Düsseldorf 2007 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 14: Molecular Clusters

MO 14.6: Vortrag

Montag, 19. März 2007, 17:45–18:00, 6D

Photoelectron spectroscopy of molecular diamonds — •Kathrin Klünder¹, Christoph Bostedt¹, Tobias Richter¹, Lasse Landt¹, Peter Zimmermann¹, Thomas Möller¹, Trevor Willey², Tony van Buuren², Jeremy Dahl³, SG Liu³, and Robert Carlson³ — ¹TU Berlin, Germany — ²LLNL, Livermore CA, USA — ³MolecularDiamond Technologies, Richmond CA, USA

Diamondoids are ideal molecular diamond clusters. They are perfectly size- and isomer-selected, neutral and hydrogen-terminated clusters in the diamond bulk lattice configuration. Diamondoids are a perfect system for investigating the electronic properties of semiconductor nanostructures in the molecular limit.

First x-ray absorption experiments of diamondoids showed no particle size dependence of the lowest unoccupied states which has been confirmed by quantum monte carlo simulations. In contrast to the unoccupied states, however, the calculations predict strong quantum size effects in the occupied states.

We have studied the highest molecular orbitals and core levels of a series of diamondoids by means of photoelectron spectroscopy. The experiments were performed at the beamline UE56/2 of the Bessy synchrotron source with a Scienta hemispherical photoelectron analyser. The valence band photoelectron spectra show a clear energy shift of the highest molecular orbitals to lower binding energies for increasing particle size. The results will be discussed and compared to recent theory.