Nanoscale Manipulating Silver Adatoms for Aqueous Plasmonic Electrochromic Devices

Abstract Plasmonic colors are attractive building blocks for flat panel displays due to their broad color gamut and unprecedented subwavelength resolution. The exploration of reversible silver (Ag) electrodeposition for switchable plasmonic colors is considered as a promising strategy toward dynamically reconfigurable color displays. To date, the current reversible Ag electrodeposition‐based electrochromic devices are energy‐inefficient as the platforms are realized in nonaqueous electrolytes that require high working voltage. However, the high working voltage in an aqueous electrolyte leads to uncontrolled nucleation growth of Ag particles, thus rendering its application for color displays impractical. Herein, the first demonstration of the manipulation of Ag adatoms for aqueous plasmonic electrochromic devices through underpotential deposition is presented. It is shown that the Ag nanoparticles underpotential deposition not only enables a reversible voltage‐activated wide range of dynamic plasmonic color change of 100 nm, but also facilitates size control of the grown Ag nanoparticles. These findings provide a favorable and novel platform for low energy‐consumption tunable photonic and nanoplasmonic devices, as well as a simple and reliable process for rapid, scalable, and green preparation of tunable plasmonic Ag nanoparticles.