ELECTROCHROMIC BEHAVIOR OF AMORPHOUS COBALTPHTHALOCYANINE THIN-FILMS

Amorphous cobaltphthalocyanine thin films were prepared by vacuum evap oration, and their electrochromic behavior and voltammograms were exam ined in LiClO4, KNO3, KCl and MgCl2 aqueous electrolytes. The amorphou s thin films prepared at the substrate temperature of -120 degrees C, clearly exhibited electrochromism in LiClO4 and KNO3 aqueous electroly tes. The specimen films underwent five color transitions (from blue to red-violet, then to blue, then to green, then to yellow-green and the n to blue) corresponding to the five peaks on the voltammograms in LiC lO4 aqueous electrolyte. The amorphous films which were evaporated in low vacuum (1.33 x 10(-1) Pa) exhibited electrochromism more clearly, compared to those evaporated in high vacuum (1.33 x 10(-4) Pa). Becaus e the former films are low in density, it is easy for anions to be inj ected and extracted in the films.