Patent ID: 7763095

Claim:
A method of producing solid silicon from molten silicon comprising (a) providing a melt of molten silicon having dispersed therein at least two different types of transition metal atoms in sufficient quantities so as to form metal alloy clusters upon cooling; and, if advantageous for said formation of metal alloy clusters upon cooling, adding to said melt additional quantities of at least one of said at least two different types of transition metal atoms; and, (b) cooling said melt until said transition metal atoms coalesce to form a plurality of metal alloy clusters, wherein said metal alloy clusters are capable of gettering one or more impurity species also present in said melt, and to retain atoms of said one or more impurity species in or on said metal alloy clusters; and, (c) cooling said melt further until solidification occurs, thereby segregating at least some of said impurity species in said metal alloy clusters.