THE ADSORPTION OF H2S ON INP(110) AND GAP(110)

The adsorption of H2S On the InP(110) and GaP(110) surfaces is studied with core-level soft X-ray photoelectron spectroscopy (SXPS) and angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) using synchrotron radiation and low energy electron diffraction (LEED). Similar effects are observed on both substrates. At dosages of the order of 5 langmuir every second spot in the clean 1 x 1 LEED pattern is extinguished. The sulphur 2p core level shows two components, a dominant, low-exposure component which scales with a satellite on the phosphorus 2p level and a lesser, high-exposure component that scales with a satellite on the indium 4d (gallium 3d) level. Possible adsorption geometries consistent with both the LEED pattern and the photoemission data are discussed.