VO2 thin films based active and passive thermochromic devices for energy management applications

VO2 thin films were fabricated by argon ion beam assisted non-reactive ac dual magnetron sputtering followed by carefully controlled thermal oxidation. This method is known to give high quality compact thin films with uniform high deposition rates. Thin films deposited on both bare glass and indium tin-oxide (ITO) coated glass substrates were studied, respectively, as passive and active thermochromic devices for their electrical and optical switching behaviors. Thin films varying in thicknesses from 65 to 250 nm were investigated. ITO film was used as an integrated heating device to activate the phase transition via an applied bias voltage. Such structures were found to bear several advantages from an application point of view.