Strain induced piezoelectric effect in black phosphorus and MoS 2 van der Waals heterostructure

Abstract

The structural, electronic, transport and optical properties of black phosphorus/MoS 2 (BP/MoS 2) van der Waals (vdw) heterostructure are investigated by using first principles calculations. The band gap of BP/MoS 2 bilayer decreases with the applied normal compressive strain and a semiconductor-to-metal transition is observed when the applied strain is more than 0.85 Å. BP/MoS 2 bilayer also exhibits modulation of its carrier effective mass and carrier concentration by the applied compressive strain, suggesting that mobility engineering and good piezoelectric effect can be realized in BP/MoS 2 heterostructure. Because the type-II band alignment can facilitate the separation of photo-excited electrons and holes, and it can benefit from the great absorption coefficient in ultra-violet region, the BP/MoS 2 shows great potential to be a very efficient ultra-violet photodetector.