TIME BEHAVIOR OF CURRENTS IN ZNS-MN METAL-INSULATOR-SEMICONDUCTOR-INSULATOR-METAL STRUCTURES

An experimental and theoretical investigation is made on the current pulse evolution, from a very low amplitude toward the steady-state shapes, if a sequence of alternative voltage pulses is applied to a ZnS:Mn metal-insulator-semiconductor-insulator-metal structure. The influence on this evolution of the voltage pulse maximum amplitude, of its rising slope, of pulse shape, and of the frequency is investigated. A quantitative model is developed which explains the current pulse evolution taking into account the competition between the multiplication of the carriers in the ZnS layer, and their recombination involving deep hole traps. The model describes the shapes of current pulse evolution and their peculiarities corresponding to different experimental conditions.