Effect of vacancy on the formation energy, density of state, electronic charge density and band structure of silicon FCC using DFT

Abstract

Study of defect have become basic in the calculation of properties of solids. Silicon crystal is one of the most industrially promising crystal and commercially profitable. Quantum espresso code whichuses plane wave and pseudo potential was used to optimize the structure and calculate the electronic properties of silicon face centered cubic. 40 Ry, and 10.4Ry were found to be the optimized parameters of the cut-off kinetic energy, k-point and lattice constant respectively. 3.02, 3.2 and 3.1 eV were respectively found to be the formation energy obtained using BLYP, PBE and LDA exchange functional. About 0.46 eV and 0.47 eV energy gaps was observed from the density of state and band structure respectively of defect-free silicon. Also uniform electronic charge density was observed.