Fine tuning of color via copolymerization and its electrochromic device application

In this study electrochemical copolymerization of 1-(perfluorophenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole and 3,4-ethylenedioxythiophene was used to fulfill a strategy in achieving desired multichromic properties. The resultant polymer displayed distinct color changes between red–violet, amber, green and blue color with good switching times and optical contrast. A direct correlation between the color of the polymer in neutral state and the applied potential during synthesis was observed. Hence, it was possible to achieve colors from maroon, red–violet, and eggplant to indigo depending on the applied potential. A dual type electrochromic device of the copolymer and poly(3,4-ethylenedioxythiophene) was constructed to evaluate the possible use of such copolymer in device applications. The device displayed multichromism, with 1.1 s switching time and good electrochromic memory.