Surface-Enhanced Raman Scattering of Single- and Few-Layer Graphene by the Deposition of Gold Nanoparticles

• Published in: Chemistry : a European journal 2011-02, Vol.17 (8), p.2381-2387
• Main Authors: Lee, Jisook, Shim, Sangdeok, Kim, Bongsoo, Shin, Hyeon Suk
• Format: Article
• Language: English
• Subjects: Chemistry; Deposition; Glass substrates; Gold; Graphene; Nanoparticles; Raman scattering; Raman spectroscopy; Silicon dioxide; Silicon substrates; Spectra; surface chemistry
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201002027

Surface‐enhanced Raman scattering (SERS) of graphene on a SiO2(300 nm)/Si substrate was investigated by depositing Au nanoparticles using thermal evaporation. This provided a maximum enhancement of 120 times for single‐layer graphene at 633 nm excitation. SERS spectra and scan images of single‐layer and few‐layer graphene were acquired. Single‐layer graphene provides much larger SERS enhancement compared to few‐layer graphene, while in single‐layer graphene the enhancement of the G band was larger than that of the 2D band. Furthermore, the D bands were identified in the SERS spectra; these bands were not observed in a normal Raman spectrum without Au deposition. Appearance of the D band is ascribed to the considerable SERS enhancement and not to an Au deposition‐induced defect. Lastly, SERS enhancement of graphene on a transparent glass substrate was compared with that on the SiO2(300 nm)/Si substrate to exclude enhancement by multiple reflections between the Si substrate and deposited Au nanoparticles. The contribution of multiple reflections to total enhancement on the SiO2(300 nm)/Si substrate was 1.6 times out of average SERS enhancement factor, 71 times. Single or few? Surface‐enhanced Raman scattering (SERS) of single‐ and few‐layer graphene by the use of Au deposition was investigated. The enhancement factor for the G band in single‐layer graphene was higher than that in few‐layer graphene.