Significant acceleration of the photoluminescence (PL) decay rate was observed in water solutions of two rare earth ions (REIs), Tb and Eu. We propose that the time-resolved PL spectroscopy data are explained by a fluorescence resonance energy transfer (FRET) between the REIs. FRET was directly confirmed by detecting the induced PL of the energy acceptor, Eu ion, under the PL excitation of the ...

In this paper we present results of photoluminescence (PL), photoluminescence excitation (PLE), and time resolved PL spectroscopy of the I13/2 → I15/2 transition in Er optical centers in GaN epilayers grown by metal-organic chemical vapor deposition. Under resonance excitation via the higher-lying inner 4f shell transitions and band-to-band excitation of the semiconductor host, the PL and PLE s...

While addition of electrolyte to sodium dodecyl sulfate suspensions of single-wall carbon nanotubes has been demonstrated to result in significant brightening of the nanotube photoluminescence (PL), the brightening mechanism has remained unresolved. Here, we probe this mechanism using time-resolved PL decay measurements. We find that PL decay times increase by a factor of 2 on addition of CsCl ...

InGaN/GaN nanorod light-emitting diode (LED) arrays were fabricated using nanoimprint and reactive ion etching. The diameters of the nanorods range from 120 to 300 nm. The integral photoluminescence (PL) intensity for 120 nm nanorod LED array is enhanced as 13 times compared to that of the planar one. In angular-resolved PL (ARPL) measurements, there are some strong lobes as resonant regime app...

An investigation is reported of the photoluminescence (PL) properties of Al3GdB4O12:Eu phosphors. Under vacuum ultraviolet excitation, Al3GdB4O12:Eu exhibited a bright red luminescence with CIE chromaticity coordinates of (0.643, 0.356) with a PL intensity of 60% of the sodium salicylate standard. The PL spectrum showed a ground state splitting pattern consistent with D3 symmetry. The PL excita...

The Lanczos method is one of the standard approaches for computing a few eigenpairs of a large, sparse, symmetric matrix. It is typically used with restarting to avoid unbounded growth of memory and computational requirements. Thick-restart Lanczos is a popular restarted variant because of its simplicity and numerically robustness. However, convergence can be slow for highly clustered eigenvalu...

A new strategy for the synthesis of fluorescent monodispersed 2-dimensional (2D) CdSe/CdS core/shell hexagonal platelet nanocrystals has been demonstrated. Because of the stronger affinity of the -NH2 group of oleylamine to the (0001Se) facet comprising three dangling bonds in CdSe seeds, oleylamine acts as the sole surfactant responsible for hindering the growth of the CdS shell in the 0001 an...

Using time-resolved photoluminescence (PL) measurements, we present an experimental verification for 100% internal quantum efficiency (IQE) of III-N wells at low temperatures. Conventional IQE such as temperature- and power-dependent PL, require a low-temperature normalization, where usually is assumed. This assumption neglects remaining nonradiative recombination that may be even cryogenic Fro...

Transient receptor potential (TRP) channels across species are expressed in sensory receptor cells, and often localized to specialized subcellular sites. In Drosophila photoreceptors, TRP-like (TRPL) channels are localized to the signaling compartment, the rhabdomere, in the dark, and undergo light-induced translocation into the cell body as a mechanism for long-term light-adaptation. We show t...

Photoluminescence (PL) in GaN or InGaN layers monitored during epitaxial growth at high temperatures permits a quasi-continuous in situ characterization of opto-electronic properties. Therefore, epitaxial parameters can now be optimized at the earliest possible stage. A pulsed and high-power UV laser was required for PL excitation at high temperatures. Herein, the underlying nonlinear mechanism...