A complementary electrochromic device based on carbon nanotubes/conducting polymers

In this study, we employed carbon nanotubes (CNTs)-modified polyaniline (PANI-CNTs) electrochromic (EC) thin film as the anodically coloring electrode and CNTs-modified poly(3,4-ethylenedioxythiophene) (PEDOT-CNTs) EC thin film as the cathodically coloring electrode. The electrochemically deposited PANI-CNTs film shows a transmittance change (ΔT) of 41.4% and a coloration efficiency (η) of 302 cm2 C−1 at 700 nm. The PANI-CNTs film was assembled in a complementary electrochromic device (ECD) with the PEDOT-CNTs film, which exhibits a ΔT of 58.5% and a coloration efficiency of 562 cm2 C−1 at 630 nm. The CNTs-modified ECD achieved a high η value of 836 cm2 C−1 at 650 nm and maintained a ΔT value of 35%, as compared to an η value of 285 cm2 C−1 and a similar ΔT value (35%) at 570 nm for a complementary PANI-PEDOT ECD without employing CNTs on both electrodes. No decay was noticed in both coloration efficiency and transmittance change after switching for 500 cycles.