Exciton dynamics in self-organized InAs/GaAs quantum dots

Using a newly-developed population mixing technique we have studied the exc iton dynamics in self-organized InAs/GaAs quantum dots (QDs). It is found t hat the exciton lifetime in self-organized InAs/GaAs QDs is around 1 ns, al most independent of InAs layer thickness. The temperature dependence of the exciton lifetime varies from sample to sample, but no obvious experimental evidence was found that the lifetime is related to the delta-function of d ensity of states in QDs. We have also found that the population mixing tech nique can be used to directly reveal the band-filling effect in the excited states of the QDs.