Optoelectronic properties of Mg doping GaN nanowires

Abstract

To investigate the influences of Mg doping and different doping sites on the electronic structures and optoelectronic properties of GaN nanowires, models of GaN, GaN(Mg)–Sur, GaN(Mg)–Sub and GaN(Mg)–Cor are built. Based on first-principles calculation, the formation energy, atomic structure, electronic structure, and optical properties of GaN nanowires are obtained. For the Mg doped nanowires, Mg atom is easier to substitute the Ga atom in the core of GaN nanowires, named as GaN(Mg)–Cor. Mg atom makes the lattice around the substituted atom distorted. In addition, the bandgap of Mg doped materials is smaller than the undoped, which results from the bandgap narrowing effect. After Mg impurity introducing, there turns up a new peak at 2.5 eV in the imaginary part of dielectric function curves, the absorption curves and the reflection curves. Besides, the other peaks of them shift to lower energy.