Methods and Apparatus for Manufacturing Monocrystalline Cast Silicon and Monocrystalline Cast Silicon Bodies for Photovoltaics

A method of manufacturing cast silicon, comprising:

• placing molten silicon in contact with at least one silicon seed crystal in a vessel having one or more side walls heated to at least the melting temperature of silicon and at least one wall for cooling;
• melting a desired portion of the at least one seed crystal by measuring the extent of melting;
• and
• forming a solid body comprising near-monocrystalline silicon by cooling the molten silicon to control crystallization, wherein the forming includes forming a solid-liquid interface at an edge of the molten silicon that at least initially parallels the at least one wall for cooling, the interface being controlled during the cooling so as to move in a direction that increases a distance between the molten silicon and the at least one wall for cooling.