Regensburg 2019 – wissenschaftliches Programm
O 15.1: Vortrag
Montag, 1. April 2019, 15:00–15:15, Kunsthalle
Photon-Induced Processes at the Bromobenzene/Cu(111) interface — •John Thomas1, Ishita Kemeny1,2, Cord Bertram1,3, Manuel Ligges1, Karina Morgenstern3, and Uwe Bovensiepen1 — 1Fakultät für Physik, Universität Duisburg-Essen — 2Stanford PULSE Institute, SLAC National Accelerator Laboratory — 3Lehrstuhl für Physikalische Chemie I, Ruhr-Universität Bochum
Bromine-substituted organic molecules are extensively used as precursors in on-surface synthesis where the molecules are activated through thermal dissociation. Hence, these synthesis processes are limited by the desorption temperature of the molecules of interest. If the desorption temperature is in the range of the dissociation temperature, photoinduced dissociation is an attractive alternative to activate these precursors. We present a systematic study of photo-induced processes in bromobenzene on Cu(111) from sub-monolayer to multilayer coverages and address structure and dissociation dynamics. Scanning tunneling microscopy delivers structural information in the regime below 0.5 monolayers where the molecules adsorb parallel to the surface. We observe the decomposition of molecular clusters and dissociation of molecules under ultraviolet photon irradiation at temperatures below 11 K. Using two-photon photoemission spectroscopy we monitor the activation of molecules through the work function change upon photo excitation and identify coverage-dependent electron attachment and dissociation processes.
This work is supported by the DFG through the cluster of Excellence RESOLV (EXC 2033).