BiFeO3 thin films were irradiated by Ar+ ions with different fluences. The rectifying and resistive switching behaviour were retained on the Au/BiFeO3/Pt stack, and the ON/OFF ratio clearly depends on the Ar+ fluence. It was observed that the transport in high resistance state changes from Poole-Frenkel conduction to space-charge-limited conduction after irradiation. While the conduction of the low resistance state is dominated by both the interface and the bulk thin film in the pristine devices, however, it is only dominated by the interface in the irradiated devices. The observed change of conduction mechanism was explained by additionally created oxygen vacancies (OVs) during irradiation, which also improves the stability of resistive switching. (C) 2014 Elsevier B.V. All rights reserved.