The non-exponential and non-Auger-like time dependence of non-equilibrium free carrier concentration decay in a semiconductor with two deep levels at high injection rates

Theoretical analysis and numerical calculations of the system of equations which models the conduction band electron capture by two deep levels shows that at the initial stages after high injection the photocurrent decay must obey hyperbolic rather than exponential type of time dependence. Under certain conditions when one of the deep levels captures electrons much faster than another level then the photocurrent time dependence has two constituents one of them being a simple hyperbola and the other hyperbola raised to the power greater than one. Such a result of our example model demonstrates that the net recombination rate is not just a simple sum of two recombination rates provided by two different recombination centers. Therefore the commonly accepted practice to treat every recombination center as independent in the analysis of experimental data is not applicable in general.