Switching behavior in p-type hydrogenated amorphous silicon with one and two blocking contacts

摘要

We compare switching behaviour in Cr/a-SiH(p)/Ag and c-Si(p)/a-Si:H(p)/Ag structures containing p-type hydrogenated amorphous silicon.The a-Si:H layer is made by hot wire chemical vapor deposition.We observed that the switching is polarity-dependent only in the sample on c-Si(p).Switching to a low-resistance state occurs at 0.4mA/cm~2 when any of the metal contacts are biased positive.When the c-Si(p) is biased positive holes are injected and no switching occurs even up to 4 A/cm~2.We suggest that the switching requires a blocking metal/a-Si(p),possibly because local electrical breakdown initiates metal filament formation.