Spatially Mapping the Plasmon Resonances of Hollow 1D Nanostructures: Hybrid A u A g Nanotubes

Abstract

Morphological control at the nanoscale paves the way to fabricate nanostructures with desired plasmonic properties. We present the nanoengineering of plasmon resonances in 1D hollow nanostructures of two different AuAg nanotubes; completely hollow nanotubes (Figure 1) and hybrid nanotubes comprising the sequential formation of solid Ag parts and hollow AuAg parts (Figure 2). Spatially resolved plasmon mapping by electron energy loss spectroscopy (EELS) revealed the presence of high order resonator‐like modes and localized surface plasmon resonance (LSPR) modes in both nanotubes. Experimental findings are accurately correlated with the boundary element method (BEM) simulations, where both experiments and simulations revealed that the plasmon resonances are intensely present inside the nanotubes. Based on the experimental and simulated results obtained in the present study, we show that the novel hybrid AuAg nanotubes possess two significant features: (i) LSPRs have been generated distinctively from the hollow and solid parts of the hybrid AuAg nanotubes which opens the way to control a broad range of plasmon resonances with one single nanostructure and (ii) the periodicity of the high order modes are disrupted due to the interaction of solid and hollow parts.