Figure 3. Comparison of graphene patterning through a synthetic sapphire mask without and with assistance of an inhomogenous vertical magnetic field in UV ozonation.

Optical topographical images of (a) the sapphire mask, and graphene patterned (b) without and (c) with assistance of the vertical magnetic field, respectively. Micro-Raman map of (d) the D band intensity crossing the edge of patterned graphene without magnetic assistance and (e) the corresponding Raman spectrum evolution for the dots outlined by the green rectangle in (d). (f) Micro-Raman map of the D band crossing the edge of patterned graphene with assistance of the vertical magnetic field and (g) the corresponding Raman spectrum evolution for the dots outlined in the green rectangle in (f). All scale bars are 100 μm.