The invention relates to lighting emitting devices and systems comprising a luminescent composition, said luminescent composition comprising: (i) a first emitting material, said first emitting material having a host lattice doped with EU.sup.3+ ions; (ii) a second emitting material, said second emitting material having a host lattice doped with Tb.sup.3+ ions; and (iii) sensitizer material, which sensitizer material is excitable in the violet-to-blue (400 to 480 nm) wavelength range and has an emission spectrum which overlaps at least partly with one or more excitation bands of the first emitting material and with which overlaps at least partly with one or more excitation bands of the second emitting material.

A garnet is doped with a lanthanide ion selected from praseodymium, gadolinium, erbium, and neodymium. For co-doping, at least two of the lanthanide ions are selected. The lanthanide ion doped garnet converts electromagnetic radiation energy of a longer wavelength of below 530 nm to electromagnetic radiation energy of shorter wavelengths in the range of 220 to 425 nm. The garnet is crystalline and is obtainable from a mixture of salts or oxides of the components, in the presence of a chelating agent, that are dissolved in acid. This is followed by a specific calcination process to produce the garnet and, optionally, to adjust particle size and increase the crystallinity of the particles. The garnet can be used to inactivate microorganisms or cells covering a surface containing silicate-based material under exposure of electromagnetic radiation energy of a longer wavelength of below 500 nm.

Provided is a particulate phosphor including a single crystal having a composition represented by a compositional formula (Y.sub.1-x-y-zLu.sub.xGd.sub.yCe.sub.z).sub.3+aAl.sub.5−aO.sub.12 (0≤x≤0.9994, 0≤y≤0.0669, 0.001≤z≤0.004, −0.016≤a≤0.315) and a particle diameter (D50) of not less than 20 μm. Also provided is a light-emitting device including a phosphor-including member that includes the phosphor and a sealing member including a transparent inorganic material sealing the phosphor or a binder including an inorganic material binding particles of the phosphor, and a light-emitting element that emits a blue light for exciting the phosphor.

A lighting apparatus including at least one light emitting diode (LED) chip configured to emit blue light; a green phosphor having a light emission peak in a range of 500 nm to 550 nm; and a red phosphor having a light emission peak in a range of 600 nm to 650 nm, in which the red phosphor includes a first red phosphor having a light emission peak in a range of 620 nm to 630 nm and a second red phosphor having a light emission peak in a range of 630 nm to 640 nm, and the full widths at half maximum of the first and second red phosphors are in a range of 20 nm to 60 nm, respectively.

It is an object of the present invention to improve light source efficiency of “a light-emitting device capable of realizing a natural, vivid, highly visible and comfortable appearance of colors or an appearance of objects” already arrived at by adopting a spectral power distribution having a shape completely different from the shape of conventionally known spectral power distributions while maintaining favorable color appearance characteristics.

The invention refers to a composite wavelength converter (1) for an LED (100), comprising a substrate (10) and an epitaxial film (20) formed by liquid phase epitaxy on the top and bottom of the substrate (10). Furthermore, the invention refers to a method of preparation of a composite wavelength converter (1) for an LED (100). Furthermore, the invention refers to a white LED light source comprising an LED (100) and an inventive composite wavelength converter (1) mounted on a light emitting surface of the LED (100).

A scintillation crystal can include a rare earth silicate, an activator, and a Group 2 co-dopant. In an embodiment, the Group 2 co-dopant concentration may not exceed 200 ppm atomic in the crystal or 0.25 at % in the melt before the crystal is formed. The ratio of the Group 2 concentration/activator atomic concentration can be in a range of 0.4 to 2.5. In another embodiment, the scintillation crystal may have a decay time no greater than 40 ns, and in another embodiment, have the same or higher light output than another crystal having the same composition except without the Group 2 co-dopant. In a further embodiment, a boule can be grown to a diameter of at least 75 mm and have no spiral or very low spiral and no cracks. The scintillation crystal can be used in a radiation detection apparatus and be coupled to a photosensor.

Provided is compatibility between adhesion to a substrate (lower layer) and durability improvement. An optical element includes a phosphor layer facing a lower layer, and a bonding layer keeping the phosphor layer in intimate contact with the lower layer. The phosphor layer includes an inorganic binder, and phosphor particle dispersed with the inorganic binder. The bonding layer includes an organic binder. The phosphor layer has a first surface facing the lower layer, a second surface opposite to the first surface, and a side surface connecting the first and second surfaces together. The bonding layer connects together the second surface, the side surface, and a surface of the lower layer to keep the phosphor layer in intimate contact with the lower layer.

A light emitting diode package including: a housing; a light emitting diode chip arranged in the housing; a wavelength conversion unit arranged on the light emitting diode chip; a first fluorescent substance distributed inside the wavelength conversion unit and emitting light having a peak wavelength in the cyan wavelength band; and a second fluorescent substance distributed inside the wavelength conversion unit and emitting light having a peak wavelength in the red wavelength band, wherein the peak wavelength of light emitted from the light emitting diode chip is located within a range of 415 nm to 430 nm.

A method of tailoring the properties of garnet-type scintillators to meet the particular needs of different applications is described. More particularly, codoping scintillators, such as Gd.sub.3Ga.sub.3Al.sub.2O.sub.12, Gd.sub.3Ga.sub.2Al.sub.3O.sub.12, or other rare earth gallium aluminum garnets, with different ions can modify the scintillation light yield, decay time, rise time, energy resolution, proportionality, and/or sensitivity to light exposure. Also provided are the codoped garnet-type scintillators themselves, radiation detectors and related devices comprising the codoped garnet-type scintillators, and methods of using the radiation detectors to detect gamma rays, X-rays, cosmic rays, and particles having an energy of 1 keV or greater.