Regensburg 2007 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 39: Nanostructures at Surfaces IV (Dots, Particles, Clusters, Arrays)

O 39.3: Vortrag

Mittwoch, 28. März 2007, 16:15–16:30, H36

Shaping of Triangular Gold Nanoparticles in Periodic Arrays by Nanosecond Laser Pulses — •Rodica Morarescu, Frank Hubenthal, and Frank Träger — Institut für Physik and Center for Interdisciplinary Nanostructure Science and Technology - CINSaT, Universität Kassel, Heinrich-Plett-Sraße 40, D-34132, Germany

In this contribution we present recent results on selective and precise tailoring of triangular gold nanoparticles using ns-pulsed laser light. The reshaping has been investigated as a function of laser fluence and wavelength. In brief, monolayers of triangular gold nanoparticles in a periodic array were prepared by nanosphere lithography. For this purpose, gold atoms were deposited through the nanosphere mask. Subsequently, the mask was removed by sonicating the sample in a solvent, leaving behind periodic arrays of triangular gold nanoparticles.The particles have been reshaped using ns-pulsed laser light with different fluences and wavelengths. The morphological and the accompanying optical changes were investigated by scanning force microscopy and extinction spectroscopy. We demonstrate that laser irradiation is an ideal tool to precisely control the shape of the metal nanoparticles and thus, their optical properties. For example, the position of the surface plasmon resonance of the particles as prepared can be tuned from 732 nm to 532 nm,depending on the applied fluence. The main advantage of laser irradiation in comparisons to, e.g., thermal annealing is that nanoparticles in a well-defined area of the sample can be addressed. Possible applications of such laser tailored nanoparticles, e.g. as anchor points for functional molecular wires, will be discussed.