Kumar, Jitendra2020-08-042023-10-262020-08-042023-10-262019ROLL NO.10615302https://gyan.iitg.ac.in/handle/123456789/1471Supervisors: Harshal B. Nemade and Pravat K. GiriTwo-dimensional materials are being widely investigated for the development of futuristic electronic devices and creating new opportunities in electronic industries. Graphene having a hexagonal honeycomb planar structure of sp2-hybridized carbon atoms has shown extraordinary electronic, mechanical and thermal properties and is considered as a potential material for use in future electronic devices. Several computational methodologies using first principles methods are providing results close to the experimental observations. Complex quantum mechanical calculations are successful in computing equilibrium in interacting materials, optical spectra, energies, electronic properties, and catalytic properties of atoms, molecules and atomic/molecular systems.This thesis mainly focuses on the research work carried out using density functional theory (DFT) based modelling to analyze electronic properties of graphene doped with 4d-transition metal atoms, interaction of niobium-doped graphene with small molecules, spin transport properties of niobium-doped AGNR, interaction of graphene with niobium and niobium compounds, and graphene-heptahelicene interface. DMoL3 code is employed to investigate single and double vacancy graphene doped with 4d-transition metal atoms and calculate their binding energies, band structures, magnetic properties, the density of states (DOS), atom projected density of states (PDOS), and charge transfer.enNANOTECHNOLOGYThesis