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

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 degrees C, but vanished in device with BiFeO3 film annealed at 600 degrees 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. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.