III–N(110) surface relaxation and its dependence on the chemical bonding

Using existing and new results obtained from first-principles pseudopotential calculations, we have studied the atomic relaxation and its dependence on the chemical bonding, on III–N(110) surfaces. It is found that the characteristics of III–N(110) surfaces differ from other III–V(110) and II–VI(110) surfaces in two important aspects: a significantly reduced surface bond rotation, and a much lower binding energy of the highest occupied surface state. Furthermore the results obtained for AlN and InN corroborate our previously proposed model of a linear relationship between the vertical buckling of the top layer and the relaxed surface bond length not only for III–N, but also for III–V and II–VI semiconductors in general.