Study On The Electronic Structure And Optical Properties Of A Two-dimensional Material With A Vertical Piled-up Heterostructure Based On First-principles

In modern materials science,low dimensional nanomaterials are widely used in integrated optical circuits,optoelectronic devices and surface plasmon polariton structures.Accurate optical parameters are necessary for designing this kind of device.The optical parameters of a typical twodimensional material are no longer isotropic,and they have different value in the plane and out-ofplane direction.And when different kinds of two-dimensional materials are stacked vertically together to form a heterostructure,optical properties of the two materials are no longer kept and optical parameters will change correspondingly.In response to this problem,based on the theoretical framework of the first principle,we applied the hybrid functional HSE06 functional of the density functional theory as the concrete means to calculate and analyze electronic structures of two-dimensional materials including graphene,six square boron nitride,molybdenum disulfide and the heterostructures formed by them,such as double vertical piling and sandwich-type heterostructures.The optical properties of these two-dimensional vertically stacked heterostructures are also calculated.For the heterostructure of graphene and six-square boron nitride,the changes of optical parameters caused by small changes in the electron structure of lattice perfect matching and lattice mismatch(two isomers in the formation of heterostructures are also discussed.In the second part of this paper,the anisotropic dielectric functions,absorption spectra,reflectance spectra,refraction spectra and electron energy loss spectra of two dimensional heterostructures are calculated.The feature points of optical parameters curves are explained in the view of electronic structures.The results and conclusions of this paper have some instructive significance for designing new two-dimensional materials and heterostructures and provide sufficient parameters for the design of integrated optical circuits and other excitation components based on two-dimensional materials and their heterostructures.