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 m-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. (C) 2000 Elsevier Science Ltd. All rights reserved.