Influência da técnica de deposição de Filmes Eletrocrômicos de WO3

Abstract

This work consists of the study of the characterization and analysis of the optical, structural, morphological and electrochemical properties of tungsten trioxide thin films (WO3 and WO3 doped with oxalic acid) on ITO substrate, for application as working electrode in electrochromic devices. Smart windows, developed from electrochromic glass, minimize the energy consumption of a building, providing the user with control over when to allow or not the passage of solar radiation, altering its optical properties (coloration) through the application of an electric potential, which can be reversed by inverting the polarization of this potential. The thin film was produced through different deposition techniques: dip-coating and spin-coating. The solutions of WO3 and WO3 doped with oxalic acid were prepared by the sol-gel process. After preparation, the precursor solutions were deposited on previously cleaned ITO substrates, through the dip-coating and spin-coating techniques to produce the thin films. The characterizations were performed through electrochemical techniques such as cyclic voltammetry, chronoamperometry, chronocoulometry and electrochemical impedance spectroscopy. The morphological, structural and optical information was extracted by means of atomic force microscopy (AFM), X-ray diffraction and UV-Vis spectroscopy. Finally, the behavior of these electrochromic films of pure WO3 and the one doped with oxalic acid obtained through the different deposition methods were compared and evaluated.