亜鉛フタロシアニン真空蒸着膜のエレクトロクロミック特性

抄録

Amorphous and polycrystalline zincphtalocyanine thin films were deposited in this study, on indium tin oxide (ITO) substrates by means of a vacuum evaporation technique, and their electrochromic properties were investigated in the electrolytic solution of 0.5M natriumchloride solved in thyleneglycol. Basic characteristics of electrochromism were measured and observed as following: cyclic voltammetry, electron and anion behavior, VIS spectroscopy, coloration efficiency, memory properties and response time. The color transition was observed from blue to purple upon oxidation and from purple to blue upon rereduction. When potential was swept in a potentiogalvanostat, charge compensation was attained upon oxidation by injection of anions from the electrolyte to the thin film and upon rereduction by expulsion of anions. As anions may be more easily injected in amorphous films, those showed electrochromism more clearly in comparison with polycrystalline films. Coloration efficiency of 250.3cm²/C was obtained at 20°C. This value was independent on the structure of the thin film, and was large in comparison with that of WO₃. Coloration officiency of more than 200cm²/C was obtained in the electrolyte temperature range from 20 to 70°C. The oxidized state with a purple color of zincphthalocyanine was stably stored even in air.