Inorganic electrochromic (EC) materials
with vibrant multicolor
change that are compatible with large-scale processing have been at
the forefront of EC technology and are crucial in a wide range of
applications, such as displays and camouflage. However, limited strategies
are available to realize such inorganic materials, and challenges
such as low color purity are yet to be overcome. Here, we demonstrate
multilayered metal–dielectric metamaterials (MMDMs) as a new
family of inorganics-based EC materials to achieve dynamic alternation
among multicolors with high contrast and high color purity, which
are structurally realized by significantly enhancing the confinement
of the incident light in specific optical frequencies. This multilayer
structure renders high reflectivity (75%), high quality factor (7.4),
and a full width at half-maximum of 60 nm before coloration and presents
a color gamut at least 40% wider than that of previously reported
metamaterials after coloration, indicating good color quality.