Acoustic-phonon-assisted localization of free excitons due to interface roughness in quantum wells

摘要

A theory of localization of free excitons due to interface roughness is presented. Using the perturbation approach, the rate of localization of free excitons through acoustic phonon emission is calculated in GaAs quantum wells as a function of the width of quantum wells, lateral size of well width fluctuation, and center-of-mass kinetic energy. It is found that the rate of localization is sensitive to the center-of-mass kinetic energy of a free exciton. The results agree with those of recent photoluminescence experiments employed to study the localization of free excitons due to roughness in GaAs quantum wells.