Browsing by Subject "Efficient energy transfer"

Now showing 1 - 3 of 3

Open Access
BODIPY based self-healing fluorescent gel formation via acylhydrazone linkage
(Royal Society of Chemistry, 2016) Ozdemir, T.; Sozmen, F.
Polymeric BODIPY derivatives with reactive functional groups undergo reversible formation of covalent bonds leading to self-healing properties. Cross-reactivity of acyl-hydrazine and aldehyde moieties forms the basis of dynamic covalent chemistry leading to sol-gel transition in this series of compounds. In addition, thin layers of absorbers show efficient energy transfer indicating a potential in solar concentration. © 2016 The Royal Society of Chemistry.
Open Access
Broadband optical transparency in plasmonic nanocomposite polymer films via exciton-plasmon energy transfer
(OSA - The Optical Society, 2016) Dhama R.; Rashed, A. R.; Caligiuri V.; El Kabbash M.; Strangi, G.; De Luca A.
Inherent absorptive losses affect the performance of all plasmonic devices, limiting their fascinating applications in the visible range. Here, we report on the enhanced optical transparency obtained as a result of the broadband mitigation of optical losses in nanocomposite polymeric films, embedding core-shell quantum dots (CdSe@ZnS QDs) and gold nanoparticles (Au-NPs). Exciton-plasmon coupling enables non-radiative energy transfer processes from QDs to metal NPs, resulting in gain induced transparency of the hybrid flexible systems. Experimental evidences, such as fluorescence quenching and modifications of fluorescence lifetimes confirm the presence of this strong coupling between plexcitonic elements. Measures performed by means of an ultra-fast broadband pump-probe setup demonstrate loss compensation of gold NPs dispersed in plastic network in presence of gain. Furthermore, we compare two films containing different concentrations of gold NPs and same amount of QDs, to investigate the role of acceptor concentration (Au-NPs) in order to promote an effective and efficient energy transfer mechanism. Gain induced transparency in bulk systems represents a promising path towards the realization of loss compensated plasmonic devices. © 2016 Optical Society of America.
Open Access
Synthesis of symmetrical multichromophoric bodipy dyes and their facile transformation into energy transfer cassettes
(2010) Bozdemir, O. A.; Cakmak, Y.; Sozmen F.; Ozdemir, T.; Siemiarczuk, A.; Akkaya, E. U.
Multichromophoric boron-dipyrromethene (Bodipy) dyes synthesized on phenylene-ethynylene platforms have been be converted to energy transfer cassettes in a one-step chemical transformation. Excitation energy transfer processes in these highly symmetrical derivatives were studied in detail, including time-re-solved fluorescence spectroscopy techniques. Excitation spectra and the emission lifetimes suggest efficient energy transfer between the donor and acceptor chromophore. These novel energy transfer cassettes, while highlighting a short-cut approach to similar energy transfer systems, could be useful as large pseudo-Stokes shift multichromophoric dyes with potential applications in diverse applications.