Time-dependent field effect in amorphous chalcogenides

Abstract

Exploratory measurements of the transient decay of the field effect in amorphous films from the system As₂ Te₃–As₂Se₃ are reported. The excess current is shown to exhibit a power-law dependence upon time over the range 5–5000 s. The rate of decay increases with increasing temperature for a given composition, and with increasing selenium concentration as the composition is varied. The data are discussed in terms of a mechanism of thermalization of excess charge carriers with localized states which are distributed over a range of energy. The possibility that the decay of the field effect is related to that of the transient photoconductivity is examined.