Browsing by Subject "Resonant energy transfer"

Now showing 1 - 3 of 3

Open Access
Fluorophore-doped core-multishell spherical plasmonic nanocavities: resonant energy transfer towards a loss compensation
(American Chemical Society, 2012-06-12) Peng, B.; Zhang, Q.; Liu, X.; Ji Y.; Demir, Hilmi Volkan; Huan, C. H. A.; Sum, T. C.; Wiong, Q.
Plasmonics exhibits the potential to break the diffraction limit and bridge the gap between electronics and photonics by routing and manipulating light at the nanoscale. However, the inherent and strong energy dissipation present in metals, especially in the near-infrared and visible wavelength ranges, significantly hampersthe applications in nanophotonics. Therefore, it is amajor challengetomitigatethe losses. One way to compensate the losses is to incorporate gain media into plasmonics. Here, we experimentally show that the incorporation of gain material into a local surface plasmonic system (Au/silica/silica dye core multishell nanoparticles) leads to a resonant energy transfer from the gain media to the plasmon. The optimized conditions for the largest loss compensation are reported. Both the coupling distance and the spectral overlap arethe key factorsto determinetheresulting energy transfer. Theinterplay of these factors leadsto a non-monotonous photoluminescence dependence as a function of the silica spacer shell thickness. Nonradiativetransferrate is increased by morethan 3 orders of magnitude attheresonant condition, which is key evidence of the strongest coupling occurring between the plasmon and the gain material.
Open Access
Green stimulated emission boosted by nonradiative resonant energy transfer from blue quantum dots
(American Chemical Society, 2016) Gao, Y.; Yu, G.; Wang Y.; Dang C.; Sum, T. C.; Sun, H.; Demir, Hilmi Volkan
Thanks to their tunability and versatility, the colloidal quantum dots (CQDs) made of II-VI semiconductor compound offer the potential to bridge the "green gap" in conventional semiconductors. However, when the CQDs are pumped to much higher initial excitonic states compared to their bandgap, multiexciton interaction is enhanced, leading to a much higher stimulated emission threshold. Here, to circumvent this drawback, for the first time, we show a fully colloidal gain in green enabled by a partially indirect pumping approach assisted by Förster resonance energy transfer process. By introducing the blue CQDs as exciton donors, the lasing threshold of the green CQDs, is reduced dramatically. The blue CQDs thus serve as an energy-transferring buffer medium to reduce excitation energy from pumping photons in a controlled way by injecting photoinduced excitons into green CQDs. Our newly developed colloidal pumping scheme could enable efficient CQD lasers of full visible colors by a single pump source and cascaded exciton transfer. This would potentially pave the way for an efficient multicolor laser for lighting and display applications.
Open Access
Plasmon-Exciton Resonant Energy Transfer: Across Scales Hybrid Systems
(Hindawi Publishing Corporation, 2016) El Kabbash, M.; Rashed, A. R.; Sreekanth, K. V.; De Luca, A.; Infusino, M.; Strangi, G.
The presence of an excitonic element in close proximity of a plasmonic nanostructure, under certain conditions, may lead to a nonradiative resonant energy transfer known as Exciton Plasmon Resonant Energy Transfer (EPRET) process. The exciton-plasmon coupling and dynamics have been intensely studied in the last decade; still many relevant aspects need more in-depth studies. Understanding such phenomenon is not only important from fundamental viewpoint, but also essential to unlock many promising applications. In this review we investigate the plasmon-exciton resonant energy transfer in different hybrid systems at the nano- and mesoscales, in order to gain further understanding of such processes across scales and pave the way towards active plasmonic devices.