Inhomogeneously broadening effect on temperature-dependent lineshape in single quantum dot luminescence

Abstract

We study, in single quantum dot (QD) luminescence, the temperature-dependent broadening mechanism due to the coupling between localized excitons and acoustic phonons as well as the environment surrounding the QD system. As a treatment of the interaction between the QD system and the environment, a configuration of excitonic eigenenergies is introduced. Using the Green's function method, analytical formulae of the lineshape of zero-phonon lines (ZPL) are given. The numerical results show that phonons inducing initial fast decay contributes to the background wings of the spectra leading to a wings-asymmetry photoluminescence (PL) spectra. Our model gives a semiquantitative description of the underlying broadening mechanism and is helpful in understanding the origin of the experimental results for the temperature dependence of the ZPL in self-assembled QDs.