6BRAGA A F B,MOREIRA S P,ZAMPIERI P R,et al.New processes for the production of solar-grade polycrystalline silicon:a review[J].Solar Energy Materials and Solar Cells,2008,92(4):418-424.
7YOSHIKAWA T,ARIMURA K,MORITA K.Boron removal by titanium addition in solidification refining of silicon with Si-Al melt[J].Metallurgical and Materials Transactions B,2005,36(6):837-842.