Tunable electronic structure of black phosphorus/blue phosphorus van der Waals p-n heterostructure

First principles calculations are used to explore the structural and electronic properties of black phosphorus/blue phosphorus (black-p/blue-p) van der Waals (vdW) p-n heterostructure. An intrinsic type-II band alignment with a direct band gap at Gamma point is demonstrated. The spatial separation of the lowest energy electron-hole pairs can be realized and make black-p/blue-p heterostructure a good candidate for applications in optoelectronics. Black-p/blue-p heterostructure exhibits modulation of its band gap and band edges by applied perpendicular electric field (E-perpendicular to). This system undergoes a transition from semiconductor to metal when subjected to a strong external E-perpendicular to. The variation of band edges and quasi-Fermi level as a function of E-perpendicular to provides further insight to the linear variation of the band gap. Our calculation results pave the way for experimental research and indicate the great application potential of black-p/blue-p vdW heterostructure in future optoelectronics. (C) 2016 AIP Publishing LLC.