Acoustical phonon broadening of the exciton line in semiconductor single quantum dots

Micro-photoluminescence (μ-PL) is used to study the temperature dependence of self-assembled quantum dots (QD) in semiconductors. The observation of the PL with temperature shows that there are two different states within the PL emission, namely the zero-phonon line and the phonon sidebands. When the temperature increases, the effect of the sidebands become clearer and show substantial broadening. The theory also shows good agreement with the experimental data, and in the present experiments, PL and μ-PL spectra have been measured at temperatures of 5 K⩽T⩽90 K in both CdTe and GaAs self-assembled QD samples.