Hydrogenation of dislocations in p-type cast-mono silicon

Abstract

Cast- or quasi-monocrystalline silicon wafers are a potential source of low-cost material in the production of crystalline silicon solar cells. Variations caused by dislocation clusters across the cast-mono ingots have been a roadblock for the industrial production of cast-mono solar cells. Post-processing hydrogenation steps are presented in this work in order to passivate defects and dislocations across the silicon wafer and improve bulk carrier lifetime and improve spatial uniformity. Improvement in bulk carrier lifetime is presented and inherent defects in cast-mono silicon are modelled using Shockley-Read-Hall (SRH) recombination theory and the change in defect parameters during the hydrogenation process is analyzed. This analysis provides a better understanding of how post processing hydrogenation affects surface and bulk recombination characteristics in dislocated regions of cast-mono silicon wafers.