Free-exciton confinement by layer stacking faults in GaSe: Evidence from time-resolved spectroscopy

Abstract

Picosecond photomodulation techniques have been applied to study the kinetics of the $n=1\mathrm{}$ free exciton in the layered semiconductor GaSe. We have observed a lack of spectral diffusion within a stochastic inhomogeneous exciton resonance at low temperatures and use this to support arguments for partial exciton localization by layer stacking faults.