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 white light emitting device includes a light emitting element having a peak wavelength at from 430 nm to 460 nm; and a fluorescent layer on the light emitting element containing a red fluorescent material and a green-yellow fluorescent material. The white light emitting device achieves high color rendering properties, a high average color rendering index Ra and a high luminescent efficiency, or a high white efficiency.

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: 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: 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 white light emitting device includes a light emitting element having a peak wavelength at from 430 nm to 460 nm; and a fluorescent layer on the light emitting element containing a red fluorescent material and a green-yellow fluorescent material. The white light emitting device achieves high color rendering properties, a high average color rendering index Ra and a high luminescent efficiency, or a high white efficiency.

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: 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 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 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 luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

Abstract: There is provided a light emitting device which includes a light emitting element having a main emission peak in the wavelength region of greater than 420 nm and equal to or less than 500 nm, and a phosphor layer formed on the light emitting element. The light emitting element of this light emitting device has a junction temperature of from 100° C. to 200° C. at the time of continuous driving. Furthermore, the phosphor layer contains a phosphor represented by the following general formula (A), which absorbs the light emitted from the light emitting element and thereby emits light having a main emission peak in the wavelength region of equal to or greater than 650 nm and equal to or less than 665 nm: (Mg1-x,AEx)a(Ge1-y,Sny)bOcHAd:zMn??(A) wherein AE represents at least one or more elements selected from the group consisting of Ca or Sr; HA represents at least one or more elements selected from the group consisting of F or Cl; 2.54?a?4.40, 0.80?b?1.10, 3.85?c?7.00, 0?d?2.00, 0?x?0.05, 0?y?0.

Abstract: A luminescent material which is featured in that it exhibits an emission peak at a wavelength ranging from 490 to 580 nm as it is excited by light having a wavelength ranging from 250 to 500 nm and that it has a composition represented by the following general formula (2): (M1-xRx)a2AlSib2Oc2Nd2??(2) (In the general formula (2), M is at least one metallic element excluding Si and Al, R is a luminescence center element, and x, a2, b2, c2 and d2 satisfy the following relationships: 0<x?1, 0.93<a2<1.3, 4.0<b2<5.8 0.6<c2<1, 6<d2<11).

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.