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 ∼107 V/m at room temperature and decreased with increasing temperature with activation energy of ∼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 ∼0.24 eV was observed. In the metallic state, activation energy for Ohmic conduction was ∼0.08 eV.