Mazher, Javed(Prof)Sinu, Melese2022-04-072023-11-182022-04-072023-11-182013-03http://etd.aau.edu.et/handle/12345678/31204Two dimensional structures like graphene nanostructures exhibit vanous phys ical properties on in-plane anchoring of fun ctional groups. We have investi gated the electronic band structure, the density of states (DOS), and the current-voltage (I-V) characteri stics of pri stine and armchair nanoribbons (AGNRs) functionali zed with aromatic ring (C6) by first- princi ples calculations with the help of ab-initio DFT code. A C6 ring structure is in-plane anchored to the nano-ribbon to maximize the effects of functionali zation on the properties of the nanostructures of various widths. Samples are theoretically modeled, both in the periodic and open system nano-device configurations, by using arm-chair nanoribbons of different widths with and without ring attachments. Subsequently, the as-prepared nano-devices are simulated and their I-V characteri stics are studied. The resul ts of these simulations are analysed by using the charge transfer, which takes place during the final self consistent calculation routines amongst the C-ring and its ribbons. We found a significant amount of change in the electro nic density of states of the semiconducting ribbons due to the presence of C6-rings. Also, we have demonstrated that the C-ring attachment can be effective ly used to tailor the energy bandgaps of the semiconducting ribbons. In addition to this we have also showed the nano-device feasibility of such ring functionalized ribbons. The property of bandgap dependence on aromatic ring is also studied. Finally the prospects of functionalized nanostruclllres of graphene are also discussed in this thesis, especially, the electronic and transport properties of armchair ribbons are di scussed with respect to ring functionalizations.enEffects of Aromatic RingThesis