Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of geometrically ordered multi-crystalline silicon may be formed that is free or substantially free of radially-distributed impurities and defects and having at least two dimensions that are each at least about 10 cm is provided.
 This invention was made with U.S. Government support under National Renewable Energy Laboratory (NREL) Subcontract No. ZDO-2-30628-03 under Department of Energy (DOE) Contract No. DE-AC36-98GO10337, awarded by DOE. The U.S. Government has certain rights in this invention.