Trap-controlled transient photoconductivity in dielectrics

Abstract

Computer programs have been developed to solve numerically the equations governing transient photoconductivity in dielectrics in the presence of a continuous distribution of traps. The Schmidlin prescription for the trap distribution equivalent to the Scher and Montroll stochastic model of dispersive transport in the small signal limit has been confirmed. It is shown that, with increasing amounts of charge in transit, the pre-transit time slope of a double logarithmic current vs. time plot increases algebraically, with the post-transit slope being largely unaffected. Investigation of other trapping distributions suggest that transient photoconductivity data will need to be supplemented by thermally stimulated conductivity, thermoluminescence, and thermally stimulated depolarization data in any work aimed at a comprehensive documentation of trapping parameters in dielectrics.