Letter pubs.acs.org/JPCL
Examining Substrate-Induced Plasmon Mode Splitting and Localization in Truncated Silver Nanospheres with Electron Energy Loss Spectroscopy Guoliang Li,†,¶ Charles Cherqui,‡,¶ Yueying Wu,§ Nicholas W. Bigelow,‡ Philip D. Simmons,∥ Philip D. Rack,§,⊥ David J. Masiello,*,‡ and Jon P. Camden*,† †
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States Department of Chemistry, University of Washington, Seattle, Washington 98195, United States § Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States ∥ Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States ⊥ Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States ‡
S Supporting Information *
ABSTRACT: Motivated by the need to study the size dependence of nanoparticle−substrate systems, we present a combined experimental and theoretical electron energy loss spectroscopy (EELS) study of the plasmonic spectrum of substrate-supported truncated silver nanospheres. This work spans the entire classical range of plasmonic behavior probing particles of 20−1000 nm in diameter, allowing us to map the evolution of localized surface plasmons into surface plasmon polaritons and study the size dependence of substrate-induced mode splitting. This work constitutes the first nanoscopic characterization and imaging of these effects in truncated nanospheres, setting the stage for the systematic study of plasmon-mediated energy transfer in nanoparticle−substrate systems.
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varying the parameters of the system, such as the particle geometry or the optoelectronic properties of the substrate.15,17−21 Electron energy loss spectroscopy (EELS) performed in a scanning transmission electron microscope (STEM) has also revealed that substrate-induced LSPR localization can be manipulated to tune the efficiency of energy transfer in nanocube−substrate systems.15 These studies indicate that energy transfer is highly dependent on the interplay between LSPRs and the electronic structure of the substrate. Because the spatial and energetic profiles of LSPRs can be tuned by varying the particle size,22−24 it is tempting to conduct a full-size study of the nanocube-substrate system to gain a deeper understanding of plasmon-mediated energy transfer. However, because nanocubes are only available in a limited size range (
