393724.fig.004a
(a)
393724.fig.004b
(b)
393724.fig.004c
(c)
Figure 4: Graphene morphology upon acid etching. (a) and (b) Optical microscope images of graphene grown on (a) Cu foil with 1 min acid (TFB) treated and (b) 20 mins acid (TFB) treated Cu foil. (c) Raman spectra of dark and bright regions as indicated (inset: difference of spectra).