An electrochromic device (ECD) has in its center an electrolyte or ion conductor, which is in contact with films that provide optical modulation, ion storage, and (transparent) electrical conduction. We review designs and properties of ECDs, giving special emphasis to infrared optical characteristics. The ECDs are categorized according to the type of electrolyte or ion conductor: liquid, solid inorganic in bulk- or thin film form, or solid organic (polymer). The electrochromic film is W oxide; this material is used in the majority of all studied ECDs.
|