Optoelectronic properties exploration of native point defects on GaN nanowires

Abstract

The formation energy, band structure and absorption features of perfect and p-type doped GaN nanowires with various point defect types (vacancy, interstitial and substitutional defects) at different positions (core, subsurface and surface) were calculated based on the first-principles calculations. The results show that NGa substitutional defects are the surface defects with the lowest formation energy in GaN nanowires. The nanowires with defects generate new impurity levels in the band structure. The emergence of NGa has turned p-type doped GaN nanowires into indirect bandgap semiconductors. At the peak of the ultraviolet absorption spectrum, all types of defects could damage the absorption characteristics of the nanowires.