Manipulating the Bulk Band Structure of Artificially Constructed van der Waals Chalcogenide Heterostructures

The bulk band structures of a variety of artificially constructed van der Waals chalcogenide heterostructures IVTe/V₂VI₃ (IV: C, Si, Ge, Sn, Pb; V: As, Sb, Bi; VI: S, Se, Te) have been systematically examined using ab initio simulations based on density functional theory. The crystal structure and the electronic band structure of the heterostructures were found to strongly depend on the choice of elements as well as the presence of van der Waals corrections. Furthermore, it was found that the use of the modified Becke-Johnson local density approximation functional demonstrated that a Dirac cone is formed when tensile stress is applied to a GeTe/Sb₂Te₃ heterostructure, and the band gap can be controlled by tuning the stress. Based on these simulation results, a novel electrical switching device using a chalcogenide heterostructure is proposed.