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O: Oberflächenphysik

O 19: Teilchen und Cluster II

O 19.6: Vortrag

Dienstag, 9. März 2004, 12:30–12:45, H39

Luminescence from gold nanoparticles mediated by plasmon emission — •T. A. Klar¹, E. Dulkeith¹, T. Niedereichholz¹, J. Feldmann¹, G. von Plessen², D. I. Gittins³, S. Mayya³, and F. Caruso^3,4 — ¹Photonics and Optoelectronics Group, Department of Physics and CeNS, Ludwig-Maximilians-Universität München — ²1. Physikalisches Institut, RWTH Aachen — ³Max-Planck-Institut für Kolloid- und Grenzflächenforschung — ⁴Department of Chemical and Biomolecular Engineering, The University of Melbourne, Australia

We observe photoluminescence emission at the particle plasmon frequency from gold nanoparticles when the nanoparticles are excited above the d - sp interband transition threshold. Estimates of quantum yields for direct emission from d - sp interband recombination in bulk metals have given quantum efficiencies of 10⁻¹⁰ [1]. In contrast, here we observe a quantum efficiency of 10⁻⁶ , which is essentially independent of the particle size. This increased quantum efficiency is explained by a two step process: Instead of a direct emission of a photon, the d - sp band recombination excites a particle plasmon which in turn decays radiatively, emitting a photon.

[1] Mooradian, Phys. Rev. Lett. 5, 185 (1969)