Absolute coverage of cesium on the Si(100)-2×1 surface

Abstract

${\mathrm{He}}^{+}$ Rutherford backscattering spectrometry has been applied to measure the absolute saturation coverage of Cs on the $\mathrm{Si}(100)\ensuremath{-}2\ifmmode\times\else\texttimes\fi{}1$ surface at room temperature. The measured Cs saturation coverage is $0.54\ifmmode\pm\else\textpm\fi{}0.02$ monolayers (ML) [1 ML is the density of surface atoms for bulk-terminated Si(100), or $6.78\ifmmode\times\else\texttimes\fi{}{10}^{14}{\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}/\mathrm{c}\mathrm{m}}^{2}].$ This result supports structural models requiring a Cs coverage of 0.5 ML and refutes several alternative models.