Nanosecond-scale hot-carrier cooling dynamics in one-dimensional quantum dot superlattices

Abstract

We report the time-resolved photoluminescence spectroscopy of nanoseconds-scale hot-carrier (HC) cooling dynamics in InAs/GaAs quantum dot superlattices (QDSLs). We demonstrate supra 1000-K time-averaged carrier temperature in the InAs/GaAs QDSLs from one-dimensional density of states restricting the phase space and energy-momentum conservation in the carrier scattering processes. The InAs/GaAs QDSLs HC energy dissipation rate was much smaller than that for InAs/GaAs multiple quantum wells and nearly excitation-photon-density independent, implying reduced efficiency of carrier-carrier scattering.