Coexistence of the bipolar and unipolar resistive switching behaviours in Au/SrTiO3/Pt cells

Abstract

The bipolar and unipolar resistive switching (BRS and URS) modes are first observed to coexist in the Au/SrTiO3/Pt cell fabricated by pulsed laser deposition. These two switching modes can be activated separately depending on the different current compliance (CC) during the electroforming process: with a lower CC (1 mA) the asymmetric BRS behaviour is measured in the voltage range −1.2 to +1 V, while the URS behaviour is observed with a higher CC (10 mA). On the basis of current–voltage characteristics, the switching mechanisms for the BRS and URS modes are considered as a change in Schottky-like barrier height and/or width at the Au/SrTiO3 interface and the formation and disruption of conduction filaments, respectively. The conversion between BRS and URS is reversible. Because each switching mode has a specific advantage, selecting the desired switching mode can broaden the application scope of the cell and enable large flexibility in terms of memory architecture.