Influence of coupled plasmon-polar optical phonon modes on the mobility of electrons in GaAs

By means of time-dependent perturbation theory, the rate for the scattering of electrons from coupled plasmon-polar optical phonon modes has been derived. This rate has been expressed in a form suitable for Monte-Carlo particle modelling. The mobility of electrons in bulk GaAs has been simulated by means of this technique, both with and without the plasmon-phonon coupled modes. Although the scattering from the coupled modes is stronger than from uncoupled phonons, the energy interval over which coupled-mode scattering takes place is small. The reduction in mobility due to coupled plasmon-phonon modes is of the order of a few per cent and peaks at 1 MV m¿1.