High Quality Granular Polycrystalline Silicon for Efficient Low-Cost PV-Applications

摘要

Solar Grade Silicon is a major producer of pure polycrystalline silicon for the PV-market. This paper presents quality and production results from operation at semi-commercial production with a patented Submerged Spout Fluid Bed process. Pilot plant tests, inert design tests and fundamental studies secured scale-up to a 200MT/y semi-commercial process in January 2005. Granular product conformed to PV requirements on both physical appearance and chemical purity. PV production tests resulted in cells with lifetime and electrical efficiencies similar to cells produced from current silicon feedstock. Long-term semi-commercial production has confirmed operation stability with good size and quality control. This demonstrated the ability of the SSFB process to produce PV-quality granular polysilicon at significantly reduced costs compared to current hot rod technology. With positive production results and fundamental understanding of process technology SGS is ready for scaling-up to commercial production and secure long-term reliable production capacities of affordable high-quality silicon.