The ground state carrier dynamics in self-assembled $(\mathrm{In},\mathrm{Ga})\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ quantum dots has been studied using time-resolved photoluminescence and transmission. By varying the dot design with respect to confinement and doping, the dynamics is shown to follow in general a nonexponential decay due to carrier correlations. Only for specific conditions in regard to optical excitation and carrier population, for example, can the decay be well described by a monoexponential form. For resonant excitation of the ground state transition, a strong shortening of the luminescence decay time is observed as compared to the nonresonant case. The results are consistent with a microscopic theory that accounts for deviations from a simple two-level picture.

• Received 25 June 2007

DOI:https://doi.org/10.1103/PhysRevB.76.165318