Energy relaxation in quantum dots

Abstract

We present the results of energy relaxation calculations for electron-hole pairs confined in a quantum dot and in strong coupling with LO phonons (excitonic polarons). We show that despite the robustness of the polaron entity, its disintegration induced by the anharmonic decay of its LO phonon component can lead to an efficient energy relaxation. We compute the time-dependent photoluminescence signals associated with the ground-state excitonic polaron as well as the photoluminescence excitation signal and the energy loss rate of an excitonic polaron in a quantum dot. Our calculations clearly evidence the existence of dot parameters where the energy relaxation is inhibited.