First-Principles Calculation of the Epitaxial Growth of GaN(0001)

The epitaxial growth of GaN(0001) is studied microscopically using the first-principles calculation. Because of the unusual nitrogen kinetics on the truncated GaN(0001), we found that the most stable site for nitrogen adatoms is not the original wurtzite lattice site but the H3 site for the case in which there is one N adatom and also the case in which there is one N adatom and one Ga adatom on the (2 × 2)-Ga surface. In order to locate the N adatom at the original wurtzite site naturally, two Ga adatoms are needed for each N adatom on the (2 × 2)-Ga surface.