The Research Of Electronic Properties And Interface Properties Of Graphene-Based Heterojunctions

Graphene,a two-dimensional carbon atom monolayer,is a popular exotic material in the 21th century,which attracting worldwide attention due to its excellent charge transport,thermal,optical and mechanical properties.These properties originate from the dimensional effects and electronic modulation in their band structure.Graphene and its derivatives are being studied in many scientific and engineering fields.Recent efforts shows that graphene-based composites can have far-reaching effects on electronic and optoelectronic devices,chemical sensors,nanocomposites and energy storage.Meanwhile,the physical nature of graphene derivatives on germanium substrate and graphene-noble transition metal dichalcogenides is one of the interesting content in this field.The main content of this paper is list as following:(1)The graphene oxide/hydrogen passivated germanium-111 composite system is investigated.We mainly study the band structure,charge distribution of this system.The vdW-DF2 method is used to investigate the weak van der Waals interaction of graphene oxide and the substrate.The results give the electronic structure and the energy of the system and respective components,and show that the two-dimensional electron gas exists at the interface.(2)Graphene/noble transition metal dichalcogenides heterostructure are studied systematically.The band structure and charge distribution of graphene/PtS2 and graphene/PdS2 heterostructure are studied by first-principles method.In the meantime,we study the effect of interlayer orientation between two different 2D materials as a tuning parameter on the electronic properties of these bilayer heterostructures.The results show that graphene/noble transition metal dichalcogenides heterostructures are quasi-Ohmic contact against interlayer angle.