Metallic impurities in multicrystalline silicon

Abstract

Secondary Ion Mass Spectroscopy is applied to cast and ribbon-grown multicrystalline silicon in an attempt to discover the major metallic impurities present in these important photovoltaic materials. By analysing a thin diffused layer, in which the impurities are concentrated, the effective sensitivity of the method is increased significantly. The results indicate that Fe and Cr are present in large quantities in cast multicrystalline silicon, while Cu exists in significant amounts in Edge-defined Film-fed Growth ribbon silicon.