Abstract： We use the multiple-scattering cluster method to calculate the sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) of S-passivated InP(100) surface. The physical origins of the resonances in the NEXAFS have been unveiled. It is shown that the most important resonance is attributed to the photoelectron scattering between the central sulfur and the nearest indium atoms. The studies show that two S-S dimers with the bond lengthes of 2.05Å and 3.05Å coexist in the surface, meanwhile the bridge and antibridge site adsorption of single S could not be ruled out. We support the scanning tunneling microscopy result that the S-passivated InP(100) surface exhibits significant disorder.
2003, Vol. 20 
