Search

CN-113903816-B - Solar cell and preparation method thereof

CN113903816BCN 113903816 BCN113903816 BCN 113903816BCN-113903816-B

Abstract

The invention provides a solar cell and a preparation method thereof, wherein a passivation layer of the solar cell is a transparent conductive layer, the transparent conductive layer comprises a compact conductive layer and a mesoporous conductive layer which are sequentially laminated, and the mesoporous conductive layer is in contact with an electrode. According to the invention, the passivation layer is replaced by the compact conductive layer and the mesoporous conductive layer which are sequentially laminated, and the mesoporous conductive layer is in contact with the electrode, so that the transmission of electrons is ensured, the defect recombination of a metal-nonmetal contact area can be optimized, the contact area of the electrode in the structure is increased, and the electrode has the characteristics of simple structure, easiness in industrial production, stable structure and the like.

Inventors

  • CHEN YIQI
  • ZHANG XUELING
  • CHEN DAMING
  • LIU WEI
  • CHEN YIFENG

Assignees

  • 天合光能股份有限公司

Dates

Publication Date
20260505
Application Date
20210817

Claims (18)

  1. 1. The solar cell is characterized in that a passivation layer on the back of the solar cell is a transparent conductive layer, the transparent conductive layer is a compact conductive layer and a mesoporous conductive layer which are sequentially stacked, and the mesoporous conductive layer is in contact with an electrode; the mesoporous conductive layer is provided with a porous structure or a surface of the mesoporous conductive layer extends over the through holes, and the dense conductive layer is not provided with a pore channel structure; The back of the substrate of the solar cell is sequentially provided with a tunneling layer, a polycrystalline silicon layer, a compact conducting layer, a mesoporous conducting layer and a back electrode in a laminated mode.
  2. 2. The solar cell according to claim 1, wherein the mesoporous conductive layer is in a grid line structure or a full coverage structure.
  3. 3. The solar cell of claim 1, wherein the mesoporous conductive layer has a gate line structure, the gate line structure of the mesoporous conductive layer is the same as the gate line structure of an adjacent electrode, and the gate line structure width of the mesoporous conductive layer is greater than the electrode gate line structure width.
  4. 4. The solar cell according to claim 1, wherein the front side of the substrate of the solar cell is provided with an emitter layer, a front side passivation layer and a front side electrode in sequence.
  5. 5. The solar cell of claim 1, wherein the dense conductive layer comprises a TiO 2 layer, a ZrO 2 layer, a Nb 2 O 5 layer, a boron doped ZnO layer, an aluminum doped ZnO layer, an IZO layer, an IWO layer, ITO layer, FTO layer, snO 2 layer, Y 2 O 3 layer, mgO layer, B 2 O 3 layer, geO 2 layer, la 2 O 3 layer, ceO 2 layer, nd 2 O 3 layer, gd 2 O 3 layer, dy 2 O 3 layer, An Er 2 O 3 layer, an Yb 2 O 3 layer, an SrTiO 3 layer, an BaTiO 3 layer, a PbTiO 3 layer, one or a combination of at least two of the PbZrO 3 layer or the NdAlO 3 layer.
  6. 6. The solar cell according to claim 1, wherein the dense conductive layer has a thickness of 10-100 nm.
  7. 7. The solar cell of claim 1, wherein the mesoporous conductive layer comprises a TiO 2 layer, a ZrO 2 layer, a Nb 2 O 5 layer, a boron doped ZnO layer, an aluminum doped ZnO layer, an IZO layer, an IWO layer, ITO layer, FTO layer, snO 2 layer, Y 2 O 3 layer, mgO layer, B 2 O 3 layer, geO 2 layer, la 2 O 3 layer, ceO 2 layer, nd 2 O 3 layer, gd 2 O 3 layer, dy 2 O 3 layer, An Er 2 O 3 layer, an Yb 2 O 3 layer, an SrTiO 3 layer, an BaTiO 3 layer, a PbTiO 3 layer, one or a combination of at least two of the PbZrO 3 layer or the NdAlO 3 layer.
  8. 8. The solar cell according to claim 1, wherein the thickness of the mesoporous conductive layer is 0.02-2 μm.
  9. 9. The solar cell of claim 1, wherein the mesoporous conductive layer has a mesoporous diameter that is greater than a diameter of particles in an electrode adjacent thereto.
  10. 10. The solar cell according to claim 1, wherein the mesoporous conductive layer has a mesoporous diameter of 0.01-2 μm.
  11. 11. A method for manufacturing a solar cell according to any one of claims 1 to 10, comprising sequentially preparing a dense conductive layer and a mesoporous conductive layer, and printing electrode paste on the surface of the mesoporous conductive layer to form an electrode.
  12. 12. The method of claim 11, wherein the dense conductive layer is prepared in a form comprising one or a combination of at least two of atomic force deposition, vapor deposition, spray coating, hydrothermal, sol-gel, spin coating, or physical sputtering.
  13. 13. The method according to claim 12, wherein the dense conductive layer is prepared by spraying, which comprises dispersing the material of the dense conductive layer in a dispersant, and spraying the material at least twice to form the dense conductive layer.
  14. 14. The method of claim 11, wherein the mesoporous conductive layer is prepared in a form comprising one or a combination of at least two of spray coating, hydrothermal, sol-gel, or spin coating.
  15. 15. The method for preparing the mesoporous conductive layer according to claim 14, wherein the mesoporous conductive layer is prepared by spraying, and the spraying method specifically comprises dispersing mesoporous conductive layer materials in a dispersing agent, circularly spraying at least twice, drying and sintering to form the mesoporous conductive layer.
  16. 16. The method according to claim 15, wherein the sintering temperature is 450-550 ℃.
  17. 17. The method of claim 15, wherein the sintering time is 25-35 min.
  18. 18. The preparation method according to claim 11, characterized in that the preparation method specifically comprises the following steps: An emitter layer, a front passivation layer and a front electrode are formed on the front surface of the substrate, and a tunneling layer, a polycrystalline silicon layer, a compact conducting layer, a mesoporous conducting layer and a back electrode are formed on the back surface of the substrate.

Description

Solar cell and preparation method thereof Technical Field The invention belongs to the technical field of batteries, and particularly relates to a solar battery and a preparation method thereof. Background TOPCon solar cells (tunnel oxide passivation contacts, tunnel Oxide Passivated Contact) are one type of solar cell that uses an ultra-thin oxide layer as the passivation layer structure. An ultrathin tunneling oxide layer and a high-doped polycrystalline silicon thin layer are prepared on the back of the battery, and a passivation contact structure is formed between the ultrathin tunneling oxide layer and the high-doped polycrystalline silicon thin layer, the structure provides good surface passivation for the back of a silicon wafer, the ultrathin oxide layer can enable multi-electron tunneling to enter the polycrystalline silicon layer and simultaneously block minority carrier hole recombination, and electrons are transmitted transversely in the polycrystalline silicon layer and collected by metal, so that metal contact recombination current is greatly reduced, and open-circuit voltage and short-circuit current of the battery are improved. In TOPCon cell structures, the SiN x passivation layer on the back of the cell cannot conduct electricity, when an electrode is printed, the slurry needs to be burnt through the SiN x passivation layer, the electrode is contacted with the bottom polysilicon layer to conduct electron transmission, the polysilicon layer is damaged in the process, further, the passivation effect of a metal-nonmetal contact area is poor, and defect recombination is increased. CN111106183A discloses a method for preparing a back surface full-passivation contact solar cell by utilizing tubular PECVD and the back surface full-passivation contact solar cell, the method comprises the following steps of pre-cleaning a silicon wafer, double-sided texturing, front surface boron diffusion, front surface laser selective doping, secondary cleaning and back surface polishing, depositing a silicon dioxide film layer and a phosphorus doped amorphous silicon carbide film layer on the back surface of tubular PECVD equipment, annealing to convert amorphous silicon carbide into microcrystalline silicon carbide, depositing an Al 2O3 passivation layer and an antireflection layer, screen printing and sintering to obtain the back surface full-passivation contact solar cell. The method has the advantages of simple process, convenient operation, low cost, good compatibility with the existing production line, good preparation controllability, high preparation efficiency, good safety and the like, can prepare the high-efficiency back full-passivation contact solar cell, is suitable for large-scale preparation, is beneficial to industrialized application, and has high use value and good application prospect. CN112670352a discloses a passivation structure applied to contact passivation battery and a preparation method thereof, comprising an N-type substrate, two positive electrodes arranged on the front side of the N-type substrate and two negative electrodes arranged on the back side of the N-type substrate, wherein the back side of the N-type substrate is provided with a SiO 2 layer, and the SiO 2 layer is provided with a doped polycrystalline SiO xNy layer. According to the scheme, the doped polycrystalline silicon oxynitride layer is used for replacing the polycrystalline silicon layer, so that the light absorption of the contact passivation layer is reduced through doping and annealing under proper conditions on the basis of ensuring that the contact resistance is not changed greatly, and the efficiency of the contact passivation type battery is improved. The existing TOPCon battery structure has the problems of complex preparation method, defects of metal-nonmetal contact, complex structure and the like, so that how to ensure that the TOPCon battery structure has a simple structure and is convenient to prepare, the defect recombination of a metal-nonmetal contact area can be optimized, the contact area of an electrode in the structure is increased, and the firmness of the electrode is enhanced, and the problems which are needed to be solved urgently at present are solved. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a solar cell and a preparation method thereof, wherein a passivation layer is replaced by a compact conductive layer and a mesoporous conductive layer which are sequentially laminated, and the mesoporous conductive layer is in contact with an electrode, so that the transmission of electrons is ensured, the defect recombination of a metal-nonmetal contact area can be optimized, the contact area of the electrode in the structure is increased, and the solar cell has the characteristics of simple structure, easiness in industrial production, stable structure and the like. To achieve the purpose, the invention adopts the following technical schem