Multielectrochromic Copolymers Based on Thiophene Derivatives: Tunable Optoelectronic Properties

In this study, a series of copolymers based on 3-methoxythiophene(MOT) and 3,4-ethylenedioxythiophene (EDOT) have been prepared by electrochemical method in boron trifluoride diethyl etherate (BFEE). The copolymers are characterized by FTIR, XPS, SEM and cyclic voltammograms. The MOT/EDOT ratio in the polymer chain decreases with the decreasing MOT/EDOT feed ratio, and low polymerization potential incorporates more EDOT units into the polymer chain. The electrochromic properties of the copolymers can be greatly tuned by the applied MOT/EDOT feed ratio. Absorption peak of the neutral copolymer presents red-shift with increasing feed ratio, and each copolymer has multicolor electrochromism. In addition, the copolymers present fast-switching response, reasonable coloration efficiency and good stability. All these indicate that the copolymers based on facile, commercial MOT and EDOT are promising candidates for electrochromic applications.