Strain and interfacial defect tailored electronic structures of two-dimensional WSe2/h-BN van der Waals heterostructure

Abstract

In this work, strain and interfacial defect tailored electronic structures of h-BN/WSe2 heterostructure are investigated systematically. The results show that the WSe2/h-BN heterostructure is a direct bandgap semiconductor (1.211[Formula: see text]eV) with type-I band alignment compared with the isolated h-BN and WSe2 monolayers. Applying the in-plane strain can well adjust the electronic structure of heterostructure, resulting in a transition from indirect to direct bandgap at the strain of −2% for the h-BN/WSe2 heterostructures. The bandgap of h-BN/WSe2 heterostructure monotonically increases at the compressive strains from −6% to −2%, whereas decreases at the tensile strains from 0% to 8%. In addition, introducing of vacancy defects and n- or p-type doping can effectively alter the band alignment of heterostructure. When the N and B vacancies or C doping are introduced in the h-BN layer, a significant transform from type-I to type-II band alignment is observed. These results suggest the h-BN/WSe2 heterostructure becomes a good candidate for the application of optoelectronics and nanoelectronics devices.