Quantitative analysis of the defects in CVD grown graphene by plasmon-enhanced Raman scattering

In this paper, a study of quantitative analysis of the defects in chemical vapor deposition (CVD) grown graphene through plasmon-enhanced Raman scattering has been performed. By designing and fabricating three-dimensional hybrid Au nano-particles/single-layer-graphene/Au nano-holes (Au NPs/SLG/ Au NHs) structures, the defects induced Raman scattering signals of SLG have been extremely enhanced. The light-graphene interaction between graphene and plasmonic nanostructures heightened the crosssection of the Raman scattering resulting in enhancing Raman signals. In the SERS spectra of graphene, the D band and D' band which associated with defects-induced double resonance (DR) Raman scattering processes have been clearly observed. A general and empirical formula has been applied to quantify graphene defects nano-crystallite (La) through the relation between the ratio of I-D/I-G and E-L(4). Additionally, an empirical formula for quantifying the defects based on the relation between I-D/I-G and E-L(4) was proposed. Besides, the Au NPs/SLG/Au NHs as a SERS substrate has been applied in detecting the fluorescein molecular under low concentration, and it exhibited good SERS performance. (C) 2020 Elsevier Ltd. All rights reserved.