Regensburg 2007 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 60: Time-Resolved Spectroscopies

O 60.9: Vortrag

Donnerstag, 29. März 2007, 17:45–18:00, H42

Space-,Time- and Energy- resolved PEEM at deposited Clusters — •Martin Rohmer, Carsten Wiemann, Michael Bauer, and Martin Aeschlimann — Department of Physics, University of Kaiserslautern, Kaiserslautern, Germany D-67663

Photoemission electron microscopy (PEEM) is a common technique to map the lateral distribution of the photoemission yield from micro- and nanostructured samples with sub-micron spatial resolution. Energy-resolved PEEM combined with the time-resolved two-photon photoemission technique (TR 2PPE) enables us to probe at the same time the ultrafast dynamics of electron excitations at surfaces (Lifetime mapping).

In this presentation we show that this setup is capable to identify very small differences (1-3 fs) in the excited state lifetime of supported clusters as result of lateral variations in the coupling efficiency to the underlying HOPG substrate. The high sensitivity of time-resolved PEEM to these temporal inhomogenities is related to the parallel acquisition mode of this technique, which significantly reduces the resolution limiting influence of systematic error arising from temporal fluctuations in the experimental parameters.