Electrochromic Metallo–Organic Nanoscale Films: A Molecular Mix and Match Approach to Thermally Robust and Multistate Solid‐State Devices

In this work, the performance of surface‐confined molecular assemblies, combined with a solid‐state electrolyte, as multicolor displays is reported. An ultraviolet (UV) crosslinked polymer is used as a matrix for the electrolyte. No dedicated ion storage layer is required to operate the laminated devices; up to 4500 redox cycles are demonstrated at a low voltage. The intense coloration and switching properties ( t  = 0.4–2.8 s) are retained even after thermally treating these devices at 100 °C  for 24 h in air. The versatility of this approach is demonstrated by the use of spray‐coated bimolecular assemblies for multicolor display fabrication. The molecular assemblies have coloration efficiencies as high as 338 cm 2 C −1 .