Electronic Structure Of Two Dimensional Transition Metal Dichalcogenides Van Der Waals Heterostructures

Heterostructures have been the basic elements of the modern semiconductor industry,and plays a key role in high speed electronic and optoelectronic devices.Heterostructures can not only improve the two dimensional layer of semiconductor material inherent defects,but also exhibit many novel features.In this paper,based on density functional theory to study the electronic structure of two dimensional transition metal dichalcogenides van der Waals heterostructures,focus on the impact of spin-orbit coupling on the electronic structure.The study provides theoretical guidance on the applications of transistors,optoelectronic devices,and spin filter devices,etc.Firstly,in the h-BN/Graphene,MoS₂/Graphene heterostructure,the linear bands around the Dirac point are preserved,a small band gap opened up at the K point,we find there is a n-type Schottky barrier heights is formed between semi-metallic Graphene and semiconducting h-BN.Considering the case of spin-orbit coupling,there is a strong spin splitting phenomenon and indicates p-doping.The h-BN/Black phosphorene heterostructure,showing n-type semiconductor properties,the semiconducting nature of monolayer h-BN and Black phosphorene are also preserved,there is no obvious spin splitting phenomenon with spin-orbit coupling.Secondly,all the XT₂/Black phosphorene?X = Mo,W;T = S,Se,Te?heterostructures exhibit the semiconducting characteristics,where both the band characters of XT₂ and Black phosphorene are preserved in the composed van der Waals heterostructures,the WSe₂/Black phosphorene van der Waals heterostructure demonstrates the type-I band alignment and the MoS₂/Black phosphorene,MoSe₂/Black phosphorene,MoTe₂/Black phosphorene,WS₂/Black phosphorene and WTe₂/Black phosphorene van der Waals heterostructures demonstrates the type-II band alignment,all of the heterostructures show the strong spin splitting phenomenon with spin-orbit coupling.Finally,for the MoX₂/WX₂?X = S,Se,Te?heterostructure,considering the case of spin-orbit coupling and electric field,the band gap and spin splitting of X-common MoX₂/WX₂?X = S,Se,Te?van der Waals heterostructures can be significantly modulated by electric field,but the electric field can't be modulates the spin splitting in X-mixing MoS₂/WSe₂ van der Waals heterostructure.