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arXiv · 1607.06591

Understanding the Plasmonics of Nanostructured Atomic Force Microscopy Tips

Alan Sanders·Richard W. Bowman·Liwu Zhang·Vladimir Turek·Daniel O. Sigle·Anna Lombardi·Lee Weller·Jeremy J. Baumberg
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Abstract

Structured metallic tips are increasingly important for optical spectroscopies such as tip-enhanced Raman spectroscopy (TERS), with plasmonic resonances frequently cited as a mechanism for electric field enhancement. We probe the local optical response of sharp and spherical-tipped atomic force microscopy (AFM) tips using a scanning hyperspectral imaging technique to identify plasmonic behaviour. Localised surface plasmon resonances which radiatively couple with far-field light are found only for spherical AFM tips, with little response for sharp AFM tips, in agreement with numerical simulations of the near-field response. The precise tip geometry is thus crucial for plasmon-enhanced spectroscopies, and the typical sharp cones are not preferred.

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Alan Sanders, Richard W. Bowman, Liwu Zhang, Vladimir Turek, Daniel O. Sigle, Anna Lombardi, Lee Weller, Jeremy J. Baumberg. 2016-07-22. Understanding the Plasmonics of Nanostructured Atomic Force Microscopy Tips. https://doi.org/10.1063/1.4964601

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