Display options
Cite
El-Khoury PZ, Gong Y, Abellan P, et al. Tip-enhanced Raman nanographs: mapping topography and local electric fields. Nano Lett. 2015;15(4):2385-90doi: 10.1021/acs.nanolett.5b00609.
El-Khoury, P. Z., Gong, Y., Abellan, P., Arey, B. W., Joly, A. G., Hu, D., Evans, J. E., Browning, N. D., & Hess, W. P. (2015). Tip-enhanced Raman nanographs: mapping topography and local electric fields. Nano letters, 15(4), 2385-90. https://doi.org/10.1021/acs.nanolett.5b00609
El-Khoury, Patrick Z, et al. "Tip-enhanced Raman nanographs: mapping topography and local electric fields." Nano letters vol. 15,4 (2015): 2385-90. doi: https://doi.org/10.1021/acs.nanolett.5b00609
El-Khoury PZ, Gong Y, Abellan P, Arey BW, Joly AG, Hu D, Evans JE, Browning ND, Hess WP. Tip-enhanced Raman nanographs: mapping topography and local electric fields. Nano Lett. 2015 Apr 08;15(4):2385-90. doi: 10.1021/acs.nanolett.5b00609. Epub 2015 Mar 09. PMID: 25741776.
Copy Download .nbib Format: NLM
Share it on

Nano Lett. 2015 Apr 08;15(4):2385-90. doi: 10.1021/acs.nanolett.5b00609. Epub 2015 Mar 09.

Tip-enhanced Raman nanographs: mapping topography and local electric fields.

Nano letters

Patrick Z El-Khoury, Yu Gong, Patricia Abellan, Bruce W Arey, Alan G Joly, Dehong Hu, James E Evans, Nigel D Browning, Wayne P Hess

Affiliations

  1. †Physical Sciences Division and ‡Environmental and Molecular Sciences Laboratory , Pacific Northwest National Laboratory, Richland, Washington 99352, United States.

PMID: 25741776 DOI: 10.1021/acs.nanolett.5b00609

Abstract

We report tip-enhanced Raman imaging experiments in which information on sample topography and local electric fields is simultaneously obtained using an all-optical detection scheme. We demonstrate how a Raman-active 4,4'-dimercaptostilbene (DMS)-coated gold tip of an atomic force microscope can be used to simultaneously map the topography and image the electric fields localized at nanometric (20 and 5 nm wide) slits lithographically etched in silver, all using optical signals. Bimodal imaging is feasible by virtue of the frequency-resolved optical response of the functionalized metal probe. Namely, the probe position-dependent signals can be subdivided into two components. The first is a 500-2250 cm(-1) Raman-shifted signal, characteristic of the tip-bound DMS molecules. The molecules report on topography through the intensity contrast observed as the tip scans across the nanoscale features. The variation in molecular Raman activity arises from the absence/formation of a plasmonic junction between the scanning probe and patterned silver surface, which translates into dimmed/enhanced Raman signatures of DMS. Using these molecular signals, we demonstrate that sub-15 nm spatial resolution is attainable using a 30 nm DMS-coated gold tip. The second response consists of two correlated sub-500 cm(-1) signals arising from mirror-like reflections of (i) the incident laser field and (ii) the Raman scattered response of an underlying glass support (at 100-500 cm(-1)) off the gold tip. We show that both the reflected low-wavenumber signals trace the local electric fields in the vicinity of the nanometric slits.

Keywords: Tip-enhanced Raman; junction plasmon; local electric fields; nanolithography; nanoscale imaging

Publication Types