Abstract: The present invention provides a fluorescent substance excellent both in quantum efficiency and in temperature characteristics, and also provides a process for producing the fluorescent substance. This fluorescent substance is an oxynitride phosphor having a low paramagnetic defect density and comprising aluminum, silicon, either or both of oxygen and nitrogen, and a metal element M, provided that the metal element M is partly replaced with an emission center element R. That phosphor can be produced by the steps of: subjecting a mixture of starting materials to heat treatment under a nitrogen atmosphere so as to obtain an intermediate fired product, and then further subjecting the intermediate fired product to heat treatment under an atmosphere of nitrogen-hydrogen mixed gas.

Abstract: The present invention provides a fluorescent substance excellent both in quantum efficiency and in temperature characteristics, and also provides a process for producing the fluorescent substance. This fluorescent substance is an oxynitride phosphor having a low paramagnetic defect density and comprising aluminum, silicon, either or both of oxygen and nitrogen, and a metal element M, provided that the metal element M is partly replaced with an emission center element R. That phosphor can be produced by the steps of: subjecting a mixture of starting materials to heat treatment under a nitrogen atmosphere so as to obtain an intermediate fired product, and then further subjecting the intermediate fired product to heat treatment under an atmosphere of nitrogen-hydrogen mixed gas.

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: The embodiment provides a process for production of an oxynitride fluorescent substance. In the process, a compound represented by the formula: (Sr,Eu)2Si5N8, silicon nitride and aluminum nitride are mixed and then fired in a nitrogen atmosphere under high pressure.

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: 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: 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 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: The fluorescent substance according to the present disclosure emits luminescence with a peak in the wavelength range of 500 to 600 nm under excitation by light with a peak in the wavelength range of 250 to 500 nm, and has an optical absorption coefficient ?560nm of 4×10?5 or less at 560 nm. The substance is represented by the following formula (1): (M1-xCex)2yAlzSi10-zOuNw??(1). In the formula, M is a metal element selected from the group consisting of Ba, Sr, Ca, Mg, Li, Na and K; and x, y, z, u and w are variables satisfying the conditions of 0<x?1, 0.8?y?1.1, 2?z?3.5, u?1, 1.8?z?u and 13?u+w?15, respectively.

Abstract: The embodiment provides a process for production of an oxynitride fluorescent substance. In the process, a compound represented by the formula: (Sr,Eu)2Si5N8, silicon nitride and aluminum nitride are mixed and then fired in a nitrogen atmosphere under high pressure.

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 process for production of an oxynitride fluorescent substance. In the process, a compound represented by the formula: (Sr,Eu)2Si5N8, silicon nitride and aluminum nitride are mixed and then fired in a nitrogen atmosphere under high pressure.

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: 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: The embodiment provides a process for production of an oxynitride fluorescent substance. An compound containing In or Ga is adopted in the process as a material thereof. The red fluorescent substance produced by the process can be combined with a semiconductor light-emitting element, so as to be used in a light-emitting device or a light-emitting module.

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: A white light emitting device of an embodiment includes: a light emitting element having a peak wavelength in a wavelength range from 430 to 470 nm both inclusive, a first fluorescent material formed over the light emitting element, and emitting light having a first peak wavelength of 530 to 580 nm both inclusive and having a first half width, and a second fluorescent material formed over the light emitting element, and emitting light having a second peak wavelength that is longer than the first peak wavelength and ranges from 570 to 620 nm both inclusive, and having a second half width that is 100 nm or less and is equal to or narrower than the first half width.

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.