Preparation of high purity crystalline silicon by electro-catalytic reduction of sodium hexafluorosilicate with sodium below 180 °C.

The growing field of silicon solar cells requires a substantial reduction in the cost of semiconductor grade silicon, which has been mainly produced by the rod-based Siemens method. Because silicon can react with almost all of the elements and form a number of alloys at high temperatures, it is high...

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Bibliographic Details
Main Authors: Yuan Chen, Yang Liu, Xin Wang, Kai Li, Pu Chen
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/25153509/pdf/?tool=EBI
Description
Summary:The growing field of silicon solar cells requires a substantial reduction in the cost of semiconductor grade silicon, which has been mainly produced by the rod-based Siemens method. Because silicon can react with almost all of the elements and form a number of alloys at high temperatures, it is highly desired to obtain high purity crystalline silicon at relatively low temperatures through low cost process. Here we report a fast, complete and inexpensive reduction method for converting sodium hexafluorosilicate into silicon at a relatively low reaction temperature (∼ 200 °C). This temperature could be further decreased to less than 180 °C in combination with an electrochemical approach. The residue sodium fluoride is dissolved away by pure water and hydrochloric acid solution in later purifying processes below 15 °C. High purity silicon in particle form can be obtained. The relative simplicity of this method might lead to a low cost process in producing high purity silicon.
ISSN:1932-6203