Switching Behavior in p-Type Hydrogenated Amorphous Silicon with One and Two Blocking Contacts

摘要

We compare switching behaviour in Cr/a-Si:H(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 0.4 mA/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.