Decay of Excess Carriers in Semiconductors

The initial and final stages of decay of excess carrier densities in a semiconductor containing one or more levels of monovalent centres are investigated in terms of the carrier transition rates. A relation for the time dependent excess free carrier lifetimes is found for the one-level model in the initial stage of decay. Solutions for the final stage of decay are pictured in kinetic diagrams. On the basis of the kinetic diagrams the temperature dependence of & TAU; is derived for the case of the one-level model. Conditions are found, under which the solution of the many-level model reduces to the solution of the one-level model.