The Electrochromic Performances of Single Phase VO2 Nanoparticled Films

Abstract

In the present work pure phase vanadium oxide VO2 nanoparticled films were synthesized using acetate based sol-gel precursors. The effect of the water: Vanadyl acetylacetonate ratio on electrochemical and structural properties of nanostructured vanadium oxide films was examined. The X-ray diffraction studies indicated that very strong crystallization of the VO2 monoclinic phase occurred for the as-deposited films at the annealing temperature of 500 degrees C. According to the atomic force microscopy and scanning electron microscopy measurements the size and morphology of the granular structured film depend on the water: Vanadyl acetylacetonate ratio. I-V curve spectra were used to compute several characteristics of the films coated on indium tin oxide substrates such as the optical density color efficiency and diffusion coefficient. Even though water: Vanadyl acetylacetonate ratio of 0.1 is expected to give the highest color efficiency value (33 cm(2)/C) higher diffusion coefficient (3.15 x 10(-12) cm(2)/s) is observed in the ratio of 0.01. As a result the correlation between the ratios and electrochromic properties of the films was established. (C) 2016 Elsevier B.V. All rights reserved.