Vanadium oxide thin films fabricated by magnetron sputtering from V and V2O5 targets

In this work, the different deposition parameters of vanadium oxide thin films by magnetron sputtering technique using V and V2O5 targets were studied. The V metal target was placed on the direct current (DC) source and the V2O5 target was coupled to the radio frequency (RF) source. The power of the targets was varied, being 40 W and 50 W for the DC source and 40 W, 50 W and 60 W for the RF. The films were deposited on Corning glass substrates, keeping the deposition time of each film at 30 min. The crystalline structure of the films was obtained by X-ray diffraction and an amorphous behavior was observed. The formation of VOx phases was observed by Raman spectroscopy and vibrational modes analysis. It is observed that the presence of the V2O5 phase increases with the applied source power. The formation of the V2O5 phase is inferred from the calculated band gaps, ranging between 2.24 and 2.60 eV for the prepared thin films. On the other hand, the hysteresis graphs between 25°C and 100°C present the characteristic behavior of thermochromic materials, and the best film appears to be obtained at a working power of 40 W from both targets.