Strain-Modulated Band Engineering in Two-Dimensional Black Phosphorus/MoS(2) van der Waals Heterojunction

[Image: see text] We investigate the band shift and band alignment of two-dimensional (2D) black phosphorus (BP)/MoS(2) van der Waals heterojunction (vdW HJ) via uniaxial strain in terms of first-principles calculations and atomic-bond-relaxation method. We find that the band gap of 2D BP/MoS(2) HJ decreases linearly with applied tensile strain and Mo–S bond breaks down at 10% tensile strain. Meanwhile, the band gap slightly increases and then monotonically decreases under compressive strain and there appears a semiconductor-to-metal transition at −11 and −12% strain in the y and x directions, respectively. Moreover, 2D BP/MoS(2) HJ maintains type-II band alignment for strain applied in the y direction whereas type-II/I band transition appears at −5% strain in the x direction. Moreover, we propose an analytical model to address the strain-modulated band engineering of 2D BP/MoS(2) vdW HJ at the atomic level. Our results suggest a promising way to explain the intrinsic mechanism of strain engineering and manipulate the electronic properties of 2D vdW HJs.