Effects of BiFeO${}_3$ thickness on the write-once-read-many-times resistive switching behavior of Pt/BiFeO${}_3$/LaNiO${}_3$ heterostructure

Thickness of the resistive switching materials is an essential factor to determine the integration density of resistive switching devices. Herein, the effect of the thickness of BFO on the write-once-read-many-times (WORM) resistive switching behavior of Pt/BFO/LNO-based devices is investigated. The thicknesses of BFO thin films are controlled in the range of 70-220 nm. All the devices exhibit WORM resistive switching behavior with high ON/OFF ratio (≈10${}^{-2}$-10${}^{-4}$), long-term data retention (>3600 s), and reliable endurance (>1000 cycles). The set voltages (V${}_{set}$) of the devices exhibit an approximately linear relation to the BFO thicknesses, while the highest ON/OFF ratio appears in the device with BFO thickness of 150 nm. The thickness-dependent resistive switching characteristic is attributed to the variation of oxygen vacancies and OFF state resistances with the increase of BFO thickness. The results underline the importance of the thickness of resistive switching materials for the future device applications. (© 2023 Wiley‐VCH GmbH)