Ab-Initio Study of Structural and Electronic Properties of α-Ge Nanowires

alpha-Ge nanowires with seven different atomic configurations such as linear, zigzag, ladder, triangular, square, dumbbell and hexagonal have been studied by means of density functional theory (DFT) calculations. The calculations have been made in self consistent manner using generalized gradient approximation (GGA) exchange correlation with revised Perdew Burke and Ernzerhoff type parameterization. The energetic stability and electronic properties of these atomic configurations show a particular dependence on the shape of the nanowires. Ge nanowire in its ladder atomic configuration is found to be the most stable structure. The detailed investigation of electronic properties shows the semiconducting behavior of ladder and triangular atomic configuration whereas the rest other configurations are metallic. The ground state properties like lattice parameter, bulk modulus and pressure derivatives have also been analyzed for the Ge nanowires. The calculated bulk moduli of all the nanowires are higher than its bulk counterpart, shows hardening of material at lower dimensions.