THERMALLY STIMULATED CURRENTS IN AMORPHOUS-SEMICONDUCTORS

An adiabatic model of trap-controlled dispersive transport is used for a theoretical investigation of thermally stimulated currents in disordered materials. It is shown that retrapping of carriers by initially occupied deep states does not significantly contribute to the thermally stimulated currents that are controlled by monomolecular recombination, or obtained under standard time-of-flight conditions. However, carrier retrapping plays a dominant role for thermally stimulated conductivity controlled by bimolecular recombination. The effect of energy-dependent carrier capture cross-sections is also analyzed and shown to result in possible erroneous interpretations of experimental data.