Charge transport in nnn and npn phosphorene junctions: The use of phosphorene pn junctions as rectifiers

Abstract

Abstract We investigate quantum charge transport of nnn and npn junctions based on two-dimensional black phosphorus (BP), phosphorene. We observe an oscillatory behavior for both the transmission probability and tunneling conductance of phosphorene nnn and npn junctions as a function of the chemical potential and width of the middle tunnel barrier. The oscillating amplitudes and periods can be controlled by means of a top gate voltage in the second segment. Because of the anisotropy of the electronic structure of phosphorene, the transmission probability depends strongly on the direction of the incident electron beam. We show that the perfect transmission can be selected by tuning the chemical potential and width of the middle region as well as the incidence angle of the carriers. In particular, for the n n n regime for the lightly doped case of the middle region, the transmission for any width of the middle region nearly becomes perfect. Under the certain conditions an electron is not allowed to tunnel through the junction that could be used as a single electron transistor. The resulting electronic properties show that the planar pn junctions (PNJs) structures based on phosphorene could be used as rectifiers, showing excellent tunability and novel functionalities. Our findings will open a new way to nanoelectronics based on field-effect tunneling transistors as well as the single electron transistors based on phosphorene heterostructures.