Investigations Of Electronic And Transport Properties Of Cutting And Doping Graphene Nanoribbons

Since entering the21st century, the study of nano-electronic devices has entereda new stage of development, with the discovery of graphene and successfulpreparation, graphene nanostructures in nano-electronic devices are considered to bepromising. It has important implications for silicon-based electronic devices beforethe performance and development, researchers believe graphene nanostructure is anideal material for the next generation of electronic devices, so graphenenanostructures has recently been one of the important research hotspot. Meanwhile,high-performance computing capabilities continue to improve now and continue toimprove the calculation method, so that we can take advantage of first-principleselectronic structure simulations of nanomaterials and studying various properties ofelectronic devices. Using first principles based on density functional theory andnonequilibrium Green’s functions,the paper systematically investigates the electronicstructure and transport properties of graphene nanoribbons defects and dopedstructures.By using nonequilibrium Green’s functions in combination with thedensity-functional theory. We investigate electronic transport properties of the edgecutting zigzag graphene nanoribbons. The models with both zigzag and armchair edgecan be got by edge cutting. The edge cutting graphene nanoribbons possess typicalsemiconductor properties due to the generated band gap. Furthermore, the model withshorter zigzag edge have wider band gap. The current of three models increasesrapidly when the bias voltage reaches the threshold voltage, which indicate its broadpotential applications in sensors and switching devices. In addition, the behavior isbest in M3structures in a appropriate bias voltage range. Hence, the resultsdemonstrate that edge cutting changed the transport properties of graphenenanoribbons.On the basis of cutting edge we doped other atoms on the cutting structure, andthus affect the transport properties of doped structure of crop, the structure isintroduced in the middle of the structure replace two carbon atoms were calculateddouble N substitution, double B substitution, as well as the structure of BN-dopedhybrid alternative electron transport properties and found that the electronic transportproperties of N-doped only limited changes occurred, and before doping compared current and voltage changes as the underlying trend. However, after double B atomdoping the transport properties has undergone great changes, compared with thecurrent trend of a lot of complexity, there are obvious than before the effects of thenegative differential conductance, by the bias continues to increase large, the currenttrend appears nonlinear oscillations, and finally when the BN doping calculated thatcurrent and voltage change is not very obvious, and not consistent with doping.We investigate electronic properties and magnetic properties of zigzag graphenenanoribbons doped by Mn atom. The calculation demonstrate that the band structureof doped graphene nanoribbons is very sensitive to changes in the location of themanganese doping, respectively, Mn-doped graphene nanoribbons, showedsemiconducting and metallic characteristics. Also the magnetic properties of ZGNRchanged. As the doping position is in the4th position, Mn-doped ZGNR showferromagnetic. This article provides a theoretical basis for the application of graphenenanoribbons in the electromagnetic field.