Optically modulated resistive switching in BiFeO₃ thin film

Abstract

Exploiting the photosensitive property of BiFeO 3 thin films, we demonstrated a resistive switching memory cell having low V set voltage (+2.0 V), an ultrahigh ON/OFF ratio of ∼10 7 and a good retention time of more than 10 6 s. Synthesis conditions were optimized during a sol–gel‐assisted spin‐coating method to get phase‐pure BiFeO 3 films on Al substrate, at room temperature. Current–voltage analysis revealed that during optical illumination, photon‐induced charge carriers migrate towards their respective electrodes along grain boundaries under an externally applied field, which initiate a substantial shift in the normal V set of +10.4 V to a lower voltage (+2.0 V). The Poole–Frenkel emission at the metal/BiFeO 3 interface is proposed and the role of electronic reconstruction at the interface is further investigated. Thus the write process in BiFeO 3 ‐based resistive‐switching devices can be modulated in a controlled manner, which has the potential for integrating current resistive switching (memristive) memory device technology towards exciting optomemristive device technology.