Substrate effect on the resistive switching in BiFeO3 thin films

BiFeO₃ thin films have been deposited on Pt/sapphire and Pt/Ti/SiO₂/Si substrates with pulsed laser deposition using the same growth conditions. Au was sputtered as the top electrode. The microscopic structure of the thin film varies by changing the underlying substrate. Thin films on Pt/sapphire are not resistively switchable due to the formation of Schottky contacts at both the top and the bottom interfaces. However, thin films on Pt/Ti/SiO₂/Si exhibit an obvious resistive switching behavior under forward bias. The conduction mechanisms in BiFeO₃ thin films on Pt/sapphire and Pt/Ti/SiO₂/Si substrates are discussed to understand the different resistive switching behaviors.