Tricolor electrochromism of copolymer based on selenophene and 3,4-ethylenedioxythiophene

A copolymer based on selenophene and 3,4-ethylenedioxythiophene was successfully synthesized by electrochemical polymerization in boron trifluoride diethyl etherate (BFEE). The resultant copolymer was characterized by cyclic voltammetry, FTIR, XPS, SEM and spectroelectrochemistry. The copolymer presented tricolor electrochromism, which was dark green-yellow (in the neutral state), blue-green (in the intermediate state) and blue (in the oxidized state). Furthermore, the optical contrast and switching time of the copolymer was found to be 19.8% and 3.2 s at 728 nm, respectively, which remained 75.1% of its original electroactivity after 200 cycles.

► A copolymer film based on selenophene and 3,4-ethylenedioxythiophene has been successfully deposited on ITO electrode in BFEE.
► The formation of the copolymer has been confirmed by CVs, FTIR and element analysis.
► The copolymer film presents tricolor electrochromism (green-yellow, blue-green and blue).
► The film has reasonable switching rate, coloration efficiency and stability.