PHONON EFFECTS ON ELECTRONIC TRANSPORT IN SINGLE ALXGA1-XAS GAAS HETEROJUNCTIONS

We have studied the transport properties of an AlxGa1-xAs/GaAs single heterostructure using a Monte Carlo method, focusing in particular on the effect of the polar interaction between electrons and phonons. A two-valley (GAMMA and L) model for both GaAs and AlxGa1-xAs layers has been used, which includes size quantization effects through the numerical self-consistent solution of the coupled Schrodinger-Poisson equations. The optical mode description is given in terms of the dielectric continuum model (DCM); within this model the alloy is described by a two-pole dielectric function, which depends on the Al composition. We have then evaluated the scattering probabilities for the confined electrons interacting with half-space and interface modes. These rates are inserted in our Monte Carlo code to study the electron response to an electric field applied along the heterointerface.