Investigation of the influence of deposition process on electrical-structure property correlation in vanadium oxide thin film smart materials

In this study, we focused on the electrical and structural properties of Vanadium Oxide (VOx) thin films produced on SiO2 and Si3N4 substrates at different duty cycle values. VOx thin films were produced by pulsed DC reactive magnetron sputtering technique. Electrical measurements were made by four point probe (FPP) technique and structural characterization by Raman spectroscopic measurements. All of the VOx thin films produced have a negative temperature coefficient of resistance (TCR). The negative temperature coefficient of resistance indicates the semiconducting property of VOx thin films. It was observed that the duty cycle value of both SiO2 and Si3N4 substrated VOx thin films increased while the plate resistance value decreased. 30% and 32.5% duty cycle materials have the lowest electrical sheet resistance. In the heating process, the activation energies for all samples are calculated. The obtained activation energy values explain the increase of the electrical conductivity of the VOx samples by the temperature increase. Raman spectroscopic measurements were performed for all VOx thin film samples at room temperature. VO2, V2O5 and V6O13 phases were observed mixedly in all thin films produced on SiO2 and Si3N4 substratum. In addition, V2O3 phase in VOx thin film samples was also determined for some duty cycle values. As a result, it has been determined that VOx thin films have mixed-phase and semiconducting properties.