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CN-122002969-A - Solar cell, preparation method thereof and photovoltaic module

CN122002969ACN 122002969 ACN122002969 ACN 122002969ACN-122002969-A

Abstract

The invention provides a solar cell, a preparation method thereof and a photovoltaic module, and relates to the technical field of photovoltaic cells. The semiconductor substrate comprises a first surface and a second surface which are oppositely arranged, wherein a first polar doping layer, a second polar doping layer and an isolation region are arranged on the first surface, doping types of the first polar doping layer and the second polar doping layer are different, the first polar doping layer is arranged around the second polar doping layer, and an outline boundary of the first polar doping layer is continuously arranged along the edge of the first surface to form a closed pattern. According to the invention, the first polar doped layers are continuously arranged in a surrounding manner, so that the doped layers in the edge area of the battery are all of the same doping type, the back periodic arrangement structure is optimized, the length of the isolation area is reduced, and the carrier recombination caused by the interface of the polar region and the isolation area is reduced, thereby improving the performance of the battery.

Inventors

  • GUAN TONGZHOU
  • SONG NAN

Assignees

  • TCL中环新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20260211

Claims (10)

  1. 1. A solar cell, comprising a semiconductor substrate, wherein the semiconductor substrate comprises a first surface and a second surface which are oppositely arranged, a first polar doping layer, a second polar doping layer and an isolation region are arranged on the first surface, and the doping types of the first polar doping layer and the second polar doping layer are different; The first polar doping layer is arranged around the second polar doping layer, and the outer contour boundary of the first polar doping layer is continuously arranged along the edge of the first surface to form a closed pattern; the first polar doped layer has a spacer between at least two parallel edges of the first surface.
  2. 2. The solar cell of claim 1, wherein an outer contour boundary of the first polar doped layer has a saw tooth profile extending from the first polar doped layer to an edge of the first surface; And/or the substrate surface between the outer contour boundary of the first polar doped layer and the edge of the first surface is provided with a squamous undulating structure; And/or the distance difference d between the wave crest and the wave trough of the sawtooth-shaped morphology and the edge of the first surface is 2-20 mu m; And/or, the scale-like undulating structure has at least 1 layer distributed in the thickness direction of the substrate; And/or, when the scale-like undulating structure is distributed with more than 2 layers along the thickness direction of the substrate, the scale-like undulating structure is distributed in a gradient along the thickness direction of the substrate, wherein the dimension d1 of the undulating structure of the region close to the first surface from the first polar doped layer toward the edge direction of the first surface in the direction intersecting the edge of the first surface is < the dimension d2 of the undulating structure of the region far from the first surface; And/or the dimension d1 of the undulating structure of the area close to the first surface from the first polar doped layer to the edge direction of the first surface is 50-95% of the dimension d2 of the undulating structure of the area far away from the first surface.
  3. 3. The solar cell according to claim 1 or 2, wherein the first polar doped layers are distributed in a continuous grid-like structure to form a mesh region surrounded by grids, wherein the second polar doped layers are arranged in the mesh region, and the isolation region is arranged between the first polar doped layers and the second polar doped layers; And/or the shape of the mesh region comprises any one of a circle, a rectangle, a regular polygon and an irregular polygon; And/or the distance between the centers of two adjacent meshes is 0.05-5 mm; and/or the area ratio of the outline perimeter of the single mesh to the mesh is (0.01-5): 1; and/or, in a single mesh, an area ratio between the second polar doped layer and the isolation region is (2-100): 1; and/or the total area of the second polar doped layer accounts for 5-50% of the total area of the first surface, and the total area of the isolation region accounts for 0.1-10% of the total area of the first surface.
  4. 4. The solar cell of claim 1, wherein an outer contour boundary of the first polar doped layer is disposed proximate an edge of the first surface of the semiconductor substrate; And/or a heavy doping region is arranged between the outline boundary of the first polar doping layer and the edge of the first surface, wherein the doping concentration of the heavy doping region is greater than that of the semiconductor substrate; And/or the ratio of the doping concentration of the heavily doped region to the doping concentration of the semiconductor substrate is (10-100): 1.
  5. 5. The solar cell according to claim 1, wherein the semiconductor substrate is made of any one of silicon, germanium, gallium arsenide, and gallium nitride; and/or the semiconductor substrate comprises an N-type doped substrate or a P-type doped substrate; And/or the semiconductor substrate has an original doping concentration of 1 e14 atm.cm -3 ~1 E16 atm.cm -3 ; And/or the doping element in the N-type doping substrate comprises any one or a combination of at least two of phosphorus, arsenic, antimony and bismuth; And/or the doping element in the P-type doped substrate comprises any one or a combination of at least two of boron, aluminum, gallium and indium.
  6. 6. The solar cell according to claim 1, wherein the materials of the first and second polar doped layers each independently comprise any one of polysilicon, amorphous silicon, and silicon carbide; And/or when the first polar doping layer is a P-type doping layer, the second polar doping layer is an N-type doping layer; And/or the concentration of the N-type doped layer is 1 E20~1 E21 atm.cm -3 , and the concentration of the P-type doped layer is 1 E19~1 E20 atm.cm -3 ; And/or the doping element in the N-type doping layer comprises any one or a combination of at least two of phosphorus, arsenic, antimony and bismuth; and/or the doping element in the P-type doped layer comprises any one or a combination of at least two of boron, aluminum, gallium and indium.
  7. 7. The solar cell according to claim 1, wherein the surfaces of the first polar doped layer, the second polar doped layer and the isolation region are each provided with a passivation layer; and/or the passivation layer is made of any one or a combination of at least two of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride and titanium oxide; And/or the thickness of the passivation layer is 1-100 nm; and/or the first surface is also provided with a first electrode and a second electrode, wherein the first electrode is in electrical contact with the first polar doped layer, and the second electrode is in electrical contact with the second polar doped layer.
  8. 8. A method of manufacturing a solar cell according to any one of claims 1 to 7, comprising: Preparing the first polar doped layer on the first surface of the semiconductor substrate; removing the first polar doped layer at the positions of the second polar doped layer and the isolation region; preparing the second polar doped layer on the first surface; and removing the second polar doping layer at the positions on the coverage area of the isolation region and the first polar doping layer to obtain the solar cell.
  9. 9. The method of claim 8, further comprising, after the step of removing the second polar doped layer at a location on the blanket area of the isolation region and the first polar doped layer, preparing a passivation layer on surfaces of the first polar doped layer, the second polar doped layer, and the isolation region, and then preparing a passivation layer on the second surface, prior to the step of obtaining the solar cell.
  10. 10. A photovoltaic module, characterized in that it comprises a solar cell according to any one of claims 1 to 7 or obtained by a preparation method according to any one of claims 8 or 9.

Description

Solar cell, preparation method thereof and photovoltaic module Technical Field The invention relates to the technical field of photovoltaic cells, in particular to a solar cell, a preparation method thereof and a photovoltaic module. Background The BC battery back structure is arranged in an interdigital mode through the P-type doped region and the N-type doped region, the front zero shielding is achieved, the incident illumination is utilized to the maximum extent, meanwhile, the tunneling contact passivation structure is adopted, the composite loss of carriers is greatly reduced, the open-circuit voltage is improved, and the BC battery is used as an efficient battery and gradually becomes a main stream product in the market. In the mainstream passivation contact technology, an electron-selective contact region (N region) of a solar cell is formed by disposing a doped layer including a dielectric layer and an N-type dopant on a substrate, and a hole-selective contact region (P region) is formed by disposing a doped layer including a dielectric layer and a P-type dopant on a substrate. In the BC battery manufacturing process, the dielectric layer and the doped layer on the surface of the isolation region need to be removed in a laser etching, chemical corrosion and other modes, so that the N, P region can not be directly contacted to generate the problems of electric leakage, carrier recombination and the like, and therefore, a passivation contact film layer which is covered on the surface of the N region or the P region and comprises the dielectric layer and the doped layer generates a fracture section at the interface position of the interface between the passivation contact film layer and the isolation region. The research shows that the carrier recombination condition of the interface position is quite serious, the published literature shows that the edge of the passivation film layer structure at the interface position is excessively etched in the subsequent processes of laser, chemical corrosion and the like, so that local passivation is invalid and micro-pits appear, and the interface position becomes a carrier recombination center, reverse saturation current densities J01 and J02 are adopted to characterize the carrier recombination condition of different areas of the surface of the BC battery, and the test finds that the interface position accounts for 60.6% of the total J02 under the condition that the interface position accounts for less than 20% of the total area, so that the area occupation ratio and the spacing of an N area and a P area are considered when the back surface graphical design of the BC battery is carried out, and how to reduce the interface length of a selective area and an isolation area through optimizing the surface graphical arrangement is considered. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a solar cell, a preparation method thereof and a photovoltaic module. In order to achieve the above object of the present invention, the following technical solutions are specifically adopted: In a first aspect, the present invention provides a solar cell, including a semiconductor substrate, where the semiconductor substrate includes a first surface and a second surface that are disposed opposite to each other, the first surface is provided with a first polar doped layer, a second polar doped layer, and an isolation region, and doping types of the first polar doped layer and the second polar doped layer are different; The first polar doping layer is arranged around the second polar doping layer, and the outer contour boundary of the first polar doping layer is continuously arranged along the edge of the first surface to form a closed pattern; wherein a spacer is provided between at least two parallel edges of the first surface and the first polarity-doped layer. Further, a spacer is arranged between at least the first polarity doping layer and two parallel edges of the first surface, wherein the semiconductor substrate is rectangular, and the spacer is arranged on the two parallel edges of the first surface, or three edges of the first surface, or four edges of the first surface. Further, the width w of the spacer is 1 to 50 μm. Further, on the first surface of the semiconductor substrate, the first polar doping layer and the second polar doping layer are arranged at intervals, wherein the isolation region is arranged between the first polar doping layer and the second polar doping layer. Further, the outer contour boundary of the first polar doped layer has a saw tooth profile extending from the first polar doped layer to an edge of the first surface. Further, the surface of the substrate between the outer contour boundary of the first polar doped layer and the edge of the first surface is provided with a squamous undulating structure. Further, the difference d between the distance from the wave crest and the wave trough