  By considering the direction of charge carriers and the conservation of
probablity current the transmission properties of graphene Zener tunnelling
nano-devices were obtained. The scattering properties were then used with an
adaptation of the Landauer formalism to calculate an analytical expression for
current and conductance. The numerical results of the IV characteristics were
then briefly discussed for the graphene step and Zener barrier. A comparison
between the theoretical model and experimental results shows the similarities
of graphene nanoribbons and infinite sheet graphene.
