Blue/green-to-transmissive electrochromic-supercapacitor bifunctional polymer films via electropolymerization containing 3,4-propylenedioxy-thiophene derivatives as novel donor units

Developing novel donor-acceptor conjugated polymers is essential to obtain desirable electrochromic properties. Herein, naphthobisthiadiazole, 2,1,3-benzothiadiazole and 2,3-dimethylquinoxaline as electron-deficient units, along with ProDOT-Me2 as an electron-rich block, to create novel donor-acceptor (D-A) type electrochromic polymers (pQWL, pBt and pDBt) for the investigation. The electrochemical/spectroelectrochemistry/colorimetry properties-structure of the ProDOT-Me2-based D-A polymers were systematically investigated. Benefiting from ProDOT-Me2 as an available donor block and matching electron-accepting units for the construction of D-A structures, pQWL and pDBt exhibited blue/green-to-transmissive with excellent electrochromic properties. The pQWL and pDBt exhibited remarkable bifunctional characteristics with reversible colors-to-high transmissive states, shorter switching times, long-term stability, good color memory, excellent coloration efficiency, low color chromaticity in the oxidation state, and large area-specific capacitance. These findings highlight the significant potential of ProDOT-Me2-based D-A polymers as versatile building units for polymer electrochromicsupercapacitor bifunctional materials.