Influence of resonant excitation and carrier lifetime on the optical properties of coupled CdSe quantum dots

Abstract

We studied the time-integrated and time-resolved photoluminescence (PL) from coupled quantum dot (QD) systems (CdSe/CdZnMnSe and CdSe/CdMnSe), which exhibited an antiferromagnetic interaction between the QDs in adjacent layers. We observed a peculiar PL peak shift with an excitation wavelength close to the bandgap of the CdSe QDs, which was attributed to a resonant excitation condition. We found that the PL lifetimes of these structures were significantly influenced by non-radiative recombination processes and that the temperature dependence of the PL intensity was strongly correlated with the PL lifetime.