A Type-II WSe2/BP heterostructure with adjustable electronic properties under external electric field and biaxial strain

Through first-principles calculations, we investigate in detail the structural, electronic, and optical properties of the stable two-dimensional WSe2/BP van der Waals heteroplasms. Firstly, the effects of different stacking angles and defects on the stability and photoelectric properties of heterostructures were verified. Then the results of band structure show that 0.78eV bandgap and Type-II band alignment are formed at the WSe2/BP vdW heterogeneous double-layer interface, which is conducive to the effective separation of photogenerated electrons and holes. The WSe2/BP heterostructure shows a wide absorption spectrum in the visible region. In addition, the WSe2/BP heterostructure change from Type-II to Type-I band alignment and then to Type-II band alignment under different electric fields. The transformation of semiconductors to metal can also be observed under stronger electric fields. Moreover, the bandgap is effectively adjusted by the biaxial strain. Therefore, these properties make the WSe2/BP heterostructure promising for future optical detection.