Phosphorous gettering method of metallurgy polycrystalline silicon wafer, silicon wafer and solar cell prepared by silicon wafer

Abstract

The invention provides a phosphorous gettering method of a metallurgy polycrystalline silicon wafer, a silicon wafer and a solar cell prepared by the silicon wafer The phosphorous gettering method includes: corroding to remove a damaged layer on the surface of the silicon wafer; rinsing the silicon wafer and drying; subjecting the silicon wafer to gettering heat treatment in a diffusion furnace, wherein the diffusion phosphorous source flow volume ranges from 650 to 700ml / min, dry oxygen flow volume ranges from 500 to 700ml / min, diffusing temperature ranges from 920 to 970 DEG C, and the diffusing time ranges from 30-45min; cooling the silicon wafer; corroding to remove a getter layer and PN junctions generated on the surface of the silicon wafer due to phosphorus diffusion; rinsing the silicon wafer and drying to obtain the gettered metallurgy polycrystalline silicon wafer. Service life of the silicon wafer is obviously prolonged, and reverse leakage current and light attenuation of the solar cell prepared by the silicon wafer are obviously reduced. The phosphorous gettering method is short in diffusing time, so that production period is shortened, energy consumption is reduced, and industrial production is suited.

Description

technical field [0001] The invention relates to a gettering method for a polycrystalline silicon wafer, in particular to a method for absorbing phosphorus in a metallurgical polycrystalline silicon wafer, as well as a polycrystalline silicon wafer made by the method and a solar cell made of the polycrystalline silicon wafer. Background technique [0002] With the development of industrialization, non-renewable energy sources such as coal and oil are frequently running out, and energy issues have increasingly become a bottleneck restricting the development of the international society and economy. More and more countries have begun to implement the "Sunshine Plan" to develop solar energy resources and seek new economic development. power. Driven by the huge potential of the international photovoltaic market, the solar cell manufacturing industries of various countries are investing huge sums of money to expand production while continuously researching and developing, explorin...

AI Technical Summary

Problems solved by technology

However, the diffusion coefficient of phosphorus in silicon is very small, and usually requires a higher diffusion temperature and a longer diffusion time to achieve the gettering effect.

Conventional phosphorus gettering methods generally use high-temperature diffusion (≥1000°C) to achieve better gettering effects, but high temperatures will cause new dislocations and other defects in silicon wafers; while medium-temperature diffusion (≤900°C) requires more A long time, generally more than 2 hours, makes the production cycle of the cell long, increases energy consumption, and is not suitable for industrialization

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