Optoelectrochemical properties of poly(5,12-dihydrothieno[3′,4′:2,3][1,4] dioxocino[6,7-b]quinoxaline-co-2,2′ bithiophene) and its electrochromic device application

In this study we investigated the electrochromic properties and electrochromic device application of poly(5,12-dihydrothieno[3',4':2,3][1,4]dioxocino[6,7-b]quinoxaline (DDQ)-co-2,2'-bithiophene (13T)). Copolymerization was successfully achieved electrochemically in acetonitrile containing 0.1 M tetrabutyl ammonium tetrafluoroborate as the supporting electrolyte by direct anodic oxidation on platinum and indium tin oxide coated glass electrodes. The structure and morphology of the copolymer were investigated by infrared spectroscopy and scanning electron microscopy (SEM). Spectroelectrochemical analysis of the resulting copolymer reflected electronic transitions at 504 nm and similar to 800 nm revealing a pi-pi* transition and polaron formation, respectively. Dual-type polymer electrochromic devices (ECDs) based on P(DDQ-co-BT) were constructed with poly(3,4-ethylenedioxythiophene) (PEDOT). Spectroelectrochemistry, switching ability and stability experiments showed that the copolymer concerned can be a good anode material for electrochromic devices.