Temperature coefficient of resistance of VO2 polycrystalline film formed by ion beam enhanced deposition

The polycrystalline VO2 film was directly prepared from V2O5 powder using the modified ion beam enhanced deposition (IBED) method and a suitable annealing. Testing results show that the IBED polycrystalline VO2 film has a single orientation, an obvious phase transition, a compact structure, and favorable processing properties. The temperature coefficient of resistance (TCR) of the film was up to more 4% and adhered hard to the substrate. The mechanism of the IBED film with higher TCR was discussed in detail. The reason why the film has a high TCR could be as follows: the oxygen vacancy and crystalline boundary in the film was decreased due to the IBED technology; with single oriented and dense texture the activation energy of electrical conduction of the IBED polycrystalline VO2 film was closer to the activation energy of VO2 crystalline in semiconductor phase which is higher than that of the VOx films prepared by other methods