All polymeric solid state electrochromic devices

Two examples of all solid state and flexible electrochromic devices assembl ed under atmospheric conditions are described. The devices were constructed using polypyrrole and polythiophene derivatives as electrochromic material s, deposited on optically transparent plastic electrodes. An elastomer, pol y(epichlorohydrin-co-ethylene oxide) containing LiClO4, was used as electro lyte. Results indicated that the systems present high optical contrast in t he visible range and fast optical response times. We also discuss some stra tegies to enhance the optical contrast and optical response time of conduct ing polymers used in electrochromic devices. (C) 1999 Elsevier Science Ltd. All rights reserved.