Electronic And Optical Properties Of Graphene Based Hybrid-nano-structures: First-principles Study

Graphene nanoribbons based hybrid-nanostructures have been attractting a lot ofscientific interests in the field of graphene based nanostructure owing to their uniqueelectronic properties and potential applications in nanoelectronics. In this thesis, westudy the electronic transport properties of graphene/graphane hybrid nanoribbonsusing the first-principles non-equilibrium Green’s function methods. Moreover, theoptical properties of graphene/boron nitride superlattices are systematically studied byusing density functional theory based first-principles calculations.(1) We study the electronic transport properties of hybrid graphene/graphanenanoribbons. The electronic transport properties of hybrid graphene/graphanenanoribbons is highly improved due to the appearance of transport platform withnontrivial conductance around the Fermi level. This enhancement attributes to theextra bands induced by the substituted graphane nanoribbons. Moreover, thisenhancement is also sensitive to the position and concentration of the substitutedgraphane nanoribbons in the hybrid system. Our results indicate that such hybridsystem is an effective approach to modulate the transport properties of zigzaggraphene nanoribbons.(2) We study the optical properties of graphene/boron nitride superlattices. Ourresults show that the band gap of graphene/boron nitride superlattices is sensitive toits width and constitution. We find that the optical properties of graphene/boronnitride superlattices show optical anisotropic characteristics, and such opticalanisotropy is also dependent on the widths and detail atomic structures ofgraphene/boron nitride superlattices. It is hoped that this intrinsic optical anisotropyfeature in graphene/boron nitride superlattices can be used to produce ellipsoidpolarized light in the optoelectronic nanodevices in the future.