A nitride phosphor having a composition containing Eu, Si, Al, N, and a group 2 element including at least one selected from the group consisting of Mg, Ca, Sr, and Ba. In the composition, a ratio of a total molar content of the group 2 element and Eu to a molar content of Al is 0.8 or more and 1.1 or less, a molar ratio of Eu is 0.002 or more and 0.08 or less, a molar ratio of Si is 0.8 or more and 1.2 or less, and a total molar ratio of Si and Al is 1.8 or more and 2.2 or less. The nitride phosphor has a first peak in a range of 17° 2θ or more and 19° 2θ or less and a second peak in a range of 34° 2θ or more and 35.5° 2θ or less in a CuKα powder X-ray diffraction pattern.

A light emitting diode package includes: 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 nitride phosphor having a composition containing Eu, Si, Al, N, and a group 2 element including at least one selected from the group consisting of Mg, Ca, Sr, and Ba. In the composition, a ratio of a total molar content of the group 2 element and Eu to a molar content of Al is 0.8 or more and 1.1 or less, a molar ratio of Eu is 0.002 or more and 0.08 or less, a molar ratio of Si is 0.8 or more and 1.2 or less, and a total molar ratio of Si and Al is 1.8 or more and 2.2 or less. The nitride phosphor has a first peak in a range of 17° 2θ or more and 19° 2θ or less and a second peak in a range of 34° 2θ or more and 35.5° 2θ or less in a CuKα powder X-ray diffraction pattern.

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 present invention belongs to the technical field of inorganic luminescent materials, particularly relates to a nitride fluorescent material, and further discloses a light-emitting device containing such a fluorescent material. The nitride fluorescent material contains a compound with a structure like M.sub.mAl.sub.xSi.sub.yN.sub.3: aR, bEu, cCe. The fluorescent material has very high physical stability and chemical stability, and the fluorescent material is better in crystallization, and thus has relatively high external quantum efficiency. When being applied to a light-emitting device, the fluorescent material can fully exert the advantages of good stability and high external quantum efficiency, and the light-emitting efficiency and stability of the light-emitting device can be further improved.

Provided is a method of producing a β-sialon fluorescent material having a high light emission intensity and an excellent light emission luminance. The method includes preparing a calcined product having a composition of β-sialon containing an activating element; grinding the calcined product to obtain a ground product; and heat-treating the ground product to obtain a heat-treated product. A specific surface area of the ground product is 0.2 m.sup.2/g or more.

The present invention relates to a light-converting material which comprises a luminescent material with semiconductor nanoparticles (quantum materials), where the semiconductor nanoparticles are located on the surface of the luminescent material and the emission from the semiconductor nanoparticles is in the region of the emission from the luminescent material. The present invention furthermore relates to a process for the preparation of the light-converting material and to the use thereof in a light source. The present invention furthermore relates to a light-converting mixture, a light source, a lighting unit which contains the light-converting material according to the invention, and a process for the production thereof.

Provided a method of producing a β-sialon fluorescent material having excellent emission intensity. The method includes providing a first composition containing aluminum, an oxygen atom, and a europium-containing silicon nitride, heat treating the first composition, contacting the heat-treated composition and a basic substance to obtain a second composition, and contacting the second composition resulting from contacting the heat-treated composition with the basic substance and an acidic liquid medium containing an acidic substance.

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 phosphor plate includes a plate-like composite including a base material and an α-type sialon phosphor present in the base material, in which, in an X-ray diffraction analysis pattern using a Cu-Kα ray, in a case in which peak intensity corresponding to the α-type sialon phosphor having a diffraction angle 2 θ in a range of 30.2° or more and 30.4° or less is defined as I.sub.α and peak intensity of a peak having a diffraction angle 2 θ in a range of 26.6° or more and 26.8° or less is defined as I.sub.β, I.sub.α, and I.sub.β satisfy 0<I.sub.β/I.sub.α≤10.