Nonvolatile unipolar resistive switching behavior of amorphous BiFeO3 films

Amorphous BiFeO3 thin films were grown on an indium tin oxide glass substrate using RF magnetron sputtering at room temperature. The resistive switching behavior of amorphous BiFeO3 thin films was investigated. The Au/amorphous BiFeO3/indium tin oxide device exhibited the stable unipolar resistive switching behavior with a substantial resistance ratio (larger than 102) between low and high resistance states and the excellent retention performance. The low resistance state exhibited a linear Ohmic behavior, while the high resistance state conduction could be ascribed to the trap controlled space-charge limited conduction mechanism. Based on the X-ray photoelectron spectroscopy, the observed resistive switching behavior was mainly attributed to the electric field induced migration of oxygen vacancies.