A Transparent to Opaque Electrochromic Device Using Reversible Ag Deposition on PProDOT‐Me2 with Robust Stability.

A hybrid device integrating both electrochromic (EC) and metal electrodepositing effects is developed. The device consists of a working electrode made with poly(3,4‐(2,2‐dimethyl‐propylenedioxy)thiophene) (PProDOT‐Me2), a counter electrode of bare indium tin oxide, and an electrolyte containing AgNO3, LiBr, and Br2. The electrolyte is specially designed to provide essential elements for both EC and electrodepositing reactions. By applying varying voltages, the device demonstrates three color states: transparent, blue, and opaque. Detailed measurements reveal that the device displays near‐zero transmittance in the opaque state and can work over 10 000 cycles, with 75.7% as the maximum optical modulation and about 5 s as its response time for both coloring and bleaching processes. This study may provide a way to break the limitation of conventional electrochromic devices (ECDs). [ABSTRACT FROM AUTHOR]