Thermally Stable Nanoporous Gold-Alumina Core-Shell with Tunable Optical Transmission

Tuning localized surface plasmon resonance (LSPR) of nanoporous metals is crucial to manipulate light within tiny volumes for the implementation of optical devices at the nanoscale. Herein, nanoporous gold-alumina core-shell films with constant gold skeleton and variable alumina sheaths are fabricated by means of chemical corrosion and subsequent atomic layer deposition. Optical transmission properties of these composite films can be tailored due to LSPR excitations of the three-dimensional gold skeleton and alterable alumina shells as the surrounded dielectrics. The widely tunable light transmission and significantly improved stability are thus suggested to incorporate nanoporous goldalumina core-shells into promising nano-devices with reliable performance.