Sol-gel-prepared ITO films for electrochromic systems

Indium tin oxide (ITO) films have been prepared by the sol-gel method using both organic and inorganic precursors. A computer-controlled dip-coating unit is designed and fabricated in our laboratory for a precise control of the parameters during the dip-coating process. These films have been characterized by X-ray diffraction, optical and electrical study and also by atomic absorption spectroscopy. The optimized coatings exhibit a sheet resistance of around 100 Omega/square and an average visible solar transmission of around 85%. A five-layer electrochromic system using these ITO layers as transparent electrodes was fabricated and tested. The performance of the electrochromic system indicates the high potential of these films for such applications, especially for large area coating.