Polymer composite with three electrochromic states

The electrochromic properties of an electrodeposited polymer composite consisting of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(3-methyl-2-{[3-(4-vinyl-benzyl)-3H-benzothiazol-2-ylidene]-hydrazono}-2,3-dihydro-benzothiazole-6-sulfonic) acid (polyABTS) are reported. Films of this polymer composite exhibit three electrochromic states in the visible region upon application of potentials at -800 mV, 0 V, and +800 mV versus Ag/AgCl, confirming that both polymers contribute, to electrochromic switching. These films exhibit ultracontrasts between the bleached state at 0 V and the blue state at -800 mV (Delta T % = 33.6% at 615 nm) and the green state at +800 mV (Delta T % = 46.3% at 393 nm). The efficiency of cathodic coloration and bleaching of this material at 615 nm is 322.1 and 396.4 cm(2) C-1, respectively, whereas the efficiency of anodic coloration and bleaching at 393 nm is 189.9 and 192.4 cm(2) C-1, respectively. In comparison to previously reported films of polypyrrole (pPy) doped with the ABTS monomer (pPy[ABTS]), thick films of PEDOT[polyABTS] exhibit an increased stability to potential cycling both because PEDOT is more resistant to overoxidation than pPy and because polyABTS is a nonleachable dopant. Reversible redox behavior, anodic and cathodic coloration, fast response times, resistance to overoxidation, ease of fabrication, and low cost make this material competitive for electrochromic applications.