Temperature dependence of the exciton homogeneous linewidth in In0.60Ga0.40As/GaAs self-assembled quantum dots -: art. no. 041308

Single dot photoluminescence spectroscopy was used to study the homogeneous linewidth Gamma of the ground-state exciton in In0.60Ga0.40As/GaAs quantum dots as function of temperature T. In high resolution experiments at 2 K, we find a linewidth that is limited by the excitonic lifetime corresponding to a dephasing time of almost a ns. The approximately linear increase of Gamma with temperature up to similar to30 mueV at 60 K is considerably weaker than in structures of higher dimensionality. For higher T we observe a strong enhancement of the linewidth reaching eventually a few meV at room temperature that depends on the confined electronic shell structure.