Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 73: Surface Dynamics: Reactions and Elementary Processes
O 73.6: Poster
Mittwoch, 9. März 2016, 18:15–20:30, Poster A
STM Tip-Induced Manipulation of Tetrahydrofuran and Diethyl Ether on Si(001) — •Tamam Bohamud1, Marcel Reutzel1, Gerson Mette1, Michael Dürr1,2, and Ulrich Höfer1 — 1Philipps-Universität, 35037 Marburg — 2Justus-Liebig Universität, 34392 Gießen
In the last decades, the adsorption of organic molecules on silicon surfaces has been subject of intense research. The resulting hybrid structures provide a promising tool to increase the functionality of semiconductor devices. In most cases, the respective adsorbate reactions are thermally induced; however, electronically induced processes may open additional reaction pathways and/or better control of single reaction channels. In this study, we investigate both lateral movement as well as chemical conversion of ether molecules on Si(001) induced by tunneling electrons from a STM tip.
The adsorption mechanism of ether molecules on Si(001) is well understood: At low temperature, a dative bond between the oxygen atom of the intact ether molecule and the Ddown state of the buckled silicon dimer is established. At room temperature, ether cleavage leads to covalent Si-O and Si-C bonds [ChemPhysChem 15, 3725 (2014), JPCC 119, 6018 (2015)]. For Diethyl Ether, a tip-induced hopping of a -C2H5 fragment is observed at positive sample bias. For Tetrahydrofuran, the tunneling electrons can induce the transition from the datively bonded intermediate state to the covalently bonded final state. In both cases, we observe a dependence on tunneling voltage and current which are discussed in terms of the underlying excitation mechanism.