Abstract
Current–voltage (I–V) characteristics were investigated in Pt/TiO2-x/Pt devices, and the effect of annealing temperature of preparing TiO2-x was studied. All the micro-fabricated Pt/TiO2-x/Pt devices in initial state show a rectifying I–V behavior, which is attributed to the Schottky-like barrier at the TiO2-x/Pt (top electrode, TE) interface. In the initial state, the forward current was observed under the positive bias. After applying a negative pulse voltage, the forward current under the negative bias was observed, demonstrating a switch of the Pt/TiO2-x/Pt diode polarity. The reproducible switch is successfully observed at a pulse voltage of ±6.0/50 ms. However, this switch behavior is absent in the Pt/TiO2-x/Pt diode after high temperature annealing as well as 400 °C. The origin of the rectifying I–V behavior in initial state and the polarity switch is attributed to the redistribution of oxygen vacancy (VO) due to applying pulse voltage.