naa a22 4500 510816223 CHVBK 20180411083508.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11468-013-9536-8 doi (NATIONALLICENCE)springer-10.1007/s11468-013-9536-8 Hubenthal Frank Institut für Physik and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), Universität Kassel, Kassel, Germany aut Increased Damping of Plasmon Resonances in Gold Nanoparticles Due to Broadening of the Band Structure [Elektronische Daten] [Frank Hubenthal] For the first time, systematic investigations of the damping parameterA of gold nanoparticles as a function of photon energy are presented. A is an essential parameter that quantifies the size-dependent optical properties of metal nanoparticles in the dielectric function. To determine the damping parameter, the dephasing time T 2 of gold nanoparticles has been systematically determined under ultrahigh vacuum conditions as a function of photon energy. Dephasing times ranging from $T_2 = 5$ fs to $T_2 = 17$ fs were measured, and subsequently, the damping parameter has been extracted. We found a strong resonance-like damping of the plasmon resonance in the vicinity of the onset of the interband transition. While the damping parameter scatters statistically around a value of $A = 0.19$ nm/fs for photon energies below $h\nu = 1.70$ eV, it increases rapidly to 0.32 nm/fs for $h\nu = 1.85$ eV. For higher photon energies, A decreases steadily to $A = 0.24$ nm/fs at $h\nu = 2.15$ eV. A comparison to former measurements as well as to theoretical predictions reveals surface scattering and a discretizing and broadening of the band structure that influences the interband transition as the most dominant size-dependent damping mechanisms. The latter, i.e., a damping via increased interband transitions, assumes a coherent damping process of the oscillating electrons and, as a consequence, the plasmon is treated as a two-level system. Thus, the results deliver new physical insight to the fundamental understanding of surface plasmons. Springer Science+Business Media New York, 2013 Plasmonics nationallicence Noble metal nanoparticles nationallicence Dephasing time nationallicence Band structure changes nationallicence Optical and damping parameter nationallicence Plasmonics Springer US; http://www.springer-ny.com 8/3(2013-09-01), 1341-1349 1557-1955 8:3<1341 2013 8 11468 https://doi.org/10.1007/s11468-013-9536-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11468-013-9536-8 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Hubenthal Frank Institut für Physik and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), Universität Kassel, Kassel, Germany aut NATIONALLICENCE 773 0- Plasmonics Springer US; http://www.springer-ny.com 8/3(2013-09-01), 1341-1349 1557-1955 8:3<1341 2013 8 11468 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer