Search

CN-122028534-A - Solar cell, preparation method thereof, cell assembly and photovoltaic system

CN122028534ACN 122028534 ACN122028534 ACN 122028534ACN-122028534-A

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 preparation method of the solar cell comprises the steps of sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer, a first semiconductor layer and first metal nano particles on the first surface of a silicon substrate, then corroding in corrosive liquid, removing the first semiconductor layer, the first initial diffusion barrier layer and the first initial tunneling layer at the covering position of the first metal nano particles, removing the rest first semiconductor layer to form a first initial doping layer, and annealing to form a first passivation layer and a first electrode. Based on the preparation method, the photoelectric conversion efficiency 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 (19)

  1. 1. A method of manufacturing a solar cell, comprising: Providing a silicon substrate, wherein the silicon substrate is provided with a first surface and a second surface which are oppositely arranged; Sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer and a first semiconductor layer on the first surface of the silicon substrate, wherein the forbidden bandwidth of the first semiconductor layer is more than or equal to 0.67eV; Forming first metal nano particles at preset positions of the first semiconductor layer to obtain a first intermediate product; etching the first intermediate product in etching solution, and removing the first semiconductor layer, the first initial diffusion barrier layer and the first initial tunneling layer at the covering part of the first metal nano particles; removing the remaining first semiconductor layer, exposing the first initial diffusion barrier layer; Forming a first initial doping layer on the first initial diffusion barrier layer to obtain a second intermediate product; Annealing the second intermediate product to diffuse doping elements in the first initially doped layer to the silicon substrate to form a first inner diffusion region, converting the first initially tunneling layer into a first tunneling layer, and converting the first initially diffusion barrier layer into a first diffusion barrier layer; forming a first passivation layer on the annealed first doped layer; and forming a first electrode on the first passivation layer to obtain a solar cell finished product.
  2. 2. The method of manufacturing a solar cell according to claim 1, wherein the first semiconductor layer is a stacked structure of one or more of a single crystal silicon layer, a polycrystalline silicon layer, an amorphous silicon layer, a single crystal germanium layer, a polycrystalline germanium layer, an amorphous germanium layer, a gallium oxide layer, a gallium arsenide layer, an indium gallium arsenide layer, an aluminum gallium arsenide layer, a gallium nitride layer, an aluminum nitride layer, an indium nitride layer, an aluminum gallium nitride layer, an indium aluminum nitride layer, and a silicon nitride layer, and/or The first metal nano-particles are one or more of gold nano-particles, silver nano-particles, platinum nano-particles, palladium nano-particles, copper nano-particles, nickel nano-particles and rhodium nano-particles.
  3. 3. The method of manufacturing a solar cell according to claim 1, wherein the first semiconductor layer is a polysilicon layer or an amorphous silicon layer, and/or The first metal nanoparticles are gold nanoparticles, silver nanoparticles or copper nanoparticles.
  4. 4. The method for manufacturing a solar cell according to claim 1, wherein the etching solution is a mixture of HF, H 2 O 2 and a solvent, and the solvent is water or ethanol.
  5. 5. The method for manufacturing a solar cell according to claim 1, wherein the etching solution is a mixture of an aqueous HF solution, an aqueous H 2 O 2 solution and ethanol, the aqueous HF solution has a concentration of 40wt% to 50wt%, the aqueous H 2 O 2 solution has a concentration of 20wt% to 40wt%, and the aqueous HF solution, the aqueous H 2 O 2 solution and the ethanol have a volume ratio of 1 (0.5 to 3) (0.8 to 5).
  6. 6. The method of manufacturing a solar cell according to claim 1, wherein the step of forming first metal nanoparticles at predetermined positions of the semiconductor layer to obtain a first intermediate product comprises: Forming a photoresist layer on the semiconductor layer; Exposing and developing to expose the first semiconductor layer at a preset position; Forming a first metal nanoparticle on the exposed first semiconductor layer; and removing the residual photoresist layer to obtain a first intermediate product.
  7. 7. The method of claim 1, wherein the first initial tunneling layer is made of one or more of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, intrinsic amorphous silicon, silicon carbide, and/or The first initial diffusion barrier layer is made of silicon nitride and/or silicon oxynitride, and/or The thickness of the first tunneling layer is 2-10 nm, and/or The thickness of the first diffusion barrier layer is 1 nm-5 nm.
  8. 8. The method of claim 1, wherein the first tunneling layer is a silicon oxide layer having a thickness of 3nm to 10nm, and/or The first diffusion barrier layer is a silicon nitride layer, and the thickness of the first diffusion barrier layer is 1 nm-3 nm.
  9. 9. The method of claim 1, wherein the first inward-expansion region has a depth of 0.1 μm or more, and/or The doping concentration of the first inner expansion region is more than or equal to 1 multiplied by 10 18 cm -3 .
  10. 10. The method of claim 1, wherein the first inward-expansion region has a depth of 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 .
  11. 11. The method of claim 1, wherein the step of forming a first initial doped layer on the first initial diffusion barrier layer to obtain a second intermediate comprises: Forming a first intrinsic crystal silicon layer on the first initial diffusion barrier layer; And adopting a diffusion source to diffuse and dope the first intrinsic crystal silicon layer to form a first initial doped layer, and obtaining a second intermediate product.
  12. 12. The method of claim 1, wherein the step of forming a first initial doped layer on the first initial diffusion barrier layer to obtain a second intermediate comprises: forming a first intrinsic amorphous silicon layer on the first initial diffusion barrier layer; and adopting a diffusion source to diffuse and dope the first intrinsic amorphous silicon layer to form a first initial doped amorphous silicon layer, and obtaining a second intermediate product.
  13. 13. The method for manufacturing a solar cell according to any one of claims 1 to 12, wherein the step of providing a silicon substrate comprises: Providing a silicon substrate; Forming a second doped layer on a second surface of the silicon substrate; the step of forming a first passivation layer on the annealed first doped polysilicon layer includes: forming a second passivation layer and a first anti-reflection layer on the second doped layer; forming a first passivation layer on the first doped polysilicon layer; The step of forming a first electrode on the first passivation layer to obtain a solar cell finished product comprises the following steps: and forming a first electrode on the first passivation layer and forming a second electrode on the first anti-reflection layer to obtain a solar cell finished product.
  14. 14. The method for manufacturing a solar cell according to any one of claims 1 to 12, wherein the step of sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer, and a first semiconductor layer on the first surface of the silicon substrate comprises: Sequentially forming a second initial tunneling layer, a second initial diffusion barrier layer and a second semiconductor layer on the second surface of the silicon substrate, wherein the forbidden bandwidth of the second semiconductor layer is more than or equal to 0.67eV; forming second metal nano particles at preset positions of the second semiconductor layer to obtain a third intermediate product; sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer and a first semiconductor layer on a first surface of the silicon substrate; Etching the first intermediate product in an etching solution, and removing the first semiconductor layer, the first initial diffusion barrier layer and the first initial tunneling layer at the covering position of the first metal nano particles, etching the first intermediate product in the etching solution, removing the first semiconductor layer, the first initial diffusion barrier layer and the first initial tunneling layer at the covering position of the first metal nano particles, and removing the second semiconductor layer, the second initial diffusion layer and the second initial tunneling layer at the covering position of the second metal nano particles; Removing the remaining first semiconductor layer and removing the remaining second semiconductor layer in the step of exposing the first initial diffusion barrier layer to expose the first initial diffusion barrier layer and the second initial diffusion barrier layer; the step of forming a first initial doping layer on the first initial diffusion barrier layer to obtain a second intermediate product comprises the following steps: Forming a first initial doping layer on the first initial diffusion barrier layer; forming a second initial doping layer on the second initial diffusion barrier layer to obtain a second intermediate product; The second intermediate product is annealed to diffuse doping elements in the first initial doping layer to the silicon substrate to form a first inner expansion area, the first initial tunneling layer is converted into a first tunneling layer, the first initial diffusion barrier layer is converted into a first diffusion barrier layer, the first initial doping layer is converted into the first doping layer, the second intermediate product is annealed to diffuse doping elements in the first initial doping layer to the silicon substrate to form a first inner expansion area, the doping elements in the second initial doping layer are diffused to the silicon substrate to form a second inner expansion area, the first initial tunneling layer is converted into a first tunneling layer, the second initial tunneling layer is converted into a second tunneling layer, the first initial diffusion barrier layer is converted into a first diffusion barrier layer, and the second initial diffusion barrier layer is converted into a second diffusion barrier layer; the step of forming a first passivation layer on the annealed first doped polysilicon layer includes: forming a second passivation layer on the second doped layer; forming a first passivation layer on the first doped layer; The step of forming a first electrode on the first passivation layer to obtain a solar cell finished product comprises the following steps: and forming a first electrode on the first passivation layer and forming a second electrode on the second passivation layer to obtain a solar cell finished product.
  15. 15. The method for manufacturing a solar cell according to any one of claims 1 to 12, wherein the step of sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer, and a first semiconductor layer on the first surface of the silicon substrate comprises: forming a mask layer on a first area on the first surface of the silicon substrate, and then forming a second doping layer by diffusion on a second area exposing the first surface; removing the mask layer; sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer and a first semiconductor layer on a first surface of the silicon substrate; forming first metal nano particles at preset positions of the first semiconductor layer, and forming first metal nano particles at preset positions of the first semiconductor layer above the first area in the step of obtaining a first intermediate product; The step of annealing the second intermediate product to diffuse the doping element in the first initial doping layer to the silicon substrate to form a first inner diffusion region, and converting the first initial tunneling layer into a first tunneling layer and converting the first initial diffusion barrier layer into a first diffusion barrier layer, wherein the step of converting the first initial doping layer into the first doping layer comprises the following steps: Annealing the second intermediate product to diffuse doping elements in the first initially doped layer to the silicon substrate to form a first inner diffusion region, converting the first initially tunneling layer into a first tunneling layer, and converting the first initially diffusion barrier layer into a first diffusion barrier layer; Removing the first tunneling layer, the first diffusion barrier layer and the first doping layer of the second region to expose the second doping layer; in the step of forming the first passivation layer on the annealed first doped layer, forming the first passivation layer on the first doped layer and the second doped layer; and forming a first electrode on the first passivation layer to obtain a solar cell finished product, wherein the first electrode and the second electrode are formed on the first passivation layer.
  16. 16. The method for manufacturing a solar cell according to any one of claim 1 to 12, wherein, Forming first metal nano-particles at preset positions of the first semiconductor layer, and forming first metal nano-particles at preset positions of the first semiconductor layer above the first area in the step of obtaining a first intermediate product; the step of forming a first initial doping layer on the first initial diffusion barrier layer to obtain a second intermediate product comprises the following steps: Forming a first initial doping layer on the first initial diffusion barrier layer; Removing the first initial tunneling layer, the first initial diffusion barrier layer and the first initial doping layer of the second region to expose the second surface; Forming a second initial tunneling layer, a second initial diffusion barrier layer and a second semiconductor layer on the second region, wherein the forbidden bandwidth of the second semiconductor layer is more than or equal to 0.67eV; forming second metal nano-particles at preset positions of the second semiconductor layer above the second region to obtain a fourth intermediate; etching the fourth intermediate product in etching solution, and removing the second semiconductor layer, the second initial diffusion barrier layer and the second initial tunneling layer at the covering part of the second metal nano particles; removing the remaining second semiconductor layer to expose the second initial diffusion barrier layer; forming a second initial doping layer on the second initial diffusion barrier layer; removing the second initial tunneling layer, the second initial diffusion barrier layer and the second initial doping layer of the first region, and exposing the first initial doping layer to obtain a second intermediate product; The second intermediate product is annealed to diffuse doping elements in the first initial doping layer to the silicon substrate to form a first inner expansion area, the first initial tunneling layer is converted into a first tunneling layer, the first initial diffusion barrier layer is converted into a first diffusion barrier layer, the first initial doping layer is converted into the first doping layer, the second intermediate product is annealed to diffuse doping elements in the first initial doping layer to the silicon substrate to form a first inner expansion area, the doping elements in the second initial doping layer are diffused to the silicon substrate to form a second inner expansion area, the first initial tunneling layer is converted into a first tunneling layer, the second initial tunneling layer is converted into a second tunneling layer, the first initial diffusion barrier layer is converted into a first diffusion barrier layer, and the second initial diffusion barrier layer is converted into a second diffusion barrier layer; The step of forming a first passivation layer on the annealed first doped layer comprises the steps of forming a first passivation layer on the first doped layer and the second doped layer; and in the step of forming the first electrode on the first passivation layer to obtain the solar cell finished product, forming the first electrode and the second electrode on the first passivation layer.
  17. 17. A solar cell prepared by the preparation method according to any one of claims 1 to 16.
  18. 18. A battery assembly comprising the solar cell of claim 17.
  19. 19. A photovoltaic system comprising the cell assembly of claim 18 or the solar cell of claim 17.

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 a uniform 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 provide a solar cell and a preparation method thereof, which can improve the 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 method for manufacturing a solar cell, comprising: Providing a silicon substrate, wherein the silicon substrate is provided with a first surface and a second surface which are oppositely arranged; Sequentially forming a first initial tunneling layer, a first initial diffusion barrier layer and a first semiconductor layer on the first surface of the silicon substrate, wherein the forbidden bandwidth of the first semiconductor layer is more than or equal to 0.67eV; Forming first metal nano particles at preset positions of the first semiconductor layer to obtain a first intermediate product; etching the first intermediate product in etching solution, and removing the first semiconductor layer, the first initial diffusion barrier layer and the first initial tunneling layer at the covering part of the first metal nano particles; removing the remaining first semiconductor layer, exposing the first initial diffusion barrier layer; Forming a first initial doping layer on the first initial diffusion barrier layer to obtain a second intermediate product; Annealing the second intermediate product to diffuse doping elements in the first initially doped layer to the silicon substrate to form a first inner diffusion region, converting the first initially tunneling layer into a first tunneling layer, and converting the first initially diffusion barrier layer into a first diffusion barrier layer; forming a first passivation layer on the annealed first doped layer; and forming a first electrode on the first passivation layer to obtain a solar cell finished product. As an improvement of the technical scheme, the first semiconductor layer is a laminated structure formed by one or more of a monocrystalline silicon layer, a polycrystalline silicon layer, an amorphous silicon layer, a monocrystalline germanium layer, a polycrystalline germanium layer, an amorphous germanium layer, a gallium oxide layer, a gallium arsenide layer, an indium gallium arsenide layer, an aluminum gallium arsenide layer, a gallium nitride layer, an aluminum nitride layer, an indium nitride layer, an aluminum gallium nitride layer, an indium aluminum nitride layer and a silicon nitride layer, and/or The first metal nano-particles are one or more of gold nano-particles, silver nano-particles, platinum nano-particles, palladium nano-particles, copper nano-particles, nickel nano-particles and rhodium nano-particles. As an improvement of the technical proposal, the first semiconductor layer is selected from a polysilicon layer or an amorphous silicon layer, and/or The first metal nanoparticles are gold nanoparticles, silver nanoparticles or copper nanoparticles. As improvement of the technical scheme, the corrosive liquid is a mixture of HF, H 2O2 and a solvent, and the solvent is water or ethanol. As an improvement of the technical scheme, the corrosion solution is a mixture of an HF aqueous solution, an H 2O2 aqueous solution and ethanol, the concentration of the HF aqueous solution is 40-50wt%, the concentration of the H 2O2 aqueous solution is 20-40wt%, and the volume ratio of the HF aqueous solution, the H 2O2 aqueous solution and the ethanol is 1 (0.5-3) (0.8-5). As an improvement of the above technical solution, in the step of forming the first metal nanoparticles at the predetermined positions of the semiconductor layer to obtain the first intermediate product: Forming a photoresist layer on the semiconductor layer; Exposing and developing to expose the first semiconductor layer at a preset position; Forming a first metal nanoparticle on the exposed first semiconductor layer; and removing the residual photoresist layer to obtain a first intermediate product. As an