Self-Referenced SERS Thermometry of Molecules on a Metallic Nanostructure
Sangwon Park, Gyu Jin Yeon, Hankyul Lee, Hyun-Hang Shin, Zee Hwan Kim
Abstract
The local temperatures of a metal nanostructure and its adsorbate carry essential information about the energy dissipation dynamics, calling for nanoscale thermometry techniques. Here we present a surface-enhanced Raman scattering (SERS) thermometry method providing an accurate local temperature of the adsorbates: we use the ratios of anti-Stokes (aS) and Stokes (S) SERS vibrational peaks at the limit of zero (0) probe laser intensity, extrapolated from the spectra acquired with varying laser intensities, as an internal reference of the spectrum–temperature correlation. This self-referencing removes most of the measurement bias and uncertainty created by the different electromagnetic enhancements in aS and S components of SERS spectra and enables reliable thermometry with an accuracy and a precision of <10 K. Using the method, we have quantified the photothermal heating of adsorbates on the surfaces of plasmon catalysts.