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Title: A vapor transport, Filtration technique for purifying silicon

Conference · · Conf. Rec. IEEE Photovoltaic Spec. Conf.; (United States)
OSTI ID:5155881

We have recently developed a Vapor Transport, Filtration (VTF) technique for purifying metallurgical grade silicon that has yielded in a single step a 99.9999/sup +/% pure silicon in a dense, coherent form. The technique is a modification of closed-cycle, hot-filament process using HC1 as a transport gas. The silicon source is a two phase composite of silicon embedded in a Cu/sub 3/Si matrix, and the purified silicon is deposited from the vapor phase onto a hot, silicon filament. The purification mechanism is a combination of the expected segregation of certain impurities associated with the vapor transport process and the diffusional trapping of impurities within the bulk of the composite source. The net result is that essentially all impurities are effectively segregated. The refined material is typically n-type with a resistivity of 0.1-1 ohm-cm and yields solar cells of 9.6% relative to a baseline of 9.6% (with no AR coating).

Research Organization:
Solar Energy Research Institute, Golden, CO
OSTI ID:
5155881
Report Number(s):
CONF-840561-
Journal Information:
Conf. Rec. IEEE Photovoltaic Spec. Conf.; (United States), Conference: 17. IEEE photovoltaic specialists conference, Orlando, FL, USA, 1 May 1984
Country of Publication:
United States
Language:
English