Surface enhanced Raman spectroscopy using 2D plasmons of InN nanostructures

TL;DR

This study demonstrates that InN nanostructures with surface electron accumulation exhibit significant surface-enhanced Raman scattering due to 2D plasmons, offering a new plasmonic platform for SERS applications.

Contribution

It reveals that 2D plasmons in InN nanostructures, driven by surface electron accumulation, are responsible for SERS enhancement, distinct from traditional 3D plasmon effects.

Findings

SERS enhancement factor of four orders observed.

Low wave number Raman peak linked to 2D plasmon excitation.

Near-field studies confirm 2D plasmon role in enhancement.

Abstract

We explored the surface enhanced Raman scattering (SERS) activity of the InN nanostructures, possessing surface electron accumulation (SEA), using the Rhodamine 6G (R6G) molecules. SERS enhancement is observed for the InN nanostructures which possess surface electron accumulation (SEA). In case of high temperature grown InN samples, a peak is observed in the low wave number (THz region) of Raman spectra of InN nanostructures originating from excitation of the two dimensional (2D) plasmons of the SEA. The enhancement factor of four orders was calculated with the assumption of monolayer coverage of analyte molecule. SERS enhancement of InN nanostructures is attributed to the 2D plasmonic nature of InN nanostructures invoking SEA, rather than the contributions from 3D surface plasmon resonance (SPR) and chemical interaction. The role of 2D plasmon excitation in SERS enhancement is corroborated by the near-field light-matter interaction studies using near-field scanning optical microscopy.