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: The embodiment provides a process for production of a green light-emitting oxynitride fluorescent material having Sr3Al3Si13O2N21 crystal structure, and also provides the fluorescent material produced by that process. An metal halide is adopted in the process as one of the starting material metal compounds. As the metal halide, a Ca or Na compound as well as a Sr compound can be preferably employed.

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: 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, 0.63<a<0.80, 2.1<b<2.63, 0<c?0.24 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 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: According to one embodiment, the luminescent material emits light with an emission peak within a wavelength range of 490 to 580 nm when excited with light having a wavelength range of 250 to 500 nm and includes a particle containing a Sr3Si13Al3O2N21-based crystal activated by Eu. The particle includes an outer region which is within a depth of 5 nm from a surface of the particle and an inner region which is deeper than the outer region. The outer region and the inner region satisfy a ratio Oouter/Oinner of 1.0 to 3.8. Oouter is an average of oxygen concentration in the outer region and Oinner is an average of oxygen concentration in the inner region.

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 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: The present invention provides a red-emitting phosphor emitting luminescence of excellent color purity with high efficiency under the excitation with near UV light, and it also provides a color image displaying device employing that phosphor. This phosphor comprises an ARS2 matrix (A is at least one of Na, K and Rb, and R is at least one of Y, Gd and Lu) doped with 0.003 to 0.3 mol % of Bi and 0.1 to 3 mol % of Mn, and is suitable as a red-emitting phosphor used in a color image displaying device without a color filter.

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, 0.63<a<0.80, 2.1<b<2.63, 0<c?0.24 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: 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 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 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: A light emitting device according to one embodiment includes a board; a light emitting element mounted on the board, emitting light having a wavelength of 250 nm to 500 nm; a red fluorescent layer formed on the element, including a red phosphor expressed by equation (1), having a semicircular shape with a diameter r; (M1?x1Eux1)aSibAlOcNd??(1) (In the equation (1), M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Al (Aliminum), rare-earth elements, and IVB group elements), an intermediate layer formed on the red fluorescent layer, being made of transparent resin, having a semicircular shape with a diameter D; and a green fluorescent layer formed on the intermediate layer, including a green phosphor, having a semicircular shape. A relationship between the diameter r and the diameter D satisfies equation (2): 2.0r(?m)?D?(r+1000)(?m).

Abstract: A light emitting device according to one embodiment includes a board; a light emitting element mounted on the board, emitting light having a wavelength of 250 nm to 500 nm; a red fluorescent layer formed on the element, including a red phosphor expressed by equation (1), having a semicircular shape with a diameter r; (M1?x1Eux1)aSibAlOcNd??(1) (In the equation (1), M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Al (Aliminum), rare-earth elements, and IVB group elements), an intermediate layer formed on the red fluorescent layer, being made of transparent resin, having a semicircular shape with a diameter D; and a green fluorescent layer formed on the intermediate layer, including a green phosphor, having a semicircular shape. A relationship between the diameter r and the diameter D satisfies equation (2): 2.0r (?m)?D(r+1000) (?m).

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 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 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.