Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Annual Subcontract Report, 1 October 2003--30 September 2004

The major objectives of this program are to continue the advancement of BP Solar polycrystalline silicon manufacturing technology. The program includes work in the following areas: Efforts in the casting area to increase ingot size, improve ingot material quality, and improve handling of silicon feedstock as it is loaded into the casting stations; developing wire saws to slice 100- m-thicksilicon wafers on 290- m centers; developing equipment for demounting and subsequent handling of very thin silicon wafers; developing cell processes using 100- -thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%; expanding existing in-line manufacturing data reporting systems to provide active process control; establishing a50-MW (annual nominal capacity) green-field Mega-plant factory model template based on this new thin polycrystalline silicon technology; facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock.