Transient Photoinjection of Holes from Amorphous Se into Poly (N−VinylCarbazole)

The transient photoinjection of holes from amorphous selenium into layers of poly ($N-\mathrm{v}\mathrm{i}\mathrm{n}\mathrm{y}\mathrm{l}\mathrm{c}\mathrm{a}\mathrm{r}\mathrm{b}\mathrm{a}\mathrm{z}\mathrm{o}\mathrm{l}\mathrm{e}$) (PVK) has been studied. A variety of techniques are described which lead to the conclusion that no barrier to injection need be invoked. The injection threshold observed in the Se:PVK structure using the xerographic condenser technique can be accounted for in terms of the achievement of space-charge-perturbed currents in the polymer dielectric. The steepness of the observed threshold arises from the field dependence of the drift mobility of holes in PVK.