Oxygen ion drifted bipolar resistive switching behaviors in TiO2–Al electrode interfaces

The rutile TiO2 thin film involving two different top electrodes (Pt and Al) clearly shows the unipolar and bipolar resistive switching transitions which are dependent on the degree of redox properties at TiO2 layer-electrode interfaces. Detailed current level analysis coupled with Auger electron spectroscopy measurements of the Pt/TiO2/Pt and Al/TiO2/Pt structures in the on/off switching states revealed the implication of oxygen ion migration induced chemical reaction at the Al–TiO2 interfaces. Therefore, it is expected that the bipolar transition nature of resistive switching with an Al electrode is the resulting formation of a thin AlOx layer due to redox reaction at Al–TiO2 layer interfaces.