Polarized plasmonic enhancement by Au nanostructures probed through raman scattering of suspended graphene

Sebastian Heeg, Roberto Fernandez-Garcia, Antonios Oikonomou, Fred Schedin, Rohit Narula, Stefan A. Maier, Aravind Vijayaraghavan, Stephanie Reich

Research output: Contribution to journalArticleResearchpeer-review

139 Citations (Scopus)

Abstract

We characterize plasmonic enhancement in a hotspot between two Au nanodisks using Raman scattering of graphene. Single layer graphene is suspended across the dimer cavity and provides an ideal two-dimensional test material for the local near-field distribution. We detect a Raman enhancement of the order of 103 originating from the cavity. Spatially resolved Raman measurements reveal a near-field localization one order of magnitude smaller than the wavelength of the excitation, which can be turned off by rotating the polarization of the excitation. The suspended graphene is under tensile strain. The resulting phonon mode softening allows for a clear identification of the enhanced signal compared to unperturbed graphene.

Original languageEnglish
Pages (from-to)301-308
Number of pages8
JournalNano Letters
Volume13
Issue number1
DOIs
Publication statusPublished - 9 Jan 2013
Externally publishedYes

Keywords

  • enhancement
  • plasmonic cavity
  • Raman spectroscopy
  • strain
  • suspended graphene

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