Infrared emittance modulation of all-thin-film electrochromic devices

All-thin-film electrochromic devices for infrared emittance modulation were manufactured using dc magnetron sputtering. The devices were cycled electrochemically, and the optical signal was measured in situ by spectrophotometry in the wavelength range 2 to 50 mum. The devices consisted of WO3 as a main electrochromic layer, ZrO2 as an ion conductor, and NixOyHz as a complementary electrochromic layer. The substrate was glass covered with indium tin oxide, and the front electrode was an evaporated Al grid. The highest emittance modulation found was between epsilon(low) = 0.33 and epsilon(high) = 0.59, which compares favourably with previously studied variable emittance devices. (C) 2004 Elsevier B.V. All rights reserved.