Nitrogen 1s core-level shifts at the NH3 saturated Si(100)-2 x 1 surface: a first-principles study

Using a first-principles approach, we investigate the effect of interdimer interactions on N Is core-level shifts at the NH3 saturated Si(100)-2 X 1 s urface. Fully relaxed model structures are generated in which -NH2 groups o n adjacent dimers in a row are located either on opposite ends (OE) or on t he same ends of the respective dimers. By comparing calculated core-level s hifts with measured photoemission spectra, we show that the OE configuratio n dominates, supporting the occurrence of an ordered coverage pattern. (C) 2001 Elsevier Science B.V. All rights reserved.