Passivation of InP 001/by sulfur

We present first-principles total-energy calculations of the InP 001.:S surface. Equilibrium atomic geometries and energies for In- and P-terminated surfaces, with different degrees of sulfur coverage were determined. We find that all P-terminated substrate surfaces are less stable than the In-terminated substrate surfaces. Therefore we conclude that structures with P–S bonds at the surface are less stable than those with In–S bonds. The most stable structure consists of a In-terminated surface covered with a full monolayer of sulfur, with another half a monolayer of sulfur incorporated into the second P substrate layer, in agreement with some recent experimental evidence. We also present an analysis of surface band characters. q1999 Elsevier Science B.V. All rights reserved.