A First-Principles Study Of The Combined Regulation Of Inserted Atoms,Defects Together With Hydrogenation On The Electronic Properties Of Graphene/Boron Nitride Heterojunctions

Hexagonal boron nitride(h-BN)monolayer is structurally similar to graphene,but the electronic properties of h-BN differ signifificantly from those of graphene.Encouragingly,their properties can be complementary.The heterostructure formed by graphene and h-BN monolayer can tailor the band structure of graphene,which is of great significance for realizing the electronic applications of graphene.In this paper,first-principles methods based on density functional theory are used to study the regulatory behavior of the electronic properties of Gra/BN heterojunction by hydrogen adsorption on the surface of the Gra/BN heterojunction double-layer and by the coexistence of interlayer insertion atoms and hydrogen adsorption.The regulation mechanism of hydrogen adsorption and interlayer insertion atoms on the properties of Gra/BN heterojunction are analysised.Studies have shown that Gra/BN heterojunction has similar properties to graphene and cannot be applied to electronic devices.After the same amount of hydrogen is adsorbed on the upper and lower surfaces,the band gap cannot be adjusted when the adsorption amount is small;When the amount of H adsorption increases,the band gap increases significantly,which shows that hydrogen adsorption has a better regulation on the electronic properties of Gra/BN heterojunction.After hydrogen adsorption,when Na atom is inserted between the Gra layer and BN layer,it is clear from the energy band and density of states diagram that the energy gap becomes 0 again,which suggests that the insertion of Na atom causes the Gra/BN double layers to change from semiconductor to metal.When Si and O are inserted between the layers,the band gap will increase,especially for O atom,the band gap will increase to 1.744 e V.It can be seen that the combination of hydrogen adsorption and interlayer atom insertion can adjust the band gap of the Gra/BN bilayer in a wide range.In addition,we also studied the regulation behavior of the simultaneous existence of B vacancy and hydrogenation on the electronic properties of the Gra/BN double-layer heterojunction.The study found the existence of B-vacancy and hydrogenation reduces the band gap of Gra/BN to 0.141 ev.Therefore,the existence of B-vacancies will lead to the transition of Gra/BN heterojunction from wild band gap semiconductor to narrow band gap semiconductor.It is concluded that hydrogen adsorption,interlayer atom insertion and defects lead to the change of Gra/BN band gap,which provides a new way for the application of graphene based two-dimensional materials.