Comment on theoretical investigation of transient space-charge-limited currents for dispersive transport in amorphous silicon

Abstract

In a recent paper on transient space-charge-limited currents for electrons (Yan et al. 1991) it was predicted that the dispersive transit time under strong carrier injection can be ten times smaller than under weak carrier injection. Because this is potentially such an important result, the basis for the decrease was examined carefully. We found that the predicted decrease resulted from the unphysical condition that the electric field at the injecting contact C(t) was allowed to be positive under strong electron injection. When the electric field at the injecting contact was restricted to negative values, no sharp drop in transit time is found.