Transport Properties Of Hexagonal Boron Nitride Nanoribbons

The transport properties of hexagonal boron nitride nanoribbons under the uniaxial strain are investigated by the Green's function method. We have found that the transport properties of armchair boron nitride nanoribbon strongly depend on the strain. In particular, the features of the conductance steps such as position and width are significantly changed by strain. As a strong tensile strain is applied on nanoribbon, the highest conductance step disappears and subsequently a dip emerges instead. The energy band structure and local current density of armchair boron nitride nanoribbon under strain are calculated and analyzed in detail to explain these characteristic. In addition, the effect of strain on the conductance of zigzag boron nitride nanoribbon is weaker than that of armchair Boron Nitride nanoribbon.In addition, we also have investigated the transport properties of zigzag hexagonal Boron Nitride nanoribbons with triangle-shaped vacancy. It is found that the transport properties are sensitive to the size and position of vacancy but for the different kinds of atom in edges. When the vacancy is on the edges of the nanoribbons, a dip appears in the conductance steps around the Fermi energy. The density of states and local density of states of zigzag boron nitride nanoribbons with triangle-shaped vacancy are calculated and analyzed in detail to explain these characteristic. While the vacancy is in the center of the nanoribbons, the conductance steps around the Fermi energy are perfect. As the size of the vacancy on the edge is adding, the dip on the steps will widen even the steps will disappear. Meanwhile, the energy gap gets wider. When two triangle-shaped vacancies are on the edge of the nanoribbons, there are more dips appearing in the conductance steps. While two vacancies are in center of the nanoribbons, only little dip appears in the conductance steps. In sum, the effect of vacancy on the edge is more evident than that of vacancy in the center.