OPTIMIZATION OF THE GROWTH-RATE OF ELECTROCHROMIC WO3 COATINGS, IN-SITU GROWN BY CHEMICAL-VAPOR-DEPOSITION AT ATMOSPHERIC-PRESSURE

Electrochromic WO3 thin films on ITO-covered glass substrates are grow n by Atmospheric Pressure Chemical Vapor Deposition (APCVD) using W(CO )6 as precursor. The process is pyrolytical decomposition of W(CO)6 in the presence of oxygen gas atmosphere. The growth rate was found to d epend strongly on the oxygen flow-rate, as well as on the argon flow-r ate through the precursor chamber. The optimization of these process p arameters leads to high growth rates in the order of 30 Angstrom/sec. Structural studies by Reflection High Energy Electron Diffraction (RHE ED) and SEM show that the films are polycrystalline WO3 with a certain degree of texturing.