Density functional calculations were carried out to study the binding energies and

diffusion barriers for adatoms on GaN surfaces. The binding energies and diffusion

barriers were calculated for Ga and N adatoms on both Ga terminated and N

terminated (00•1) surfaces, subjected to a hydrostatic compressive and tensile

strain in the range of 0–5%. An understanding of the changes in adatom binding

and diffusion under differing growth conditions was obtained. For example, the

diffusion barrier of a Ga adatom was maximum for a 1% compressive strain and

decreases rapidly at higher strains whereas the diffusion barrier for a N adatom was

lowest at a 1% tensile strain and increases as the strain increases on a N terminated

surface. These changes can explain differences in optimal growth conditions on

bulk III-Nitride substrates as opposed to on III-Nitride template layers grown on

foreign substrates.

Density Functional Calculations of the Strain Effects on Binding Energies and

Adatom Diffusion on (0001) GaN Surfaces. J.R.Grandusky, V.Jindal, J.E.Raynolds S.Guha, F.Shahedipour-Sandvik: Materials Science and Engineering B, 2009,

158[1-3], 13-8