Application Of Graphene And Related Nanostructures

In recent year, low dimensional nanostructures has become the focus ofnano science and technology and condensed matter physics. Graphene is arapidly rising star on the horizon of materials science and condensed-matterphysics. This strictly two-dimensional material exhibits extraordinaryelectrical properties,Properties of graphene can be tuned by clipping，absorbates, exert electronic field to achieve expected function inapplication.Using first principle and based on the density functional theory, weinvestigate features and actual application of graphene relatednanostructures. Our calculation shows that double vacancy could tuneelectrical properties of armchair graphene nanoribbons (AGNRs).Notable isthat oxygen could influence magnetic and electrical properties of graphenenanomesh. These results have important potential application in providingthe theoretical direction for the application of graphene in the electrionicdevices.First of all, we investigate the magnetic and electrical properties ofoxidation-passivated graphene nanomesh. All defects graphene change theelectronic structures of graphene, and the defects of different shape showinfluence on the graphene magnetic properties. Unlike hydrogen-passivatedresults, the oxygen-passivated graphene nanoholes can attain a lower energyconfiguration by adopting a nonplanar geometry and show different magneticproperties. As the defect size increase, the defects of oxygen passivationgraphene change from nonmagnetic materials to ferrimagnetic materials. Ourworkes suggests that oxygen atom could be used to manipulate the electronicstructures of graphene nanoholes and supply valuable theoretical guidancesfor graphene-based electronic device failure design.Then we introduce the effect of the double vacancy on the electronic properties of armchairgraphene nanoribbons (AGNRs).Results show that the system is the most stablewhen the vacancy is at edge site. It is found that all the divacancies defectsalways decrease the band gap of AGNRs，lead to varying electronic structures.As the increase of the width of the nanoribbons, the band gap becomevolatility weakened.