Regensburg 2004 – wissenschaftliches Programm
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O: Oberflächenphysik
O 45: Zeitaufgelöste Spektroskopie II
O 45.5: Vortrag
Freitag, 12. März 2004, 12:15–12:30, H39
Time-Resolved Laser-Synchrotron 2 Photon Photoemission — •Annette Pietzsch, Franz Hennies, Vijayalakshmi Sethuraman, Alexander Föhlisch, and Wilfried Wurth — Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
Time-resolved two-Photon Photoemission (2PPE) allows the investigation of unoccupied electronic states by populating them with a pump pulse and probing them with a delayed probe pulse. There, the intensity from a certain intermediate state is measured as a function of the variable delay time between the two pulses. Since optical lasers have a limited energy range, excitation with a laser pulse followed by subsequent probing of a synchrotron pulse offers the great advantage of being tunable in energy. This technique of time-resolved laser-synchrotron 2PPE has been performed in a proof-of-principle experiment at the MBI-Beamline at BESSY.
The ns-electron dynamics at the BaF2/Si(001) interface has been investigated revealing the relaxation time scale of silicon band bending at the interface. The excitation and decay processes of excited states in C60 films have been studied leading to an estimation of the life time of the laser excited states.
This project is funded by the DFG in the framework of the priority program "Dynamics of Electron Transfer Processes at Interfaces".