TY - JOUR
T1 - Electronic relaxation dynamics in isolated and aggregated hollow gold nanospheres
AU - Knappenberger, Kenneth
AU - Schwartzberg, Adam M.
AU - Dowgiallo, Anne Marie
AU - Lowman, Casey A.
PY - 2009/10/7
Y1 - 2009/10/7
N2 - (Figure Presented) Electronic relaxation and interparticle electromagnetic coupling processes in hollow gold nanospheres (HGNs) and HGN aggregates are described. These plasmon-tunable HGNs exhibit an unexpected, but systematic, blue shift of the surface plasmon resonance spectral position when the particles are aggregated. Femtosecond transient absorption measurements and finite-difference time-domain (FDTD) calculations are used to demonstrate that this blue shift is the result of delocalization of the Fermi-gas over multiple particles, an effect not observed with solid spherical particles. The ultrafast electron-phonon coupling lifetimes for the thin-shelled HGNs increase upon aggregation, indicating significant enhancement in interparticle electromagnetic coupling. For instance, a 48-nm HGN with a shell thickness of 7 nm shows ultrafast electron-phonon coupling with a lifetime of 300 ± 100 fs, and upon aggregation, this lifetime increases to 730 ± 140 fs. The experimental data strongly suggest that confinement effects in HGNs allow for enhanced energy transport over nanometer distances and this effect can be applied to developing more efficient devices, including photovoltaics.
AB - (Figure Presented) Electronic relaxation and interparticle electromagnetic coupling processes in hollow gold nanospheres (HGNs) and HGN aggregates are described. These plasmon-tunable HGNs exhibit an unexpected, but systematic, blue shift of the surface plasmon resonance spectral position when the particles are aggregated. Femtosecond transient absorption measurements and finite-difference time-domain (FDTD) calculations are used to demonstrate that this blue shift is the result of delocalization of the Fermi-gas over multiple particles, an effect not observed with solid spherical particles. The ultrafast electron-phonon coupling lifetimes for the thin-shelled HGNs increase upon aggregation, indicating significant enhancement in interparticle electromagnetic coupling. For instance, a 48-nm HGN with a shell thickness of 7 nm shows ultrafast electron-phonon coupling with a lifetime of 300 ± 100 fs, and upon aggregation, this lifetime increases to 730 ± 140 fs. The experimental data strongly suggest that confinement effects in HGNs allow for enhanced energy transport over nanometer distances and this effect can be applied to developing more efficient devices, including photovoltaics.
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U2 - 10.1021/ja903086g
DO - 10.1021/ja903086g
M3 - Article
C2 - 19788321
AN - SCOPUS:70349617691
VL - 131
SP - 13892
EP - 13893
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 39
ER -