Characterizing Localized Surface Plasmons Using Electron Energy-Loss Spectroscopy.

Electron energy-loss spectroscopy (EELS) offers a window to view nanoscale properties and processes. When performed in a scanning transmission electron microscope, EELS can simultaneously render images of nanoscale objects with subnanometer spatial resolution and correlate them with spectroscopic information at a spectral resolution of ∼10–100 meV. Consequently, EELS is a near-perfect tool for understanding the optical and electronic properties of individual plasmonic metal nanoparticles and few-nanoparticle assemblies, which are significant in a wide range of fields. This review presents an overview of basic plasmonics and EELS theory and highlights several recent noteworthy experiments involving the interrogation of plasmonic metal nanoparticle systems using electron beams.