Structural, electrical and optical properties of thermochromic VO2 thin films obtained by reactive electron beam evaporation

Abstract

We present the structural and physical characterization of vanadium dioxide (VO2) thin films prepared by reactive electron beam evaporation from a vanadium target under oxygen atmosphere. We correlate the experimental parameters (substrate temperature, oxygen flow) with the films structural properties under a radiofrequency incident power fixed to 50W. Most of the obtained layers exhibit monocrystalline structures matching that of the monoclinic VO2 phase. The temperature dependence of the electrical resistivity and optical transmission for the obtained films show that they present thermoelectric and thermochromic properties, with a phase transition temperature around 68°C. The results show that for specific experimental conditions the VO2 layers exhibit sharp changes in electrical and optical properties across the phase transition.