Signal Enhancement from Tunable SERS Substrates: Design and Demonstration of Multiple Regimes of Enhancement

Nayak, DR and Bhat, N and Venkatapathi, M and Umapathy, S (2018) Signal Enhancement from Tunable SERS Substrates: Design and Demonstration of Multiple Regimes of Enhancement. In: Journal of Physical Chemistry C, 122 (16). pp. 9134-9140.

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Abstract

The interaction between plasmonic nanoparticle and substrate is of utmost importance for optimal design of surface-enhanced Raman spectroscopy (SERS) substrates. Substrates can either quench or enhance the strength of the localized plasmon resonance of nanoparticles depending on the optical properties. The substrate optical properties were modified by introducing different dielectric films between silver nanoparticle and silicon base substrates. The thickness of the films was varied over a large range (5-200 nm) to observe SERS enhancement because of nonradiative and radiative interactions of the plasmons and the substrate. Energy transfer between the plasmons and the polarization charges in Si was observed for a film thickness of less than 10 nm where SERS intensity followed the permittivity trend of the spacer film. As the spacer thickness increases beyond 40 nm, the effect of Si base substrate subsides and the enhancement/quenching of the SERS signals exhibit an oscillatory behavior with the thickness of the film. The extent of enhancement and quenching can be tuned by optical property of substrate and the excitation wavelength of choice.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry C
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to the American Chemical Society.
Keywords:	Dielectric films; Energy transfer; Optical properties; Plasmonics; Plasmons; Raman spectroscopy; Silver nanoparticles, Excitation wavelength; Localized plasmon resonance; Oscillatory behaviors; Plasmonic nanoparticle; Polarization charges; Radiative interactions; Surface enhanced Raman spectroscopy; Thickness of the film, Substrates
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry Division of Interdisciplinary Sciences > Computational and Data Sciences Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	08 Aug 2022 06:34
Last Modified:	08 Aug 2022 06:34
URI:	https://eprints.iisc.ac.in/id/eprint/75573

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