Progress in Solarex Crystalline Silicon PVMaT Program

The objectives of this NREL sponsored Photovoltaic Manufacturing Technology (PVMaT) Program are to advance Solarex's cast polycrystalline silicon manufacturing technology, reduce module production cost in half, increase module performance and expand Solarex's commercial production capacity by a factor of three. To meet these objectives Solarex has: 1) Modified the casting process and stations togrow larger ingots; 2) Developed wire saws to cut wafers on as little as 400 ..mu..m centers; 3) Developed a laboratory process to increase cell efficiencies to 15% using back surface fields, mechanical texturing and gettering; 4) Modified the casting, wires saw and cell processes in order to fabricate larger wafers and cells; 5) Improved the automated assembly of modules, reducing laborrequirements and increasing throughput; 6) Developed a frameless module with a lower cost backsheet and a simple, low cost electrical termination system; and 7) Determined the stress levels leading to wafer breakage and designed equipment for automated handling of thin wafers.