Temperature and excitation dependence of the luminescence spectra of InAs quantum dots

Temperature dependence of the photoluminescence (PL) spectra of InAs/GaAs self organised quantum dots (QDʹs) have been studied. By deconvoluting these spectra using multiple gaussian fits, we have observed, at low excitation density, the thermally activated quenching of the QDʹs ground state. Our study, at high excitation density, shows a decrease of the FWHM of the QD PL band versus temperature. This effect is correlated to the thermally carriers injection from narrower QDʹs to larger ones through the wetting layer. Finally we have shown that the temperature effects can be compensated by the excitation density.