Luminous transmittance and phase transition temperature of VO2:Ce thin films prepared by DC reactive magnetron sputtering
Vanadium dioxide (VO2) and cerium-doped vanadium dioxide (VO2:Ce) thin films were prepared by DC reactive magnetron sputtering from vanadium metallic target and V-Ce alloy targets. Luminous transmittance and phase transition temperatures of the films were studied. The Shimadzu SOLIDSPEC-3700 DUV-VIS-NIR spectrophotometer was used to measure the transmittance and reflectance of the films. The phase transition temperature (τc) of the films was obtained from both the transmittance and sheet resistance against temperature curves. A change in sheet resistance of 2 to 3 orders of magnitude was observed for both undoped and Ce-doped VO2 films. Comparison between undoped and doped VO2 films revealed that cerium inclusion altered both the visible and infrared transmittance of VO2 thin films. Luminous transmittance was slightly enhanced while τc was slightly depressed by cerium inclusion in VO2. A two-step increase in transmittance observed in the cooling loop in pure VO2 was found to be suppressed by cerium inclusion.
Keywords: vanadium dioxide, luminous transmittance, phase transition temperature