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