An investigation was made of the structural and electronic properties and formation
energies of vacancy, interstitial and antisite defects, as well as complex formation,
in wurtzite InN using first-principles calculations. The N interstitial, which formed
a split-interstitial configuration with an N2-like bonding, had the lowest formation
energy under N-rich conditions in p-type material, where it was a triple donor. It
was found that indium vacancies had a tendency to form clusters; which resulted in
local nitrogen-rich regions and the formation of Nx-molecular-like bonds. These
complexes were amphoteric, had a relatively high formation energy and formed
more readily under N-rich conditions. The nitrogen vacancy was a low-energy
defect under more In-rich conditions and, in p-type material, it acted as a single and
triple donor. In the neutral and negative charge states, it was found that nitrogen
vacancies also preferred to be situated close to one another and to cluster: giving
rise to local In-rich regions with electron localization at the metallic-like bonding
configurations. The indium antisite in the 4+ charge state was the lowest-energy
defect under In-rich conditions in p-type material and thus also acted as a donor.
Vacancies and Interstitials in Indium Nitride: Vacancy Clustering and Molecular
Bond-Like Formation from First Principles. X.M.Duan, C.Stampfl: Physical
Review B, 2009, 79[17], 174202