Research paper of the month
November 2013 - Three-dimensional imaging of localised surface plasmon resonances of metal nanoparticles
Metal nanoparticles display many remarkable optical properties governed by localised surface plasmon resonances (LSPRs) whose sensitivity to structure, composition and local environment has given rise to a wide range of potential applications. To better understand the relationship between the nanostructure and the LSPRs, we have developed a three-dimensional imaging technique to probe the surface plasmon excitation at the nanoscale. In this paper, we show how using high energy resolution electron energy loss spectroscopy (EELS), novel spectral processing methods and compressed sensing electron tomography, we can reveal the three-dimensional morphology of LSPRs in a silver nanocube. We show, in conjunction with EELS simulations, how the addition of a substrate leads to a hybridization of the fundamental modes of excitation and the formation of five key LSPR components which are revealed in the 3D image. The figure shows a combined 3D rendering of these five LSPR components for a 100nm silver nanocube.
The work was a collaboration between the Department of Materials Science and Metallurgy and the Department of Chemical Engineering and Biotechnology.
Olivia Nicoletti, Francisco de la Peña, Rowan K. Leary, Daniel J. Holland, Caterina Ducati and Paul A. Midgley Nature (2013) 502 80–84.