LAUSR

Abstract Rational design of novel high-performance conjugated polymers is still central to the field of polymer electrochromics. In this work, a novel 3-methylselenophene-EDOT hybrid polymer is designed and electrosynthesized from the molecular precursor of 3-methylselenophene end-capped with 3,4-ethylenedioxythiophene (EDOT). The structural characterization, physicochemical properties, micromorphology, electrochemical behaviors, and electrochromic performance are systematically explored to reveal the structure-property relationship of both the precursor and the hybrid polymer. The precursor with planar structure exhibits a much lower onset oxidation potential (0.5 V) than that of both 3-methylselenophene (1.17 V) and EDOT (1.23 V). Low-potential electropolymerization yields smooth and compact hybrid polymer film with high conductivity (10−1 S cm−1) and excellent electrochemical stability under cyclic electrical loads. The 3-methylselenophene-EDOT hybrid polymer also exhibits the obvious color changes from brownish yellow in the reduced to transparent sky blue upon oxidization with favorable optical contrast (39%, 990 nm), high coloration efficiency (161 cm2/C) and fast response time (1.3 s) under low switching voltages.