Non-volatile bipolar resistive switching in sol-gel derived BiFeO3 thin films

TL;DR

This study demonstrates stable, low-voltage bipolar resistive switching in sol-gel derived BiFeO3 thin films, highlighting their potential for non-volatile memory applications with good endurance and retention.

Contribution

It introduces a simple sol-gel method to fabricate BiFeO3 thin films exhibiting reliable bipolar resistive switching with detailed conduction mechanism analysis.

Findings

Maximum Ion/Ioff ratio of ~450

Set and reset voltages around 1.1 V and -1.5 V

Retention time of ~10^4 seconds without degradation

Abstract

BiFeO3 thin films are deposited on FTO coated glass substrates using a simple sol-gel deposition technique, limiting thickness about 70 nm and Ag/BiFeO3/FTO RRAM devices are prepared. The devices showed low-voltage bipolar switching with the maximum Ion/Ioff ~ 450, and low set and reset voltages ~ 1.1 V and -1.5 V, respectively. The devices are stable against on-off cycles with ~ 104 s retention time without any significant degradation. The variations in the set and reset voltages are 0.4 V and 0.6 V, respectively. We found that ohmic and trap-controlled space charge limited conductions are responsible for low and high resistance states, respectively. The resistive switching mechanism is attributed to the formation and rupturing of the metal filament during the oxidation and reduction of Ag ions for the set and reset states.