Electronic and vibrational surface-enhanced Raman scattering: from atomically defined Au(111) and (100) to roughened Au.

ABSTRACT: In surface-enhanced Raman spectra, vibrational peaks are superimposed on a background continuum, which is known as one major experimental anomaly. This is problematic in assessing vibrational information especially in the low Raman-shift region below 200 cm^-1, where the background signals dominate. Herein, we present a rigorous comparison of normal Raman and surface-enhanced Raman spectra for atomically defined surfaces of Au(111) or Au(100) with and without molecular adsorbates. It is clearly shown that the origin of the background continuum is well explained by a local field enhancement of electronic Raman scattering in the conduction band of Au. In the low Raman-shift region, electronic Raman scattering gains additional intensity, probably due to a relaxation in the conservat

SUBMITTER: Inagaki M 

PROVIDER: S-EPMC8162194 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature