The electrochromic performances of single phase VO2 nanoparticled films

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 °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 cm2/C), higher diffusion coefficient (3.15 × 10− 12 cm2/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.