height difference between the surface of the first leakage doped layer away from the substrate and the second sub-region of the first surface is greater than or equal to 1 micrometer and less than or equal to 15 micrometers.

6. The solar cell according to claim 3, characterized in that: When the substrate of the second sub-region is adjacent to the side of the first sub-region and is not in contact with the first leakage doped layer, a trench is also provided on the substrate between the first leakage doped layer and the substrate of the second sub-region. The bottom of the trench is recessed into the substrate relative to the surface of the first sub-region of the first surface other than the trench.

7. The solar cell according to claim 6, characterized in that: The height difference between the bottom of the trench and the second sub-region of the first surface is greater than or equal to 3 micrometers and less than or equal to 15 micrometers.

8. The solar cell according to claim 1, characterized in that: The sheet resistance of the first leakage doped layer is less than the sheet resistance of the first doped layer, and / or the sheet resistance of the second leakage doped layer is less than the sheet resistance of the second doped layer.

9. The solar cell according to claim 8, characterized in that: One of the first leakage doped layer and the second leakage doped layer is an N-type doped layer and the other is a P-type doped layer; the sheet resistance of the N-type doped layer is 50-200 ohms per square, and the sheet resistance of the P-type doped layer is 50-250 ohms per square.

10. The solar cell according to claim 1, characterized in that: The doping concentration of the surface of the first leakage doped layer away from the substrate is greater than the doping concentration of the surface of the first doped layer away from the substrate, and / or the doping concentration of the second leakage doped layer is greater than the doping concentration of the second doped layer.

11. The solar cell according to claim 10, characterized in that: The ratio of the doping concentration of the surface of the first leakage doped layer away from the substrate to the doping concentration of the surface of the first doped layer away from the substrate is greater than 1 and less than or equal to 3. The ratio of the doping concentration of the second leakage doped layer on the surface away from the substrate to the doping concentration of the second doped layer on the surface away from the substrate is greater than 1 and less than or equal to 3.

12. The solar cell according to claim 2, characterized in that: The second barrier layer may be made of the same or different material as the first tunneling layer; The first barrier layer may be made of the same material as or different from the second tunneling layer.

13. The solar cell according to claim 12, characterized in that: The material of the second barrier layer includes at least one of silicon oxide, silicon nitride, silicon carbide, and intrinsic polycrystalline silicon; The material of the first barrier layer includes at least one of silicon oxide, silicon nitride, silicon carbide, and intrinsic polycrystalline silicon.

14. The solar cell according to claim 2, characterized in that: A second barrier layer is disposed between the second leakage doped layer and the substrate, and when a first barrier layer is disposed between the first leakage doped layer and the substrate, the sum of the thicknesses of the second barrier layer and the first barrier layer is greater than or equal to 1 nanometer and less than or equal to 10 nanometers, and the sum of the thicknesses of the first barrier layer, the second barrier layer, the first tunneling layer and the second tunneling layer is greater than or equal to 3 nanometers and less than or equal to 14 nanometers.

15. The solar cell according to claim 2, characterized in that: The thickness of the second barrier layer is greater than or equal to 0.5 nanometers and less than or equal to 5 nanometers; The thickness of the first barrier layer is greater than or equal to 0.5 nanometers and less than or equal to 5 nanometers; The sum of the thicknesses of the second barrier layer and the second tunneling layer is greater than or equal to 1.5 nanometers and less than or equal to 7 nanometers. The sum of the thicknesses of the first barrier layer and the first tunneling layer is greater than or equal to 1.5 nanometers and less than or equal to 7 nanometers.

16. The solar cell according to claim 2, characterized in that: An isolation zone is provided between the adjacent first area and second area; The first sub-region is located within the isolation zone, and the second sub-region is located within the second zone; or, the first sub-region is located within the first zone, and the second sub-region is located within the isolation zone; or, both the first sub-region and the second sub-region are located within the isolation zone.

17. The solar cell according to claim 16, characterized in that: When the first sub-region is located within the isolation region and the second sub-region is located within the second region, the dimension of the second barrier layer along the first direction is larger than the dimension of the first leakage doped layer along the first direction; wherein, the first direction is parallel to the edge of the second leakage doped layer adjacent to the first leakage doped layer. When the first sub-region is located within the first region and the second sub-region is located within the isolation region, the dimension of the first barrier layer along the first direction X is greater than the dimension of the second leakage doped layer along the first direction X.

18. The solar cell according to claim 17, characterized in that: When the first sub-region is located within the isolation region and the second sub-region is located within the second region, the size of the second barrier layer along the first direction is greater than or equal to 30 micrometers and less than or equal to 300 micrometers, and the size of the second barrier layer along the second direction is greater than or equal to 30 micrometers and less than or equal to 300 micrometers; wherein, the second direction is perpendicular to the first direction. When the first sub-region is located within the first region and the second sub-region is located within the isolation region, the size of the first barrier layer along the first direction is greater than or equal to 30 micrometers and less than or equal to 300 micrometers, and the size of the first barrier layer along the second direction Y is greater than or equal to 30 micrometers and less than or equal to 300 micrometers.

19. The solar cell according to claim 2, characterized in that: The set value is less than or equal to 500 W / m 2 .

20. A battery assembly, characterized in that, Includes the solar cell according to any one of claims 1-19.

21. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 20.

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