Sol-gel coatings on large area glass sheets for electrochromic devices

The preparation of vanadium and tungsten oxide coatings is described using vanadium oxide tri-2-propoxide/2-propanol and tungsten penta-ethoxide/2-propanol solutions. These solutions are dip coated onto K-glass substrates and cured. For vanadium oxide coatings it is shown that sol-gel/dip coat processing is a feasible production technology for very homogeneous vanadium oxide coatings on large area sheets with good electrochromic properties. Homogeneous vanadium/titanium oxide coatings with a titanium contents up to 40% and charge capacities up to 45 mC/cm2 are obtained. Homogeneous tungsten oxide coatings with reasonable electrochromic properties (coloration efficiency up to 34 cm2/C and transmission changes up to 5:1) are prepared.