Modelling thermally-stimulated currents in disordered semiconductors

Abstract

We report a computer modelling study of thermally stimulated currents in thin film semiconductors. In a multi trapping context, we examine this method as a ‘spectroscopy’ of the energy distribution of localised states. We consider so-called ‘weak’ and ‘strong’ re-trapping conditions, the use of non-physical ‘effective’ attempt-to-escape frequencies and the effect of lifetime variation as distributions relax. We show that for strong re-trapping in distributed states, the energy scale can be better approximated by the quasi-Fermi level position and propose that the density of states may alternatively be computed using the easily determined derivative of the quasi-Fermi energy with respect to temperature.