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Accomplishing equilibrium in terms of transfer efficiency for dual-band wireless energy transfer (WET) system remains as one of key concerns particularly in the implementation of a single transmitter device which supports simultaneous energy and data transfer functionality. Three stages of design method are discussed in addressing the aforementioned concern. A single layer dual-band printed spiral resonator for non-radiative wireless energy transfer operating at 6.78 MHz and 13.56 MHz is presented. By employing multi-coil approach, measured power transfer efficiency for a symmetrical link separated at axial distance of 30 mm are 72.34% and 74.02% at the respective frequency bands. When operating distance is varied between 30 mm to 38 mm, consistency of simulated peak transfer efficiency above 50% is achievable.

Here we designed and synthesized CdSe/CdSe1-xTex core/crown nanoplatelets (NPLs) with controlled crown compositions by using the core-seeded-growth approach. We confirmed the uniform growth of the crown regions with well-defined shape and compositions by employing transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. By precisely tuning the composition of the CdSe1-xTex crown region from pure CdTe (x = 1.00) to almost pure CdSe doped with several Te atoms (x = 0.02), we achieved tunable excitonic properties without changing the thickness of the NPLs and demonstrated the evolution of type-II electronic structure. Upon increasing the Te concentration in the crown region, we obtained continuously tunable photoluminescence peaks within the range of ∼570 nm (for CdSe1-xTex crown with x = 0.02) and ∼660 nm (for CdSe1-xTex crown with x = 1.00). Furthermore, with the formation of the CdSe1-xTex crown region, we observed substantially improved photoluminescence quantum yields (up to ∼95%) owing to the suppression of nonradiative hole trap sites. Also, we found significantly increased fluorescence lifetimes from ∼49 up to ∼326 ns with increasing Te content in the crown, suggesting the transition from quasi-type-II to type-II electronic structure. With their tunable excitonic properties, this novel material presented here will find ubiquitous use in various efficient light-emitting and -harvesting applications. Agency for Science, Technology and Research (A*STAR) National Research Foundation (NRF) Accepted version The authors gratefully acknowledge the financial support from Singapore National Research Foundation under the programs of NRF-NRFI2016-08 and NRF-CRP-6-2010-02 and the Science and Engineering Research Council, Agency for Science, Technology and Research (A*STAR) of Singapore; EU-FP7 Nanophotonics4Energy NoE; and TUBITAK EEEAG 114E449 and 114F326. H.V.D. acknowledges support from ESF-EURYI and TUBAGEBIP. Y.K., O.E., and T.E. acknowledge support from TUBITAK BIDEB.

Recent studies show that the spectral behaviour of localized surface plasmon resonances (LPSRs) in metallic nanoparticles su er from both a redshift and a broadening in the transition from the far- to the near-field regimes. An interpretation of this efect was given in terms of the evanescent and propagating components of the angular spectrum representation of the radiated eld. Due to the increasing interest awakened by magnetodielectric materials as a both low-loss material option for nanotechnology applications, and also for their particular scattering properties, here we study the spectral response of a magnetodielectric nanoparticle as a basic element of a dielectric nano-antenna. This study is made by analyzing the changes su ered by the scattered electromagnetic field when propagating from the surface of this dielectric nanostructure to the far-zone in terms of propagating and evanescent plane wave components of the radiated fields. This research was supported by MICINN (Spanish Ministry of Science and Innovation) with project FIS2013- 45854-P.

An all-solution processed and all-colloidal laser is demonstrated using tailored CdSe/CdS core/shell quantum dots, which exhibit highly stable and low-threshold optical gain owing to substantially suppressed non-radiative Auger recombination. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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 hampers the applications in nanophotonics. Therefore, it is a major challenge to mitigate the 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 are the key factors to determine the resulting energy transfer. The interplay of these factors leads to a non-monotonous photoluminescence dependence as a function of the silica spacer shell thickness. Nonradiative transfer rate is increased by more than 3 orders of magnitude at the resonant condition, which is key evidence of the strongest coupling occurring between the plasmon and the gain material. © 2012 American Chemical Society.

We proposed and demonstrated architectural tuning of color chromaticity by controlling photoluminescence decay kinetics through nonradiative Förster resonance energy transfer in the heterostructure of layer-by-layer spaced CdTe nanocrystal (NC) solids. We achieved highly sensitive tuning by precisely adjusting the energy transfer efficiency from donor NCs to acceptor NCs via controlling interspacing between them at the nanoscale. By modifying decay lifetimes of donors from 12.05 to 2.96 ns and acceptors from 3.68 to 14.57 ns, we fine-tuned chromaticity coordinates from (x,y) = (0.575,0.424) to (0.632, 0.367). This structural adjustment enabled a postsynthesis color tuning capability, alternative or additive to using the size, shape, and composition of NCs. © 2009 American Institute of Physics.