Unidirectional threshold resistive switching in Au/NiO/Nb:SrTiO3 devices

A voltage-induced unidirectional threshold resistive switching has been reported for Au/NiO/Nb:SrTiO3 devices fabricated by pulsed laser deposition. The devices show the threshold resistive switching behavior only for the positive voltages, determined by the forming process. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the as-grown samples with different thicknesses suggest that the I-V and C-V properties are dominated by the Schottky junction at the NiO/Nb:SrTiO3 interface and NiO film, respectively, indicating the formation of conductive filaments in NiO film. Furthermore, the effect of NiO-film thickness on the resistive switching, as well as the I-V and C-V characteristics, indicates that the unidirectional threshold resistive switching originates from the combined contributions of the interfacial Schottky junction modulation and the bipolar threshold switching related to the unstable conductive filament in NiO film. Our research results provide additional insights into t...