Rectifying behavior in twisted bilayer black phosphorus nanojunctions mediated through intrinsic anisotropy.

We explore the possibility of using van der Waals bonded heterostructures of stacked together 2D bilayer black phosphorus (BP) for nanoscale device applications. The electronic properties of BP in AA stacking and 90° twisted are studied with density functional theory. Furthermore, we study the homogeneous nanojunction architecture of BP to use its anisotropic properties. Using the first principles simulations along with the NEGF approach, we calculate the quantum transport properties of the nanojunction setup. The interlayer direction dependent current characteristics are explained in different setups. Our result revealed that the 90° twisted nanojunction device would be a potential rectifier despite having no p-n junction characteristics only due to the intrinsic anisotropy of the material, making tunneling between armchair- and zigzag-directional BP sheets asymmetric.