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Upconversion photoluminescence can eliminate problems associated with autofluorescence and scattered excitation light in homogeneous luminescence-based assays without need for temporal resolution. We have demonstrated a luminescence resonance energy-transfer-based assay utilizing inorganic upconverting (UPC) lanthanide phosphor as a donor and fuorescent protein as an acceptor. UPC phosphors are excited at near-infrared and they have narrow-banded anti-Stokes emission at visible wavelengths enabling measurement of the proximity-dependent sensitized emission with minimal background. The acceptor alone does not generate any direct emission at shorter wavelengths under near-infrared excitation. A competitive model assay for biotin was constructed using streptavidin-conjugated [Er.sup.3+], [Yb.sup.3+]-doped UPC phosphor as a donor and biotinylated phycobiliprotein as an acceptor. UPC phosphor was excited at near-infrared (980 nm) and sensitized acceptor emission was measured at red wavelength (600 nm) by using a microtitration plate fluorometer equipped with an infrared laser diode and suitable excitation and emission filters. Lower limit of detection was in the subnanomolar concentration range. Compared to time-resolved fluorometry, the developed assay technology enabled simplified instrumentation. Excitation at near-infrared and emission at red wavelengths render the technology also suitable to analysis of strongly colored and fluorescent samples, which are often of concern in clinical immunoassays and in high-throughput screening.

Highly emissive (with an external quantum yield exceeding 35 percent at a 365-nanometer excitation wavelength) broadband phosphors can be synthesized from a tetraalkoxysilane sol-gel precursor and a variety of organic [...]

[gamma]-AlON:[Er.sup.3+] Phosphors with different [Er.sup.3+] concentration for upconversion luminescence are prepared by a combination of carbothermal reduction and nitridation and solid-state synthesis methods. The pump power dependence has shown a two-photon process involved in the upconversion luminescence and the ratio of red emission relative to green emission is increased with the increase in [Er.sup.3+] concentration.

Sr2CeO4 blue phosphor particles were prepared with an emulsion liquid membrane system, which could be utilized as a micro reactor for the preparation of size- and morphology-controlled fine particles. The composite oxalate particles obtained were sub micrometer size and much smaller than those prepared in the homogeneous aqueous solutions.

The suitability of newly synthesized series of haloborate phosphors is investigated with the general formula M2B5O9X:Ce(super 3+) (M = Sr or Ca; X = Br or Cl) for thermal neutron detection and with reduced sensitivity to gamma background. The storage properties such as yield of photostimulated luminescence (PSL) and thermoluminescence are reported.

The concept of phosphors having high cathodoluminescence (CL) efficiency at low voltages and high current densities, and the surface modification of phosphors are studied to improve field emission display (FED) phosphor efficiency and maintenance. It is reported that CL efficiency decreases with surface charging, which may occur due to the high resistance of phosphor materials.

Two spectroscopic techniques that are very sensitive to low concentration of activators in phosphor lattices are discussed. Mossbauer and laser Raman spectroscopy have benefited from considerable technological advances and these techniques are becoming increasingly user-friendly.

The synthesis, structure and photoluminescence properties are described for the three-coordinate mononuclear and dinuclear complexes. Ag1, Cu1, and Cu2 exhibit blue pyrazole-based structures emissions with short phosphorescence lifetimes, 101-102 micro sec , due to an internal heavy-metal effect.

The red thin-film phophors were fabricated based on a ZnO:(La,Eu)OF nanocomposite structure by dispersing (La,Eu)OF nanoparticles in a ZnO film matrix. Studies found that Ga doping increases the cathodoluminescence (CL) intensity of the film.

The mechanisms leading to improved brightness, efficiency, and stability of alternating-current thin-film electroluminescent (ACTFEL) ZnS:Mn phosphors is studied. Electrical properties data are used to determine whether there is a reduced amount of static space charge in the codoped films, resulting in large average field, increased excitation efficiency, and increased charge multiplication.

A study was conducted, by using the cathodoluminescence (CL) and photoluminescence (PL), to compare the film phosphors of Gd2O3:Eu(super 3+), which were deposited on quartz glass plates by pulsed laser deposition (PLD), to thin film phosphors composed of Y2O3:Eu(super 3+). The result shows that film characteristics and luminescent properties cab be altered significantly by the PLD processing conditions.

A study was conducted to examine the cathodoluminescence (CL) intensity and spectral distribution effects when coatings of Al2O3 or MgO were deposited on Y2O3:Eu and Y2SiO3:Tb phosphors. The result shows that thicker coatings attenuated the CL intensity, from the phosphors under electron beam bombardment, are stronger than thinner coatings.

A physical model of a cathodoluminescent (CL) device, which describes a change of both luminescent and electrophysical characteristics of phosphor surface under low-energy electron excitation, is described. The effect of the change of electrical conductivity of phosphor screen, stimulated by electron irradiation is the main reason for CL relaxation processes.

The pulsed cathodoluminescence (CL) and photoluminescence (PL) decay of radiation from several excited states in three common phosphor systems as well as the steady state CL efficiency is measured. The nonradiative decay routes lead to CL efficiency losses, which are enhanced, as the electron beam energy is reduced.

Cheap, efficient, and cool, fluorescent tubes are so common that it is hard to imagine a public or office building without them. But they are not ideal. They contain mercury, [...]

The synthesis, structure and photoluminescence of a new intrinsic yellow phosphor, NTHU-6, which has a unique MOF-like organic-inorganic hybrid open framework with high photoluminescence quantum efficiency (PLQE), are described. NTHU-6 has higher PLQE than NTHU-4 and it has displayed a hillock-like absorption band extended into the visible region.