Reversible Degradation of Photoluminescence in Si/SiGe Three Dimensional Nanostructures

Abstract

We report the degradation of low temperature photoluminescence (PL) from Si/SiGe threedimensional cluster morphology nanostructures under continuous photoexcitation. The PL intensity initially decreases slowly for about 15 minutes, and then decreases rapidly, until only ~ 10% of the original PL intensity remains. A complete recovery of the PL requires restoring the sample temperature to ~ 300K. We propose that a slow accumulation of charge in SiGe clusters enhances the rate of Auger recombination and results in the observed PL degradation.