Laser-induced photoluminescence enhancement in a room-temperature emitting SiGe-based alloy quantum well

An enhancement of photoluminescence (PL) intensity was observed at room temperature in a SiGe/Si quantum well under continuous laser illumination. The laser-induced PL enhancement was found to be an irreversible process characterized by a time constant which decreases with increasing excitation power density. A modified defect reduction model based on recombination-enhanced defect reaction is invoked to interpret the PL enhancement in terms of an improvement in the crystal quality of quantum well layers induced by laser radiation.