TEMPERATURE EFFECTS ON THE RADIATIVE RECOMBINATION IN SELF-ASSEMBLED QUANTUM DOTS

Several ensembles of self-assembled quantum dots (QDs) based on the Al InAs/AlGaAs and InGaAs/GaAs material systems have been investigated us ing photoluminescence (PL), PL excitation (PLE) and time-resolved PL ( TRPL). The influence of the temperature is measured by monitoring shar p spectral features (as narrow as similar to 90 mu eV) obtained when p robing the PL of small QD ensembles (few hundreds QDs). Thermionic emi ssion of the photocarriers out of the QD potential is found to be the dominant mechanism leading to the thermal quenching or the PL and temp erature-independent linewidths are observed up to the onset of the PL quenching.