AN X-RAY STANDING-WAVE STUDY OF H2S ADSORPTION ON INP(110)

The sulphur adsorption site for H2S-dosed InP(110) has been determined using normal-incidence x-ray standing waves (NIXSW) using the (220), (022) and (113) Bragg planes for triangulation. Photoabsorption was mo nitored by photoelectron emission from the S 1s, P 1s and In 3d(5/2) c ore levels. The sulphur was found to be located in the phosphorus site s of the continued-layer structure, bonding to the surface indium. Usi ng Auger electron emission for surface-sensitive NIXSW, it was found t hat H2S adsorption lifts the relaxation of the clean surface.