Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 11: C/diamond
HL 11.2: Vortrag
Montag, 25. Februar 2008, 11:15–11:30, EW 202
Optical properties and electronic structure of size- and shape-selected nanodiamonds — •Lasse Landt1, Kathrin Klünder1, Trevor Willey2, Tony van Buuren2, Jeremy Dahl3, Robert Carlson3, Thomas Möller1, and Christoph Bostedt1 — 1Technische Universität Berlin, Germany — 2Lawrence Livermore National Laboratory, USA — 3MolecularDiamond Technologies, USA
Diamondoids can be considered the smallest possible cage-like subunits that can be excised from diamond lattice closing the gap between large hydrocarbon molecules and nanodiamonds. Diamondoids are fully sp3-hybridized and show no surface reconstruction due to full hydrogen-passivation.
The optical and electronic properties of perfectly size- and structure-selected, neutral diamondoids ranging in size from 0.5 to 1 nm have been determined by means of PES, XAS, and optical absorption measurements. All data were taken from high purity samples in the gas phase revealing optical gap and band edges with near theoretical purity. We find that the optical properties of the perfectly size- and shape-selected nanocrystals exhibit strong shape dependence unlike band edges or ionization potentials which have also been determined. The observed isomeric dependencies of the optical gap will be discussed and first experimental data on the influence of targeted surface modification (e.g. thiols, alcohols) will be presented.