Patent ID: 7265890

Claim:
An electrochromic device for controlling emissivity from a body in a spectral region comprising wavelengths between about five and thirty microns, the device comprising a substrate abutting the body when the device is in use, the substrate having a plurality of vacuum-deposited thin films disposed thereon, the thin films comprising at least: a substrate electrode deposited directly on the substrate; a plurality of active layers comprising at least an electrochromic layer, an electrolyte layer and an ion storage portion, the plurality of active layers characterized by a transmittance in the spectral region that is controllable by application of a voltage across the plurality of active layers; and a substantially transparent silver layer distal from the substrate; wherein the ion storage portion comprises one of: a dual layer structure having a first layer comprising vanadium pentoxide and a second layer, distinct from the first layer, comprising brown praseodymium oxide; and a mixed metal oxide layer comprising vanadium and praseodymium and a diffusion barrier layer comprising one of a transparent conducting oxide and praseodymium oxide, wherein the diffusion barrier layer is selected to prohibit diffusion of the silver into the layer comprising vanadium pentoxide.