CN-122028552-A - Solar cell, preparation method thereof, cell assembly and photovoltaic system

Abstract

The invention relates to the field of photovoltaic cells, and particularly discloses a solar cell, a preparation method thereof, a cell assembly and a photovoltaic system. The solar cell comprises a silicon substrate, a first tunneling layer, a first diffusion barrier layer, a first doping layer, a first passivation layer and a first electrode. The silicon substrate is provided with a first surface and a second surface which are oppositely arranged, at least one first inner expansion area is arranged on the first surface or the second surface along a second direction, at least one hole is arranged on the first diffusion barrier layer, so that a doping source of the first doping layer is diffused into the silicon substrate through the hole to form the first inner expansion area, the first doping layer comprises first parts and second parts which are alternately distributed along the second direction, the doping concentration of the first parts is larger than that of the second parts, and the first parts are correspondingly arranged with the first inner expansion area. By implementing the invention, the photoelectric conversion efficiency of the solar cell can be improved.

Inventors

• Feng Junhang
• ZHANG SHENGLI
• WANG YONGQIAN

Assignees

• 浙江爱旭太阳能科技有限公司
• 珠海富山爱旭太阳能科技有限公司
• 山东爱旭太阳能科技有限公司
• 天津爱旭太阳能科技有限公司

Dates

Publication Date

20260512

Application Date

20251231

Claims (17)

1. 1. A solar cell, comprising: The device comprises a silicon substrate, a first electrode, a second electrode, a first electrode and a second electrode, wherein the silicon substrate is provided with a first surface and a second surface which are oppositely arranged, and at least one first inner expansion area is arranged on the first surface or the second surface along a second direction; the first tunneling layer is arranged on the first surface; The first diffusion barrier layer is provided with at least one hole, so that a doping source of the first doping layer diffuses into the silicon substrate through the hole to form the first inner diffusion region; The first doping layer comprises first parts and second parts which are alternately distributed along a second direction, wherein the first parts and the second parts extend along the first direction, the doping concentration of the first parts is larger than that of the second parts, and the first parts and the first inner expansion area are correspondingly arranged; a first passivation layer disposed on the first doped layer, and And the first electrode is arranged on the first passivation layer and is in contact with the first doped layer.
2. 2. The solar cell according to claim 1, wherein the thickness of the first tunneling layer is 2nm to 10nm, and/or The first tunneling layer is a lamination formed by one or more of a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, a silicon oxynitride layer, an intrinsic amorphous silicon layer, a silicon carbide layer and a magnesium fluoride layer; the thickness of the first diffusion barrier layer is 1 nm-5 nm, and/or The first diffusion barrier layer is a lamination formed by one or more of a silicon nitride layer, a silicon carbide layer, a silicon oxynitride layer, a silicon oxycarbide layer, a silicon carbonitride layer and an aluminum oxide layer.
3. 3. The solar cell according to claim 1, wherein the first tunneling layer is a silicon oxide layer having a thickness of 3nm to 10nm, and/or The thickness of the first diffusion barrier layer is 1 nm-3 nm, and/or The first diffusion barrier layer is a silicon nitride layer or a silicon carbide layer.
4. 4. The solar cell according to claim 1, wherein the depth of the first internal expansion region is not less than 0.1 μm, and/or The doping concentration of the first internal expansion region is more than or equal to 1 multiplied by 10 18 cm -3 , and/or The doping concentration of the first part is not less than 1 multiplied by 10 20 cm -3 , and/or The doping concentration of the second part is less than or equal to 5 multiplied by 10 20 cm -3 .
5. 5. The solar cell according to claim 1, wherein the depth of the first inward expansion region is 0.1 μm to 0.5 μm, and/or The doping concentration of the first internal expansion region is 1×10 18 cm -3 ~5×10 19 cm -3 , and/or The doping concentration of the first part is 3×10 20 cm -3 ~5×10 21 cm -3 , and/or The doping concentration of the second part is 5×10 19 cm -3 ~5×10 20 cm -3 .
6. 6. The solar cell of claim 1, wherein the first doped layer comprises a plurality of first portions and second portions alternately arranged along a second direction, wherein the widths of the plurality of first portions in the second direction are the same or different, and the widths of the plurality of second portions in the second direction are the same or different; a first doped layer under the first electrode includes the first portion and/or the second portion.
7. 7. The solar cell of claim 1, wherein the first doped layer comprises a plurality of first portions and second portions alternately arranged along a first direction, wherein the plurality of second portions have different widths in the second direction, and wherein the plurality of first portions have the same width in the second direction; The first doped layer below the first electrode is the second part, and the width of the first electrode in the second direction is smaller than the width of the second part below the first electrode in the second direction.
8. 8. The solar cell according to claim 1, wherein the width of the first portion in the second direction is 2 μm to 100 μm, and the width of the second portion in the second direction is 30 μm to 100 μm.
9. 9. The solar cell of claim 1, wherein a distribution density of pinholes of the first tunneling layer under the first portion is greater than a distribution density of pinholes of the first tunneling layer under the second portion.
10. 10. The solar cell of any one of claims 1-9, wherein the first inner diffusion region, the first tunneling layer, the first diffusion barrier layer, the first doped layer, the first passivation layer, and the first electrode are all disposed on the first surface; the solar cell further comprises a doped layer, a second passivation layer, an anti-reflection layer and a second electrode which are sequentially arranged on the second surface, and the second electrode is in contact with the doped layer.
11. 11. The solar cell of any one of claims 1-9, wherein the first tunneling layer, the first diffusion barrier layer, the first doped layer, the first passivation layer, and the first electrode are all disposed on the first surface; The solar cell further comprises a second tunneling layer, a second diffusion barrier layer, a second doped layer, a second passivation layer and a second electrode which are sequentially arranged on the second surface, at least one through hole is formed in the second diffusion barrier layer, so that a doping source of the second doped layer diffuses into a silicon substrate through the through hole to form a first inner expansion area, the second doped layer comprises at least one third portion and at least one fourth portion in a first direction, the doping concentration of the third portion is larger than that of the fourth portion, the third portion is arranged corresponding to the first inner expansion area, and the second electrode is in contact with the second doped layer.
12. 12. The solar cell of any one of claims 1-9, wherein the first surface of the silicon substrate comprises first and second regions alternately arranged along the second direction; the first inner expansion region, the first tunneling layer, the first diffusion barrier layer, the first doping layer, the first passivation layer and the first electrode are all arranged in the first region; And a passivation layer and a second electrode are sequentially laminated in the second region, and the second electrode is in contact with the silicon substrate.
13. 13. The solar cell of any one of claims 1-9, wherein the first surface of the silicon substrate comprises first and second regions alternately arranged along the second direction; the first inner expansion region, the first tunneling layer, the first diffusion barrier layer, the first doping layer, the first passivation layer and the first electrode are all arranged in the first region; The second region is provided with at least one second inner diffusion region along a first direction, at least one through hole is formed in the second diffusion barrier layer, so that a doping source of the second doping layer diffuses into a silicon substrate through the through hole to form the second inner diffusion region, the second doping layer comprises at least one third part and at least one fourth part along the first direction, the doping concentration of the third part is larger than that of the fourth part, the third part is correspondingly arranged with the first inner diffusion region, and the second electrode is in contact with the second doping layer.
14. 14. A method for manufacturing a solar cell according to any one of claims 1 to 13, comprising: Providing a silicon substrate; sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer and a first doping layer on the silicon substrate to obtain a first intermediate; forming a doping source layer on the first intermediate; Pushing a doping source of the doping source layer to the first doping layer by using laser, forming at least one hole on the first initial diffusion blocking layer, pushing the doping source of the first doping layer into the silicon substrate through the hole to form at least one first inner expansion area, wherein the first doping layer forms a first part and a second part after laser treatment; removing the residual doping source layer to obtain a second intermediate; forming a first passivation layer on the second intermediate; And forming a first electrode on the first passivation layer, wherein the first electrode is in contact with the first doped layer.
15. 15. The method of claim 14, wherein the doped source layer is a phosphosilicate glass layer, a borosilicate glass layer, a boron doped silicon paste layer, a phosphorus doped silicon paste layer, a liquid phosphorus source layer, or a liquid boron source layer.
16. 16. A battery assembly comprising a solar cell according to any one of claims 1 to 13.
17. 17. A photovoltaic system comprising the cell assembly of claim 16.

Description

Solar cell, preparation method thereof, cell assembly and photovoltaic system Technical Field The invention relates to the field of photovoltaic cells, in particular to a solar cell, a preparation method thereof, a cell assembly and a photovoltaic system Background In a passivation contact structure (TOPCon) of a tunneling oxide layer of a conventional solar cell, after the tunneling oxide layer is prepared, a large number of pinholes are formed on the tunneling oxide layer by heat treatment, so that when a doped polysilicon layer is prepared subsequently, a doping source of the doped polysilicon layer is diffused into a silicon substrate through the pinholes to form an inner diffusion layer. Although a certain inner expansion layer is favorable for carrier transmission, when the inner expansion area is more, auger recombination is easy to increase, open-circuit voltage is reduced, and the photoelectric conversion efficiency of the solar cell is further affected. Disclosure of Invention The invention aims to solve the technical problem of providing a solar cell and a preparation method thereof, which can effectively improve photoelectric conversion efficiency. The invention also solves the technical problem of providing a battery assembly and a photovoltaic system. In order to solve the above problems, the present invention discloses a solar cell comprising: The device comprises a silicon substrate, a first electrode, a second electrode, a first electrode and a second electrode, wherein the silicon substrate is provided with a first surface and a second surface which are oppositely arranged, and at least one first inner expansion area is arranged on the first surface or the second surface along a second direction; the first tunneling layer is arranged on the first surface; The first diffusion barrier layer is provided with at least one hole, so that a doping source of the first doping layer diffuses into the silicon substrate through the hole to form the first inner diffusion region; The first doping layer comprises first parts and second parts which are alternately distributed along a second direction, wherein the first parts and the second parts extend along the first direction, the doping concentration of the first parts is larger than that of the second parts, and the first parts and the first inner expansion area are correspondingly arranged; a first passivation layer disposed on the first doped layer, and And the first electrode is arranged on the first passivation layer and is in contact with the first doped layer. As an improvement of the technical scheme, the thickness of the first tunneling layer is 2 nm-10 nm, and/or The first tunneling layer is a lamination formed by one or more of a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, a silicon oxynitride layer, an intrinsic amorphous silicon layer, a silicon carbide layer and a magnesium fluoride layer; the thickness of the first diffusion barrier layer is 1 nm-5 nm, and/or The first diffusion barrier layer is a lamination formed by one or more of a silicon nitride layer, a silicon carbide layer, a silicon oxynitride layer, a silicon oxycarbide layer, a silicon carbonitride layer and an aluminum oxide layer. As an improvement of the technical scheme, the first tunneling layer is a silicon oxide layer with the thickness of 3 nm-10 nm, and/or The thickness of the first diffusion barrier layer is 1 nm-3 nm, and/or The first diffusion barrier layer is a silicon nitride layer or a silicon carbide layer. As an improvement of the technical proposal, the depth of the first inner expansion area is more than or equal to 0.1 mu m, and/or The doping concentration of the first internal expansion region is more than or equal to 1 multiplied by 10 18cm-3, and/or The doping concentration of the first part is not less than 1 multiplied by 10 20cm-3, and/or The doping concentration of the second part is less than or equal to 5 multiplied by 10 20cm-3. As an improvement of the technical scheme, the depth of the first inner expansion area is 0.1-0.5 mu m, and/or The doping concentration of the first internal expansion region is 1×10 18cm-3~5×1019cm-3, and/or The doping concentration of the first part is 3×10 20cm-3~5×1021cm-3, and/or The doping concentration of the second part is 5×10 19cm-3~5×1020cm-3. As an improvement of the above technical scheme, the first doped layer comprises a plurality of first parts and second parts which are alternately distributed along the second direction, wherein the widths of the first parts in the second direction are the same or different, and the widths of the second parts in the second direction are the same or different; a first doped layer under the first electrode includes the first portion and/or the second portion. As an improvement of the above technical scheme, the first doped layer comprises a plurality of first parts and second parts which are alternately distributed along a first direction, wherein