A complementary electrochromic device based on carbon nanotubes/conducting polymers

► Carbon nanotubes-modified PEDOT and PANI thin films have been studied. ► Increased values of transmittance change and coloration efficiency are found in both films. ► Fabricating an electrochromic device based on PEDOT-CNTs and PANI-CNTs polymer films. ► The proposed ECD demonstrates a high coloration efficiency of 836 cm2 C−1.