Asymmetric bipolar resistive switching in solution-processed Pt/TiO2/W devices

The resistive switching characteristics of Pt/TiO2/W devices in a submicrometre via-hole structure are investigated. TiO2 film is grown by the sol-gel spin coating technique. The device exhibits reversible and reproducible bistable resistive switching with a rectifying effect. The Schottky contact at the Pt/TiO2 interface limits electron injection under reverse bias resulting in a rectification ratio of >60 at 2V in the low-resistance state. The switching mechanism in our device can be interpreted as an anion migration-induced redox reaction at the tungsten bottom electrode (W). The rectifying effect can significantly reduce the sneak path current in a crossbar array and provide a feasible way to achieve high memory density.