MEDIUM PURITY METALLURGICAL SILICON AND METHOD FOR PREPARING SAME

摘要

Process for preparing photovoltaic quality silicon comprises: oxygen or chlorine refining giving a product with <= 100 ppm of iron, re-melting in a neutral atmosphere in electrical crucible furnace, transfer of molten silicon to plasma refining in crucible furnace; refining under plasma with a plasmagenic gas; and pouring into ingot-mold under controlled atmosphere by segregated solidification. An Independent claim is also included for the purified silicon obtained.