Tunable Schottky barrier in planar two-dimensional metal/black phosphorus heterojunctions

Abstract Edge contact between two-dimensional materials and metal can achieve small contact resistance because of strong interaction. In this work, we study the electronic properties of in-plane black phosphorus (BP) based heterojunctions with graphene (Gra) and boropheneβ 12 (Boroβ12 ) electrodes using first principle calculations. The small Schottky barrier along zigzag direction of BP is shown in Gra/BP/Gra and Boroβ 12/BP/Boroβ12 heterojunctions because of the anisotropy of BP. The applied strain can modulate both the electron barrier and the hole barrier for armchair BP based heterojunction. In addition, we find that electric field not only can modulate the height of the Schottky barrier effectively but also the type of Schottky contact of Gra/BP/Gra and Boroβ12/BP/Boroβ12 structures. The results suggest a promising way to design tunable Schottky diodes based on Gra/BP/Gra and Boroβ12/BP/Boroβ12 heterojunctions through modulating the electric field.