A preparation method of a TOPCon structure battery

Abstract

The invention relates to a preparation method of a TOPCon structure battery, comprising the following steps: (1) cleaning and velvet making; (2) prepare that pn junction by boron diffusion and carrying out high-temperature treatment; (3) After high temperature treatment, the temperature is controlled to 850 DEG C-900 DEG C, a BSG layer with a thickness of 50 nm or more is grown on that surface ofthe silicon wafer by inlet oxygen; (4) carry out acid cleaning and etch on that back side with the boron diffusion layer as the front side; (5) prepare a tunneling oxide layer and a doped thin film silicon layer; (6) carry out alkali cleaning on that front surface to remove the excess polysilicon layer generated by the winding plating on the front surface; (7) Remove BSG / PSG; (8), double-sided passivation; (9) Screen printing sintering. The production process of the invention can remove the wrapping plating, simplifies the process and improves the product performance without separately increasing the preparation process of the mask.

Description

technical field [0001] The invention belongs to the field of solar cells, and in particular relates to a preparation method of a TOPCon structure cell. Background technique [0002] The Tunneling Oxide Passivated Contact (TOPCon) solar cell is a new type of silicon solar cell proposed by the Fraunhofer Institute for Solar Energy Research in Germany in recent years. The battery uses an n-type silicon wafer, and the back of the silicon wafer is covered with a layer of silicon oxide layer below 2nm as a passivation tunneling layer, and then covered with a layer of doped thin-film silicon layer to passivate the back of the battery, and the tunneling oxide layer is passivated. The basic battery structure of chemical contact solar cells is that the back structure is an n-type silicon wafer, a passivation tunneling layer, a doped n-type thin film silicon layer, and a metal electrode layer. When the battery is working, electrons tunnel through the n-type silicon wafer. The silicon ...

AI Technical Summary

Problems solved by technology

[0003] At present, some battery manufacturers in China have applied this technology to the production of large-scale silicon wafer batteries. When preparing TOPCon batteries, most of them use LPCVD equipment when depositing silicon oxide layers and doped thin-film silicon layers. It is inevitable that there will be a phenomenon of winding plating, and this winding plating will have a certain negative impact on the conversion efficiency of the battery

[0004] In the existing technology, most of the special materials (such as SiCx, SiNx, etc.) are used as the mask layer when dealing with winding plating. This operation requires an additional process to make the mask, and the mask layer is removed after depositing a thin film silicon layer, which is cumbersome to operate.