Morphology-dependent energy transfer of polyfluorene nanoparticles decorating InGaN/GaN quantum-well nanopillars
Author
Erdem, T.
Ibrahimova, V.
Jeon, D. W.
Lee, I. H.
Tuncel, D.
Demir, Hilmi Volkan
Date
2013Source Title
Journal of Physical Chemistry C
Print ISSN
1932-7447
Publisher
American Chemical Society
Volume
117
Issue
36
Pages
18613 - 18619
Language
English
Type
ArticleItem Usage Stats
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Abstract
Conjugated polymer nanoparticles (CPNs),
prepared in aqueous dispersion from poly[(9,9-bis{3-
bromopropyl}fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1,3}-thiodiazole)] (PFBT-Br), are incorporated into a nanopillar
architecture of InGaN/GaN multiple quantum wells
(MQWs) to demonstrate a new organic/inorganic class of
nanostructured excitonic model system. This hybrid system
enables intimate integration for strong exciton−exciton
interactions through nonradiative energy transfer (NRET)
between the integrated CPNs and MQW pillars. The NRET of
these excitonic systems is systematically investigated at varied
temperatures. In these hybrids, InGaN/GaN MQWs serve as the donor of the NRET pair, while immobilized PFBT-Br polymer
serves as the acceptor. To understand morphology-dependent NRET, PFBT-Br CPNs coating InGaN/GaN MQWs are made to
defold into polymer chains by in situ treatment with a good solvent (THF). The experimental results indicate that NRET is
significantly stronger in the case of CPNs compared with their defolded polymer chains. At room temperature, while the NRET
efficiency of open polymer chains−nanopillar system is only 10%, PFBT-Br CPNs exhibit a substantially higher NRET efficiency
of 33% (preserving the total number of polymer molecules). The NRET efficiency of the nanoparticle systems is observed to be
25% at 250 K, 22% at 200 K, 19% at 150 K, and 15% at 100 K. On the other hand, the defolded polymer chains exhibit
significantly lower NRET efficiencies of 17% at 250 K, 16% at 200 K, 11% at 150 K, and 5% at 100 K. This work may potentially
open up new opportunities for the hybrid organic/inorganic systems where strong excitonic interactions are desired for light
generation, light harvesting, and sensing applications.