Provided is a wavelength conversion member that is less decreased in luminescence intensity with time by irradiation with light of an LED or LD and a light emitting device using the wavelength conversion member. A wavelength conversion member is formed of an inorganic phosphor dispersed in a glass matrix, wherein the glass matrix contains, in % by mole, 30 to 85% SiO.sub.2, 0 to 20% B.sub.2O.sub.3, 0 to 25% Al.sub.2O.sub.3, 0 to 3% Li.sub.2O, 0 to 3% Na.sub.2O, 0 to 3% K.sub.2O, 0 to 3% Li.sub.2O+Na.sub.2O+K.sub.2O, 0 to 35% MgO, 0 to 35% CaO, 0 to 35% SrO, 0 to 35% BaO, 0.1 to 45% MgO+CaO+SrO+BaO, and 0 to 4% ZnO, and the inorganic phosphor is at least one selected from the group consisting of an oxide phosphor, a nitride phosphor, an oxynitride phosphor, a chloride phosphor, an oxychloride phosphor, a halide phosphor, an aluminate phosphor, and a halophosphate phosphor.

A radiation-emitting optoelectronic component may include a semiconductor chip or a semiconductor laser which, in operation of the component, emits a primary radiation in the UV region or in the blue region of the electromagnetic spectrum. The optoelectronic component may further include a conversion element comprising a first phosphor configured to convert the primary radiation at least partly to a first secondary radiation having a peak wavelength in the green region of the electromagnetic spectrum between 475 nm and 500 nm inclusive. The first phosphor may be or include BaSi.sub.4Al.sub.3N.sub.9, SrSiAl.sub.2O.sub.3N.sub.2, BaSi.sub.2N.sub.2O.sub.2, ALi.sub.3XO.sub.4, M*.sub.(1−x*−y*−z*) Z*.sub.z*[A*.sub.a*B*.sub.b*C*.sub.c*D*.sub.d*E*.sub.e*N.sub.4-n*O.sub.n*], and combinations thereof.

A europium-doped β-sialon phosphor particle. When the element concentration of a Si atom on the surface portion of the particle that is obtained by analyzing a cross section of the phosphor particle by the energy dispersive X-ray analysis method is indicated by Ps [at %], and the element concentration of a Si atom near the center of the particle that is obtained by an analysis by the same method is indicated by Pc [at %], the Pc-Ps value is 3 at % or more.

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.

To provide a semiconductor light emitting device which is capable of accomplishing a broad color reproducibility for an entire image without losing brightness of the entire image. A light source provided on a backlight for a color image display device has a semiconductor light emitting device comprising a solid light emitting device to emit light in a blue or deep blue region or in an ultraviolet region and phosphors, in combination. The phosphors comprise a green emitting phosphor and a red emitting phosphor. The green emitting phosphor and the red emitting phosphor are ones, of which the rate of change of the emission peak intensity at 100° C. to the emission intensity at 25° C., when the wavelength of the excitation light is 400 nm or 455 nm, is at most 40%.

A light emitting device comprises a light emitting element having a light emission peak wavelength in a range of 400 nm or more and 490 nm or less and a first fluorescent material having a light emission peak wavelength in a range of 570 nm or more and 680 nm or less, and emits light having a correlated color temperature being 1,950 K or less, an average color rendering index Ra being 51 or more, a full width at half maximum of a light emission peak having a maximum light emission intensity in a light emission spectrum of the light emitting device being 110 nm or less, and a first glare index Ls1/L that is a ratio of a first effective radiance Ls1 to a luminance L being 0.493 or less, wherein Ls1 and L are as defined in the disclosure.

Systems and methods to provide multiple channels of light to form a blended white light output, the systems and methods utilizing recipient luminophoric mediums to alter light provided by light emitting diodes. The predetermined blends of luminescent materials within the luminophoric mediums provide predetermined spectral power distributions in the white light output.

A phosphor plate including a base material, and a plate-shaped composite including phosphors dispersed in the base material, in which in a case in which an absorption spectrum of light having a wavelength of 300 nm to 700 nm is measured, when an absorbance at 455 nm is defined as A455(%), an absorbance at 700 nm is defined as A700(%), and a thickness of the phosphor plate is defined as T (mm), (A700/A455)/T satisfies 0.01 or more and 1.00 or less.

Provided is a method for producing a wavelength conversion sintered body that emits light under irradiation of excitation light. The method for producing a wavelength conversion sintered body includes: preparing a molded body obtained by molding a mixture containing an α-SiAlON fluorescent material and aluminum oxide particles and having a content of Ga of 15 ppm by mass or less; and primary calcining the molded body at a temperature in a range of 1,370° C. or more and 1,600° C. or less to obtain a first sintered body.

A light emitting device comprises a light emitting element having a light emission peak wavelength in a range of 400 nm or more and 490 nm or less and a first fluorescent material having a light emission peak wavelength in a range of 570 nm or more and 680 nm or less, and emits light having a correlated color temperature being 1,950 K or less, an average color rendering index Ra being 70 or more, a full width at half maximum of a light emission peak having the maximum light emission intensity being 110 nm or less, and a ratio B/L of an effective radiance B to a luminance L being 0.151 or less, wherein the luminance of light emitted by the light emitting device in a range of 300 nm or more and 800 nm or less when B and L is as defined in the disclosure.