Multi-excitonic structures in GaAs quantum dots proved by photon correlation spectroscopy

Abstract

We studied micro-photoluminescence (μ-PL) spectra of a single GaAs self-assembled quantum dot (QD) using a pulsed excitation light source. At low excitation, we observed single photon emission from a neutral exciton in an isolated QD. For higher excitation, multiple peaks appeared in the spectra, reflecting the formation of exciton complexes. Cross-correlation functions between these lines showed either bunching or antibunching behavior, depending on whether the relevant emission was from a biexcitonic cascade or a charged exciton recombination.