Dual-type electrochromic devices based on both n- and p-dopable poly(dithieno[3,4-b,3′,4′-e]-[1,4]-dithiine)

Polydithieno[3,4-b,3′4′-e]-[1,4]-dithiine (PDTH), being both n- and p-dopable, reveals remarkable color changes as both anodically and cathodically coloring material. In order to investigate its utilization in the electrochromic devices, three different transmissive/absorbtive type polymer electrochromic devices based on both p-type and n-type PDTH were assembled. These are, namely (1) p-type PDTH/poly(3,4-ethylenedioxythiophene) (PEDOT); (2) polythiophene/n-type PDTH; (3) p-type PDTH/n-type PDTH. Spectroelectrochemistry, switching ability, stability and open-circuit memory of the devices were investigated by UV–vis spectrophotometer and cyclic voltammetry. These devices exhibit reasonable switching times and stability under atmospheric conditions.