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 to grow larger ingots; (2) developed wire saws to cut wafers on as little as 400 μm 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 (15.2 cm by 15.2 cm) wafers and cells; (5) improved the automated assembly of modules, reducing labor requirements 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