A solar cell and photovoltaic module

Abstract

The application discloses a solar cell and a photovoltaic module, comprising: a silicon substrate, a first surface of which has two opposite first edges and two opposite second edges; a first doped layer and a second doped layer arranged on the first surface, and the conductive types of the first doped layer and the second doped layer are different; a first current collecting electrode arranged on the first doped layer and a second current collecting electrode arranged on the second doped layer, which are alternately arranged along a first direction and extend along a second direction; a first edge soldering area and a second edge soldering area, which are arranged adjacent to one of the two first edges respectively; the first edge soldering area comprises a first edge soldering part and a first edge terminal line, and the first edge terminal line is electrically connected with the first current collecting electrode; the second edge soldering area comprises a second edge soldering part, and the second edge soldering part is electrically connected with the second current collecting electrode; the second current collecting electrode is discontinuous at the first edge soldering area; the first current collecting electrode is discontinuous at the second edge soldering part, and the first current collecting electrode and the second current collecting electrode are continuously arranged between the second edge soldering part and the adjacent second edge.

Description

Technical Field

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

[0002] Currently, with the gradual depletion of fossil fuels, solar cells are becoming increasingly widely used as a new energy alternative. A solar cell is a device that converts sunlight into electrical energy.

[0003] Factors affecting the photoelectric conversion efficiency and yield of solar cells include electrical losses, which include the resistance loss of the material itself, contact loss of the electrodes, contact loss between the solder ribbon and the solar cell, and problems such as poor soldering between the solder ribbon and the solar cell.

[0004] Therefore, there is an urgent need in the field to provide a solar cell that can reduce electrical losses, thereby improving the photoelectric conversion efficiency of the corresponding solar cell and the yield of photovoltaic modules. Summary of the Invention

[0005] The purpose of this invention is to provide a solar cell and a photovoltaic module to reduce electrical losses, thereby improving the photoelectric conversion efficiency of the solar cell and the yield of the photovoltaic module.

[0006] In a first aspect, the present invention provides a solar cell, comprising: A silicon substrate has a first surface and a second surface opposite to each other. The first surface has two opposite first edges and two opposite second edges. The first edges are parallel to a first direction, and the second edges are parallel to a second direction. The first direction and the second direction intersect. A first doped layer and a second doped layer are alternately disposed on the first surface along a first direction, and the first doped layer and the second doped layer have different conductivity types. The first collector electrode is disposed on the first doped layer; The second collector electrode is disposed on the second doped layer, and the first collector electrode and the second collector electrode are alternately arranged along the first direction and extend along the second direction; The first edge welding area and the second edge welding area are arranged opposite to each other and are respectively adjacent to one of the two first sides; the first edge welding area includes a connected first edge welding part and a first edge end line, the first edge end line extends along a first direction toward the adjacent second side, and both the first edge welding part and the first edge end line are electrically connected to the first collector electrode; the second edge welding area includes a second edge welding part, and the second edge welding part is electrically connected to the second collector electrode. Along the second direction, the second current collector electrode is intermittently disposed at the first edge welding area; the first current collector electrode is intermittently disposed at the second edge welding portion, and both the first and second current collector electrodes are continuously disposed at the position between the second edge welding portion and the adjacent second side.

[0007] With the above technical solution in mind, considering the differences in carrier collection and transport performance between collector electrodes of different polarities, differentiated designs are implemented in the first and second edge welding regions of the solar cell. Specifically, a first edge end line is provided in the first edge welding region, while no end line structure is provided in the second edge welding region. The first collector electrode is electrically connected to the first edge end line and the first edge welding portion of the same polarity, and the first collector electrode and the first edge end line are arranged in a cross shape. The second collector electrode is intermittently provided in the first edge welding region of the opposite polarity. By electrically connecting the first edge end line to multiple first collector electrodes near the first edge, the carriers collected by the first collector electrode are directly transported to the first edge end line and led out through the interconnects welded to the first edge welding portion, thereby reducing the transport distance of carriers in the first collector electrode, reducing the transport resistance, and improving the transport efficiency of edge carriers by the first collector electrode.

[0008] Meanwhile, the second edge welding area does not have a terminal line structure. The second collector electrode is electrically connected to the second edge welding part of the same polarity. The first collector electrode is intermittently arranged at the second edge welding part of the opposite polarity. Both the first and second collector electrodes are continuously arranged between the second edge welding part and the adjacent second side. That is, the first collector electrode of the opposite polarity to the second edge welding area does not need to be intermittently arranged between the second edge welding part and the adjacent second side for insulation. Therefore, compared with the collector grid line with a broken edge, the carriers need to be transferred to the same polarity pad located at the edge through a separate edge grid line. In this application, the first collector electrode near the edge of the second edge welding area extends continuously in a straight line to the adjacent same polarity welding area, thereby reducing the transmission distance of the carriers on the first collector electrode at the edge, reducing the transmission resistance, and improving the transmission efficiency of the first collector electrode for edge carriers. Moreover, the first doped layer corresponding to the first collector electrode is also continuously arranged here, reducing the area of ​​the gap region caused by the terminal line structure, thereby increasing the effective carrier collection area of ​​the first doped layer and improving the carrier collection efficiency of the first collector electrode. This reduces the occurrence of blackened edges on the solar cells in the electroluminescence pattern. The combined structural design of the current collector electrode reduces electrical losses by minimizing resistance and electrode contact losses, thereby improving the photoelectric conversion efficiency of the solar cell and the yield of the photovoltaic module.

[0009] In some possible implementations, the first collector electrode is continuously disposed along the first edge end line. This allows the first collector electrode to be continuously printed along the first edge end line, simplifying the structure of the electrode printing screen and increasing the contact area between the first collector electrode and the first edge end line, thereby improving the reliability of the electrical connection.

[0010] In some possible implementations, solar cells also include: The first edge collector electrode is located between the first edge welding area and an adjacent first edge, the first edge collector electrode extends along a first direction, and the first edge collector electrode is electrically connected to the second collector electrode; The second edge collector electrode is located between the second edge welding area and the adjacent other first edge. The second edge collector electrode extends along the first direction and is electrically connected to the second collector electrode. The third edge collector electrode extends along the second direction and is adjacent to the second side. The first edge collector electrode and the second edge collector electrode are both electrically connected to the third edge collector electrode. The first edge collector electrode, the second edge collector electrode, and the third edge collector electrode have the same polarity.

[0011] With the above technical solution, the three edge collector electrodes form an ohmic contact with the second doped layer located at the edge of the solar cell. This not only allows for the collection of edge carriers, but also ensures that the first, second, and third edge collector electrodes have the same polarity. The first edge collector electrode near the first edge welding area is electrically connected to the second collector electrode located at the edge and disconnected by the first edge end line. The second edge collector electrode near the second edge welding area is electrically connected to the continuous second collector electrode located at that edge. This allows the carriers collected by the second collector electrodes at the middle and edge positions of the cell edge region B to be collected by the first, second, and third edge collector electrodes and then transported to the welding part, thus playing a partial role in collecting the carriers and improving the transport efficiency of edge carriers.

[0012] In some possible implementations, the widths of the first, second, and third edge collector electrodes are greater than the width of the first or second collector electrode. Since the three edge collector electrodes have a certain current-collecting function, they are electrically connected to the second collector electrode located at the edge, enabling the transmission of charge carriers to the second collector electrode located near the edge. This arrangement increases the carrier transmission distance of the second collector electrode, increasing the transmission resistance and affecting the carrier transmission efficiency. Therefore, the widths of the three edge collector electrodes can be set to be larger than the widths of the first or second collector electrode to reduce the transmission resistance, improve the carrier transmission efficiency of the three edge collector electrodes, and thus improve the transmission efficiency of the second collector electrode electrically connected to the edge collector electrodes.

[0013] In some possible implementations, the number of first edge collector electrodes is greater than or equal to two, and they are spaced apart along a second direction; the number of second edge collector electrodes is greater than or equal to two, and they are spaced apart along a second direction; the number of third edge collector electrodes adjacent to the same second edge is greater than or equal to two, and they are spaced apart along a first direction. That is, the carriers collected by the second collector electrodes are transported through at least two first edge collector electrodes, at least two second edge collector electrodes, and at least two third edge collector electrodes arranged side-by-side, thereby reducing the transmission resistance of the three edge collector electrodes, improving the carrier transmission efficiency of the three edge collector electrodes, and further improving the transmission efficiency of the second collector electrodes electrically connected to the edge collector electrodes.

[0014] In some possible implementations, the ratios of the widths of the first edge collector electrode, the second edge collector electrode, and the third edge collector electrode to the width of the second collector electrode range from 1:1 to 4:1. And / or, the ratio of the width of the first edge collector electrode, the width of the second edge collector electrode, the width of the third edge collector electrode to the width of the first collector electrode is in the range of 1:1 to 4:1.

[0015] With the above technical solution, if the width ratio is less than 1:1, the reduction in transmission resistance of the three edge collector electrodes is limited, which is not conducive to improving carrier transmission efficiency. If the width ratio is greater than 4:1, the width of the three edge collector electrodes is too large, increasing the risk of edge collector electrode misalignment during printing, reducing the yield of solar cell fabrication, and also increasing electrode cost. Therefore, considering improving carrier transmission efficiency, reducing parasitic absorption, and lowering electrode cost, the width ratio of the three edge collector electrodes to the width of the second collector electrode in this application is selected to be 1:1 to 4:1, and the width ratio of the three edge collector electrodes to the width of the first collector electrode is selected to be 1:1 to 4:1.

[0016] In some possible implementations, the solar cell also includes a first edge welding zone; The first edge welding area is adjacent to the first edge welding area and is located on the side of the first edge welding area away from the first edge collector electrode. The first edge welding area is electrically connected to the second collector electrode. Along the second direction, the distance between the first edge current collector electrode and the first edge welding area is less than the distance between the first edge welding area and the first edge welding area.

[0017] And / or, the solar cell also includes a second edge welding area; The second edge welding area is arranged adjacent to the second edge welding area and is located on the side of the second edge welding area away from the second edge current collector electrode. The second edge welding area is electrically connected to the first current collector electrode. Along the second direction, the distance between the second edge current collector electrode and the second edge welding area is less than the distance between the second edge welding area and the second edge welding area.

[0018] By employing the above technical solution, the length of the second collector electrode located between the first edge welding area and the first edge collector electrode is prevented from being excessively long. This reduces the transmission path of the current flowing from this portion of the second collector electrode to the first edge collector electrode and the third edge collector electrode before reaching the first edge welding area, thus reducing transmission resistance. Furthermore, the length of the second collector electrode located between the second edge welding area and the second edge collector electrode is also prevented from being excessively long. This further reduces the transmission path of the current flowing from this portion of the second collector electrode to the second edge welding area after reaching the second edge collector electrode and the third edge collector electrode, reducing transmission resistance and further improving the transmission efficiency of the second collector electrode.

[0019] In some possible implementations, the one-dimensional dimension of the first edge weld is smaller than that of the second edge weld. Since the end-line structure of the second edge weld region is eliminated, the number of current-collecting points between the second collector electrode and the second edge weld region is reduced. Therefore, the one-dimensional dimension of the second edge weld can be designed to be larger, reducing its transmission resistance and improving its transmission efficiency. Furthermore, for the relatively weakly conductive second doped layer, by making the one-dimensional dimension of the second edge weld disposed on the second doped layer larger, the contact area between the second edge weld and the second doped layer is increased, reducing contact resistance and improving the carrier transport efficiency of the second doped layer.

[0020] In some possible implementations, the solar cell further includes a first intermediate welding portion and a second intermediate welding portion located between a first edge welding portion and a second edge welding portion. The first intermediate welding portion and the second intermediate welding portion are alternately arranged along a second direction. The first intermediate welding portion is electrically connected to a first current collector electrode, and the second intermediate welding portion is electrically connected to a second current collector electrode. The one-dimensional dimension of the first intermediate welding portion is smaller than the one-dimensional dimension of the second intermediate welding portion.

[0021] In the above technical solution, the first intermediate weld portion and the second intermediate weld portion are used to connect to current collector electrodes of different polarities. For the second current collector electrode with a relatively long transmission path, by setting a larger one-dimensional dimension of the second intermediate weld portion electrically connected to the second current collector electrode, the transmission resistance of the second intermediate weld portion is reduced, and the transmission efficiency of the second intermediate weld portion to the carriers collected by the second current collector electrode is improved. Furthermore, for the second doped layer with relatively weak conductivity, by setting a larger one-dimensional dimension of the second intermediate weld portion disposed on the second doped layer, the contact area between the second intermediate weld portion and the second doped layer is increased, the contact resistance is reduced, and the carrier transmission efficiency to the second doped layer is improved.

[0022] In some possible implementations, the length of the first edge weld and the first intermediate weld is 0.6 mm to 1.3 mm; the width of the first edge weld and the first intermediate weld is 0.5 mm to 1.3 mm; the length of the second edge weld and the second intermediate weld is 0.6 mm to 1.5 mm; and the width of the second edge weld and the second intermediate weld is 0.5 mm to 1.5 mm.

[0023] In some possible implementations, along the first direction, the width of the first collector electrode is smaller than the width of the second collector electrode. Since the transmission path of the second collector electrode is longer than that of the first collector electrode, to compensate for the transmission efficiency loss due to the increased transmission path of the second collector electrode, and to address the relatively weak conductivity of the second doped layer, the width of the second collector electrode disposed on the second doped layer is made wider. This reduces the contact resistance between the second collector electrode and the second doped layer, and also reduces the transmission resistance of the second collector electrode, thereby improving its transmission efficiency. Combined with the arrangement of a terminal line in the first edge welding region and a terminal-free line in the second edge welding region, the carrier transport efficiency of both the first and second collector electrodes is comprehensively improved.

[0024] In some possible implementations, along the first direction, the width of the first collector electrode is 60 μm to 120 μm, and the width of the second collector electrode is 80 μm to 150 μm.

[0025] In some possible implementations, along the first direction, the width of the first doped layer is smaller than the width of the second doped layer. For the second doped layer, which has relatively weak conductivity, its collection capability for charge carriers is improved by increasing its width and thus its area. Simultaneously, for a wider second collector electrode, the second doped layer needs to be wider to match the larger second collector electrode, reducing the risk of leakage due to electrode misalignment during printing.

[0026] In some possible implementations, the ratio of the width of the first collector electrode to the width of the first doped layer ranges from 1:14 to 5:8. If the ratio of the width of the first collector electrode to the width of the first doped layer is less than 1:14, the width of the first collector electrode is too small, which is not conducive to current collection and results in a large resistance. When the width ratio is greater than 5:8, the width of the first collector electrode is too large, which is not conducive to electrical isolation and results in a large material consumption.

[0027] The ratio of the width of the second collector electrode to the width of the second doped layer ranges from 1:14 to 4:5. If the ratio is less than 1:14, the width of the second collector electrode is too small, which is not conducive to current collection and results in a large resistance. If the ratio is greater than 4:5, the width of the second collector electrode is too large, which is not conducive to electrical isolation and results in a large material consumption.

[0028] In some possible implementations, the first surface includes a first region and a second region, a first doped layer is disposed in the first region, and a second doped layer is disposed in the second region; the roughness of the first region is greater than the roughness of the second region.

[0029] With the above technical solution, since the electrode size disposed on the first doped layer is smaller than the electrode size disposed on the second doped layer, the electrode includes a terminal line, a solder joint, and a current collector electrode. Therefore, the surface contact area between the electrode on the first doped layer and the first region is small. Setting the surface roughness of the first region to be larger can effectively increase the contact area between the electrode on the first region and the surface of the first region, increase the bonding force between the electrode and the first region, and reduce the risk of the electrode (especially the solder joint responsible for soldering to the interconnect) detaching from the surface of the first region.

[0030] In some possible implementations, the first doped layer is an N-type doped layer, and the second doped layer is a P-type doped layer. Since boron doping in a P-type doped layer is more difficult than phosphorus doping in an N-type doped layer, the lower doping level in the P-type doped layer results in weaker transport performance between the P-type doped layer and the electrode compared to the N-type doped layer. The first collector electrode disposed on the N-type doped layer is an N-type collector electrode, and the second collector electrode disposed on the P-type doped layer is a P-type collector electrode. A first edge terminal line is provided in the first edge welding area of ​​the N-type layer, while no terminal line structure is provided in the second edge welding area of ​​the P-type layer. The N-type collector electrode is electrically connected to the first edge terminal line and the first edge welding portion of the same polarity, and the N-type collector electrode and the first edge terminal line are arranged intersectingly. The P-type collector electrode is intermittently disposed in the first edge welding area of ​​the opposite polarity. The first edge terminal line is electrically connected to multiple N-type collector electrodes near the first side, allowing the carriers collected by the N-type collector electrodes to be directly transferred to the first edge terminal line and led out through the interconnects welded to the first edge terminal line. This reduces the carrier transmission distance in the N-type collector electrode, reduces the transmission resistance, and improves the carrier transmission efficiency of the N-type collector electrode for edge carriers. Meanwhile, the P-type second edge welding area does not have a terminal line structure. The P-type collector electrode is electrically connected to the second edge welding part of the same polarity, while the N-type collector electrode is intermittently arranged at the second edge welding part of the opposite polarity. Both the N-type and P-type collector electrodes are continuously arranged between the second edge welding part and the adjacent second side. That is, the N-type collector electrode of the opposite polarity to the second edge welding area does not need to be intermittently arranged between the second edge welding part and the adjacent second side for insulation. Therefore, compared to the collector grid line with a broken edge, which requires a separate edge grid line to transmit to the position... Compared to the same polarity pads at the edge, the N-type collector electrode of this application extends continuously in a straight line to the adjacent same polarity soldering area near the edge of the second edge soldering area. This reduces the transmission distance of the edge on the N-type collector electrode, reduces the transmission resistance, and improves the transmission efficiency of the N-type collector electrode for edge carriers. Furthermore, the N-type doped layer corresponding to the N-type collector electrode is also continuously disposed here, reducing the area of ​​the ineffective gap region caused by the end line structure. This increases the effective carrier collection area of ​​the N-type doped layer and improves the carrier collection efficiency of the N-type collector electrode.

[0031] Furthermore, for the P-type doped layer with relatively weak conductivity, by increasing the one-dimensional dimensions of the second edge weld and the second intermediate weld on the P-type doped layer, and by making the width of the P-type collector electrode on the P-type doped layer wider, the contact area between the second edge weld, the second intermediate weld, the P-type collector electrode and the P-type doped layer is increased, thereby reducing the contact resistance between the second edge weld, the second intermediate weld, the P-type collector electrode and the P-type doped layer, as well as reducing the transmission resistance of the P-type collector electrode, thus improving the carrier transport efficiency of the P-type doped layer.

[0032] In some possible implementations, the first edge collector electrode, the second edge collector electrode, and the third edge collector electrode are P-type polarities.

[0033] With the above technical solution, the three P-type edge collector electrodes form an ohmic contact with the P-type doped layer located at the edge of the solar cell. This not only allows for the collection of edge carriers, but also ensures that all three edge collector electrodes are P-type. The first P-type edge collector electrode near the first edge welding area of ​​the N-type is electrically connected to the P-type collector electrode located at the edge and disconnected by the first edge end line. The second P-type edge collector electrode near the second edge welding area of ​​the P-type is electrically connected to the continuous P-type collector electrodes located at that edge. This allows the carriers collected by the P-type collector electrodes located at the middle and edge positions of the cell edge region B to be combined to the first, second, and third P-type edge collector electrodes and then transported to the P-type welding part, thus playing a partial role in current collection and improving the carrier transport efficiency at the P-type edge.

[0034] In some possible implementations, the first surface includes a first region and a second region, with a first doped layer disposed in the first region and a second doped layer disposed in the second region; Solar cells also include an intrinsic amorphous silicon layer, a tunneling oxide layer, and a transparent conductive layer; A tunneling oxide layer is disposed in a first region and located between a silicon substrate and a first doped layer, the first doped layer including a doped polysilicon layer; An intrinsic amorphous silicon layer is disposed in the second region and located between the silicon substrate and the second doped layer. The second doped layer includes one or more of a doped amorphous silicon layer and a doped microcrystalline silicon layer. A transparent conductive layer is disposed on the first doped layer and the second doped layer, and the transparent conductive layer is disconnected in the overlapping area of ​​the first region and the second region; a first current collector is disposed on the transparent conductive layer corresponding to the first doped layer, and a second current collector is disposed on the transparent conductive layer corresponding to the second doped layer.

[0035] When the above technical solution is adopted, the solar cell is a back contact hybrid cell, that is, the first region on the back of the cell is configured as a tunneling oxide passivation contact structure composed of a tunneling oxide layer and a doped polycrystalline silicon layer, and the second region is configured as a heterojunction passivation contact structure composed of an intrinsic amorphous silicon layer and one or more of a doped amorphous silicon layer and a doped microcrystalline silicon layer, so that the back contact cell has the characteristics of both a tunneling oxide passivation contact structure and a heterojunction passivation contact structure.

[0036] In some possible implementations, the first and second current collector electrodes are made of copper paste. Using base metal copper as the electrode material reduces the cost of the electrodes while still meeting conductivity requirements.

[0037] Secondly, the present invention also provides a photovoltaic module, comprising: A battery string, which is formed by electrically connecting a plurality of solar cells as described in any of the above; Interconnectors are electrically connected to the solar cells; And an encapsulation layer that covers the surface of the battery string.

[0038] Since photovoltaic modules use solar cells described in any of the above descriptions, they have the same beneficial effects as the aforementioned solar cells, and will not be elaborated further. Attached Figure Description

[0039] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the overall electrode structure of the first side of a solar cell provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of an electrode structure at a local location on the first surface of a solar cell, provided as an embodiment of the present invention. Figure 3 This is a partial schematic diagram of the electrode structure of a solar cell provided in an embodiment of the present invention; Figure 4 A schematic diagram of the current collector electrode and doped layer of a solar cell provided in an embodiment of the present invention; Figure 5 A schematic diagram of a longitudinal cross-sectional structure of a solar cell provided in an embodiment of the present invention; Figure 6 This is a partial schematic diagram of the electrode structure of a solar cell provided in an embodiment of the present invention.

[0040] Figure label: 10 is the first edge welding area, 11 is the first edge welding part, 12 is the first edge end line, 13 is the first intermediate welding part, 14 is the first collector electrode, 15 is the second edge welding area, and 16 is the first intermediate end line; 20 is the second edge welding area, 21 is the second edge welding part, 22 is the second current collector electrode, 23 is the first edge current collector electrode, 24 is the second edge current collector electrode, 25 is the third edge current collector electrode, 26 is the second intermediate welding part, 27 is the first edge welding area, and 28 is the second intermediate end line; 300 is the silicon substrate, 301 is the first region, 302 is the second region, 31 is the first edge, and 32 is the second edge; 400 is a tunneling oxide passivation contact structure, 401 is a first doped layer, 500 is a heterojunction passivation contact structure, 501 is a second doped layer, and 600 is a transparent oxide layer. A is the middle region, B is the edge region, 701 is the first connecting part, and 702 is the second connecting part. Detailed Implementation

[0041] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0042] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0044] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] like Figures 1-5As shown, this embodiment of the invention provides a solar cell, including a silicon substrate 300, a first doped layer 401, a second doped layer 501, a first current collector 14, a second current collector 22, a first edge welding region 10, and a second edge welding region 20. The silicon substrate 300 has opposing first and second surfaces. The first surface has two opposing first edges 31 and two opposing second edges 32. The first edges 31 are parallel to a first direction, and the second edges 32 are parallel to a second direction. The first and second directions intersect, for example, they can be perpendicular to each other. Along the first direction, the first surface is divided into two edge regions B and an intermediate region A located between the two edge regions B. The first doped layer 401 and the second doped layer 501 are alternately disposed on the first surface along the first direction. The first doped layer 401 and the second doped layer 501 have different conductivity types, being either N-type or P-type, respectively. The first current collector 14 is provided with… The first collector electrode 14 is disposed on the first doped layer 401 and has the same polarity as the first doped layer 401. It forms an ohmic contact with the first doped layer 401 and can be used to collect the charge carriers of the first doped layer 401. The second collector electrode 22 is disposed on the second doped layer 501 and has the same polarity as the second doped layer 501. It forms an ohmic contact with the second doped layer 501 and can be used to collect the charge carriers of the second doped layer 501. The first collector electrode 14 and the second collector electrode 22 are arranged alternately along a first direction and extend along a second direction. In some cases, the first doped layer 401 with the first collector electrode 14 and the second doped layer 501 with the second collector electrode 22 are both strip-shaped doped layers. The first collector electrode 14 and the first doped layer 401 extend in the same direction, and the second collector electrode 22 and the second doped layer 501 extend in the same direction. At least one edge region B is provided with a first edge welding area 10 and a second edge welding area 20. That is, there may be only one edge region B with a first edge welding area 10 and a second edge welding area 20, or there may be both edge regions B with a first edge welding area 10 and a second edge welding area 20. Within the same edge region B, the first edge welding area 10 and the second edge welding area 20 are arranged opposite to each other in the second direction and are respectively adjacent to one of the two first sides 31. The first edge welding area 10 and the second edge welding area 20 are both adjacent to the second side 32. The first edge welding area 10 includes a connected first edge welding part 11 and a first edge end line 12. The first edge end line 12 extends along the first direction toward the adjacent second side 32. The first edge welding part 11 and the first edge end line 12 are both electrically connected to the first collector electrode 14. The polarity of the first edge welding area 10 is the same as the polarity of the first collector electrode 14. The second edge welding area 20 includes a second edge welding part 21 without an end line structure. The second edge welding part 21 is electrically connected to the second collector electrode 22. The polarity of the second edge welding area 20 is the same as the polarity of the second collector electrode 22.

[0047] Among them, such as Figure 2 As shown, along the second direction, i.e. the extension direction of the second collector electrode 22, the second collector electrode 22 is intermittently disposed at the first edge welding area 10 so that the second collector electrode 22 is intermittently insulated from the opposite polarity of the first edge welding area 10; the first collector electrode 14 is intermittently disposed at the second edge welding portion 21 so that the first collector electrode 14 is intermittently insulated from the opposite polarity of the second edge welding portion 21; the first collector electrode 14 and the second collector electrode 22 are both continuously disposed at the position between the second edge welding portion 21 and the adjacent second side 32.

[0048] By employing the above technical solution, electrodes of different polarities are placed on the same surface of the silicon substrate 300, reducing shading on the other side and minimizing shading losses in the solar cell. Considering the differences in carrier collection and transport performance between current collector electrodes of different polarities, differentiated designs are implemented in the first edge welding region 10 and the second edge welding region 20 of the solar cell. For example... Figure 2 As shown, specifically, a first edge end line 12 is provided in the first edge welding area 10, while no end line structure is provided in the second edge welding area 20. The first collector electrode 14 is electrically connected to the first edge end line 12 and the first edge welding part 11 of the same polarity, and the first collector electrode 14 is overlapped or penetrated with the first edge end line 12. The second collector electrode 22 is intermittently provided in the first edge welding area 10 of opposite polarity. By electrically connecting the first edge end line 12 with multiple first collector electrodes 14 near the first edge 31, the charge carriers collected by the first collector electrode 14 are directly transmitted to the first edge end line 12 and led out through the interconnects welded to the first edge welding part 11, thereby reducing the transmission distance of charge carriers in the first collector electrode 14, reducing the transmission resistance, and improving the transmission efficiency of the first collector electrode 14 for edge charge carriers.

[0049] Meanwhile, the second edge welding area 20 does not have a terminal wire structure. The second collector electrode 22 is electrically connected to the second edge welding portion 21 of the same polarity. The first collector electrode 14 is intermittently disposed at the second edge welding portion 21 of opposite polarity. Both the first collector electrode 14 and the second collector electrode 22 are continuously disposed between the second edge welding portion 21 and the adjacent second side 32. That is, the first collector electrode 14, which is of opposite polarity to the second edge welding area 20, does not need to be intermittently disposed between the second edge welding portion 21 and the adjacent second side 32 for insulation. Therefore, compared to the case where the collector grid line with a broken edge requires a separate edge grid line to be transferred to the same polarity pad located at the edge, this application... The first collector electrode 14, located near the edge of the second edge welding area 20, extends continuously in a straight line to the nearest welding area of ​​the same polarity (i.e., the second edge welding area 15). This reduces the transport distance of charge carriers on the first collector electrode 14 at this edge, reduces the transport resistance, and improves the transport efficiency of the first collector electrode 14 for edge charge carriers. Furthermore, the first doped layer 401 corresponding to the first collector electrode 14 is also continuously disposed here, reducing the area of ​​the gap region caused by the end-line structure. This increases the effective carrier collection area of ​​the first doped layer 401, improves the carrier collection efficiency of the first collector electrode 14, and reduces the phenomenon of edge blackening in the electroluminescence pattern of the solar cell. In summary, the above-mentioned structure of the collector electrode reduces electrical losses by reducing resistance loss and electrode contact loss, thereby improving the photoelectric conversion efficiency of the solar cell and the reliability of its operation after module formation.

[0050] like Figure 2 As shown, in some embodiments, the first collector electrode 14 is continuously disposed along the first edge end line 12. That is, based on the electrical connection between the first collector electrode 14 and the first edge end line 12, the first collector electrode 14 has a continuous structure along the first edge end line 12, thereby allowing the first collector electrode 14 to be continuously printed along the first edge end line 12. This simplifies the structure of the electrode printing screen and increases the contact area between the first collector electrode 14 and the first edge end line 12, improving the reliability of the electrical connection. In other embodiments, while maintaining the electrical connection with the first edge end line 12, the first collector electrode 14 can also be disconnected at the first edge end line 12.

[0051] like Figure 1 and Figure 2As shown, in some embodiments, the solar cell further includes a first edge collector electrode 23, a second edge collector electrode 24, and a third edge collector electrode 25 located within the edge region B; wherein, the first edge collector electrode 23 is located between the first edge welding region 10 and a first side 31 adjacent to the first edge welding region 10, the first edge collector electrode 23 extends along a first direction, and the first edge collector electrode 23 is electrically connected to the second collector electrode 22; the second edge collector electrode 24 is located between the second edge welding region 20 and another first side 31 adjacent to the second edge welding region 20, the second edge collector electrode 24 extends along the first direction, and the second edge collector electrode 24 is electrically connected to the second collector electrode 22; the third edge collector electrode 25 extends along a second direction and is adjacent to the second side 32, and both the first edge collector electrode 23 and the second edge collector electrode 24 are electrically connected to the third edge collector electrode 25. In addition, the second intermediate terminal line 28, which is electrically connected to the second collector electrode 22, is electrically connected to the third edge collector electrode 25; the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 have the same polarity, which is the same as the polarity of the second collector electrode 22, and are disposed on the second doped layer at the edge of the solar cell.

[0052] With the above technical solution, the three edge collector electrodes form ohmic contacts with the second doped layer located at the edge of the solar cell. This not only allows for the collection of edge carriers, but also ensures that the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 have the same polarity. The first edge collector electrode 23 is electrically connected to the second collector electrode 22, which is disconnected by the first edge end line 12 near the first edge 31. The second edge collector electrode 24 is electrically connected to the continuous second collector electrode 22 near the other first edge 31. This allows the carriers collected by the second collector electrodes 22 at the middle and edge positions of the edge region B in the second direction to be channeled to the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 before being transported to the welding part, thus playing a partial channeling role and improving the collection and transport efficiency of edge carriers on the second doped layer. In some embodiments, the widths of the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 are greater than the width of the first collector electrode 14 or the second collector electrode 22. Since the three edge collector electrodes have a certain current collection function, they are electrically connected to the second collector electrode 22 located at the edge, and the carriers of the second collector electrode 22 located near the first side 31 are transmitted. The setting of this edge collector electrode increases the transmission distance of the carriers in the second collector electrode 22, and the transmission resistance increases, which affects the carrier transmission efficiency. Therefore, the width of the three edge collector electrodes can be set to be larger than the width of the first collector electrode 14 or the second collector electrode 22 to reduce the transmission resistance of the edge collector electrodes, improve the carrier transmission efficiency of the three edge collector electrodes, and thus improve the carrier transmission efficiency of the second collector electrode 22 electrically connected to the edge collector electrodes.

[0053] like Figures 1-3As shown, in some embodiments, the number of first edge collector electrodes 23 is greater than or equal to two, for example, two, three, four, etc., and these first edge collector electrodes 23 are spaced apart along the second direction; the number of second edge collector electrodes 24 is greater than or equal to two, for example, two, three, four, etc., and these second edge collector electrodes 24 are spaced apart along the second direction; the number of third edge collector electrodes 25 adjacent to the same second side 32 is greater than or equal to two, and they are spaced apart along the first direction. That is, the carriers collected by the second collector electrode 22 are transported through at least two first edge collector electrodes 23, at least two second edge collector electrodes 24, and at least two third edge collector electrodes 25 arranged side by side, so as to reduce the transmission resistance of the three edge collector electrodes, improve the carrier transport efficiency of the three edge collector electrodes, and thus improve the carrier transport efficiency of the second collector electrode 22 electrically connected to the edge collector electrodes. Specifically, two first edge current collector electrodes 23, two second edge current collector electrodes 24, and two third edge current collector electrodes 25 are disposed on a second doped layer near the edge of the solar cell. Two edge current collector electrodes or one edge current collector electrode can be disposed at the corner of the solar cell.

[0054] In addition, while having at least two edge collector electrodes, the width of the three edge collector electrodes can be increased, further reducing the transmission resistance of the three edge collector electrodes and improving the carrier transmission efficiency to the second collector electrode 22.

[0055] In some embodiments, the ratios of the widths of the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 to the width of the second collector electrode 22 range from 1:1 to 4:1, for example, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, etc.; and / or, the ratios of the widths of the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 to the width of the first collector electrode 14 range from 1:1 to 4:1, for example, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, etc.

[0056] When using the above technical solution, if the ratio of the width of the edge collector electrode to the width of the second collector electrode 22 is less than 1:1, or the ratio of the width of the edge collector electrode to the width of the first collector electrode 14 is less than 1:1, the reduction in the transmission resistance of the three edge collector electrodes is limited, which is not conducive to improving the carrier transmission efficiency. If the ratio of the width of the edge collector electrode to the width of the second collector electrode 22 is greater than 4:1, or the ratio of the width of the edge collector electrode to the width of the first collector electrode 14 is greater than 4:1, the width of the three edge collector electrodes is too large, which increases the risk of edge collector electrode misalignment during the printing process, reduces the yield of solar cell fabrication, and the excessive width also increases the electrode cost. Therefore, considering improving the carrier transport efficiency of the edge collector electrodes, increasing the fabrication yield, and reducing the electrode cost, the ratio of the width of the three edge collector electrodes to the width of the second collector electrode 22 in this application is selected to be in the range of 1:1 to 4:1, and the ratio of the width of the three edge collector electrodes to the width of the first collector electrode 14 is selected to be in the range of 1:1 to 4:1.

[0057] Preferably, the ratios of the widths of the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 to the width of the second collector electrode 22 are in the range of 1:1 to 2:1; and / or, the ratios of the widths of the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 to the width of the first collector electrode 14 are in the range of 1:1 to 2:1. Under these preferred conditions, the edge collector electrodes are not excessively wide, thus avoiding increased printing difficulty.

[0058] Specifically, the width of the edge collector electrode is 110 μm, the width of the first collector electrode 14 is 60 μm, and the width of the second collector electrode 22 is 80 μm.

[0059] like Figure 1 and Figure 2As shown, in some embodiments, the solar cell further includes a first edge welding region 27 located within edge region B. The first edge welding region 27 is adjacent to the first edge welding region 10 and located on the side of the first edge welding region 10 away from the first edge collector electrode 23. The first edge welding region 27 may include a connected second intermediate end line 28 and a second intermediate welding portion 26. The second intermediate end line 28 extends along a first direction and is electrically connected to the third edge collector electrode 25. The polarity of the first edge welding region 27 is the same as the polarity of the second collector electrode 22, and the first edge welding region 27 is electrically connected to the second collector electrode 22. The polarity of the first edge welding region 27 is different from the polarity of the first edge welding region 10 and the first collector electrode 14, which is intermittently disposed at the first edge welding region 27. Along a second direction, the distance between the first edge collector electrode 23 and the first edge welding region 10 is less than the distance between the first edge welding region 10 and the first edge welding region 27.

[0060] It should be noted that the distance between the first edge collector electrode 23 and the first edge welding area 10 refers to the distance between the center line of the first edge collector electrode 23 and the center line of the first edge welding area 10 (first edge end line 12), and the distance between the first edge welding area 10 and the first edge welding area 27 refers to the distance between the center line of the first edge welding area 10 (first edge end line 12) and the center line of the first edge welding area 27 (second middle end line 28).

[0061] By adopting the above technical solution, the length of the second collector electrode 22 located between the first edge welding area 10 and the first edge collector electrode 23 will not be too long. This reduces the transmission path of this part of the second collector electrode 22 after it flows to the first edge collector electrode 23 and the third edge collector electrode 25 and then to the first edge welding area 27, thereby reducing the transmission resistance and further improving the carrier transmission efficiency in the second collector electrode 22.

[0062] like Figure 1 and Figure 2As shown, similarly, in this embodiment, the solar cell further includes a second edge welding area 15 located within edge region B. The second edge welding area 15 is adjacent to the second edge welding area 20 and located on the side of the second edge welding area 20 away from the second edge current collector electrode 24. The second edge welding area 15 may include a first intermediate end line 16 and a first intermediate welding portion 13. The first intermediate end line 16 extends along a first direction. The polarity of the second edge welding area 15 is the same as the polarity of the first current collector electrode 14. The second edge welding area 15 is electrically connected to the first current collector electrode 14. The polarity of the second edge welding area 15 is different from the polarity of the second edge welding area 20 and the second current collector electrode 22. The second current collector electrode 22 is intermittently disposed at the second edge welding area 15. Along the second direction, the distance between the second edge current collector electrode 24 and the second edge welding area 20 is less than the distance between the second edge welding area 20 and the second edge welding area 15.

[0063] It should be noted that the distance between the second edge current collector 24 and the second edge welding area 20 refers to the distance between the center line of the second edge current collector 24 and the center line of the second edge welding area 20 (second edge welding part 21), and the distance between the second edge welding area 20 and the second edge welding area 15 refers to the distance between the center line of the second edge welding area 20 (second edge welding part 21) and the center line of the second edge welding area 15 (first intermediate end line 16).

[0064] With the above technical solution, the length of the second collector electrode 22 located between the second edge welding area 15 and the second edge collector electrode 24 will not be too long. This reduces the transmission path of this part of the second collector electrode 22 after it flows to the second edge collector electrode 24 and the third edge collector electrode 25 and then to the second edge welding area 15, thereby reducing the transmission resistance and further improving the carrier transmission efficiency in the second collector electrode 22.

[0065] like Figure 2 and Figure 4 As shown, in some embodiments, the one-dimensional dimension of the first edge weld portion 11 is smaller than the one-dimensional dimension of the second edge weld portion 21. The shapes of the first edge weld portion 11 and the second edge weld portion 21 can be rectangular, circular, etc. The one-dimensional dimension refers to the length, width, or diameter of the edge weld portion. When comparing the one-dimensional dimensions of the first edge weld portion 11 and the second edge weld portion 21, a unified parameter comparison is used. Since the end line structure of the second edge weld area 20 is eliminated, the number of current collection points between the second collector electrode 22 and the second edge weld area 20 is reduced. Therefore, the one-dimensional dimension of the second edge weld portion 21 is set to be larger, reducing the transmission resistance of the second edge weld portion 21 and improving the transmission efficiency of the second edge weld portion 21.

[0066] like Figure 1 and Figure 2 As shown, in some embodiments, the solar cell further includes a first intermediate weld portion 13 and a second intermediate weld portion 26 located within the edge region B. The first intermediate weld portion 13 and the second intermediate weld portion 26 are located between the first edge weld portion 11 and the second edge weld portion 21. The first intermediate weld portion 13 and the second intermediate weld portion 26 are alternately arranged along a second direction. The first intermediate weld portion 13 is disposed on the first doped layer, and the second intermediate weld portion 26 is disposed on the second doped layer. The first intermediate weld portion 13 has the same polarity as the first current collector 14 and is electrically connected. The second current collector 22 is disconnected at the first intermediate weld portion 13 and is not electrically connected for insulation. The second intermediate weld portion 26 has the same polarity as the second current collector 22 and is electrically connected. The first current collector 14 is disconnected at the second intermediate weld portion 26 and is not electrically connected for insulation. The one-dimensional dimension of the first intermediate weld portion 13 is smaller than the one-dimensional dimension of the second intermediate weld portion 26. The shapes of the first intermediate welding part 13 and the second intermediate welding part 26 can be rectangular, circular, etc. The one-dimensional dimension refers to the length, width or diameter of the intermediate welding part. When comparing the one-dimensional dimensions of the first intermediate welding part 13 and the second intermediate welding part 26, the one-dimensional dimensions use a unified parameter comparison.

[0067] In the above technical solution, the first intermediate welding portion 13 and the second intermediate welding portion 26 are respectively used to connect to collector electrodes of different polarities. Since the charge carriers of the second collector electrode 22 located at the edge need to be transferred to the welding area of ​​the same polarity through the edge collector electrode, for the second collector electrode 22 with a relatively long transmission path, by setting the one-dimensional size of the second intermediate welding portion 26 electrically connected to the second collector electrode 22 to be larger, the transmission resistance of the second intermediate welding portion 26 is reduced, and the transmission efficiency of the second intermediate welding portion 26 for the charge carriers collected by the second collector electrode 22 is improved. In addition, by setting the one-dimensional size of the second intermediate welding portion 26 disposed on the second doped layer to be larger, the contact area between the second intermediate welding portion 26 and the second doped layer is increased, the contact resistance is reduced, and the larger-sized second intermediate welding portion 26 can connect more or wider second collector electrodes 22, thereby improving the transmission efficiency of the charge carriers of the second doped layer to the second collector electrode 22 and the second intermediate welding portion 26.

[0068] In some embodiments, the lengths of the first edge welding portion 11 and the first intermediate welding portion 13 can be 0.6mm to 1.3mm, for example, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, etc.; the widths of the first edge welding portion 11 and the first intermediate welding portion 13 can be 0.5mm to 1.3mm, for example, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, etc.; the second edge... The length of the second edge weld portion 21 and the second intermediate weld portion 26 is 0.6mm to 1.5mm, for example, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc.; the width of the second edge weld portion 21 and the second intermediate weld portion 26 is 0.5mm to 1.5mm, for example, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc. It should be noted that the length of the weld portion refers to the distance between two opposite edges along the first direction, and the width of the weld portion refers to the distance between two opposite edges along the second direction.

[0069] In some embodiments, the size of the weld portion disposed on the first doped layer 401 is equal to the size of the weld portion disposed on the second doped layer 501, that is, the one-dimensional size of the first edge weld portion 11 is equal to the one-dimensional size of the second edge weld portion 21, the one-dimensional size of the first intermediate weld portion 13 is equal to the one-dimensional size of the second intermediate weld portion 26, and so on. When the sizes of the weld portions disposed on the first doped layer 401 and the weld portions disposed on the second doped layer 501 can meet the collection efficiency of carriers in the doped layer, the sizes of the weld portions on the first doped layer 401 and the second doped layer 501 can be set to be equal. In this case, the process difficulty in the printed electrode process can be reduced and the production capacity can be increased.

[0070] It should be noted that, in this embodiment, the term 'equal dimensions' is not limited to an ideal state of absolute equality. In practical applications, considering the common process errors in electrode fabrication, as long as the difference between the weld portion on the first doped layer 401 and the weld portion on the second doped layer 501 is within the acceptable error range of conventional processes (e.g., ±5%, or a specific absolute error value), and the intended function of the present invention can be achieved, it should be considered as 'equal' as referred to in this embodiment.

[0071] In some embodiments, the first intermediate terminal line 16 is electrically connected to the first intermediate weld portion 13, and the second intermediate terminal line 28 is electrically connected to the second intermediate weld portion 26. The widths of the first edge terminal line 12 and the first intermediate terminal line 16 are smaller than the width of the second intermediate terminal line 28 to improve the carrier transport efficiency of the second collector electrode 22. The widths of the first edge terminal line 12 and the first intermediate terminal line 16 can be 80 μm to 350 μm, and the width of the second intermediate terminal line 28 can be 120 μm to 430 μm.

[0072] like Figure 4 As shown, in some embodiments, along the first direction, the width W1 of the first collector electrode 14 is smaller than the width W2 of the second collector electrode 22. Since the charge carriers of the second collector electrode 22 located at the edge need to be transferred to the same polarity welding area through the edge collector electrode, the transmission path of the second collector electrode 22 is longer than that of the first collector electrode 14. In order to compensate for the loss of transmission efficiency of the second collector electrode 22 due to the increased transmission path, and for the second doped layer 501 with relatively weak conductivity, the width of the second collector electrode 22 disposed on the second doped layer 501 is set to be wider, thereby reducing the contact resistance between the second collector electrode 22 and the second doped layer 501, and reducing the transmission resistance of the second collector electrode 22, thus improving the transmission efficiency of the second collector electrode 22. Combined with the configuration of the end line of the first edge welding area 10 and the configuration of the endless line of the second edge welding area 20, the carrier transmission efficiency of the first collector electrode 14 and the second collector electrode 22 is comprehensively improved.

[0073] In some embodiments, the width W1 of the first current collector electrode 14 along the first direction is 50 μm to 120 μm. For example, the width W1 can be 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, etc. If the width W1 of the first current collector electrode 14 is less than 60 μm, it is not conducive to the carrier transport of the first current collector electrode 14 and the reliable bonding with the first doped layer 401. If the width W1 of the first current collector electrode 14 is greater than 120 μm, the width of the first current collector electrode 14 is too wide. On the one hand, it increases the electrode cost. On the other hand, the first current collector electrode 14 is prone to exceed the range of the first doped layer 401 during the printing process, resulting in leakage or serious recombination problems, which is not conducive to improving the cell conversion efficiency and reducing the yield in the solar cell fabrication process.

[0074] Furthermore, the width W2 of the second collector electrode 22 is 70μm to 150μm. For example, the width W2 can be 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 125μm, 130μm, 135μm, 140μm, 145μm, 150μm, etc. It is sufficient that the width W1 of the first collector electrode 14 is less than the width W2 of the second collector electrode 22. If the width W2 of the second current collector electrode 22 is less than 80 μm, it will hinder the carrier transport of the second current collector electrode 22 and its reliable bonding with the second doped layer 501. If the width W2 of the second current collector electrode 22 is greater than 150 μm, the width W2 of the second current collector electrode 22 will be too wide. On the one hand, this will increase the cost of the electrode. On the other hand, the second current collector electrode 22 will easily exceed the range of the second doped layer 501 during the printing process, leading to leakage or serious recombination problems. This will not improve the cell conversion efficiency and will reduce the yield in the solar cell manufacturing process.

[0075] like Figure 4 As shown, in some embodiments, along the first direction, the width W3 of the first doped layer 401 is smaller than the width W4 of the second doped layer 501. For the second doped layer 501, which has relatively weak conductivity, by setting the width W4 of the second doped layer 501 to be wider, the area of ​​the second doped layer 501 is increased, thereby improving the carrier collection capability of the second doped layer 501. Simultaneously, for the increased width of the second collector electrode 22, the second doped layer 501 needs to be wider to match the wider second collector electrode 22, reducing the risk of leakage due to displacement of the second collector electrode 22 during printing.

[0076] like Figure 4 As shown, in some embodiments, the ratio of the width W1 of the first collector electrode 14 to the width W3 of the first doped layer 401 ranges from 1:14 to 5:8. If the ratio of the width W1 of the first collector electrode 14 to the width W3 of the first doped layer 401 is less than 1:14, the width of the first collector electrode 14 is too small, which is not conducive to current collection and results in a large resistance. When the width ratio is greater than 5:8, the width of the first collector electrode 14 is too large, which is not conducive to electrical isolation and results in a large material consumption.

[0077] Similarly, the ratio of the width W2 of the second collector electrode 22 to the width W4 of the second doped layer 501 ranges from 1:14 to 4:5. If the ratio of the width W2 of the second collector electrode 22 to the width W4 of the second doped layer 501 is less than 1:14, the width of the second collector electrode 22 is too small, which is not conducive to current collection and results in a large resistance. When the width ratio is greater than 4:5, the width of the second collector electrode 22 is too large, which is not conducive to electrical isolation and results in a large material consumption.

[0078] It should be noted that the width calculation method for the first doped layer 401 and the second doped layer 501 here refers to the width that can be used for electrode printing positions. For example, the first doped layer 401 and the second doped layer 501 are spaced apart, such as... Figure 4 As shown, the width of the first doped layer 401 and the second doped layer 501 is the distance between the two edges along the first direction. Alternatively, the first doped layer 401 and the second doped layer 501 may have overlapping regions, such as... Figure 5 As shown, the width of the first doped layer 401 and the second doped layer 501 is the distance between the two edges along the first direction, and the overlapping portion should be removed.

[0079] In some embodiments, such as Figure 1 and Figure 6 As shown, the solar cell includes multiple sets of first connecting portions 701 and multiple sets of second connecting portions 702 located in the central region A. Each set of first connecting portions 701 includes multiple first connecting portions 701 spaced apart along a first direction, and each set of second connecting portions 702 includes multiple second connecting portions 702 spaced apart along the first direction. The first connecting portions 701 are electrically connected to a first current collector electrode, and the second connecting portions 702 are electrically connected to a second current collector electrode 22. Each set of first connecting portions 701 and a corresponding welding area of ​​the same polarity are located in the same first direction, and each set of second connecting portions 702 and a corresponding welding area of ​​the same polarity are located in the same first direction. The multiple sets of first connecting portions 701 and multiple sets of second connecting portions 702 are arranged alternately along a second direction. The width of the first connecting portions 701 and the second connecting portions 702 is greater than the width of the current collector electrode, which can provide a larger welding area during the series connection of the solar cell through the interconnect, improving the reliability of the welding between the central region A of the solar cell and the interconnect. Furthermore, the area of ​​the first connecting portion 701 is larger than the area of ​​the second connecting portion 702. In this case, the contact area between the first connection portion 701 and the first doped layer 401 can be increased, the tension between the first connection portion 701 and the solar cell can be enhanced, and the risk of the first connection portion 701 or the interconnect component falling off can be reduced. By reducing the contact loss between the interconnect component and the solar cell and the poor solder joint between the interconnect component and the solar cell, electrical losses are reduced, thereby improving the conversion efficiency and yield of the solar cell.

[0080] like Figure 2 and Figure 5As shown, in some embodiments, the first doped layer 401 is an N-type doped layer, and the doping element in the N-type doped layer is one or more Group VA elements such as phosphorus, arsenic, antimony, and bismuth. The second doped layer 501 is a P-type doped layer, and the doping element in the P-type doped layer is one or more Group IIIA elements such as boron, gallium, indium, and thallium. Since boron doping in the P-type doped layer is more difficult than phosphorus doping in the N-type doped layer, the lower doping level in the P-type doped layer results in weaker transport performance between the P-type doped layer and the electrode compared to the N-type doped layer. The first collector electrode 14 disposed on the N-type doped layer is an N-type collector electrode, and the second collector electrode 22 disposed on the P-type doped layer is a P-type collector electrode. A first edge end line 12 is disposed in the first edge bonding region 10 of the N-type, and no end line structure is disposed in the second edge bonding region 20 of the P-type. The N-type collector electrode is electrically connected to the first edge end line 12 and the first edge bonding portion 11 of the same polarity, and the N-type collector electrode and the first edge end line 11 of the N-type are arranged intersectingly. The P-type collector electrode is intermittently disposed in the first edge bonding region 10 of the N-type. By electrically connecting the first edge end line 12 of the N-type to multiple N-type collector electrodes near the first edge 31, the charge carriers collected by the N-type collector electrode are directly transferred to the first edge end line 12 of the N-type and led out through the interconnects welded to the first edge bonding portion 11, thereby reducing the electron transmission distance in the N-type collector electrode, reducing the transmission resistance, and improving the transmission efficiency of the N-type collector electrode for edge electrons. Meanwhile, the second edge welding area 20 of the P-type does not have an end wire structure. The P-type collector electrode is electrically connected to the second edge welding part 21 of the P-type. The N-type collector electrode is intermittently arranged at the second edge welding part 21 of the P-type. Both the N-type and P-type collector electrodes are continuously arranged between the second edge welding part 21 and the adjacent second side 32. That is, the N-type collector electrode, which is of opposite polarity to the second edge welding area 20 of the P-type, does not need to be intermittently arranged between the second edge welding part 21 and the adjacent second side 32 for insulation. Therefore, compared to the collector grid line with a broken edge, a separate edge grid line is required to transmit to... Compared to the same polarity pads located at the edge, the N-type collector electrode of this application extends continuously in a straight line to the adjacent same polarity pad (i.e., the second edge pad 15) near the edge of the second edge welding area 20. This reduces the transmission distance of electrons on the N-type collector electrode at the edge, reduces the transmission resistance, and improves the transmission efficiency of the N-type collector electrode for edge electrons. Furthermore, the N-type doped layer corresponding to the N-type collector electrode is also continuously disposed here, reducing the area of ​​the ineffective gap region caused by the end line structure. This increases the effective carrier collection area of ​​the N-type doped layer and improves the electron collection efficiency of the N-type collector electrode.

[0081] Furthermore, for the P-type doped layer with relatively weak conductivity, by increasing the one-dimensional dimensions of the second edge welding portion 21 and the second intermediate welding portion 26 disposed on the P-type doped layer, and by increasing the width of the P-type collector electrode disposed on the P-type doped layer, the contact area between the second edge welding portion 21, the second intermediate welding portion 26, the P-type collector electrode and the P-type doped layer is increased, thereby reducing the contact resistance between the second edge welding portion 21, the second intermediate welding portion 26, the P-type collector electrode and the P-type doped layer, and reducing the transmission resistance of the P-type collector electrode, the hole transport efficiency of the P-type doped layer is improved.

[0082] like Figure 2 As shown, in some embodiments, the first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25 are P-type polarities. The three P-type edge collector electrodes form ohmic contacts with the P-type doped layer located at the edge of the solar cell. This not only allows for the collection of edge holes from the P-type doped layer, but also ensures that all three edge collector electrodes are P-type. The P-type first edge collector electrode near the N-type first edge welding region 10 is electrically connected to the P-type collector electrode located at the edge and disconnected by the N-type first edge end line 12. The P-type second edge collector electrode near the P-type second edge welding region 20 is electrically connected to the continuous P-type collector electrodes located at that edge. This allows the holes collected by the P-type collector electrodes at the middle and edge positions of the cell edge region B to be channeled to the P-type first edge collector electrode 23, the second edge collector electrode 24, and the third edge collector electrode 25, and then transported to the P-type welding portion, thus partially acting as a confluencer and improving the hole transport efficiency at the edge of the P-type doped layer.

[0083] like Figure 2 and Figure 5As shown, in some embodiments, the solar cell provided in this application is a back-contact hybrid cell. The first surface of the silicon substrate 300 includes a first region 301 and a second region 302. A first doped layer is disposed in the first region 301, and a second doped layer is disposed in the second region 302. The solar cell also includes an intrinsic amorphous silicon layer, a tunneling oxide layer, and a transparent conductive layer. The tunneling oxide layer is disposed in the first region 301 and located between the silicon substrate 300 and the first doped layer. The first doped layer includes a doped polycrystalline silicon layer, such that the tunneling oxide layer and the doped polycrystalline silicon layer form a tunneling oxide passivation contact structure 400, that is, the first region 301 forms a tunneling oxide passivation contact structure 400. An intrinsic amorphous silicon layer is disposed in the second region 302 and located between the silicon substrate 300 and the second doped layer. The second doped layer includes one or more of a doped amorphous silicon layer and a doped microcrystalline silicon layer, such that the intrinsic amorphous silicon layer and one or more of the doped amorphous silicon layer and the doped microcrystalline silicon layer form a heterojunction passivation contact structure 500, that is, the second region 302 forms a heterojunction passivation contact structure 500. A transparent conductive layer 600 is disposed on the first doped layer and the second doped layer, and the transparent conductive layer 600 is disconnected in the overlapping region of the first region 301 and the second region 302. A first collector electrode 14 is disposed on the transparent conductive layer 600 corresponding to the first doped layer, and a second collector electrode 22 is disposed on the transparent conductive layer 600 corresponding to the second doped layer. The transparent conductive layer 600 is an oxide conductive layer, such as one or more of indium tin oxide, indium zinc oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, boron-doped zinc oxide, indium gallium zinc oxide, and antimony-doped titanium dioxide.

[0084] It should be noted that the first region 301 and the second region 302 overlap in the first direction. For example, the heterojunction passivation contact structure 500 of the second region 302 is partially stacked on the tunneling oxide passivation contact structure 400 of the first region 301. The tunneling oxide passivation contact structure 400 conducts electricity with the first current collector 14 through the transparent conductive layer 600, and the heterojunction passivation contact structure 500 conducts electricity with the second current collector 22 through the transparent conductive layer 600. Since the transparent conductive layer 600 has strong lateral conductivity, in order to achieve electrical insulation between the first region 301 and the second region 302, the transparent conductive layer 600 is disconnected in the overlapping region of the first region 301 and the second region 302.

[0085] like Figure 5 and Figure 6As shown, in some embodiments, the first surface of the silicon substrate 300 includes a first region 301 and a second region 302. A first doped layer 401 is disposed in the first region 301, and a second doped layer 501 is disposed in the second region 302. Along a first direction, the first region 301 and the second region 302 are alternately disposed. The roughness of the first region 301 is less than the roughness of the second region 302. It should be noted that the roughness of the first region 301 refers to the roughness of the outermost surface of the first region 301 (which can be the surface of the first doped layer 401 or the surface of the corresponding region of the silicon substrate 300), and the roughness of the second region 302 refers to the roughness of the outermost surface of the second region 302 (which can be the surface of the second doped layer 501 or the surface of the corresponding region of the silicon substrate 300).

[0086] When using the above technical solution, since the surface roughness of the first region 301 is set to be relatively small in the above embodiment, the size of the first connection portion 701 disposed on the first doped layer 401 in the intermediate region A is larger than the size of the second connection portion 702 disposed on the second doped layer 501. This results in a larger contact area between the first connection portion 701 on the first doped layer 401 and the surface of the first region 301. In other words, increasing the size of the first connection portion 701 can effectively increase the contact area between the first connection portion 701 on the first region 301 and the surface of the first region 301, increase the bonding force between the first connection portion 701 and the first region 301, and reduce the risk of the first connection portion 701 responsible for welding to the interconnect being detached from the surface of the first region 301.

[0087] In other embodiments, since the surface roughness of the first region 301 is set to be relatively small in the above embodiments, the size of the first connection portion 701 disposed on the first doped layer 401 in the intermediate region A is equal to the size of the second connection portion 702 disposed on the second doped layer 501. While ensuring the bonding force between the first connection portion 701 and the first region 301, the size of the second connection portion 702 can be reduced. Since the roughness of the second region 302 is relatively large, reducing the size of the second connection portion 702 can reduce the amount of electrode paste used and save production costs while ensuring the bonding force between the second connection portion 702 and the second region 302. It should be understood that the term 'equal dimensions' in this embodiment includes permissible deviations within the conventional manufacturing tolerances in the art, and is not strictly mathematical equality.

[0088] When the above technical solution is adopted, the solar cell is a back contact hybrid cell, that is, the first region 301 on the back of the cell is configured as a tunneling oxide passivation contact structure 400 composed of a tunneling oxide layer and a doped polycrystalline silicon layer, and the second region 302 is configured as a heterojunction passivation contact structure 500 composed of an intrinsic amorphous silicon layer and one or more of a doped amorphous silicon layer and a doped microcrystalline silicon layer, so that the back contact cell has the characteristics of both the tunneling oxide passivation contact structure 400 and the heterojunction passivation contact structure 500.

[0089] Since the conductivity of doped amorphous silicon is relatively weak when the second doped layer is used, and boron doping in the P-type doped layer is more difficult than phosphorus doping in the N-type doped layer, the lower doping level in the P-type doped layer results in weaker transport performance between the P-type doped layer and the electrode compared to the N-type doped layer. Therefore, in the back-contact hybrid cell structure, the width of the P-type doped layer is greater than the width of the N-type doped layer, and the width of the P-type current collector electrode is greater than the width of the N-type current collector electrode to improve the hole collection and transport efficiency of the P-type doped layer. The back-contact hybrid cell in this application, combined with the differentiated design of the two side edge electrode structures described above, balances the carrier transport and collection efficiencies of the P-type and N-type doped layers.

[0090] In other embodiments, the solar cell may also be a back contact cell with only a tunneling oxide passivation contact structure, that is, both the first and second regions on the back side of the silicon substrate form a tunneling oxide passivation contact structure. Specifically, both the first doped layer and the second doped layer include a doped polycrystalline silicon layer, and the tunneling oxide layer is disposed in the first and second regions and located between the silicon substrate and the first doped layer, as well as between the silicon substrate and the second doped layer.

[0091] In some embodiments, the silicon substrate can be an N-type or P-type silicon substrate, or an intrinsic silicon substrate. In terms of crystal type, the silicon substrate 4 can be monocrystalline silicon, polycrystalline silicon, microcrystalline silicon, or other materials. The P-type dopant source is a boron tribromide or boron trichloride, or a trivalent element or compound. In some embodiments, when the P-type dopant source is a boron source, the dopant element is boron; a boron tribromide or boron trichloride, or a trivalent element or compound, can be used as the dopant source. Specifically, boron dopant elements in a predetermined region can be diffused into the upper surface of the silicon substrate through a doping process (e.g., laser doping, plasma-guided doping, or ion implantation). The N-type dopant source can be any one of phosphorus, arsenic, or antimony. Specifically, when the dopant element is phosphorus, phosphorus can be diffused onto the surface of the silicon substrate through a doping process (e.g., thermal diffusion, ion implantation, etc.).

[0092] In some embodiments, the first current collector 14 and the second current collector 22 are made of copper paste. Using base metal copper as the electrode material reduces the cost of the electrode while maintaining conductivity. The width of the first current collector 14, made of copper paste, is smaller than the width of the second current collector 22. For back-contact hybrid cells, amorphous silicon is used as the second doped layer. Since the conductivity is relatively weak, setting the width of the second current collector 22 on the amorphous silicon doped layer to be larger is beneficial to improving the carrier transport efficiency of the amorphous silicon layer. Moreover, even with a wider second current collector 22, the electrode cost can still be reduced compared to silver electrodes due to the use of base metal copper.

[0093] It should be noted that the first collector electrode 14 and the second collector electrode 22 are made of copper paste. A seed layer can also be provided between the first collector electrode 14 and the second collector electrode 22 and the doped layer. The seed layer can be made of materials such as silver and nickel, which can prevent copper from diffusing into the silicon substrate, avoiding serious recombination problems, and can also improve the contact performance between the collector electrode and the doped layer. Since the seed layer can be locally provided under the collector electrode, the electrode cost can still be reduced even if silver paste is used.

[0094] In some embodiments, the materials of the first current collector 14 and the second current collector 22 may also be silver paste, nickel paste, silver-coated copper paste, silver-coated nickel paste, etc.

[0095] Based on the solar cells described in any of the above embodiments, this invention also provides a photovoltaic module, including a cell string, interconnecting components, and an encapsulation layer; wherein, the cell string is formed by electrically connecting a plurality of solar cells as described in any of the above embodiments; the interconnecting components are electrically connected to the solar cells; and the encapsulation layer covers the surface of the cell string. The encapsulation layer may include cover plates and back plates located on both sides of the cell string, as well as encapsulating films and other structures for encapsulation. Since the photovoltaic module uses the solar cells described in any of the above embodiments, it has the same beneficial effects as the solar cells described above, and will not be described again.

[0096] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0097] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A solar cell, characterized by, include: A silicon substrate has a first surface and a second surface opposite to each other. The first surface has two opposite first edges and two opposite second edges. The first edges are parallel to a first direction, and the second edges are parallel to a second direction. The first direction and the second direction intersect. A first doped layer and a second doped layer are alternately disposed on the first surface along the first direction, and the first doped layer and the second doped layer have different conductivity types; The first collector electrode is disposed on the first doped layer; The second collector electrode is disposed on the second doped layer, and the first collector electrode and the second collector electrode are alternately arranged along the first direction and extend along the second direction; The first edge welding area and the second edge welding area are disposed opposite to each other and are respectively disposed adjacent to one of the two first sides; the first edge welding area includes a connected first edge welding part and a first edge end line, the first edge end line extends along the first direction toward the adjacent second side, and both the first edge welding part and the first edge end line are electrically connected to the first collector electrode; the second edge welding area includes a second edge welding part, and the second edge welding part is electrically connected to the second collector electrode. Along the second direction, the second current collector electrode is intermittently disposed at the first edge welding area; the first current collector electrode is intermittently disposed at the second edge welding portion; and both the first current collector electrode and the second current collector electrode are continuously disposed between the second edge welding portion and the adjacent second side.

2. The solar cell according to claim 1, characterized in that, The first current collector electrode is continuously disposed at the first edge end line.

3. The solar cell according to claim 1, characterized in that, The solar cell also includes: A first edge collector electrode is located between the first edge welding area and an adjacent first edge, the first edge collector electrode extends along the first direction, and the first edge collector electrode is electrically connected to the second collector electrode; The second edge collector electrode is located between the second edge welding area and another adjacent first edge, the second edge collector electrode extends along the first direction, and the second edge collector electrode is electrically connected to the second collector electrode; The third edge collector electrode extends along the second direction and is adjacent to the second edge, and both the first edge collector electrode and the second edge collector electrode are electrically connected to the third edge collector electrode; The first edge collector electrode, the second edge collector electrode, and the third edge collector electrode have the same polarity.

4. The solar cell according to claim 3, characterized in that, The widths of the first edge collector electrode, the second edge collector electrode, and the third edge collector electrode are greater than the width of the first collector electrode or the second collector electrode; Alternatively, the number of the first edge collector electrodes is greater than or equal to 2, and they are arranged at intervals along the second direction; the number of the second edge collector electrodes is greater than or equal to 2, and they are arranged at intervals along the second direction; the number of the third edge collector electrodes adjacent to the same second edge is greater than or equal to 2, and they are arranged at intervals along the first direction.

5. The solar cell according to claim 3, wherein The ratio of the width of the first edge collector electrode to the width of the second collector electrode is in the range of 1:1 to 4:1; And / or, the ratio of the width of the first edge collector electrode to the width of the first collector electrode ranges from 1:1 to 4:

1.

6. The solar cell of claim 3, wherein, The solar cell also includes a first edge welding area; The first edge welding area is disposed adjacent to the first edge welding area and is located on the side of the first edge welding area away from the first edge current collector electrode. The first edge welding area is electrically connected to the second current collector electrode. Along the second direction, the distance between the first edge current collector electrode and the first edge welding area is less than the distance between the first edge welding area and the first edge welding area; And / or, the solar cell further includes a second edge welding area; The second edge welding area is disposed adjacent to the second edge welding area and is located on the side of the second edge welding area away from the second edge current collector electrode. The second edge welding area is electrically connected to the first current collector electrode. Along the second direction, the distance between the second edge current collector and the second edge welding area is less than the distance between the second edge welding area and the second edge welding area.

7. The solar cell of claim 1, wherein The one-dimensional dimension of the first edge welded portion is smaller than the one-dimensional dimension of the second edge welded portion; And / or, the solar cell further includes a first intermediate welding portion and a second intermediate welding portion, located between the first edge welding portion and the second edge welding portion, the first intermediate welding portion and the second intermediate welding portion being alternately arranged along the second direction, the first intermediate welding portion being electrically connected to the first current collector electrode, and the second intermediate welding portion being electrically connected to the second current collector electrode; The one-dimensional dimension of the first intermediate welded part is smaller than the one-dimensional dimension of the second intermediate welded part.

8. The solar cell of claim 6, wherein, The lengths of the first edge weld and the first intermediate weld are 0.6mm to 1.3mm; the widths of the first edge weld and the first intermediate weld are 0.5mm to 1.3mm. The lengths of the second edge weld and the second intermediate weld are 0.6mm to 1.5mm; the widths of the second edge weld and the second intermediate weld are 0.5mm to 1.5mm.

9. The solar cell of claim 1, wherein, Along the first direction, the width of the first collector electrode is smaller than the width of the second collector electrode; And / or, along the first direction, the width of the first collector electrode is 60μm~120μm, and the width of the second collector electrode is 80μm~150μm.

10. The solar cell of claim 1, wherein, Along the first direction, the width of the first doped layer is smaller than the width of the second doped layer.

11. The solar cell according to claim 1, characterized in that, The ratio of the width of the first collector electrode to the width of the first doped layer ranges from 1:14 to 5:

8. The ratio of the width of the second collector electrode to the width of the second doped layer ranges from 1:14 to 4:

5.

12. The solar cell of claim 1, wherein, The first surface includes a first region and a second region, the first doped layer is disposed in the first region, and the second doped layer is disposed in the second region; The roughness of the first region is less than that of the second region.

13. The solar cell of claim 1, wherein, The first doped layer is an N-type doped layer, and the second doped layer is a P-type doped layer.

14. The solar cell of claim 1, wherein, The first edge collector electrode, the second edge collector electrode, and the third edge collector electrode are P-type polarities.

15. The solar cell according to any one of claims 1 to 14, characterized in that The first surface includes a first region and a second region, the first doped layer is disposed in the first region, and the second doped layer is disposed in the second region; The solar cell also includes an intrinsic amorphous silicon layer, a tunneling oxide layer, and a transparent conductive layer; The tunneling oxide layer is disposed in the first region and located between the silicon substrate and the first doped layer, wherein the first doped layer includes a doped polysilicon layer. The intrinsic amorphous silicon layer is disposed in the second region and located between the silicon substrate and the second doped layer, wherein the second doped layer includes one or more of a doped amorphous silicon layer and a doped microcrystalline silicon layer. The transparent conductive layer is disposed on the first doped layer and the second doped layer, and the transparent conductive layer is disconnected in the region where the first region and the second region overlap; the first current collector is disposed on the transparent conductive layer corresponding to the first doped layer, and the second current collector is disposed on the transparent conductive layer corresponding to the second doped layer.

16. The solar cell according to any one of claims 1-14, characterized in that, The first and second current collector electrodes are made of copper paste.

17. A photovoltaic module, characterized by include: A battery string, wherein the battery string is formed by electrically connecting a plurality of solar cells as described in any one of claims 1-16; Interconnector, electrically connected to the solar cell; And an encapsulation layer that covers the surface of the battery string.

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