Intense fluorescence of Au20

Yu C, Harbich W, Sementa L, Ghiringhelli LM, Aprá E, Stener M, Fortunelli A, Brune H (2017)

Publication Type: Journal article

Publication year: 2017

Journal

Journal of Chemical Physics AIP Publishing

Book Volume: 147

Article Number: 074301

Journal Issue: 7

DOI: 10.1063/1.4996687

Abstract

Ligand-protected Au clusters are non-bleaching fluorescence markers in bio- and medical applications. Here we show that their fluorescence can be an intrinsic property of the Au cluster itself. We find a very intense and sharp fluorescence peak located at λ=739.2 nm (1.68 eV) for Au20 clusters in a Ne matrix held at 6 K. The fluorescence reflects the Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital (HOMO-LUMO) diabatic bandgap of the cluster. Au20 shows a very rich absorption fine structure reminiscent of well defined molecule-like quantum levels. These levels are resolved since Au20 has only one stable isomer (tetrahedral); therefore our sample is mono-disperse in cluster size and conformation. Density-functional theory (DFT) and time-dependent DFT calculations clarify the nature of optical absorption and predict both main absorption peaks and intrinsic fluorescence in fair agreement with experiment.

Authors with CRIS profile

Luca Ghiringhelli

Involved external institutions

École Polytechnique Fédérale de Lausanne (EPFL)

Switzerland (CH) Consiglio Nazionale delle Ricerche (CNR) / National Research Council of Italy

Italy (IT) Environmental Molecular Sciences Laboratory (EMSL)

United States (USA) (US) Università degli Studi di Trieste

Italy (IT) Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI)

Germany (DE)

How to cite

APA:

Yu, C., Harbich, W., Sementa, L., Ghiringhelli, L.M., Aprá, E., Stener, M.,... Brune, H. (2017). Intense fluorescence of Au20. Journal of Chemical Physics, 147(7). https://doi.org/10.1063/1.4996687

MLA:

Yu, Chongqi, et al. "Intense fluorescence of Au20." Journal of Chemical Physics 147.7 (2017).

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