AC conductivity of porous silicon from Monte Carlo simulations

The AC conductivity of a percolation model with local energetical disorder for porous Silicon in three dimensions, sigma(omega), is studied by Monte C arlo simulations. The model includes both diffusion and recombination proce sses and sigma(omega) is obtained by a Fourier transform of the mean-square displacement of the carriers, where hopping diffusion of a single type of carrier (either an electron or an exciton) and two types of carriers (an el ectron and a hole) are considered. It is found that at low temperatures, th e behavior of sigma(omega) depends sensitively on the type of carrier consi dered.