TiO2/Au/TiO2 multilayer thin films: Novel metal-based transparent conductors for electrochromic devices

Transparent conductors based on Au films, with thicknesses in the 2.6 < d < 9.8 nm range, were made by DC magnetron sputtering onto glass. The films went from an 'island' structure at low thicknesses to a uniform structure at d > 8 nm, as seen from electron microscopy, electrical resistance, and spectrophotometric transmittance and reflectance. Optical data for uniform films were given a consistent interpretation within the Drude model. Optimized TiO2/Au/TiO2 films, with a luminous transmittance of 80%, were found to have good electrochemical durability and may be useful for applications in electrochromic devices.