Title: Enhanced visible light transmittance and phase transition in ZnO or VO2 or AL2O3 bilayer thin film for energy efficient smart windows

Abstract

To ameliorate the limitation of low visible light transmittance of smart window, single phase Vanadium dioxide (VO2) and bilayer of Zinc oxide ZnO/VO2 on Al2O3 substrate were fabricated using the Radio frequency (RF) sputtering technique. These films were deposited at 500 degrees Celsius and GIXRD was performed at different temperature ranges starting from 28 degrees Celsius which goes up to 90 degrees Celsius. Structural Phase transition was witnessed from monoclinic to rutile phase after a critical temperature (Tc) of 68 degrees Celsius. Structural characterization was done using the X-rays diffraction(XRD) analysis technique at grazing incidence mode by using monochromatic X – rays (λ = 0.06926 nm). Further, the morphology of the surface structures was studied by using field emission scanning electron microscopy (FESEM). The visible light transmittance change was studied using the Ultra Violet (UV) – Vis spectroscopy in transmittance mode at room temperature. This increased transmittance of the bilayer deposited can be a potential way out to have more efficient smart windows.