Post-breakdown conduction in thin film Al(Al2O3)CdSAl switching element

Abstract

Thin film sandwich structures of the type Al(Al2O3)CdSAl, where the Al2O3 layer is thermally grown at room temperature and the CdS layer has a conductivity of the order of 5 × 10-9 Ω-1 cm-1, exhibit bistable switching in the post-breakdown stage. This stage, which consists of two distinct states of high and low conductivity, was studied with the help of conductivity and small signal capacitance measurements. It was found, as a result of these measurements, that the value of ionized donor density in the high conductivity state is about twice that in the low conductivity state, and further, that both the contacts are non-ohmic. In view of these results, the dominant mechanism of conduction in the post-breakdown stage was ascertained to be the one involving field ionization of traps. © 1972.