Studies On The Electronic Structures And Optical Properties Of The Heterostructures Based On Two-dimensional InSe

The discovery of graphene was a stone with its waves,opening the door of two-dimensional(2D)materials.Based on the scientific researches to date,these 2D materials shows excellent physical properties:high optical transparency,high carrier mobility and good electroconductibility.Recently,among the numerous modulations of regulating the perfomance of 2D materials,constructing heterostructures via stacking two different 2D materials has been a favorable approach.In this letter,based on the first-principles calculations,the electronic structures and optical properties of the indium selenide-based heterostructures are systematically studied:PtSe₂/InSe?SnSe₂/InSe and tellurene/InSe heterostructure.The main contents and results are as follows:Firstly,the calculations of the PtSe₂/InSe vd W heterostructures show that with diverse stacking configurations,PtSe₂/InSe vd W heterostructures are all stable and appear a typical type-I band alignment.In addition,the interlayer coupling can effectively regulate the banding energy and band gap values(range from 0.560 e V to 1.037 e V)of our understudy heterostructures.Moreover,with regard to the optical properties of PtSe₂/InSe vd W heterostructures,one can observe a high optical absorption strength with the order of magnitude of 10⁶and broad optical absorption from near infrared to ultraviolet light region,which much better than the optical performance of intrinsic PtSe₂and InSe monolayers.Secondly,the results of the SnSe₂/InSe vd W heterostructure indicate that the SnSe₂/InSe vd W heterostructures with the most stable stacking patterns presented a type II band alignment with non-ignorable orbital hybridization.In addition,by calculating the optical absorption coefficient of the corresponding monolayers and heterostructures,it is found that the optical characteristics of the heterojunction are obviously enhanced compared to that of intrinsic SnSe₂and InSe monolayers.The optical absorption coefficient can be up to 1.2×10⁶cm^-1and it can absorb a broad range from near-infrared to visible light region.Finally,for the tellurene/InSe vd W heterostructure,the results demonstrate that the heterostructure is stable and possesses a type I band arrangement with obvious orbital hybridization.In addition,the excellent optical properties of tellurene and InSe monolaters can be well retained and intergrated in the construction of tellurene/InSe vd W heterostructure.And its optical absorption coefficient is as high as0.8×10⁶cm^-1.Meanwhile,the near-infrared to ultraviolet light can be widely absorbed in this heterostructure.