Abstract
A theoretical study of the emission of acoustic phonons from quasi-2D excitons in quantum wells is presented. Considering the relaxation of quasi-2D excitons involving interaction with longitudinal and transverse acoustic phonons via deformation potential and piezoelectric coupling, we calculate the rate of emission of acoustic phonons as a function of exciton density, exciton temperature, width of quantum wells, and angles of phonon emission. In this calculation, the anisotropies in the sound velocity and coupling constants and dependence of in-"plane effective mass on well width are taken into account.