Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Final Subcontract Report, 1 April 2002--28 February 2006

The major objectives of this program were to continue advances of BP Solar polycrystalline silicon manufacturing technology. The Program included work in the following areas. (1.) 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. (2.) Developing wire saws to slice 100-..mu..m-thick silicon wafers on 290-..mu..m-centers. (3.) Developing equipment for demounting and subsequent handling of very thin silicon wafers. (4.) 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%. (5.) Expanding existing in-line manufacturing data reporting systems to provideactive process control. (6.) Establishing a 50-MW (annual nominal capacity) green-field Mega-plant factory model template based on this new thin polycrystalline silicon technology. (7.) Facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock..