Monte Carlo simulation of hole mobilities in an InGaAs/GaAs strained layer quantum well

Abstract

The mobility and velocity-field characteristic of holes in an In0.18Ga0.82As/GaAs strained quantum well have been obtained using a Monte Carlo simulation, for lattice temperatures of 77 K and 4.2 K. The simulation incorporates a four-band Luttinger-Kohn bandstructure calculation to account for the effects of heavy-light mixing on the subband energy dispersions and wavefunctions, intra- and inter-subband phonon scattering and intrasubband alloy scattering processes are considered. The simulated 77 K phonon limited hole mobility shows a 600% enhancement over the measured and simulated values in GaAs heterostructures, but most of this enhancement is removed by alloy scattering. At 4.2 K alloy scattering is again primarily responsible for the order of magnitude difference observed between the hole mobilities in GaAs and InGaAs quantum wells. The effect of other scattering processes-impurity, plasmon-phonon and interface roughness scattering-on the hole mobility in the InGaAs/GaAs system is also discussed.