Statistics of charge carrier recombination at radiation defect clusters in silicon

Abstract

Abstract Charge carrier recombination in n-type Si (ρ = 10-1000Ω · cm) irradiated by y-rays of stopping spectrum with the maximum quantum energy Em = 100 MeV has been studied. It has been found from the measurements of dose, temperature and injection dependences of carrier lifetime (τ) that the main recombination centers which are formed under such irradiation are the divacancies involved in radiation defect (RD) clusters. It has been shown that the dependence of the coefficient for radiation damage of τ on crystal doping level obtained in experiment cannot be described within the framework of the known models of the carrier recombination at RD clusters. Recombination statistics have been proposed which take into account not only the height of potential barrier around a RD cluster but the relation K s between the volumes of outer and inner charges of RD clusters. Recombination rate at the defects in the cluster is assumed to increase by a factor of K s as compared to recombination rate at the same number ...