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Title: Imaging the Optical Fields of Functionalized Silver Nanowires through Molecular TERS

Abstract

We image 4-mercaptobenzonitrile-functionalized silver nanowires (~20 nm diameter) through tipenhanced Raman scattering (TERS). The enhanced local optical field-molecular interactions that govern the recorded hyperspectral TERS images are dissected through hybrid finite-difference time-domain-density functional theory simulations. Our forward simulations illustrate that the recorded spatio-spectral profiles of the chemically functionalized nanowires may be reproduced by accounting for the interaction between orientationally averaged molecular polarizability derivative tensors and enhanced incident/scattered local fields polarized along the tip axis. In effect, we directly map the enhanced optical fields of the nanowire in real space through TERS. The simultaneously recorded atomic force microscopy (AFM) images allow a direct comparison between our attainable spatial resolution in topographic (13 nm) and TERS (5 nm) imaging measurements performed under ambient conditions. Overall, our described protocol enables local electric-field imaging with few nm precision through molecular TERS, and it is therefore generally applicable to a variety of plasmonic nano-structures.

Authors:
; ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1496831
Report Number(s):
PNNL-SA-139471
Journal ID: ISSN 1948-7185
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry Letters
Additional Journal Information:
Journal Volume: 9; Journal Issue: 24; Journal ID: ISSN 1948-7185
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English

Citation Formats

Bhattarai, Ashish, Crampton, Kevin T., Joly, Alan G., Kovarik, Libor, Hess, Wayne P., and El-Khoury, Patrick Z. Imaging the Optical Fields of Functionalized Silver Nanowires through Molecular TERS. United States: N. p., 2018. Web. doi:10.1021/acs.jpclett.8b03324.
Bhattarai, Ashish, Crampton, Kevin T., Joly, Alan G., Kovarik, Libor, Hess, Wayne P., & El-Khoury, Patrick Z. Imaging the Optical Fields of Functionalized Silver Nanowires through Molecular TERS. United States. doi:10.1021/acs.jpclett.8b03324.
Bhattarai, Ashish, Crampton, Kevin T., Joly, Alan G., Kovarik, Libor, Hess, Wayne P., and El-Khoury, Patrick Z. Sat . "Imaging the Optical Fields of Functionalized Silver Nanowires through Molecular TERS". United States. doi:10.1021/acs.jpclett.8b03324.
@article{osti_1496831,
title = {Imaging the Optical Fields of Functionalized Silver Nanowires through Molecular TERS},
author = {Bhattarai, Ashish and Crampton, Kevin T. and Joly, Alan G. and Kovarik, Libor and Hess, Wayne P. and El-Khoury, Patrick Z.},
abstractNote = {We image 4-mercaptobenzonitrile-functionalized silver nanowires (~20 nm diameter) through tipenhanced Raman scattering (TERS). The enhanced local optical field-molecular interactions that govern the recorded hyperspectral TERS images are dissected through hybrid finite-difference time-domain-density functional theory simulations. Our forward simulations illustrate that the recorded spatio-spectral profiles of the chemically functionalized nanowires may be reproduced by accounting for the interaction between orientationally averaged molecular polarizability derivative tensors and enhanced incident/scattered local fields polarized along the tip axis. In effect, we directly map the enhanced optical fields of the nanowire in real space through TERS. The simultaneously recorded atomic force microscopy (AFM) images allow a direct comparison between our attainable spatial resolution in topographic (13 nm) and TERS (5 nm) imaging measurements performed under ambient conditions. Overall, our described protocol enables local electric-field imaging with few nm precision through molecular TERS, and it is therefore generally applicable to a variety of plasmonic nano-structures.},
doi = {10.1021/acs.jpclett.8b03324},
journal = {Journal of Physical Chemistry Letters},
issn = {1948-7185},
number = 24,
volume = 9,
place = {United States},
year = {2018},
month = {12}
}