First-principles Investigation For The Transmition Characteristic Of Graphene Nanoribbons Affected By Deformation

The21st century is the period with rapid development of Electronic Science andTechnology. Moore’s Law predicted that the performance of electronic componentswill be enhanced to double every18months. With the size of electronic devicesgetting smaller and smaller, the devices size is close to the molecular scale, then thestudy of nano-scale electronic devices become more and more important. In1991,Professor Sumio Iijima in Japan’s NEC Laboratory found multi-layer carbonnanotube structure coaxial by high-resolution electron microscopy in the graphite arcdischarge product, commonly known as multi-walled carbon nanotubes, and it set offcarbon nano-materials boom. In the later several years, once a new nano materalstructure was synthetized, it became immediately a focal material in nano academiccircles. For the different nano materials, e.g., the nanotube, graphene, graphenenanoribbon and new nano structure graphyne, the experimental and theoreticalresearch results built a solid foundation of mechanisms in application of those nanoelectronic devices. In our research, we found that carbon-based materials not onlypossess strong mechanical properties, but also behave very excellent and uniqueelectrical properties. It was found that the nano materials with different chiralities orin different directions show different electron transport properties. Because of theirbrilliant transport characteristics, carbon-based nanomaterials will be very novel inthe design of elecreical devices. Graphene have been successfully fabricated in thelaboratory, which provides experimental support for the development ofnano-electronic materials. But the graphene and graphene nanoribbons can’t be a flattwo-dimensional structure in the process of preparation, so the graphene materialsunder strain or stress become the focus in the academic circle.In this article, we discusse the electrical properties under different strainsystematically in order to identify the variation of transport properties of graphenenanoribbons under different strains. The first chapter describes the present status ofcarbon nanomaterials and the purpose and significance of this study on strain for thetransport properties of graphene nanoribbons. The second chapter gives the basicmethods of molecular simulation and density functional theory. The third chapterstates the conductivity of the graphene nanoribbons with different chirality and widthrespectively. Chapter IV analyzes the transport properties of the Zigzag graphene nanoribbons under different strain load. The first principle combined with thenon-equilibrium Green’s function method is applied to calculate the transportproperties of graphene nanoribbons. The mechanism is given by analyzing the statesof density of the system. Chapter V analyzes the transport properties of the Zigzaggraphene nanoribbons under different strain load. The first principle combined withthe non-equilibrium Green’s function method is applied to calculate the transportproperties of graphene nanoribbons. The mechanism is given by analyzing the statesof density of the system. Finally, a summary of the work done above is made andsome conclusions are given.