AN ELECTROCHROMIC DEVICE COMBINING POLYPYRROLE AND WO3 .1. LIQUID ELECTROLYTE

In this work we assembled an electrochromic device using as active mat erials an organic conductive polymer and a transition metal oxide. We studied the materials used to assemble the device separately, and in c omplete devices. These materials were: polypyrrole doped with dodecyls ulfate and tungsten oxide. The substrates used were glass slides coate d with tin doped indium oxide, and the electrolyte was a propylene car bonate solution of lithium perchlorate. We adjusted the charge balance and the chromatic contrast of the devices by controlling the thicknes s of the polypyrrole films. To illustrate the results obtained, we des cribe two devices with different polypyrrole film thicknesses. The chr omatic contrast in the visible and near-infrared wavelength range is 4 0% and the electrical and optical properties of the devices remain unc hanged after 10(4) double potential chronoamperometric steps. Copyrigh t (C) 1996 Elsevier Science Ltd