Temperature dependence of the phonon broadening of the Si 2<i>p</i>XPS line

Abstract

High-resolution silicon 2p photoemission measurements have been obtained using a recently designed state of the art high resolution monochromatized Al x-ray source with our enhanced multidetection system. The temperature dependence of the phonon broadening of the Si 2p XPS core lines has been investigated. Up to 470 K there is an increase in linewidth with temperature qualitatively consistent with phonon broadening. In the temperature range \ensuremath{\gtrsim}470 K there is a decrease in linewidth with increasing temperature possibly due to enhanced core hole screening. The electron-phonon coupling constant S for lightly doped Si was estimated to be in the order of 15 for the temperature region showing a phonon broadening, but the linewidth variation does not behave in a manner consistent with conventional theory. \textcopyright{} 1996 The American Physical Society.