The basic properties of point defects, such as local geometries, positions of charge-transfer levels, and formation energies, were calculated using density-functional theory, both in the bulk and on the (110) surface of InP, InAs and InSb. Based upon these results the electronic properties of bulk and surface defects, defect segregation, and compensation were analysed. In comparing the relative stability of the surface and bulk defects, it was found that the native defects generally had higher formation energies in the bulk. From this it could be concluded that at equilibrium there was a considerably larger fraction of defects at the surface and under non-equilibrium conditions defects were expected to segregate to the surface, given sufficient time. In most cases the charge state of a defect changes upon segregation, altering the charge-carrier concentrations. The photo-thresholds were also calculated for the three semiconductors and were found to be in good agreement with experimental data.

Point Defects on the (110) Surfaces of InP, InAs and InSb - a Comparison with Bulk. A.Höglund, C.W.M.Castleton, M.Göthelid, B.Johansson, S.Mirbt: Physical Review B, 2006, 74[7], 075332 (10pp)