Oxygen migration process in the interfaces during bipolar resistance switching behavior of WO3-x-based nanoionics devices

Bipolar resistance switching (BRS) behavior and the effects of atmosphere (air, vacuum, O-2 gas, or N-2 gas) on BRS behavior occurred in the top and bottom interfaces in the M-(top electrode)/WO3-x/Pt-(bottom electrode) (M = Pt, Au) devices were investigated. Stable BRS only can be obtained in the interface with Pt electrode. And, the top Pt/WO3-x interface exhibited stable BRS only in an oxygen-rich atmosphere (air and O-2 gas). In contrast, the bottom WO3-x/Pt interface showed stable BRS under any atmosphere. Based on the x-ray photoelectron spectroscopy measurement on Pt, Au/WO3-x interfaces, it is identified that the oxygen migration process during resistance switching mainly occurs between the Pt/WO3-x interface and Pt electrode. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4726084]