Thermal broadening of the exciton line in III–V semiconductor quantum dots

We present results on the influence of temperature on the exciton lineshape in self-assembled III–V semiconductor quantum dots. Micro photoluminescence (μ-PL) is used to observe the temperature dependence of the exciton line in self-assembled GaAs and InGaAs semiconductor single quantum dots (QDs). 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. The sidebands and the zero-phonon line both show non-linear characteristics with respect to temperature. 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 5K ≤ T ≤ 90 K in GaAs and InGaAs self-assembled QD samples. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)