A fast-switching electrochromic device with a surface-confined 3D metallo-organic coordination assembly

Abstract

Demonstrated herein is a fast (<1 s)-switching solid-state electrochromic device (t = 0.49 s for coloration and 0.90 s for bleaching), fabricated with a novel imidazolium-linked [Fe(terpyridine)2]²⁺ chromophore-based surface-confined three dimensional metallo-organic coordination assembly. The device also exhibits promising electrochromic attributes such as high coloration efficiency (η = 275 cm² C⁻¹), moderate operating voltage (from −2 V to +3.2 V) and transmittance contrast (ΔT = 40%), and high cycling stability (up to 4500 cycles).