REFLECTING ELECTROCHROMIC DEVICES

Unstructured all-solid-state thin-film electrochromic devices (ASTFEDs) with variable reflectance have been developed on the basis of hydrogen-tungsten bronzes. The characteristic compounds of these systems are a transparent electrode (ITO), an electrochromic WO3-layer, solid-state ion-conducting layers ('electrolytes'), an integrated reflecting layer, and a hydrogen-storing layer. The total thickness of such structures is only a few microns. They are enclosed between the substrate glass and a second glass plate and are thus protected from the environment. Different modes of construction are compared, the electrochemistry of the thin-layer cells is discussed, the tasks and characteristics of the thin-film arrangements and their important features are shown, and possible applications are described.