Thin films of tungsten oxide (WO3) were deposited on GZO-coated B270 glass substrates and thin films of Ta2O5 were
deposited on B270 glass substrates by electron beam gun evaporation at high vacuum pressure of 3×10-5 Torr and varied
oxygen pressures ranging from 1.0×10-4 to 6.0×10-4 Torr. The optical properties of the electro-chromic (EC) film were
measured by a spectrophotometer. The optical modulation (ΔT) of the tungsten oxide thin film deposited at an oxygen
pressure of 1.0×10-4 Torr was found to be ΔT = 67.46% at λ=550nm. The optimum optical properties for deposition of
Ta2O5 were attained at an oxygen pressure of 4x10-4 Torr. Gallium doped zinc oxide (GZO) was used as a conductive
layer instead of ITO. A five layer EC device (Glass/GZO/WO3/Ta2O5/NiO/Al) has been design and fabricated.