Characterization of graphene edge functionalization by grating enhanced Raman spectroscopy

Abstract

The edges of graphene, a two-dimensional carbon allotrope, are an emerging research area with wide applications in catalysis and electronics. To improve the metrology of functionalized graphene edges we propose localized surface plasmon polariton (LSPP)-enhanced Raman spectroscopy on a metallic grating substrate. We demonstrate a large enhancement of edge related Raman features at 1450 cm⁻¹ and 1530 cm⁻¹ which are associated with armchair and zigzag hydrogen-terminated graphene edges, respectively. The graphene edges act as good scatterers to excite LSPP on a noble metal surface while the periodic structures boost the total Raman peaks of the graphene layer. Specifically, the scattering enhancement on the graphene edges make the edge modes strong. Our results highlight the potential of LSPP-enhanced Raman spectroscopy as an efficient characterization tool for graphene edge functionalization.