Efficient photothermal conversion polycrystalline silicon plate and preparation method thereof

Abstract

The invention discloses an efficient photothermal conversion polycrystalline silicon plate and a preparation method thereof. A first coating, a second coating and a third coating are sequentially arranged on the surface of a crucible from inside to outside, then an isolated layer of certain thickness is laid at the bottom of the crucible, and polycrystalline silicon raw materials are contained in the crucible; the crucible containing the polycrystalline silicon raw materials is placed in a melting furnace with an electron beam generating device to be treated, then a silicon solution is obtained, cooling, crushing, acid pickling and drying are carried out, and then a crystal growing stage is carried out; after the crystal growing stage is carried out, the temperature of a temperature control thermocouple and the rate of upward movement of a side heat insulation cage are regulated, meanwhile, water vapor and hydrogen doped argon is introduced, and directional solidification is carried out; after molten silicon is completely crystallized, annealing and cooling are carried out, and the efficient photothermal conversion polycrystalline silicon plate is formed. The process is easy to operate, scientific, reasonable and high in production efficiency, the content of boron, phosphorus and metal impurities in the polycrystalline silicon plate can be effectively reduced, complete polycrystalline silicon is prepared, little crystal growing dislocation is generated, the grain boundary is proper, and the photothermal conversion efficiency is improved.

Description

technical field [0001] The invention relates to the field of polysilicon preparation technology, in particular to a high-efficiency light-to-heat conversion polysilicon plate and a preparation method thereof. Background technique [0002] The photovoltaic industry is one of the fastest growing high-tech industries in the world in the 21st century. Polysilicon is the cornerstone of the global electronics industry and photovoltaic industry. Solar cells made of silicon materials have stable performance, long life, better light-to-heat conversion functions, and lower costs than other solar cells. In order to produce solar cells with lower cost and better performance, industrial silicon (MG-Si) is used as raw material and refined by metallurgical methods to produce solar-grade silicon (SOG-Si). Solar-grade silicon contains a variety of impurities, among which phosphorus, boron, and metal impurities seriously affect the conversion efficiency and stability of silicon solar cells. ...

AI Technical Summary

Problems solved by technology

At present, the metallurgical method used in China uses a large amount of silicon material to be put into the crucible to grow crystals. The impurity content in the crucible is more than 1000 times that of the silicon material. The impurities in the crucible enter the silicon ingot in a large amount during the ingot casting process, thereby introducing impurities. Cause secondary pollution and limit the conversion efficiency of polysilicon cells