Seeking the Dirac cones in the MoS2/WSe2 van der Waals heterostructure

Ab initio calculations show that the bandgap of MoS2-WSe2 heterostructures can be significantly tuned by thickness engineering, perpendicular electric fields, and forming spin-valley coupling Dirac cones at the K and K' valleys. The intrinsic band structure of the MoS2-WSe2 heterobilayer is found to be a direct bandgap, in which the conduction band minimum is located at the MoS2 layer, but the valence band maximum lies in the WSe2 layer, forming a type-II band alignment, which can be changed easily into type-I band alignment by applying perpendicular electric fields. The special dispersion relation like the Dirac cone and each of these band alignments have particular applications in enabling different varieties of devices. Published by AIP Publishing.