Intelligent color-varying windows: High contrast electrochromic triarylamine-based polyimide devices

Electrochromic devices (ECDs) spanning from colorless to black have garnered increasing attention in both fundamental scientific research and potential applications in recent years. To address the need for a multi-response optoelectronic material capable of efficient black conversion (black color/emission dual switching), we developed a novel triarylamine-based polyimide polymer, named CpO-PI, employing an innovative design strategy. This polymer incorporates two triphenylenediamine monomers linked to CpODA, resulting in exceptional properties. CpO-PI exhibits full wavelength absorption across the visible light spectrum in both natural and oxidized states, with boasting commendable solubility, thermal stability, and photoluminescence (PL) activity. Leveraging tungsten trioxide as the counter electrode in the optimized ECD, it achieved remarkable optical contrast (up to 99 %), distinct pure EC characteristics, robust memory performance, and high coloring efficiency (CE = 695 cm²·C⁻¹) in the energized oxidation state. Our study not only presents a pioneering approach towards developing efficient EC materials but also underscores the potential of utilizing triphenylamine chromophore-based polyimides in the next generation of electrochromic fluorescent devices. These findings are poised to invigorate further exploration in the field of EC technology.