부산대학교 도서관

Exploiting the photosensitive property of BiFeO3 thin films, we demonstrated a resistive switching memory cell having low Vset voltage (+2.0 V), an ultrahigh ON/OFF ratio of ∼107 and a good retention time of more than 106 s. Synthesis conditions were optimized during a sol-gel-assisted spin-coating method to get phase-pure BiFeO3 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 Vset of +10.4 V to a lower voltage (+2.0 V). The Poole-Frenkel emission at the metal/BiFeO3 interface is proposed and the role of electronic reconstruction at the interface is further investigated. Thus the write process in BiFeO3-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. [ABSTRACT FROM AUTHOR]