Title Nanorattles with tailored electric field enhancement
Date 22.06.2017
Number 53352
Abstract Nanorattles are metallic core–shell particles with core and shell separated by a dielectric spacer. These nanorattles have been identified as a promising class of nanoparticles, due to their extraordinary high electric-field enhancement inside the cavity. Limiting factors are reproducibility and loss of axial symmetry owing to the movable metal core; movement of the core results in fluctuation of the nanocavity dimensions and commensurate variations in enhancement factor. We present a novel synthetic approach for the robust fixation of the central gold rod within a well-defined box, which results in an axisymmetric nanorattle. We determine the structure of the resulting axisymmetric nanorattles by advanced transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). Optical absorption and scattering cross-sections obtained from UV-vis-NIR spectroscopy quantitatively agree with finite-difference time-domain (FDTD) simulations based on the structural model derived from SAXS. The predictions of high and homogenous field enhancement are evidenced by scanning TEM electron energy loss spectroscopy (STEM-EELS) measurement on single-particle level. Thus, comprehensive understanding of structural and optical properties is achieved for this class of nanoparticles, paving the way for photonic applications where a defined and robust unit cell is crucial.
Publisher Nanoscale
Identifier 0
Citation Nanoscale 9 (2017) 9376-9385
Authors Schnepf, M. J. ; Mayer, M. ; Kuttner, C. ; Tebbe, M. ; Wolf, D. ; Dulle, M. ; Altantzis, T. ; Formanek, P. ; Förster, S. ; Bals, S. ; König, T. ; Fery, A.

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