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 present embodiment is to provide a blue light-emitting phosphor that enables a white light-emitting device with high color rendering properties to be formed. The phosphor exhibits a luminescence peak in a wavelength range of 430 to 490 nm when excited with light having a luminescence peak within a wavelength range of 250 to 430 nm, wherein the phosphor includes a composition represented by the following formula (1): ((SrpM1?p)1?xCex)3?ySi13?zAl3+zO2+uN21?w (1) (wherein M is at least one of alkaline earth metals; and 0?p?1, 0<x?1, ?0.1?y?0.6, ?3.0?z?0.4, ?1.5<u??0.3, and ?3.0<u?w?1.0 are satisfied).

Abstract: The embodiment of the present disclosure provides a phosphor exhibiting an emission peak in the wavelength range of 500 to 600 nm under excitation by light having a peak in the wavelength range of 250 to 500 nm. This phosphor is in the form of particles having a median size of 5 to 40 ?m inclusive, shows a luminous efficiency of more than 70%, and has a composition represented by the following formula (1): ((SrpM1-p)1-xCex)2yAlzSi10-zOuNw??(1). In the formula, M is at least one of the alkaline earth metals, and p, x, y, z, u and w satisfy the conditions of 0?p?1, 0<x?1, 0.8?y?1.1, 2?z?3.5, 0<u?1, 1.5?z?u, and 13?u+w?15, respectively.

Abstract: The embodiment of the present disclosure provides a phosphor exhibiting an emission peak in the wavelength range of 565 to 600 nm under excitation by light having a peak in the wavelength range of 250 to 500 nm. The emission peak has a half width of 115 to 180 nm inclusive. This phosphor has a crystal structure of Sr2Si7Al3ON13, and is activated by cerium.

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 phosphor 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 phosphor has a composition represented by (M1-xCex)2yAlzSi10-zOuNw (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 0<x?1, 0.8?y?1.1, 2?z?3.5, 0<u?1, 1.8?z?u, and 13?u+w?15). The phosphor has a crystalline aspect ratio of 1.5 to 10.

Abstract: A light emitting device includes a light emitting element that emits light having a wavelength of 250 nm to 500 nm and a fluorescent layer that is disposed on the light emitting element. The fluorescent layer includes a phosphor having a composition expressed by the equation, ((M1?x1Eux1)3?ySi13?zAl3+zO2+uN21?w), and an average particle diameter of 12 ?m or more, wherein in the equation, M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Al, rare-earth elements, and IVB group elements, and x1, y, z, u, and w satisfy each of the inequalities simultaneously, that is to say each of the following inequalities is satisfied by the choice of values of the identified paramaters within the noted ranges of 0<x1<1, ?0.1<y<0.3, ?3<z?1, ?3<u?w?1.5, 2<u, w<21.

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; 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: According to one embodiment, the phosphor 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 phosphor has a composition represented by (M1-xCex)2yAlzSi10-zOuNw (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 0<x?1, 0.8?y?1.1, 2?z?3.5, 0<u?1, 1.8?z?u, and 13?u+w?15). The phosphor has a crystalline aspect ratio of 1.5 to 10.

Abstract: According to one embodiment, the phosphor exhibits a luminescence peak within a wavelength range of 500 to 600 nm when it is excited with light having an emission peak within a wavelength range of 250 to 500 nm. The phosphor has a composition represented by (M1-xCex)2yAlzSi10-zOuNwBs (M represents Sr and a part of Sr may be substituted by at least one selected from the group consisting of Ba, Ca and Mg; and x, y, z, u, w and s satisfy 0<x?1, 0.8?y?1.1, 2?z?3.5, 1<u?1, 1.5?z?u, 13?u+w?15, and 0<s<0.245.

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 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 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: 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: A white light emitting device according to an embodiment includes: a light emitting element having a peak wavelength in a wavelength range of 430 nm or more and 470 nm or less; a first fluorescent material emits light with a first peak wavelength of 525 nm or more and 560 nm or less; a second fluorescent material emits light with a second peak wavelength longer than the first peak wavelength; and a third fluorescent material emits light with a third peak wavelength of 620 nm or more and 750 nm or less, which is longer than the second peak wavelength. The first fluorescent material and the second fluorescent material has a composition of MSi?O?N?, and when the first peak wavelength is denoted by ?1 (nm), whereas the second peak wavelength is denoted by ?2 (nm), 1100??1+?2 and ?2??1?60 are satisfied.

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 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 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.