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We discuss the preparation and performance of various electrochromic devices based on sol- gel deposited thin films. The films are deposited by dip-coating from alcohol-based sol-gel precursor solutions and the process is well suited to scaling up to large areas for window production. The coloration and bleaching performance of the devices is compared with the performance of individual films colored in liquid electrolytes, as well as with devices deposited using sputtered and evaporated films. Devices are based on sol-gel deposited tungsten oxide thin films which forms the active electrode. A range of counter-electrode materials have been tested, including sol-gel deposited vanadium pentoxide and titania films. Various ion conductors have been tested with these films, including simple, doped PEO and hartolyte, as well as a range of other polymers and inorganic ion conductors. Results will be presented showing the optical switching performance of the devices and comparing the performance of the devices with other device configurations. Initial results show that the sol- gel-based devices exhibit good switching performance, but the devices are sensitive to the details of the precursor solution used. Long term switching performance is an important issue in window applications, and the behavior of the sol-gel deposited films under repeated cycling will also be discussed, in particular a significant difference between the performance in liquid electrolytes and solid-state devices.
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