RECENT ADVANCES IN UPGRADING METALLURGICAL GRADE (MG) SILICON FOR SOLAR GRADE (SoG) SILICON FEEDSTOCK

摘要

As the price of photovoltaic (PV) electricity approaches grid parity, the potential explosion in demand for PV means that the solar grade silicon (SoG Si) industry will need a rapidly scaleable, inexpensive and less capital-intensive source of silicon. A recent advance in the refining of metallurgical grade silicon (MG Si) into SoG Si by a slagging/gettering technique promises such a rapidly scaleable process. We have demonstrated reduction of phosphorus (P) in MG Si from 26 ppm to 0.51 ppm and a reduction of boron (B) from 19 ppm to 7 ppm using just such a process.