Surface-enhanced Raman scattering studies of few-layer graphene on silver substrate with 514 nm excitation

Few-layer graphene was prepared by deoxidizing graphite oxide. Surface-enhanced Raman scattering (SERS) spectrum of graphene on Ag substrate was presented with 514 nm excitation. More than nine Raman lines are shown in the 100–3200 cm−1. The intensities of all lines are enhanced. Besides D mode at 1347 cm−1, G peak at 1581 cm−1, G∗ band at ∼2458 cm−1, and G′ band at ∼2691 cm−1, there are two features in low frequency area at about 239 cm−1 and 992 cm−1 separately, one line in high frequency area at about 2900 cm−1 with a shoulder appearing at ∼2860 cm−1. According to SERS, the structure of graphene was analyzed. Furthermore, the increase of D/G intensity ratio in SERS shows the SERS has much potential to be applied in controlling synthesis quality of graphene. In addition, low frequency Raman lines presented in SERS show application potential in analyzing the layer number, stacked style and edge of graphene.