Abstract: The present embodiments provide a yellow light-emitting fluorescent substance of high luminous efficiency and also a production method thereof. This substance is represented by the formula (1): (M1-xREx)2yAlzSi10-zOuNw ??(1) (in the formula, M is at least one element selected from the group consisting of Ba, Sr, Ca, Mg, Li, Na and K), and emits luminescence with a peak within 500 to 600 nm when excited by light of 250 to 500 nm. In the emission spectrum of the substance, the emission band with the above peak has a half-width corresponding to an energy difference of 0.457 eV or less. The substance can be obtained by pulverizing a material mixture so that the D90 value may be 5 ?m or less and then by firing the pulverized mixture.

Abstract: The present disclosure provides a phosphor excellent in temperature characteristic and capable of highly efficiently emitting yellow light with a wide half-width in the emission spectrum. This phosphor emits luminescence with a peak wavelength of 500 to 600 nm under excitation by light with a peak wavelength of 250 to 500 nm, and is represented by the following formula (1): (M1-xCex)2yAlzSi10-zOuNvCw??(1) [M is mainly Sr and may be partly replaced with at least one element selected from the group consisting of Ba, Ca and Mg; and x, y, z, u, v and w satisfy the conditions of 0<x?1, 0.8?y?1.1, 2?z?3.5, 0<u?1.5, 0.01?w?0.1 and 13?u+v+w?15, respectively].

Abstract: The embodiment of the present disclosure provides yellow luminescent substance having high luminous efficiency. This fluorescent substance is represented by the formula (1): (M1-xREx)2yAlzSi10-zOuNwCla??(1) (in the formula, M is at least one element selected from the group consisting of Ba, Sr, Ca, Mg, Li, Na and K), and it emits luminescence with a peak within 500 to 600 nm when excited by light of 250 to 500 nm.

Abstract: The embodiment of the present disclosure provides a phosphor having such high luminous efficiency as to be capable of realizing a light-emitting device suffering less from color drift even when working with high power. This phosphor is a Ce-activated phosphor having a crystal structure of Sr2Si7Al3ON13, and emitting luminescence with a peak wavelength of 500 to 600 nm under excitation by light with a peak wavelength of 250 to 500 nm. The XRD profile of the phosphor measured with Cu—K? line radiation according to Bragg-Brendano method shows diffraction lines having the intensities I0 and I1 at diffraction angles 2?s in the ranges of 31.55-31.85° and 24.75-250.5°, respectively, on the condition that the ratio of I1/I0 is 0.24 or less.

Abstract: The embodiment provides a red light-emitting fluorescent substance represented by the following formula (1): (M1-xECx)aM1bAlOcNd??(1). In the formula (1), M is an element selected from the group consisting of IA group elements, IIA group elements, IIIA group elements, IIIB group elements, rare earth elements and IVA group elements; EC is an element selected from the group consisting of Eu, Ce, Mn, Tb, Yb, Dy, Sm, Tm, Pr, Nd, Pm, Ho, Er, Cr, Sn, Cu, Zn, As, Ag, Cd, Sb, Au, Hg, Tl, Pb, Bi and Fe; M1 is different from M and is selected from the group consisting of tetravalent elements; and x, a, b, c and d are numbers satisfying the conditions of 0<x<0.2, 0.55<a<0.80, 2.10<b<3.90, 0<c?0.25 and 4<d<5, respectively. This substance emits luminescence having a peak in the wavelength range of 620 to 670 nm when excited by light of 250 to 500 nm.

Abstract: A light-emitting device of an embodiment includes a light-emitting element emitting blue excitation light and a first phosphor excited by the blue excitation light and emitting fluorescence. A peak wavelength of the fluorescence is not shorter than 520 nm and shorter than 660 nm and the peak wavelength of the fluorescence shifting in the same direction when a peak wavelength of the blue excitation light shifts. The first phosphor is one of a yellow phosphor emitting yellow fluorescence, a green phosphor emitting green fluorescence, a yellow-green/yellow phosphor emitting yellow-green/yellow fluorescence and a red phosphor emitting red fluorescence.

Abstract: The embodiment of the present disclosure provides a light-emitting device capable of both realizing neutral white color and having high luminous efficiency. The device has a blue-light emitting semi-conductor element and a luminescent layer containing a mixture of fluorescent substances. The mixture contains first and second phosphors. The first phosphor is activated with Ce and emits luminescence with a peak wavelength of 540 to 560 nm, and the second phosphor emits luminescence with a peak wavelength of 580 to 610 nm and is represented by the following formula (2): (Sr1-x2Eux2) Sia2Alb2Oc2Nd2Ce2 ??(2).

Abstract: According to one embodiment, the luminescent material emits light having an luminescence peak within a wavelength range of 550 to 590 nm when excited with light having an emission peak in a wavelength range of 250 to 520 nm. The luminescent material has a composition represented by the following formula 1. (Sr1-xEux)aSibAlOcNd??formula 1 wherein x, a, b, c and d satisfy following condition: 0<x?0.16, 0.50?a?0.70, 2.0?b?2.5 0.45?c?1.2, 3.5?d?4.5, and 3.6?d/c?8.0.

Abstract: A light emitting device according to one embodiment includes a board; plural first light emitting elements mounted on the board to emit light having a wavelength of 250 nm to 500 nm; plural second light emitting elements mounted on the board to emit light having a wavelength of 250 nm to 500 nm; a first fluorescent layer formed on each of the first light emitting elements, the first fluorescent layer including a first phosphor; and a second fluorescent layer formed on each of the second light emitting elements, the second fluorescent layer including a second phosphor. The second phosphor is higher than the first phosphor in luminous efficiency at 50° C., and is lower than the first phosphor in the luminous efficiency at 150° C.

Abstract: A light emitting device according to one embodiment includes: a board; plural first light emitting units each including a first light emitting element and a first fluorescent layer formed on the first light emitting element having a green phosphor; plural second light emitting units each including a second light emitting element and a second fluorescent layer formed on the second light emitting element having a red phosphor; the second fluorescent layers and the first fluorescent layers being separated in a non-contact manner with gas interposed there between; and plural third light emitting units each including a third light emitting element and a resin layer formed on the third light emitting element having neither a green phosphor nor the red phosphor, the third light emitting units being disposed between the first light emitting units and the second light emitting units.

Abstract: The present embodiments provide a europium-activated oxynitride phosphor and a production method thereof. This phosphor emits red luminescence having a peak at 630 nm or longer and can be produced by use of inexpensive oxides as raw materials containing alkaline earth metals such as strontium. The oxynitride phosphor is activated by a divalent europium and represented by the formula (1): (M1-xEux)AlaSibOcNdCe ??(1). In the formula, M is an alkaline earth metal, and x, a, b, c, d and e are numbers satisfying the conditions of 0<x<0.2, 1.3?a?1.8, 3.5?b?4, 0.1?c?0.3, 6.7?d?7.2 and 0.01?3?0.1, respectively.

Abstract: According to one embodiment, the luminescent material exhibits a luminescence peak in a wavelength ranging from 500 to 600 nm when excited with light having an emission peak in a wavelength ranging from 250 to 500 nm. The luminescent material has a composition represented by Formula 1 below: (M1-xCex)2yAlzSi10-zOuNw??Formula 1 wherein M represents Sr and a part of Sr may be substituted by at least one selected from Ba, Ca, and Mg; x, y, z, u, and w satisfy following conditions: 0<x?1, 0.8?y?1.1, 2?z?3.5, u?1 1.8?z?u, and 13?u+w?15.

Abstract: According to one embodiment, the luminescent material shows a luminescence peak in a wavelength range of 570 to 670 nm when excited with light having an emission peak in a wavelength range of 250 to 520 nm. The luminescent material includes a host material having a crystal structure substantially same as the crystal structure of Sr2Si7Al3ON13. The host material is activated by Eu, and includes Sr and Ca to satisfy a relationship of 0.008?MCa/(MSr+MCa)?0.114, where MCa is a number of moles of Ca and MSr is a number of moles of Sr.

Abstract: According to one embodiment, the luminescent material emits light having an luminescence peak within a wavelength range of 550 to 590 nm when excited with light having an emission peak in a wavelength range of 250 to 520 nm. The luminescent material has a composition represented by the following formula 1. (Sr1-xEux)aSibAlOcNd??formula 1 wherein x, a, b, c and d satisfy following condition: 0<x?0.16, 0.50?a?0.70, 2.0?b?2.5 0.45?c?1.2, 3.5?d?4.5, and 3.6?d/c?8.0.

Abstract: A light emitting device according to one embodiment includes a light emitting element that emits light having a wavelength of 380 nm to 470 nm; a CASN first red phosphor that is disposed on the light emitting element; a sialon second red phosphor that is disposed on the light emitting element; and a sialon green phosphor that is disposed on the light emitting element.

Abstract: A light emitting device includes a board and a light emitting element mounted on the board, emitting light having a wavelength of 250 nm to 500 nm. A red fluorescent layer is formed on the element and includes a red phosphor (M1?x1Eux1)aSibAlOcNd having a semicircular shape with a radius r, where M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Aluminum, rare-earth elements, and IVB group elements. An intermediate layer is formed on the red fluorescent layer, being made of transparent resin, having a semicircular shape with a radius D; and a green fluorescent layer is formed on the intermediate layer, including a green phosphor, having a semicircular shape. A relationship between the radius r and the radius D is 2.0r(?m)?D?(r+1000)(?m).

Abstract: A light emitting device according to embodiments has: a substrate; first light emitting units arranged along a first straight line on the substrate; second light emitting units arranged along a second straight line on the substrate, the second straight line being parallel to the first straight line, the second light emitting units having an emission color different from the first light emitting units; and third light emitting units arranged along a third straight line on the substrate, the third straight line being parallel to the first and second straight lines, the third light emitting units having an emission color different from the first and second light emitting units, wherein a distance between light emitting units of a same emission color is longer than a minimum distance between light emitting units of different emission colors.

Abstract: A light emitting device according to one embodiment includes a light emitting element that emits light having a wavelength of 250 nm to 500 nm; plural red fluorescent layers that are formed above the light emitting element to include a red fluorescent material, the red fluorescent layers being disposed at predetermined intervals; and plural green fluorescent layers that are formed above the light emitting element to include a green fluorescent material, a distance between the light emitting element and the green fluorescent layers being larger than a distance between the light emitting element and the red fluorescent layers.

Abstract: The embodiment provides a red light-emitting fluorescent substance represented by the following formula (1): (M1-xECx)aM1bAlOcNd ??(1). In the formula (1), M is an element selected from the group consisting of IA group elements, IIA group elements, IIIA group elements, IIIB group elements, rare earth elements and IVA group elements; EC is an element selected from the group consisting of Eu, Ce, Mn, Tb, Yb, Dy, Sm, Tm, Pr, Nd, Pm, Ho, Er, Cr, Sn, Cu, Zn, As, Ag, Cd, Sb, Au, Hg, Tl, Pb, Bi and Fe; M1 is different from M and is selected from the group consisting of tetravalent elements; and x, a, b, c and d are numbers satisfying the conditions of 0<x<0.2, 0.55<a<0.80, 2.10<b<3.90, 0<c?0.25 and 4<d<5, respectively. This substance emits luminescence having a peak in the wavelength range of 620 to 670 nm when excited by light of 250 to 500 nm.

Abstract: A light emitting device according to one embodiment includes a light emitting element that emits light having a wavelength of 380 nm to 470 nm; a CASN first red phosphor that is disposed on the light emitting element; a sialon second red phosphor that is disposed on the light emitting element; and a sialon green phosphor that is disposed on the light emitting element.