Ensemble Monte Carlo simulation of optical excitation of AlGaAs

Ternary semiconductor alloys such as Al_xGa_1-xAs provide a challenge to our understanding of the physics of alloy effects in semiconductors. It is well known that Al_xGa_1-xAs is a two-mode alloy, even though the material is supposed to be a smooth random alloy. Recent experimental work has suggested that there is a non-monotonic behavior to the relative scattering strength of the Al mode. We have studied the transport of a range of alloys using the ensemble Monte Carlo (EMC) approach, incorporating the two LO modes, non-equilibrium phonons, and the full electron-electron interaction. We find that anomalies in the ratio of scattering strength, as measured by Raman scattering, are sensitive to the details of the phonon distribution function and the shape of the Raman signal with time. Differences in various reported results arise primarily from differences in measurement technique.