A systematic study of carrier–LO-phonon scattering rates in quantum wells is presented by using a many-body perturbative formalism. Starting from the self-energy for a confined electron gas interacting with LO-phonons information is obtained about the emission scattering rates. A comparison is made between the cases for three-dimensional phonons and confined phonons. Scattering rates are calculated as function of temperature, well-width and carrier concentration for GaAs and CdTe. Confined LO-phonons in quantum wells offer the possibility of tuning scattering rates with the well width. The extension of this calculation to an asymmetric double quantum well allows to study intraband and interband emission phonon rates, which are proposed to be coherently controlled for future device applications.