Figure 1

Two-dimensional Raman intensity map for bilayer graphene. (a) I_2D/I_G ratio (ratio of 2D to G peak intensities). (b) I_2D (intensity of 2D peak). (c) I_G (intensity of G peak). (d), (e) and (f) show I_2D/I_G, I_2D and I_G, respectively, for a different area. BLG was grown by using CVD on 300-nm of evaporated Ni film under CH₄/Ar (23:200 sccm) at 1,000°C for 120 s. The total area of each view map is 200 μm × 200 μm.