Electronic Properties Of Periodic Bent Graphene

Nowadays,electronic devices are the basis of information technology.Miniaturization,integration and intelligence are the development direction of the electronic devices.Differently with Silicon and metal materials,graphene structure can keep its stability and electrical properties at nanoscale.Researches on graphene electronic properties are helpful to manufacture the emerging electronic devices,and regulate the performance of the devices,thus to satisfy people’s needs.Graphene is a zero-gap semiconductor.In many practical applications,it is critical that the band gap can be changed by controlling the electronic properties of graphene structures,enabling the application of graphene in nanoelectronic devices.In this thesis,the electronic properties of periodic bending graphene were studied by using density functional theory(DFT)on the basis of the projector-augmented wave(PAW)formalism.For both armchair and zigzag edges of graphene,we discussed periodic smooth bending and stepped bending graphene respectively.This paper is divided into five chapters.In chapter 1,we introduced the new material,graphene,which have drawn great attention in recent years.The research progress of graphene is also briefly described.In chapter 2,the various techniques are reviewed from the view point of theoretical respect,including three basic approximations in band theory,density functional theory,exchange-correlation function,pseudopotential method,and the Vienna Ab-inito Simulation Package(VASP).In chapter 3,we studied the energy bandgaps of the two kinds of periodic armchair’s edge bent graphenes: smooth-bent graphene and stepped graphene.In chapter 4,we studied the energy bandgaps of the two kinds of periodic zigzag’s edge bent graphenes.The finale chapter presents a brief summary of the thesis.