Effects of band Gap opening on an NPN bilayer grapheme junction

Abstract

The energy dispersion relations for the electrons and holes in bilayer graphene are parabolic in shape, i.e., they are non relativistic, and they touch at the K and K′ points. A (band) gap between the two relationships can be easily induced,which converts the bilayer graphene from being a zero-gap semiconductor into a gapped semiconductor. The changes in several of the transport properties of a bilayer graphene-based npn junction are simulated. It is seen that the presence of a band gap in the p-region leads the dependence of the transmission probabilities on the parameters of the junction to be different from those in the absence of the gap. It becomes possible to control the current flow in the npn junction by adjusting the thickness and height of the p-region. Increasing the band gap makes the control more sensitive to these adjustments.