Unipolar resistive switching behavior in sol-gel synthesized FeSrTiO3 thin films

Abstract

A robust unipolar resistive switching (URS) was successfully observed in sol-gel derived perovskite type Fe-doped strontium titanate (FeSTO) thin films, deposited on an ITO-coated glass substrate by a spin-coating technique. The surface topography of the films was characterized by atomic force microscopy that suggested a smooth surface with an average surface roughness nearly 1-2 nm. The crystal structure, URS phenomena, current-voltage characteristics, and dielectric and impedance behavior were analyzed for both high resistance state (HRS) and low resistance state (LRS). The X-ray photoelectron spectroscopy (XPS) was also employed to investigate the valence states of the host and dopants elements. The Au/FeSTO/ITO device offers a large resistance ratio of HRS and LRS (Roff/Ron) around 105, long stable retention characteristics for 104 s, and a distinguished and large non-overlapping voltage window of ∼4 to 6 V for SET and RESET operations.