ABSTRACT
Decades before the discovery of graphene, it was theoretically predicted that graphene will possess extremely high carrier mobility and an ambipolar field effect [1,2]. This prediction geared up the early experiments that wired mechanically exfoliated flakes by e-beam lithography [3,4]. After several experiments with these graphene samples, researchers firmly believe that graphene will be a wonder material for the next generation of semiconductor devices. The extraordinary electronic properties of graphene can be attributed to the extreme quality of its two-dimensional (2D) crystal lattice [5-7]. The extreme quality here corresponds to an unusually low defect density, which typically serve as the scattering centers that inhibit charge transport.
