A light emission device including 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 fluorescent member including a first fluorescent material having a light emission peak wavelength in a range of 510 nm or more and less than 580 nm, a second fluorescent material having a light emission peak wavelength in a range of 580 nm or more and 680 nm or less and a full width at half maximum of 15 nm or more and 100 nm or less, and a third fluorescent material having a light emission peak wavelength in a range of 600 nm or more and 650 nm or less and a full width at half maximum of 14 nm or less, and having a melanopic ratio (MR) value in a specified range at a certain correlated color temperature.

Provided is a method for producing a phosphor, using a nitride raw material, that gives a high-reliability (Sr,Ca)AlSiN.sub.3-based nitride phosphor at a productivity higher than before. The method comprises a mixing step of mixing raw materials and a calcining step of calcining the mixture obtained in the mixing step and, in producing the phosphor having a crystalline structure substantially identical with that of (Sr,Ca)AlSiN.sub.3 crystal as the host crystal, a strontium nitride containing SrN, Sr.sub.2N, or the mixture thereof as the main crystalline phase, as determined by crystalline phase analysis by powder X-ray diffractometry, and having a nitrogen content of 5 to 12 mass % is used as part of the raw materials.

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%.

The invention provides a method for providing a luminescent particle (100) with a hybrid coating, the method comprising: (i) providing a luminescent core (102) comprising a primer layer (105) on the luminescent core (102); (ii) providing a main ALD coating layer (120) onto the primer layer (105) by application of a main atomic layer deposition process, the main ALD coating layer (120) comprising a multilayer (1120) with two or more layers (1121) having different chemical compositions, and wherein in the main atomic layer deposition process a metal oxide precursor is selected from a group of metal oxide precursors comprising Al, Zn, Hf, Ta, Zr, Ti, Sn, Nb, Y, Ga, and V; (iii) providing a main sol-gel coating layer (130) onto the main ALD-coating layer (120) by application of a main sol-gel coating process, the main sol-gel coating layer (130) having a chemical composition different from one or more of the layers (1121) of the multilayer (1120).

An illumination module includes a light mixing cavity with an interior surface area and window that are physically separated from an LED. A portion of the window is coated with a first wavelength converting material and a portion of the interior surface area is coated with a second wavelength converting material. The window may be coated with LuAG:Ce. The window may also be coated with a third wavelength converting material with a peak emission wavelength between 615-655 nm where the spectral response of light emitted from the window is within 20% of a blackbody radiator at the same CCT. The LED may emit a light that is converted by the light mixing cavity with a color conversion efficiency ratio greater than 130 lm/W where the light mixing cavity includes two photo-luminescent materials with a peak emission wavelengths between 508-528 nm and 615-655 nm.

Embodiments of the present invention provide a bluish green phosphor represented by Formula 1 below. In particular, the bluish green phosphor and a light emitting device package including the same may have improved luminescence characteristics and properties due to influence of cations and anions included in a composition formula:
A.sub.aB.sub.bO.sub.cN.sub.dG.sub.eD.sub.fE.sub.g:RE.sub.h  [Formula 1] wherein A is at least one selected from the group consisting of Be, Mg, Ca, Sr, Ba and Ra elements, B is at least one selected from the group consisting of Si, Ge and Sn elements, G is any one of C, Cl, F and Br elements, D is one element or a mixture type of two or more elements selected from Li, Na and K, E is at least one selected from the group consisting of P, As, Bi, Sc, Y and Lu, RE is at least one selected from the group consisting of Eu, Ce, Sm, Er, Yb, Dy, Gd, Tm, Lu, Pr, Nd, Pm and Ho, 0<a≦15, 0<b≦15, 0<c≦15, 0<d≦20, 0<e≦10, 0<f≦6, 0<g≦6, and 0<h≦10.

Disclosed is a light-emitting device which comprises: a light-emitting element for emitting a first light in a blue wavelength band; a first wavelength converter for converting the first light into a second light; a second wavelength converter for converting the first light into a third light; and a third wavelength converter for converting the first light into a fourth light, wherein the first to fourth lights have central wavelengths which satisfy the following relationship: [Expression 1] λ1<λ2<λ3<λ4 (wherein λ1 is the central wavelength of the first light; λ2 is the central wavelength of the second light; λ3 is the central wavelength of the third light; and λ4 is the central wavelength of the fourth light.).

A method is disclosed for forming a blended phosphor composition. The method includes the steps of firing precursor compositions that include europium and nitrides of at least calcium, strontium and aluminum, in a refractory metal crucible and in the presence of a gas that precludes the formation of nitride compositions between the nitride starting materials and the refractory metal that forms the crucible. The resulting compositions can include phosphors that convert frequencies in the blue portion of the visible spectrum into frequencies in the red portion of the visible spectrum.

A light emitting device includes a light emitting element having a peak emission wavelength of 410 nm to 440nm and a phosphor member. The phosphor member includes a first phosphor having a peak emission wavelength of 430 nm to 500 nm and containing an alkaline-earth phosphate, a second phosphor having a peak emission wavelength of 440 nm to 550 nm and containing at least one of an alkaline-earth aluminate and a silicate containing Ca, Mg, and Cl, a third phosphor having a peak emission wavelength of 500 nm to 600 nm and containing a rare-earth aluminate, a fourth phosphor having a peak emission wavelength of 610 nm to 650 nm and containing a silicon nitride containing Al and at least one of Sr and Ca, and a fifth phosphor having a peak emission wavelength of 650 nm to 670 nm and containing a fluorogermanate.

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.