Results on the microstructural, optical and electrochromic properties of spray-deposited MoO3 thin films by the influence of W doping

Undoped and W-doped MoO3 thin films were prepared onto the glass and fluorine doped fin oxide coated glass substrates by the spray pyrolytic decomposition of molybdenum (V) chloride (MoCl5) precursor solution. X-ray diffraction analyses confirm that all the films are polycrystalline possessing an orthorhombic phase of MoO3. Surface morphological analyses reveal that the films have intermixed irregular shaped flakes-like morphology. Cyclic voltammetric studies reveal that the colour-bleaching kinetics, coloration efficiency, and electrochemical stability of the MoO3 thin films are strongly dependent upon the microstructural features of the films which, in turn, are influenced by W doping. Maximum coloration efficiency and optimum electrochemical stability have been found for the film doped with 3 at% W. Chronoamperometry analyses reveal that the 1 at% W-doped film exhibits optimal reversibility as well as good switching response. Impedance spectroscopy studies have been carried out by analyzing the Nyquist impedance plots and the Bode plots by fitting it to the equivalent electrical circuit (EEC) model using Nova software.