Bipolar Resistive Switching Characteristic of Epitaxial NiO Thin Film on Nb-Doped Substrate

Epitaxial NiO film was grown on 0.7% Nb-doped SrTiO3 substrates by pulsed laser deposition. The I-V characteristics of Ag/NiO/Nb-SrTiO3/In device show reproducible and pronounced bipolar resistive switching without forming process which was induced by the NiO/Nb-SrTiO3 junctions, and the resistive switching ratio HRS/LRS can reach 103 at the read voltage of −0.5 V. Furthermore, the resistance states can be controlled by changing the max forward voltage, reverse voltage, or compliance current, indicating multilevel memories. These results were discussed by considering the role of carrier injection trapped/detrapped at the interfacial depletion region of the heterojunction.