Polaron interaction in InAs/GaAs quantum dots and resonant photoluminescence

In an adiabatic approach, the efficiency of the electron-phonon interaction (EPI) can be determined by measuring the ratio between the intensities of two of the phonon replicas that EPI induces in photoluminescence (PL) spect ra. in low-dimensional structures such as InAs/GaAs quantum dots (QDs), thi s ratio depends on the excitation energy E-exc. Moreover. the evolution of the PL spectra intensity and lineshape with E-exc is quite elaborate. We re produce well this evolution for E-exc ranging from far below to above the G aAs bandgap by introducing an effective Huang Rhys factor S, a commonly use d measure of EPI. Nevertheless, the value of S remains much higher than pre dicted in an adiabatic model, which can hardly account for the reported dep endence of S on QD size and shape. The likely source of this lack of consis tency is briefly discussed.