Effects of band gap opening on an n–p–n bilayer graphene junction

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 n–p–n 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 n–p–n junction by adjusting the thickness and height of the p-region. Increasing the band gap makes the control more sensitive to these adjustments.

Research highlights► We investigate the current flows through gapped bilayer-graphene n–p–n junction. ► Energy gap is opened by applying voltage across bilayer graphene. ► Increasing band gap leads the gate-control current to be of high sensitivity. ► It is applicable for gate-control field effect transistors (FET's).