Bluish-green semipolar GaInN/GaN light emitting diodes were realized on the {11̄01} side facets of selectively grown GaN stripes with an on-wafer optical output power of 240μW@20mA for about 500 nm emission wavelength. Structural investigations using TEM, SEM, HRXRD and AFM could be related to the luminescence properties in PL and CL. The defect-related luminescence peaks at 3.3 eV and 3.41 eV, ...

In the present work, antireflective sub-wavelength structures have been fabricated on fluorescent 6H-SiC to enhance the white light extraction efficiency by using the reactive-ion etching method. Broadband and omnidirectional antireflection characteristics show that 6H-SiC with antireflective sub-wavelength structures suppress the average surface reflection significantly from 20.5 % to 1.01 % o...

AlN/GaN/sapphire heterostructures with AlN gate film thickness of 3–35 nm are characterized using photoreflectivity ~PR! and photoluminescence ~PL! spectroscopy. Under a critical AlN film thickness, the luminescence from the GaN channel layer near the interface proves to be excitonic. No luminescence related to the recombination of the two-dimensional electron gas ~2DEG! is observed, in spite o...

To meet the continual demands of more-sensitive immunoassays, the synthesis of novel luminescent Eu(III) chelate labels having similar substituted 4-(phenylethynyl)pyridine chromophores in three different chelate structure classes are reported. Significantly enhanced luminescence intensities were obtained, evidently caused by the intra-ligand charge transfer (ILCT) mediated sensitization, but t...

Yttrium aluminum garnet nanoparticles both undoped and doped with lanthanide ions (Ce, Eu, Dy and Tb) having average size around 30 (73nm) nm were prepared by glycine nitrate combustion method followed by annealing at a relatively low temperature of 800 1C. Increase in the annealing temperature has been found to improve the luminescence intensity and for 1200 1C heated samples there exists stro...

Two optical methods were used simultaneously to evaluate the effect of a vasoactive drug hydralazine on oxygenation and blood flow in SA-1 tumors in A/J mice. A novel luminescence-based optical sensor (OxyLite instrument, Oxford Optronix, UK) was used to monitor partial pressure of oxygen (pO2) in tumors. Laser Doppler flowmetry was used to assess relative blood perfusion in tumors. Measurement...

It is commonly known that halogenation tends to decrease the luminescence quantum yield of an organic dye, owing to the high electronegativity and heavy-atom effect of the halogen atom. However, based on an investigation of the effects of halogenation on the luminescence of the oligo(phenylene vinylene) (OPV) framework, we demonstrate that halogenation can have positive impact on the solid-stat...

Mn-doped ZnS nanocrystals based on low dopant concentrations (0-2%) and coated with a shell of Zn(OH)2 have been prepared via soft template and precipitation reaction. The results indicate that the ZnS:Mn nanocrystal is cubic zinc blende structure and its diameter is 3.02 nm as demonstrated by XRD. Measured by TEM, the morphology of nanocrystals is a spherical shape, and their particle size (3-...

A new signal processing approach for fiberoptical sensors, microoptodes, is presented. All signal generation and processing is completely based on a fast, low-cost DSP (Digital Signal Processor). This enables the implementation of new features such as a simultaneous multi-frequency measurement to resolve different analytical parameters in the luminescence signal. For instance, a hybrid sensor w...