We study electroabsorption (EA) behavior of InGaN/GaN quantum structures grown using epitaxial lateral overgrowth (ELOG) in correlation with their dislocation density levels and in comparison to steady state and time-resolved photoluminescence measurements. The results reveal that ELOG structures with decreasing mask stripe widths exhibit stronger EA performance, with a maximum EA enhancement f...

Optically clear and stable dispersions of brightly photoluminescent Si nanoparticles were obtained by covalent attachment of alkenoic compounds to the particles. Quenching of photoluminescence by ethylamine, diethylamine, triethylamine, pyrazine, and piperazine was investigated. The photoluminescence was quenched by the action of these nitrogenous species, but in some cases could be partially r...

The microscopic orientation and position of photoactive molecules is crucial to the operation of optoelectronic devices such as OLEDs and solar cells. Here, we introduce a shape-persistent macrocyclic molecule as an excellent fluorescent probe to simply measure (i) its orientation by rotating the excitation polarization and recording the strength of modulation in photoluminescence (PL) and (ii)...

2.7 times increase in room temperature photoluminescence (PL) intensity and 3.2 times increase in electroluminescence (EL) intensity were observed in blue multi-quantum-well (MQW) GaN/InGaN light emitting diodes (LEDs) as a result of introduction of nano-needle structure embedded with Ag nanoparticles (NPs) into n-GaN film underlying the active MQW region and thick p-GaN contact layer of LEDs. ...

This review describes a series of representative synthesis processes, which have been developed in the last two decades to prepare silicon quantum dots (QDs). The methods include both top-down and bottom-up approaches, and their methodological advantages and disadvantages are presented. Considerable efforts in surface functionalization of QDs have categorized it into (i) a two-step process and ...

Photoluminescence of highly structured ZnO layers comprising well-shaped hexagonal rods is presented. The ZnO rods (length 500-1,000 nm, diameter 100-300 nm) were grown in air onto a preheated soda-lime glass (SGL) or ITO/SGL substrate by low-cost chemical spray pyrolysis method using zinc chloride precursor solutions and growth temperatures in the range of 450-550°C. We report the effect of th...

Europium-doped yttrium silicate (Y2SiO5:Eu ) nanophosphors were successfully synthesized by flame spray pyrolysis method. The effect of silicon concentration on the crystal structure and morphology of the Y2SiO5:Eu 3+ phosphors were investigated. Asprepared phosphor consists of spherical nanoparticles with filled morphology, high crystallinity, narrow size distribution, and intense photolumines...

This work reports a rigorous and comprehensive three-dimensional electromagnetic computation to investigate and design photoluminescence enhancement from a single silicon-vacancy center (SVC) in a nanodiamond crystal embedded in various metallic nanoantennae, each having a different geometry. The study demonstrates how each antenna design enhances the photoluminescence of SVCs in diamond. In pa...

Temperatureand excitation-power-dependent photoluminescence measurements were carried out for the multilayer structure of Ge islands grown on a Si~001! substrate by gas-source molecular-beam epitaxy. When the excitation power increases from 10 to 400 mW, the photoluminescence peak from the Ge islands showed a large linear blueshift of 34 meV while that of the wetting layers did not change much....

Long-term observations of photoluminescence at the single-molecule level were until recently very difficult, due to the photobleaching of organic fluorophore molecules. Although inorganic semiconductor nanocrystals can overcome this difficulty showing very low photobleaching yield, they suffer from photoblinking. A new marker has been recently introduced, relying on diamond nanoparticles contai...