Fast and slow states at the interface of amorphous silicon and silicon nitride

Abstract
The effects of a graded composition layer at the amorphous silicon/nitride interface are studied using transient photoconductivity. The graded layer causes a large increase in the density of slow states (electrons trapped within the nitride), but does not influence the fast interface states. The kinetics of trapping and release are measured and a model of field assisted hopping and thermal excitation is proposed. The different origins of slow and fast states are also discussed.