A Novel Fabrication Technique of High-Purity Silicon for Solar Cell Application.II.

摘要

The technique to synthesize silicon from silicon tetrachloride by reduction reaction with zinc at high temperatures was re-examined for the purpose of providing high-purity silicon materials for silicon solar-cell industries.The new findings which should be added to our previous paper(Annual Report of the Ceramics Research Laboratory,Vol.4,p37-42,2005)are as follows:1)Single-crystal silicon fibers can be best grown at 1200 deg C or lower temperatures.2)The Zn and SiCl_4 vapors would be better reacted in the temperature range 1200-1250 deg C.3)The present intermittent injection method of SiCl_4 tends to cause an abrupt backward-flow of air from the exhaust gas outlet into the reaction furnace due to a large difference in the vapor pressure of species and their volumetric change in the reduction reaction,and should be replaced with a method allowing a continuous injection.