Characterization of X-ray induced damage in alkanethiolate monolayers by high-resolution photoelectron spectroscopy

Synchrotron-based high-resolution X-ray. photoelectron spectroscopy was for the first time applied to investigate the damage in self-assembled monolay ers (SAMs) of alkanethiols (AT) on Au caused by soft X-rays. The observed c hanges in AT SAMs and, in particular, the appearance of a new, irradiation- induced sulfur species are identical to those caused by electron bombardmen t, implying that most of the damage is produced by the photoelectrons and s econdary electrons. The irradiation-induced sulfur species is identified as a dialkyl sulfide distributed within the AT film. Only minutes of monochro matized X-ray irradiation at an undulator beamline destroys the AT adlayer completely.