Modification of alkaneselenolate monolayers by low-energy electrons

The effect of low-energy (50 eV) electron irradiation on alkaneselenolate (AS) self-assembled monolayers (SAMs) was studied by synchrotron-based X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. As a test system, SAMs of dodecaneselenolate (C12Se) were used, and an analogous dodecanethiolate (C12S) SAM was taken as a reference. Both the alkyl matrix and headgroup-substrate interface in AS SAMs were found to be affected by a variety of closely interrelated irradiation-induced processes, which mostly follow a pseudo first-order kinetics and level off at high irradiation doses. The crosssections of the most prominent processes were obtained and found to be in a range of 2-3 × 10^-16 cm ². The values are very close to the parameters for analogous alkanethiolate (AT) SAMs, which exhibit similar behavior upon exposure to low-energy electron irradiation. At the same time, the saturation values of the fingerprint parameters for some irradiation-induced processes in AS SAMs appeared to be slightly smaller than the values for analogous AT films. This is explained by a stronger headgroup-substrate bond in the case of selenium.