Classical simulations of the properties of group-III nitrides

We present interatomic pair potential parameters derived for the GalnAlN sy stem. Potentials are fitted to bulk material properties, such as lattice co nstants and elastic and dielectric constants, and are then employed to calc ulate Schottky and Frenkel defect energies in GaN, InN and AIN. Schottgy de fects are found to be lower in energy than Frenkel defects, suggesting that vacancies are more readily formed in the group-III nitrides. The formation energies of both Schottky and Frenkel defects in all the nitrides are foun d to depend on the size of the cation. Solution energies indicate that InN readily dissolves in both GaN and AIN, at least at low concentration.