Structural and electronic properties of MoS2, WS2, and WS2/MoS2 heterostructures encapsulated with hexagonal boron nitride monolayers

In this study, we investigate the structural and electronic properties of MoS2, WS2, and WS2/MoS2 structures encapsulated within hexagonal boron nitride (h-BN) monolayers with first-principles calculations based on density functional theory by using the recently developed non-local van der Waals density functional (rvv10). We find that the heterostructures are thermodynamically stable with the interlayer distance ranging from 3.425 Å to 3.625 Å implying van der Waals type interaction between the layers. Except for the WS2/h-BN heterostructure which exhibits direct band gap character with the value of 1.920 eV at the K point, all proposed heterostructures show indirect band gap behavior from the valence band maximum at the Γ point to the conduction band minimum at the K point with values varying from 0.907 eV to 1.710 eV. More importantly, it is found that h-BN is an excellent candidate for the protection of intrinsic properties of MoS2, WS2, and WS2/MoS2 structures. © 2017 Author(s)

Structural and electronic properties of MoS2, WS2, and WS2/MoS2 heterostructures encapsulated with hexagonal boron nitride monolayers

Yelgel, Celal/0000-0003-4164-477X; Gulseren, Oguz/0000-0002-7632-0954WOS: 000407742400034In this study, we investigate the structural and electronic properties of MoS2, WS2, and WS2/MoS2 structures encapsulated within hexagonal boron nitride (h-BN) monolayers with first-principles calculations based on density functional theory by using the recently developed non-local van der Waals density functional (rvv10). We find that the heterostructures are thermodynamically stable with the interlayer distance ranging from 3.425 angstrom to 3.625 angstrom implying van der Waals type interaction between the layers. Except for the WS2/h-BN heterostructure which exhibits direct band gap character with the value of 1.920 eV at the K point, all proposed heterostructures show indirect band gap behavior from the valence band maximum at the Gamma point to the conduction band minimum at the K point with values varying from 0.907 eV to 1.710 eV. More importantly, it is found that h-BN is an excellent candidate for the protection of intrinsic properties of MoS2, WS2, and WS2/MoS2 structures. Published by AIP Publishing.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [115F024]OG acknowledges the support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 115F024. the numerical calculations reported in this paper were fully performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources)