# Energetics of native point defects in GaN: a density-functional study

## TL;DR

This study uses advanced density-functional theory to accurately analyze native point defects in GaN, revealing their formation energies and charge transition levels, and clarifying their roles in doping behavior.

## Contribution

It provides a first-principles calculation of defect energetics in GaN with band edges aligned to hybrid functional results, improving upon previous semilocal methods.

## Key findings

- Nitrogen vacancy is the most stable defect in Ga-rich conditions but unlikely to cause autodoping.
- Gallium vacancy does not compensate n-type doping in GaN.
- Calculated defect formation energies differ significantly from previous semilocal results.

## Abstract

We study the formation energies of native point defects in GaN through density-functional theory. In our first-principles scheme, the band edges are positioned in accord with hybrid density functional calculations, thus yielding a band-gap in agreement with experiment. With respect to previous semilocal calculations, the calculated formation energies and charge transition levels are found to be significantly different in quantitative terms, while the overall qualitative trend remains similar. In Ga-rich conditions, the nitrogen vacancy corresponds to the most stable defect for all Fermi energies in the band gap, but its formation energy is too high to account for autodoping. Our calculations also indicate that the gallium vacancy does not play any compensating role in n-type GaN.