Thermalization process of a photo-generated plasma in semiconductors

The kinetics of ultra-fast processes which leads to the thermalization condition of a photo-excited plasma in semiconductor systems is studied theoretically. We analyse the time evolution of a carrier population generated by a finite optical pulse, from the beginning of the pulse until the time in which the carrier population reaches a quasi-equilibrium condition. We calculate the energy fluxes caused by the main interaction mechanisms along the different stages the system passes through. Our analysis is done by using a set of non-linear rate equations which govern the time evolution of the carrier population in the energy space. We consider the main interaction mechanisms, including dynamic screening and phonon population effects. (Author)