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Indexed by:会议论文

Date of Publication:2010-10-16

Included Journals:EI、Scopus

Volume:2

Page Number:319-322

Abstract:Silicon is used as a substrate for photovoltalc conversion of energy and the photovoltalc properties of the polycrystalline silicon depend mainly on the crystalline structure (grain size and presence of defects) and of the purity of the material. Off-spec scrap silicon from the semiconductor industry is used as solar grade silicon (SOG-Si). However, because it is difficult to secure a steady supply of this material, development of a process to produce at low cost silicon is therefore definitely necessary. In this research, the technique of silicon purification in an electron beam furnace was used, where the melting occurs in a high vacuum and the impurities were extracted by evaporation. Metallurgical grade silicon (MG-Si) in the granulose form with leaching, with an initial purity of 99. 88% in mass were used as starting materials. The final purity was above 99.99% in mass. This result demonstrated that this process was technically viable. This paper mainly studied the impurity distribution in the sample and the macro-and microstructure of the sample after electron beam melting. Meantime, the growth mechanism of crystal was also discussed.