Probing the limits of plasmonic enhancement using a two-dimensional atomic crystal probe
Open Access
- 29 August 2018
- journal article
- research article
- Published by Springer Science and Business Media LLC in Light: Science & Applications
- Vol. 7 (1), 1-11
- https://doi.org/10.1038/s41377-018-0056-3
Abstract
Achieving larger electromagnetic enhancement using a nanogap between neighboring metallic nanostructures has been long pursued for boosting light–matter interactions. However, the quantitative probing of this enhancement is hindered by the lack of a reliable experimental method for measuring the local fields within a subnanometer gap. Here, we use layered MoS2 as a two-dimensional atomic crystal probe in nanoparticle-on-mirror nanoantennas to measure the plasmonic enhancement in the gap by quantitative surface-enhanced Raman scattering. Our designs ensure that the probe filled in the gap has a well-defined lattice orientation and thickness, enabling independent extraction of the anisotropic field enhancements. We find that the field enhancement can be safely described by pure classical electromagnetic theory when the gap distance is no <1.24 nm. For a 0.62 nm gap, the probable emergence of quantum mechanical effects renders an average electric field enhancement of 114-fold, 38.4% lower than classical predictions.Keywords
Funding Information
- National Natural Science Foundation of China (11674255, 11404247, 11674256)
This publication has 47 references indexed in Scilit:
- Chemical mapping of a single molecule by plasmon-enhanced Raman scatteringNature, 2013
- Plasmons in Strongly Coupled Metallic NanostructuresChemical Reviews, 2011
- Plasmonics for extreme light concentration and manipulationNature Materials, 2010
- Nanogap-engineerable Raman-active nanodumbbells for single-molecule detectionNature Materials, 2009
- Large single-molecule fluorescence enhancements produced by a bowtie nanoantennaNature Photonics, 2009
- Surface-Enhanced Raman Excitation Spectroscopy of a Single Rhodamine 6G MoleculeJournal of the American Chemical Society, 2008
- Probing the Structure of Single-Molecule Surface-Enhanced Raman Scattering Hot SpotsJournal of the American Chemical Society, 2008
- Spectroscopy of Single Hemoglobin Molecules by Surface Enhanced Raman ScatteringPhysical Review Letters, 1999
- Single Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)Physical Review Letters, 1997
- Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman ScatteringScience, 1997