There is disclosed an electrochromic element in which an oxidative color-forming layer is composed of an organic material and a reductive color-forming layer is composed of an inorganic material. The electrochromic element comprises a pair of electrodes, at least one of which is transparent, the oxidative...http://www.google.de/patents/US4750816?utm_source=gb-gplus-sharePatent US4750816 - Electrochromic element comprising an organic, oxidative color-forming layer and an inorganic, reductive color-forming layer
