A. Filippetti et al., Anomalous relaxations and chemical trends at III-V semiconductor nitride nonpolar surfaces, PHYS REV B, 59(12), 1999, pp. 8026-8031
Relaxations at nonpolar surfaces of semiconductor III-V compounds result fr
om a competition between dehybridization and charge transfer. First-princip
les calculations for the (110) and (10 (1) over bar 0) faces of zinc-blende
and wurtzite AlN, GaN, and InN reveal an anomalous behavior as compared wi
th ordinary III-V semiconductors. Additional calculations for GaAs and ZnO
suggest close analogies with the latter. We interpret our results in terms
of the larger ionicity (charge asymmetry) and bonding strength (cohesive en
ergy) in the nitrides with respect to other III-V compounds, both essential
ly due to the strong valence potential and absence of p core states in the
lighter anion. The same interpretation applies to Zn IT-VI compounds. [S016
5-1829(99)00211-8].