Programmable dual electrochromism in azine linked conjugated polymer

A conjugated polymer consisting of tri-EDOT and azine groups was synthesized and explored for a programmable dual electrochromic device. Electrochemical doping (oxidation) and de-doping (reduction) resulted in the two distinct redox pairs, depending on the applied potential range. In situ spectroelectrochemical analyses revealed that the stepwise redox process of two units was associated with dual electrochromic responses: tri-EDOT unit for purple electrochromism followed by azine unit for blue electrochromism. Dual electrochromism of purple and blue was attainable at below 1.0 V which could induce the color transition upon the potential application of around +/- 1 V. Maximum coloration efficiency of 393 cm(2)/C with a response time of 1 s was obtained. (C) 2017 Optical Society of America