Theoretical study of the stabilization mechanisms of the different stable oxygen incorporated (10̄10) surface of III-nitrides

By using the first-principles calculation methods, the stable structures of oxygen incorporated (10̄10) surface of AlN and InN are explored in comparison with that of GaN. The one for AlN is found to be V _Al-(O_N)₃, a complex of Al vacancy and three substitutional O in N sites, while the one for InN is consistent with that of GaN, which is comprised by two monolayers of O replacing the N atoms, denoted by 2(_ON). The stabilization mechanisms of the two surface structures and the origin of the discrepancy between AlN and GaN are further given by analyzing their electronic structures.