Bias-induced metastable transverse conduction in doping-modulated amorphous silicon superlattices

Bias-induced metastabilities in the transverse conductance of doping-modulated n-p-n-p hydrogenated amorphous silicon (a-Si:H) superlattices have been studied. The electronic transport takes place through the diffusion over the potential barrier in the transverse direction for the n-p-n-p multilayer with moderate n- and p-layer doping concentration. The tunneling current through the localized states in the gap is dominant for the multilayer with a p layer of high doping concentration. The currents through the localized gap states increase after high-voltage-bias annealing, indicating that the density of dangling bonds in p and n layers increases during the bias annealing.