Modulation of the resistive switching of BiFO3 thin films through electrical stressing

The resistive switching (RS) of Au/BiFeO3/SrRuO3 samples was shown to be controllable by using a thermal treatment and an electrical stressing method. Such a modulation of resistive switching effect can be associated to the oxygen vacancy movement and redistribution within the BiFeO3 thin film and the trapping/detrapping of charge carriers at the interfaces. After the application of a negative voltage to the thin film for a stressing period, a resistive switching reversal effect occurred and the current retention ability in the low resistance state increased, indicating an increase in the trap density at the interface and an enhancement of the charge carrier trapping ability. The trap density, trap level, and Schottky barrier height all display corresponding trends in their values as a result of the modulation of RS effect. The results indicate that the greater the accumulation of oxygen vacancies at any the film/electrode interface, when a reverse bias is applied the higher the resistance ratio was under reverse bias. Its diffusion process was likely to be hindered and the trapped charge carriers could be retained after a long time of electrical stressing.