Figure 4.

(a) Modulation of Fermi level with respect to gate biasing in single layer graphene. The inset shows a schematic of the band structure of pristine graphene with the presence of the Fermi level at the Dirac point (Reprinted from [31], with permission from Elsevier, 2010). (b) Refractive index and extinction coefficient for monolayer (red), bilayer (blue) and monolayer graphene with thermal oxide (black) (Republished with the permission of Royal Society of Chemistry, from [39]; permission conveyed through Copyright Clearance Center, Inc. (Danvers, MA, USA), 2015).