Computational Studies of Bismuth-Doped Zinc Oxide Nanowires

Abstract

A computational modeling methodology is described, which is based on the total-energy and defect calculations using the density and hybrid functionals in combination with the supercell approach. This methodology is employed to study the structure and energetics of zinc oxide (ZnO) nanowires, and the electrical properties of a bismuth-doped zinc oxide (ZnO: Bi) nanowire. A simple model is developed, where the nanowire formation energy is expressed as a function of the nanowire diameter and cross-sectional morphology (hexagonal or triangular). Defect calculations are employed to characterize the ZnO: Bi nanowire, in regard to the location and charge-state of the dopant. The latter indicates that the dopant atoms are mostly substituted into the Zn sites on the nanowire surface, and therefore Bi in ZnO electrically acts as a donor.