Abstract
A full Monte Carlo technique for the study of electron and phonon dynamics in bulk GaAs, InP and in AlGaAs-GaAs quantum wells has been presented. The method does not require any assumption on the form of the distribution function, and provides a detailed microscopic description of the transport phenomena. For the photoexcitation case, it has been shown that during the initial stage of the relaxation a strong emission of LO phonons occur which drives the phonon distribution function out of equilibrium. The presence of a perturbed LO phonon population causes a reduction of the cooling rate of photoexcited electrons