Density functional theories study on optoelectronic properties of arsenic-doped GaN nanowires

The electronic and optical properties of As-doped GaN nanowires have been investigated using density functional theory. The energy gaps of As-doped GaN nanowires with different concentrations exhibit indirect band gaps, and the band gaps are decreasing with the increasing doping concentration. The results predicate that alloys exhibit a typical semiconductivity. Moreover, the optical properties, including the complex dielectric function, optical refractive index, energy-loss function, reflectivity, and absorption coefficient are discussed for radiation up to 30 eV. With the increase of the As-fraction, the material gradually exhibits noticeable anisotropy in the photon energy range of 0-15 eV. Quickly increases the static dielectric constant and obviously red-shifts the absorption edge. The results are in good agreement with experimental data reported previously. Furthermore, the work gives a theoretical guidance for the preparation of As-doped GaN optoelectronic nanodevices.