Electron-phonon scattering rates in semiconductor quantum wells with thin AlAs layers

Abstract

We have studied the effects on the phonon spectrum and on the electron--longitudinal-optical-phonon scattering rates in GaAs/AlAs quantum wells of additional thin AlAs layers in the wells. The confined and interface phonon modes and the electron-phonon scattering rates in these structures have been calculated using a dielectric continuum approach for the phonons. Model electron wave functions are used for the quantum well that are taken to be unaffected by the additional AlAs layer. The system with an additional AlAs layer is found to have intrasubband electron scattering rates that are increased modestly compared to those for the corresponding quantum wells due to the influence of the interface phonon modes associated with the additional layer. These results confirm that scattering rates in general depend only weakly on the effects of the structure of the quantum-well system on the phonon spectra.