Electronic structure simulation study of aluminum nitride and zinc oxide nanowires.

摘要

In this work, electronic structure simulation results of Aluminum Nitride (AlN) and Zinc Oxide (ZnO) nanowires are presented. These calculations were performed using a self-consistent first principles approach employing norm-conserving pseudopotentials. Regarding AlN nanowires, we were interested in the surface properties and effect of surface passivation on the electronic structure. ZnO nanowires with screw dislocations were recently found to be a new route to nanowire growth. Hence we were interested in the stability, growth and electronic structure properties of these wires with screw dislocations. The electronic structure properties of AlN nanowires were found to be heavily surface dependent. Passivation with hydrogen considerably opened up the gap. Passivating Al with N and H with F also opened up the gap and quantum confinement effects were observed. Cubic AlN nanowires were also investigated and it was found that [110] surface wires were energetically favored when compared to [100] surface wires. The gap again opens up on passivation with hydrogen. ZnO nanowires with screw dislocations were investigated and it was found that at the minimum Burgers vector length, the cost of surface creation is higher than the elastic energy and hence filled core wires are preferred over hollow core ones. The band gaps of ZnO wires shrink when a closed core dislocation is present.