Electrically activated thin film optical coatings as functional layers in electrochromic devices

This study presents results on technology and characterization of molybdenum oxide, tungsten oxide and mixed oxide films based on Mo and W. These films were deposited by low-temperature carbonyl CVD process at atmospheric pressure and by simplified sol–gel method using spinning and spraying approaches. The obtained films were structurally and optically investigated. The films show good optical quality with optical transmittance of about 70% in the visible spectral range. Cyclic voltammograms as well as the transmittance modulation at different wavelengths in the visible spectral range were measured to characterize the electrochromic behaviour of the films. The colour efficiencies of the optimized films are in the order of 110–115 cm2/C, in case of spray deposited WO3-sol–gel films—130 cm2/C.