الفهرس 
1.1. SiliconOnly 14 pages are availabe for public view
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Abstract
This thesis target is to apply the first-principle study on the electronic structure of crystalline solid materials face centered cubic (fcc) Diamond Silicon (Si), body centered cubic (bcc) Iron (Fe), fullerene 𝐶60 , pure graphene and doped graphene with Boron, Aluminum and Nitrogen, respectively.Our investigated results derived from First-principle calculations based on Density Functional Theory (DFT). The DFT calculations were implemented by Burai 1.3 graphical user interface (GUI) based on Quantum Espresso software.
The DOS profiles of these materials show that Fe is magnetic material while Si and 𝐶60are non-magnetic. The results on band structures further reveal that Fe is metallic and conductor while Si and 𝐶60 are semiconductors. Electronic structure results showed that the pure graphene has a linear dispersion at high symmetry K point and has zero band gap. By B, Al and N doping p-type and ntype are induced respectively in the sheet of graphene. The increasing of dopants atoms alters graphene from semimetal to semiconductor material. The maximum band gap appears when placed dopants in the same sub lattice of graphene due to effect of combined symmetry breaking of sub lattices and the band gap will be closed when dopants are placed at neighboring positions (alternate sublattice positions). The energy gaps were opened after B, Al, and N doping. The gap value of B-doped graphene,0.08 eV, Al- doped graphene 0.23 eV and N-doped graphene, 0.11 eV. Doping graphene with B, Al converts pure graphene to p-type semiconductor while doping graphene with N convert pure graphene to n-type semiconductor.
These results provide the possibility of using doped graphene in electronic devices such as replacements to Pt based catalysts in Polymer Electrolytic Fuel Cell (PEFC), electrochemistry, catalysis, sensors, biology, and optical device.