Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Annual Subcontract Report, 1 April 2002--30 September 2003 (Revised)

The goal of BP Solar's Crystalline PVMaT program is to improve the present polycrystalline silicon manufacturing facility to reduce cost, improve efficiency, and increase production capacity. Key components of the program are: increasing ingot size; improving ingot material quality; improving material handling; developing wire saws to slice 100 ..mu..m thick silicon wafers on 200 ..mu..m centers;developing equipment for demounting and subsequent handling of very thin silicon wafers; developing cell processes using 100 ..mu..m 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 a 50 MW (annual nominalcapacity) green-field Mega plant factory model template based on this new thin polycrystalline silicon technology; and facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock.