Optimization of Thermochromic Coatings for Smart Window Applications

VO2 based thermochromic thin films can be successfully used for coating usual windows in order to minimize the energy consumption of buildings through a specific temperature driven Metal to Insulator Transition (MIT). A careful analysis on the wide possibilities to optimise such coatings with respect to the desired properties of MIT, followed mainly via the temperature variation of the electron transport properties is reported. Some optimized coatings, investigated by morpho-structural methods as X-Ray Diffraction and Transmission Electron Microscopy and finally by electron transport measurements, have shown stable and reproducible variations of resistivity by about 3 orders of magnitude, over temperatures ranging from 45 ℃ to 65 ℃ and with narrow hysteretic behavior, quite sensitive to processing parameters. The effect of partial pressure of oxygen during the Pulsed Laser Deposition process as well as of the considered substrate are mainly investigated in this work.