Nanoplasmonics has opened up the gates for numerous innovations. Recent studies
showed that metal nanoparticles, when introduced into the solar cells and organic
light emitting diodes, would greatly enhance their efficiencies. Though these advances
are promising, they require a tool for investigating the interactions occuring at the
microscopic level to further optimize their performance. In that context, we are
interested in understanding the energy transfer mechanism between molecules in the
vicinity of metal nanoparticle. Time-resolved
fluorescence intensity and anisotropy
experiments on single and clusters of Silver-Silica core-shell nanoparticles coated with
Rhodamine B(RB) dye molecules, (Ag-SiO2-RB) were performed. We witnessed the
signature of the interaction between RB molecules and metal nanoclusters in the form
of the enhanced
fluorescence intensity decay rates. The
fluorescence lifetime of RB in
the vicinity of the nanoparticles was (600 +/- 100) ps, as compared to (2.4+/-0.3)ns in
the absence of nanoparticle. While the anisotropy of RB molecules in the absence of
nanoparticle has remained almost constant(0.075+/-0.029) over long times; anisotropy
in the presence of particles showed wide range of values immediately after excitation.
Surprisingly high anisotropy values, at about 10 ns after excitation, were observed
with a mean of about (0.145+/-0.025). We interpret the high and low initial anisotropies
of the clusters, relative to the case of RB alone, to be due to the interaction of dye molecules with collective plasmon modes of the clusters. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-06-30 23:29:38.658
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/6593 |
| Date | 05 July 2011 |
| Creators | BOBBARA, SANYASI RAO |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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