Rectifying behavior of graphene/h-boron-nitride heterostructure

The rectifying behavior of a simple graphene/boron-nitride heterostructure between two semi-infinite electrodes is investigated by using the non-equilibrium Green's function method. Also a simple analytical model is used to explain the current-voltage characteristic of a typical heterostructure. The Hamiltonian of nanostructure is written in the tight-binding model and the interaction of heterostructure with left and right leads is studied in the wide-band approximation. The current-voltage curve of graphene/boron-nitride shows an asymmetric behavior and negative-differential-resistance in the positive bias voltage which is explained in the simple model. By increasing the ribbon width, current increases and the peak-to-valley current ratio decreases. All the G/h-BN shows a large rectification ratio in a certain voltage region. The rectification behavior in the hetero-junction is related to the barrier potential at the interface of two structures.