Graphene has been an interesting material for scientists and engineers by
virtue of its remarkable properties. It has unique electronic properties with zero
bandgap at the Dirac point. The absence of bandgap in graphene limits its application
in electronics. The formation of graphene nanoribbons and substitutional doping of
graphene are the methods to manipulate the geometric and hence electronic structure of
graphene. Starting from the geometric and electronic properties of graphene, this
chapter involves a discussion on the geometric and electronic structure of graphene
nanoribbons and substitutionally doped graphene systems based on first principles
studies.
Keywords: Doping, Electronic properties, Graphene nanoribbons, Graphene.
