Photocarrier recombination in AlyIn1-yAs/AlxGa1-x as self-assembled quantum dots

Ensembles of self-assembled quantum dots (QD's) are investigated using photoluminescence (PL) and resonant time-resolved PL in the visible spectrum. Faster carrier relaxation/recombination dynamics (similar to 250 ps) are observed for resonant excitations. The influence of the temperature and the intensity of excitation is also measured by monitoring sharp spectral features (similar to 200 mu eV) obtained when probing the PL of small ensembles (similar to 600 QD's). Temperature-independent linewidths are observed up to 70 K (k(B)T much greater than 200 mu eV). For higher excitation intensity, however, the collective background, emitted by the ensemble of QD's, is enhanced relative to the amplitude of the individual sharp spectral features.