Microscopic Photoluminescence Study of InAs Single Quantum Dots Grown on (100) GaAs

Abstract
We report ultranarrow (≤60 µeV) photoluminescence (PL) lines originating from single InAs quantum dots (QDs) sandwiched by Al0.35Ga0.65As barrier layers, demonstrating their δ-function-like density of states (DOS). The temperature dependence of the full-width at half maximum (FWHM) was studied between 10 and 90 K. It linearly increased with increasing temperature from 40 to 80 K (∼7 µeV/K), suggesting the existence of an excitonic dephasing mechanism. Pure dephasing of excitons due to exciton-phonon interactions in acoustic phonon mode was suggested as a possible mechanism for the PL line broadening.