Abstract
We report systematic temperature-dependent measurements of photoluminescence spectra in self-assembled InGaAs/InAs/GaAs quantum dots (QDs). We have studied the rise in temperature of the ground-state homogeneous linewidth.
A theoretical model is presented and accounts for the phonon-assisted broadening of this transition in individual QD. We have estimated the homogeneous linewidth of an individual QD from PL spectra of self-organized InAs/GaAs QDs by isolating the PL of each individual QD and fitting the narrow line associated with self-organized QDs through a Lorentzian convoluted by a Gaussian. We have observed a strong exciton–LO–phonon coupling (
γ
LO) which becomes the dominating contribution to the linewidth above the temperature of 45
K. We have also derived the activation energy (Δ
E) of the exciton–LO–phonon coupling, zero temperature linewidth (
Γ
0) and the exciton-LA-phonon coupling parameter (
γ
Ac). We report that our values are close to the values found in the literature for single InGaAs QD and InAs QD.