Reversible alternation between bipolar and unipolar resistive switching in La-SrTiO₃ thin films

The alternation from bipolar to unipolar resistive switching is observed in perovskite La_0.01Sr_0.99TiO₃ thin films. These two switching modes can be activated separately depending on the compliance current (I_comp) during the electroforming process: with a higher I_comp (5 mA) the unipolar resistance switching behavior is measured, while the bipolar resistance switching behavior is observed with a lower I_comp (1 mA). On the basis of I–V characteristics, the switching mechanisms for the URS and BRS modes are considered as being a change in the Schottky-like barrier height and/or width at the Pt/La-SrTiO₃ interface and the formation and disruption of conduction filaments, respectively.