| AVS 54th International Symposium | |
| Surface Science | Friday Sessions |
| Session SS1-FrM |
| Session: | Surface Dynamics |
| Presenter: | M. Zharnikov, Universität Heidelberg, Germany |
| Authors: | M. Zharnikov, Universität Heidelberg, Germany S. Neppl, Technische Universität München, Germany A. Shaporenko, Universität Heidelberg, Germany U. Bauer, Technische Universität München, Germany D. Menzel, Technische Universität München, Germany P. Kao, Pennsylvania State University D. Allara, Pennsylvania State University P. Feulner, Technische Universität München, Germany |
| Correspondent: | Click to Email |
Whereas static conductance of molecules arranged in self-assembled monolayers (SAMs) has been extensively studied, less is known about the dynamics of the charge transfer in these systems. We show that the latter phenomena can be successfully addressed by resonant Auger electron spectroscopy, using the core hole clock (CHC) method. For the test system, nitrile-substituted alkanethiolate SAMs, we obtained clear, quantitative results on the characteristic transfer time of the resonantly excited electron along the molecular chain to the conductive substrate in good agreement with theory. As compared to previous studies, the charge transfer pathway in our experiment was unambiguously defined by resonant excitation of the nitrile tailgroup attached to the alkyl backbone. This particular tailgroup occurs to be a good candidate for such studies because of a suitable core hole lifetime (CLT) and the large contrast between resonant and non-resonant core decay spectra. The approach, used by us, avoids any contact and reproducibility problems and, by selection of suitable ligands with appropriate values of CLT and resonance position, spans a wide dynamic range. Extension to other functional groups is possible and promises to become a very valuable new source of information on charge dynamics in layers important for molecular electronics.