Annealing effect on the bipolar resistive switching behaviors of BiFeO3 thin films on LaNiO3-buffered Si substrates

Abstract

We reported the annealing effect on the electrical behaviors of BiFeO3 thin films integrated on LaNiO3 (LNO) layers buffered Si substrates by sol–gel spin-coating technique. All the BiFeO3 thin films exhibit the reversible bipolar resistive switching behaviors with Pt/BiFeO3/LNO configuration. The electrical conduction mechanism of the devices was dominated by the Ohmic conduction in the low resistance state and trap-controlled space charged limited current in the high resistance state. Good diode-like rectification property was observed in device with BiFeO3 film annealed at 500°C, but vanished in device with BiFeO3 film annealed at 600°C. This was attributed to the asymmetrical contact between top and bottom interfaces as well as the distinct oxygen vacancy density verified by XPS. Furthermore, the modification of Schottky-like barrier due to the drift of oxygen vacancies was suggested to be responsible for the resistance switching behaviors of Pt/BiFeO3/LNO devices.