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

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.