Tunable electronic and optical properties of new two-dimensional Blue P/MoSe2 van der Waals heterostructures with the potential for photocatalysis applications

Strain modulation is one of the most popular tuning methods for the electronic properties of low-dimensional systems. In the present work, by using first principles study, strain engineering is used to module the band gap transition of two novel van der Waals (vdW) heterostructures based on two-dimensional (2D) Blue P (Blue Phosphorene) supported on MoSe2, producing Blue P-MoSe2 systems. The Blue P-MoSe2 vdW heterostructures could withstand 8% of the applied tensile strain. The electronic structure of the Blue P-MoSe2 vdW heterostructures could be changed effectively under the tensile force. The band gap changed from direct to indirect under the strain and could be tuned in the range of 0.075-1.284 eV. At approximately -4% of the applied strain, there was a transition of the valence band maximum (VBM). A wider range of light absorption could be obtained under the strain. Furthermore, MoSe2 acts as an electron-donating layer in the Blue P-MoSe2 vdW heterostructure, and the potential drop across the interface can generate a large built-in electric field across the interface; this electric field plays a crucial role in preventing the recombination of photogenerated charges. Our results provide a prospect for the future applications of two-dimensional materials in electronic and optoelectronic devices.