Progress in Research and Development of Solar-grade Silicon Preparation by Electron Beam Melting

Abstract

Electron beam melting is an effective method to remove volatile impurities in silicon due to its characteristics of high energy density and high vacuum degree, which has huge advantages and wide application prospects in preparation of solar-grade silicon. Currently it has been successfully applied in industry and become one of the key procedures for preparation of solar-grade silicon by metallurgical route. Based on the thermodynamic principle of the volatile impurities removal, the removal efficiency and mechanism are summarized in this paper. According to current problems of this technology combined with our own experience, the emphasis of current research is reviewed from the points of numerical simulation, energy-saving melting technology and coupling with directional solidification technology. The future development direction of this technology is also proposed.