Ultraconfined Plasmonic Hotspots Inside Graphene Nanobubbles

Z Fei; J J Foley 4th; W Gannett; M K Liu; S Dai; G X Ni; A Zettl; M M Fogler; G P Wiederrecht; S K Gray; D N Basov

doi:10.1021/acs.nanolett.6b04076

Ultraconfined Plasmonic Hotspots Inside Graphene Nanobubbles

Nano Lett. 2016 Dec 14;16(12):7842-7848. doi: 10.1021/acs.nanolett.6b04076. Epub 2016 Nov 14.

Authors

Z Fei^{1

2

3}, J J Foley 4th^{2

4}, W Gannett^{5

6}, M K Liu^{1

7}, S Dai¹, G X Ni¹, A Zettl^{5

6}, M M Fogler¹, G P Wiederrecht², S K Gray², D N Basov^{1

8}

Affiliations

¹ Department of Physics, University of California, San Diego , La Jolla, California 92093, United States.
² Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States.
³ Department of Physics and Astronomy, Iowa State University , Ames, Iowa 50011, United States.
⁴ Department of Chemistry, William Paterson University , Wayne, New Jersey 07470, United States.
⁵ Department of Physics, University of California at Berkeley , Berkeley, California 94720, United States.
⁶ Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
⁷ Department of Physics and Astronomy, Stony Brook University , Stony Brook, New York 11794, United States.
⁸ Department of Physics, Columbia University , New York, New York 10027, United States.

PMID: 27960518
DOI: 10.1021/acs.nanolett.6b04076

Abstract

We report on a nanoinfrared (IR) imaging study of ultraconfined plasmonic hotspots inside graphene nanobubbles formed in graphene/hexagonal boron nitride (hBN) heterostructures. The volume of these plasmonic hotspots is more than one-million-times smaller than what could be achieved by free-space IR photons, and their real-space distributions are controlled by the sizes and shapes of the nanobubbles. Theoretical analysis indicates that the observed plasmonic hotspots are formed due to a significant increase of the local plasmon wavelength in the nanobubble regions. Such an increase is attributed to the high sensitivity of graphene plasmons to its dielectric environment. Our work presents a novel scheme for plasmonic hotspot formation and sheds light on future applications of graphene nanobubbles for plasmon-enhanced IR spectroscopy.

Keywords: FDTD simulation; Graphene nanobubbles; heterostructures; nanoinfrared imaging; plasmon hotspots.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.