Self-consistent recombination scheme in porous silicon under intense laser excitation

An experimental investigation of the general characteristics of nonradiative and radiative recombination of charge carriers in strongly excited porous silicon is presented. It is shown that photoconductivity, photomagnetoelectric effect, quantum yield, and intensity of visible radiation of porous silicon demonstrates strong nonlinearities against laser excitation intensity. It is suggested that the band-to-band Auger recombination is dominant similar to that in crystalline silicon, whereas the visible luminescence is determined by the bimolecular process. The non-equilibrium density of charge carriers Delta n approx = 10 exp 19 cm exp -3 , and the bimolecular radiative recombination coefficient Brad < = 9 mult 10 exp -14 cm exp 3 /s have been found.