Hydrogen-Induced Tuning of Plasmon Resonance in Palladium-Silver Layered Nanodimer Arrays

Reversible tuning of localized surface plasmon resonances is achieved with strong resonance intensity in the near-IR region using hydrogen uptake into dimeric nanostructures of Pd-Ag layered nanodots. The resonance feature in the present dimer is characterized by hybridized plasmon modes between two adjacent Pd-Ag layered nanodots with similar plasmonic features. In contrast, the resonance of a conventional Pd-Ag heterodimer is considered to be a perturbed plasmon mode between Pd and Ag nanodots with different plasmonic features. The strong symmetric interactions in the layered dimers lead to a large peak shift with hydrogen uptake into the Pd layers, while the weak asymmetric interactions in the heterodimers result in a decrease in the band intensity. The flexible tailoring of the resonance intensity, wavelength, and tunability of the layered nanostructures provides the possibility for novel functionalized plasmonic materials or devices to be realized.