Monte Carlo Calculations of Parallel and Perpendicular Electron Transport in Gallium-Arsenide Heterolayers
Theoretical studies of transient and steady-state transport at low temperatures for electrons in GaAs single well heterojunction structures were performed. This work contains the most complete numerical study in terms of electronic states and scattering mechanisms for these important artificial semiconductor structures. Polar optical, acoustic phonon scattering (coupled by the deformation potential or piezoelectrically) and ionized impurity scattering are taken into consideration. The interaction of the electrons among themselves are also accounted for through the effect of plasmons and single pair collisions. All the rates are calculated using self-consistent envelope wave functions for up to 5 electronic subbands. Ensemble Monte Carlo simulations which incorporate electron-electron scattering and the effect of degeneracy are used to study the dynamics of the electrons for various values of the electric field. The dependence of the mobility on the value chosen for the deformation potential constant is shown. The results show that is screening of the acoustic phonons is taken into account, a good fit to experiments is obtained with a higher value for D than normally accepted in GaAs, but do not confirm other theoretical ideas such as scattering induced negative differential resistance.
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign