Tuned exciton kinetics in self-organized InGaAs/GaAs quantum dots

The exciton dynamics in self-organized InGaAs/GaAs quantum dots with systematically varying structural properties is investigated by time-resolved photoluminescence spectroscopy. Decreasing the lateral confinement by ex-situ annealing increases the exciton lifetime and accelerates intradot relaxation. The altered exciton dynamics is attributed to the decreasing electron–hole overlap in the annealed QDs, resulting from the smoother confinement potential. The results demonstrate the effect of the actual confinement potential on the exciton–photon and exciton–phonon interactions, pointing out possible pathways to device optimization.