Observation of electric field-assisted phase transition in thin film vanadium oxide in a metal-oxide-semiconductor device geometry

We report the observation of electric field-assisted phase transition across a vanadium oxide thin film. The threshold field for initiation of transition was similar to 10(7) V/m at room temperature and decreased with increasing temperature with activation energy of similar to 0.2 eV. Electron transport mechanisms were investigated using both current-in-plane and out-of-plane devices and the results correlated very well. In the insulator phase, Poole-Frenkel emission was determined to be a dominant mechanism at high fields, while in the low field regime, Ohmic behavior with activation energy of similar to 0.24 eV was observed. In the metallic state, activation energy for Ohmic conduction was similar to 0.08 eV.