Effect Of Stacking Ways And Stacked Layers On The Electronic Properties Of Armchair Graphene Nanoribbons

Recently a new type of material come out, resounding whole world. It is an atomic monolayer composed of the honeycomb structure with sp2hybrid and the scientific community call it graphene. Impressively, it has many remarkable electronic properties, therefore scientists around the world make a great deal of researches from theory to application such as band structure, atomic impurite,topological lattic defects,localized states near edges, atomic absorptions, raman spectroscopy, transport properties and so on. In nanoelectronics, intriguing physical properties of graphene and its derivatives have a potential applicable value, for the low dimensional systems of physics provides a good opportunity. Using a tight-binding approximation, we investigate different stacking ways and different stacked layers on the electronic properties of armchair graphene nanoribbons in this thesis.There are five chapters in the thesis. The first chapter introduces the process of graphene derivatives discovery and particular physical properties of graphene. The second chapter presents the tight-binding approximation theory. The third chapter introduces different stacking ways and different stacked layers model of armchair graphene nanoribbons and associated energy dispersion are given. The fourth chapter analyses effect of different stacking ways and different stacked layers on the electronic properties of armchair graphene nanoribbons.The last chapter are conclusions and outlook.In section I, first we introduce the discovery of graphen derivatives, minutely introduce the peculiar property of physics, for instance unusual energy dispersion, anomalous quantum hall effect, landau level and so on. Then we present different geometric topology of layer armchair graphene nanoribbons. At last, we give each different stacking ways of few-layer graphene.In section II, we mainly present the theory about tight-binding approximation. Its basic starting point was that there is atomic-field existence near the atom, when the electronic movement nearby, we can try to treat the role of other atom-fields as perturbation action. Then we can get the relationship between the atomic energy level and the band gap of the crystal.In section III, we introduce different stacking ways and different stacked layers model of armchair graphene nanoribbons. Using a tight-binding approximation, we investigate analytical solutions of wave function of AA-stacked or AB-stacked bilayer armchair graphene nanoribbons and few-layer armchair graphene nanoribbons.In section IV, we analyse band structure of different geometric topology bilayer armchair graphene nanoribbons and few-layer armchair graphene nanoribbons and analytical solutions of wave function and associated energy dispersion are given. Through theoretical calculation, we found that geometric topology of bilayer armchair graphene nanoribbons is changed, and band structure and gap also changed accordingly; In addition, band structure changes regularly and gap index decreases with increase of armchair graphene nanoribbon (AGNRs) layers when AGNRs with width n is constant.Conclusions and outlook are given in chapter5.