22 February

Fundamentals of surface-enhanced Raman scattering using molecular, one - and two- dimensional Raman probes

Thursday 22 February 2018, 03:00pm

ICN2 Seminar Hall, ICN2 Building, UAB

By Prof. Stephanie Reich, Fachbereich Physik, Freie Universitat Berlin, Berlin, Germany 

Short Abstract: Surface-enhanced Raman scattering (SERS) describes the giant enhancement of the Raman cross section close to a metal surface. SERS can detect single molecules by optical spectroscopy. Its variant, tip-enhanced scattering (TERS) increases the resolution of Raman imaging down to the molecular limit. Despite the wide-spread use of plasmon-enhanced Raman spectroscopy in imaging and materials characterization its fundamental principles remain debated. The dominant mechanism for SERS is thought to be plasmonic enhancement; the large Raman cross section is explained as an enhancement by the localized surface plasmons of metal nanoparticles.

I will present out research line on plasmon-enhanced Raman scattering in graphene, carbon nanotubes and organic molecules. The enhancement is induced by the plasmons of well-controlled lithographically prepared gold nanodimers. Our system allows to study the fundamental of SERS, its selection rules, and to quantify the plasmonic contribution to the Raman enhancement. We also present first results on hyperspectral tip-enhanced Raman scattering that maps out optical transitions in real space with nanoscale resolution