Nichia Corporation

Kenichi Aoyagi

Shoji Hosokawa

Takashi Kaide

Motoharu Morikawa

Takuya Nakabayashi

Tetsuya Ishikawa

Yuya Takahashi

Tomohisa Kishimoto

Suguru Takashima

Tadayoshi Yanagihara

Masato Aihara

Takeshi Kihara

Hitomi Miki

Provided a method of producing a &#x3b2;-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.

Method of producing beta-sialon fluorescent material

Provided is a method of producing a &#x3b2;-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 &#x3b2;-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/g or more.

Method of producing &#x3b2;-sialon fluorescent material

A method for producing &#x3b2;-sialon fluorescent material having excellent emission intensity is provided. The method for producing &#x3b2;-sialon fluorescent material includes providing a composition comprising silicon nitride that contains aluminium, an oxygen atom, and europium, heat treating the composition, contacting the heat-treated composition with a basic substance, and washing the composition, which has been contacted with the basic substance, with an acidic liquid medium.

Method  for producing &#x3b2;-sialon fluorescent material

A wavelength converting member comprising a first wavelength converting layer containing: a first fluorescent material having a light emission peak wavelength in a range of 620 nm or more and 660 nm or less; a second fluorescent material having a light emission peak wavelength in a range of 510 nm or more and 560 nm or less; and a resin, wherein the average particle diameter, as measured according to a Fisher Sub-Sieve Sizer method, of the first fluorescent material is in a range of 2 &#x3bc;m or more and 30 &#x3bc;m or less, wherein the second fluorescent material comprises a &#x3b2;-SiAlON fluorescent material, the circularity of the &#x3b2;-SiAlON fluorescent material is 0.7 or more, and the volume average particle diameter, as measured according to a laser diffraction scattering particle size distribution measuring method, of the &#x3b2;-SiAlON fluorescent material is in a range of 2 &#x3bc;m or more and 30 &#x3bc;m or less, and wherein the thickness of the first wavelength converting layer is in a range of 50 &#x3bc;m or more and 200 &#x3bc;m or less.

Wavelength converting member and light emitting device

A method for producing a &#x3b2;-sialon fluorescent material superior in light emitting luminance is provided. The method includes heat-treating a first mixture containing an aluminum compound, a europium compound, and a first silicon oxynitride compound to obtain a first heat-treated product, and heat-treating a second mixture containing the first heat-treated product, an aluminum compound, a europium compound, and a second silicon oxynitride compound, which has a larger oxygen content than the first silicon oxynitride compound, to obtain a second heat-treated product.

Method for producing beta-sialon fluorescent material

A method for producing a &#x3b2;-sialon fluorescent material can be provided. The method includes preparing a composition containing silicon nitride that contains aluminium, an oxygen atom, and europium, heat-treating the composition in a rare gas atmosphere or in a vacuum, and contacting the heat-treated composition with a gas containing elemental fluorine.

Method for producing &#x3b2;-sialon fluorescent material

A method for producing a &#x3b2;-sialon fluorescent material is provided. The method includes heat-treating a mixture containing an aluminum compound, a first europium compound, and silicon nitride to obtain a first heat-treated product; and heat-treating the first heat-treated product with a second europium compound in a rare gas atmosphere to obtain a second heat-treated product.

An object of the present invention is to provide a light emitting device which emits light of deep yellowish color with high luminance. The light emitting device of the present invention comprises a light emitting element having a peak emission wavelength shorter than 490 nm, a fluorescent material for wavelength conversion which absorbs light from the light emitting element and emits light of a wavelength longer than that of the light from the light emitting element, and a filter which cuts off a part of a mixed light produced by mixing the light of the light emitting element and the light of the fluorescent material, wherein the light transmitted through the filter has a chromaticity coordinate on the chromaticity diagram according to CIE 1931 plotted in a region defined by a first point (x=0.450, y=0.450), a second point (x=0.250, y=0.650), a third point (x=0.350, y=0.750) and a fourth point (x=0.250, y=0.750) and in the region defined by a closed curve consisting of the monochromatic locus and the purple boundary.

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Tokushima, Japan

Kenichi Aoyagi