Research On The Electron Transport Characteristics Of Graphene Nanoribbons And Their Field Effect Tubes

Graphene nanoribbons such as a novel carbon-nanomaterials has some special performance due to its nanometer scale,and its electronic transport properties can be adjusted by controlling the geometry or doping.This means that graphene nanoribbons has important implications for research and production of the next generation of new nano-electronic devices.In this dissertation we study the electron transport properties of graphene nanoribbons and the electron transport properties of graphene nanoribbons field-effect transistors.Specifically divided into three pieces of content:(1)Based on density functional theory and non-equilibrium green function method.We studied the electron transport properties of graphene nanoribbons of different factors including chirality,width,boundary and electrostatic doping,we analyze the band structure,density of states,transmission spectrum and I-V cruve.As a conclusion we found that Zigzag grapheme nanoribbons(ZGNR)exhibit excellent metallic properties while Armchair grapheme nanoribbons(AGNR)show semiconductor characteristics.With the increase in width,ZGNR will exhibit more inhibition of current,AGNR will reflect larger conductive current.(2)The multi-scale simulation framework of nano-semiconductor devices is adopted.The Hamiltonian matrix of the system is extracted based on the density functional theory,and a tight-binding Hamiltonian matrix is constructed using the maximum localization method.We achieved the performance assessment of real nanoelectronic devices and analyzed the transport properties of graphene nanoribbon field-effect transistors of different factors,including different channel width and different saturation with different atoms.We found that in comparison of the width,different saturation will have more effect in controlling of transport properties of grapheme nanoribbon field-effect transistors.