Ultrafast Dynamics of Gold-Based Nanocomposite Materials

Published

May 1, 2003

Author(s)

Joseph S. Melinger, V D. Kleiman, D McMorrow, Franziska Grohn, Barry J. Bauer, Eric J. Amis

Abstract

The ultrafast electron dynamics are investigated for small ((2.5 4.0) nm average diameter) Au nanoparticles contained in two different types of organic-inorganic nanocomposites. In one case, an aqueous solution contains Au nanoparticles embedded inside polyamidoamine (PAMAM) dendrimers. In the other case, hexanethiol-passivated (HT) Au nanoparticles are suspended in dichloromethane solution. Femtosecond two-color pump-probe spectroscopy is used to excite and probe the dynamics of the Au nanoparticles in the region of the surface plasmon resonance. The transient response is measured as a function of laser excitation fluence (Joules/cm2). For the metal-dendrimer nanocomposites, the transient response consists of a single exponential decay that relaxes with a timeconstant of less than 1.2 ps, and is due mainly to electron-phonon coupling. The relaxation timescale shows a weak dependence on the size of the Au nanoparticle embedded inside the dendrimer, and a weak dependence on excitation fluence.

Citation

Journal of Physical Chemistry A

Volume

107

Issue

No. 18

Pub Type

Journals

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Keywords

Au, dendrimer, nanoparticles, nanoposites, ultrafast dynamics

Citation

Melinger, J. , Kleiman, V. , McMorrow, D. , Grohn, F. , Bauer, B. and Amis, E. (2003), Ultrafast Dynamics of Gold-Based Nanocomposite Materials, Journal of Physical Chemistry A, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852058 (Accessed November 5, 2025)