Structural color and near-infrared tunability of ruthenium-coated anodic aluminum oxide by atomic layer deposition

Here, we systematically investigate optical behaviors of ruthenium (Ru)-coated nanoporous anodic aluminum oxide (AAO) nanoarchitectures in the visible and near-Infrared (NIR) regions, where they are fabricated by an atomic layer deposition (ALD) process. Depending on the Ru thickness and the AAO dimensions, the Ru nanoarchitectures could be completely changed (tubular-type or wire-type Ru nanostructures), and the corresponding optical properties are critically affected. Brilliant structural colors are found from the Ru-coated AAO nanostructures, in which the color display covers the full visible range. Beyond the visible region, we also examine the optical behaviors of Ru-coated AAO nanostructures in the NIR region.