Size and temperature dependence of the plasmon absorption of colloidal gold nanoparticles

TitleSize and temperature dependence of the plasmon absorption of colloidal gold nanoparticles
Publication TypeJournal Article
Year of Publication1999
AuthorsLink, S, EL-Sayed, MA
JournalJournal of Physical Chemistry B
Volume103
Pagination4212-4217
Date PublishedMay
ISBN Number1089-5647
Accession NumberWOS:000080646700002
Abstract

The size and temperature dependence of the plasmon absorption is studied for 9, 15, 22, 48, and 99 nm gold nanoparticles in aqueous solution. The plasmon bandwidth is found to follow the predicted behavior as it increases with decreasing size in the intrinsic size region (mean diameter smaller than 25 nm), and also increases with increasing size in the extrinsic size region (mean diameter larger than 25 nm). Because of this pronounced size effect a homogeneous size distribution and therefore a homogeneous broadening of the plasmon band is concluded for all the prepared gold nanoparticle samples. By applying a simple two-level model the dephasing time of the coherent plasmon oscillation is calculated and found to be less than 5 fs. Furthermore, the temperature dependence of the plasmon absorption is examined. A small temperature effect is observed. This is consistent with the fact that the dominant electronic dephasing mechanism involves electron-electron interactions rather than electron-phonon coupling.

DOI10.1021/jp984796o