Fig. 1. (a) Raman spectrum (473 nm laser source) of CVD graphene grown on a 50 nm Ni film supported by a SIO2/Si substrate. (b) Raman spectrum (532 nm laser source) of graphene islands on the SiO2/Si substrate after removal of the Ni film using etchant solution. The optical image of graphene islands on the SiO2/Si substrate is shown in the inset.
