Electronic Properties of Graphene and Graphene Nanoribbons

Monolayer graphene has a conical energy dispersion relation and a high Fermi velocity (10^8cm/s). Its perfect two-dimensional (2D) structure allows the possibility of planar lithography and lateral band engineering. Because of these properties graphene holds a great potential in electronic devices. The electronic and transport properties of graphene and graphene nanoribbons (GNR) have ignited a lot of interests since its experimental realization in 2004 by Novoselov et al. In this work, we calculated the band structures of graphene and graphene nanoribbons using the tight binding technique. For graphene nanoribbons with complicated structures, the band structures were evaluated numerically. We also calculated the carrier distribution in graphene and nanoribbons as a function of temperature and Fermi level. Quantum capacitance was derived and discussed due to its importance in nanoelectronics. Last, we applied non-equilibrium Green's function (NEGF) formalism to evaluate transport degradation due to the edge roughness in short nanoribbons.