Non Isothermal Dispersive Transient Currents in Non-Homogeneous Insulating Layers

In the present work the authors have investigated the influence of spatial non-homogeneity of trap distribution on thermally stimulated currents (TSC) due to transport of carriers in insulating layers. It has been assumed that at zero time carriers are generated only in a thin layer near one of the contacts. They have proved that for both non-dispersive and dispersive transport the initial increase of TSC is strongly dependent on the spatial distribution of traps. On the other hand, the dependence of TSC maximum on electric field strength, layer thickness and heating rate, and in the case of dispersive transport also on the final current decay, is almost the same as for a homogeneous trap distribution. The analytical results have been found to agree satisfactorily with the results of Monte Carlo simulation of non-isothermal carrier transport for all the model spatial and energetic trap distributions considered. The possibility of determining spatial trap distribution on the basis of the measured TSC has been discussed.