Electrosynthesis and characterization of a multielectrochromic copolymer of 1,4-bis(2-thienyl)-naphthalene with 2,2′-bithiophene

► A copolymer based on 1,4-bis(2-thienyl)-naphthalene and 2,2′-bithiophene is electrochemically synthesized. ► The obtained copolymer film exhibits five different colors under various voltages. ► Maximum contrast and response time of the copolymer film are measured as 32.7% and 0.59 s at 750 nm, respectively.