Full-Color-Adjustable Nanophotonic Device Adopting Electrochromic Poly(3,4-ethylenedioxythiophene) Thin Films

Intercalation-based organic polymers that shift their colors during ion insertion and extraction provide a significant basis for existing electrochromic technology. Nevertheless, the complexity of modifying the structure in the skeleton or combining several diverse polymers to produce a full-color range has restricted the practical applications of electrochromic materials. Herein, we demonstrate two configurations of the poly(3,4-ethylenedioxythiophene) (PEDOT) Fabry–Perot (F–P) nanocavity-type electrochromic devices fabricated by spray coating lossless PEDOT on the F–P metasurfaces (Cr/ITO/Ag/Cr), which allows full-color response by simply controlling the thickness of dielectric layer indium tin oxide (ITO). However, the reflected light from the PEDOT F–P nanocavity-type electrode can be modulated by electrically controllable optical absorption of PEDOT. Besides, the subtle brightness regulation could be obtained in our F–P nanocavity electrochromic devices via altering the PEDOT thickness. Overall, our results offer a novel perspective for versatile color control of PEDOT.