In situ mitigation of muon-induced defects in high lifetime crystalline silicon

Crystalline silicon is used in >90% of solar cells in production, and requires both high quality material and a good understanding of the charge carrier behaviour within. Muon-based techniques are valuable tools to probe the charge carrier behaviour. However, previous muon experiments demonstrated that high-lifetime crystalline silicon could be damaged on exposure to muons, with formation of defects in the form of electron traps. These defects can be overcome by post-exposure processing, including annealing and deposition of passivating dielectrics (i.e., Al2O3). In this proposal, we seek to modify the experimental setup for silicon experiments – exposing high lifetime silicon to muons at elevated temperatures, within a hydrogen-rich environment, or both – to determine whether these defects can be ‘repaired’ in situ.