ELECTRON-INTERFACE PHONON-SCATTERING IN ASYMMETRIC SEMICONDUCTOR QUANTUM-WELL STRUCTURES

Electron-interface phonon scattering rates in asymmetric single quantu m well and step quantum well structures are calculated by means of the interaction Frohlich-like Hamiltonian between an electron and interfa ce optical phonons in a four-layer heterostructure given recently. The intrasubband and intersubband electron scattering rates are given as functions of quantum well width, step width and step height. We have f ound that the electron scattering depends strongly on the potential pa rameters and the usual selectio rules for these transitions are broken down in asymmetric heterostructures; the interface LO modes are more important than the interface TO modes for the electron-interface phono ns scattering in heterostructures; the intrasubband scattering rates a re insensitive functions of step width and step height, and the inters ubband scattering rates are complicated functions of step height funct ions of step height and step width in step quantum wells. Moreover, we have also observed that the scattering rates for intrasubband transit ions have no obvious changes in the case that the first or second subb and energy level crosses the step height in a step quantum well.