Abstract
The usual Shockley - Read - Hall statistics is generalized to involve recombination between two different traps A and B in distributed non-interacting trap-pairs. Characteristics of inter-trap (A to B) and band-to-trap recombinations are numerically surveyed as regards their dependence on the thermal equilibrium Fermi level, the excitation intensity and the interaction between A and B. The inter-trap A to B recombination rate peaks if the Fermi level is near the energy level of trap A or B in the case of moderate excitation and moderate interaction. The inter-trap recombination rate saturates at characteristic values when these parameters become large. We find that for strong interaction between the traps the inter-trap recombination saturates. The reason is that the recombination between the upper trap and the valence band as well as the recombination between the lower trap and the conduction band can then be neglected. Saturation occurs also for strong excitation since then the occupation probabilities approach unity for the upper trap and zero for the lower trap.