Influence Of Au₂Cl₆ Doping On The Properties Of Graphene

Graphene has led to the upsurge of graphene research since its unique honeycomb-shaped two-dimensional planar structure when graphene has been discovered,.The unique crystal structure provides unique transport properties to the nearly massless carriers.Therefore,graphene is considered to be a good basic material for the future electronics industry in the polysilicon era.Graphene has great research value in the aspect of the basic research in quantum physics and condensed state physics.The method of doped graphene with the atoms or molecules to improves the properties to satisfies the application in sensors,transistors,etc.,has become a major means for improving the performance of graphene.Therefore,the adsorption of graphene by Au₂Cl₆ was studied in this paper.The main work is as follows:Firstly,the graphene and other related materials were introduced,then the structure,properties and several main preparation methods of graphene were introduced,and the application and modification of graphene and the research background of this article were discussed.Secondly,the development and basic ideas of the first principles were introduced.The theoretical basis of the first principles——density functional theory,was introduced in detail,and the CASTEP software package based on this theory and its application were introduced.Thirdly,the software’s parameter setting and using method were introduced.The models of bilayer graphene,Au₂Cl₆ doped bilayer graphene on the one side and at the interlayer were constructed and optimized and calculated.The optimized structure parameters,structure’s formation energy,work function and band structure were studied.The results showed that the work function was significantly improved and the forbidden band width was significantly increased when doping at the interlayer and doping on the one side,and the p-type graphene was successfully obtained.In addition,the p-type graphene obtained by the interlayer doping has better stability than the surface doping.Then,in order to study whether the conclusion obtained from Au₂Cl₆ doped bilayer graphene was applicable to multi-layer graphene,the same research on monolayer graphene was conducted in this paper.The results showed that the data obtained form the models of the single-side doped bilayer graphene and monolayer graphene were essentially in the same at all aspects.Therefore,we believe that the results are independent of the number of graphene layers and are only related to the doping position of the Au₂Cl₆ molecule.Finally,in order to clarify the charge transfer in the doped graphene structure,the charge density maps and the density of states of the structures were analyzed.The analysis results showed that there was no charge transfer between Au₂Cl₆ and graphene and only charge redistribution occurred.The interaction between them is van der Waals.The method of doping graphene with Au₂Cl₆ interlayer not only can improve the work function of graphene and open the bandgap of graphene,but also has outstanding stability.Considering the poor stability was a major problem that surface-doped p-type graphene faced in practical applications and this study showed that interlayer doping of Au₂Cl₆ on graphene was a promising preparation method for p-type graphene.