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gated in poor solvent with fluorescence quantum yields up to
90%, demonstrative of a phenomenon of aggregation-induced
emission. Both molecules and polymers exhibit the feature of
aggregation-enhanced two-photon excited fluorescence. Large
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observed in the nanoaggregates of P1–P3, whose values can be
further enhanced by using an excitation source of shorter
wavelengths. Thin solid films of P2 and P3 show high refractive
indices (RI ¼ 1.7649 ꢂ 1.6873) in a wide wavelength region of
ꢀ
400–1700 nm, high modified Abbe numbers, and low optical
€
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Acknowledgements
11 N. Kato, Y. Katayama, H. Semba and K. Limura, Jpn. J. Appl. Phys.,
2010, 49, 031601.
This work was partially supported by the Research Project
Competition of HKUST (RPC11SC09 and RPC10SC13), the
Research Grants Council of Hong Kong (604711, 603509,
HKUST2/CRF/10), the University Grants Committee of Hong
Kong (AoE/P-03/08), and the National Science Foundation of
China (20634020 and 20974028). B. Z. T. is thankful for the
support from Cao Guangbiao Foundation of Zhejiang Univer-
sity. Gabriel Ramos-Ortiz is thankful for the CONACYT grant
(grant J49512F).
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