Dependence on temperature of homogeneous broadening of InGaAs/InAs/GaAs quantum dot fundamental transitions

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.