Abstract: In a gallium arsenide crystal body, an etching pit density of the gallium arsenide crystal body is more than or equal to 10 cm?2 and less than or equal to 10000 cm?2, and an oxygen concentration of the gallium arsenide crystal body is less than 7.0×1015 atoms·cm?3. In a gallium arsenide crystal substrate, an etching pit density of the gallium arsenide crystal substrate is more than or equal to 10 cm?2 and less than or equal to 10000 cm?2, and an oxygen concentration of the gallium arsenide crystal substrate is less than 7.0×1015 atoms·cm?3.

Abstract: The present invention provides a light emitting device that makes it possible to provide an image display apparatus having a wide color reproduction range. The light emitting device includes a light emitting element that emits blue light; a Mn2+-activated ?-AlON phosphor that is a green phosphor; and a Mn4+-activated phosphor that is a red phosphor. The green light emitted by the Mn2+-activated ?-AlON phosphor has an emission-spectrum peak wavelength of not less than 518 nm and not more than 528 nm.

Abstract: A light-emitting device includes a light-emitting element that emits blue light, a Mn2+-activated ?-AlON green phosphor, and a dispersing material in which the green phosphor is dispersed. The green phosphor has an in-crystal Mn concentration of 2.5 wt % or more. The shortest path of the blue light through the dispersing material is 1 mm long or shorter.

Abstract: A light-emitting device includes a light-emitting element that emits blue light, a Mn2+-activated ?-AlON phosphor and a Eu2+-activated ?-SiAlON phosphor that are excited by the blue light to emit green light, and a red phosphor that is excited by the blue light to emit red light. The weight ratio of the Mn2+-activated ?-AlON phosphor to the Eu2+-activated ?-SiAlON phosphor is from 20 to 75.

Abstract: A light-emitting device includes a light-emitting element configured to emit excitation light, and a phosphor layer in which phosphor particles are dispersed so as to emit fluorescence in response to the excitation light. The phosphor layer includes a constitutional unit derived from an ionic liquid having a polymerizable functional group. The light-emitting device further includes a protective layer that seals the light-emitting element therein.

Abstract: A phosphor containing particle including a core portion which is a particulate matter of resin including a constitutional unit derived from an ionic liquid with a semiconductor nanoparticle phosphor dispersed therein and a shell portion which is a matter in a form of a layer of resin which includes a constitutional unit derived from an ionic liquid and coats at least a portion of the core portion, and a phosphor containing particle including a particulate matter of resin including a constitutional unit derived from an ionic liquid with a semiconductor nanoparticle phosphor dispersed therein and a metal oxide layer coating at least a portion of the particulate matter of resin. A light emitting device including a light source and a wavelength converter in which phosphor containing particles are dispersed in a translucent medium, and a phosphor containing sheet in which phosphor containing particles are dispersed in a sheet-shaped translucent medium.

Abstract: A light-emitting device includes a light-emitting element configured to emit excitation light, and a phosphor layer in which phosphor particles are dispersed so as to emit fluorescence in response to the excitation light. The phosphor layer includes a constitutional unit derived from an ionic liquid having a polymerizable functional group. The light-emitting device further includes a protective layer that seals the light-emitting element therein.

Abstract: A wavelength conversion member includes a light-transmitting medium and phosphor-containing particles dispersed in the light-transmitting medium and including a resin and a semiconductor nanoparticle phosphor dispersed in the resin, wherein the phosphor-containing particles have a particle size that is equal to or larger than a particle size of the semiconductor nanoparticle phosphor and that is equal to or smaller than a minimum thickness of the wavelength conversion member.

Abstract: A light-emitting device includes a light-emitting element that emits blue light, a Mn2+-activated ?-AlON green phosphor, and a dispersing material in which the green phosphor is dispersed. The green phosphor has an in-crystal Mn concentration of 2.5 wt % or more. The shortest path of the blue light through the dispersing material is 1 mm long or shorter.

Abstract: A wavelength converting member includes silica glass and a plurality of fluorescent material particles including an oxynitride or nitride fluorescent material and dispersed in the silica glass. The plurality of fluorescent material particles include at least two kinds of fluorescent material particles including (i) first fluorescent material particles that emit a fluorescence having a first peak wavelength and (ii) second fluorescent material particles that emit a fluorescence having a second peak wavelength. The wavelength converting member has a density within a range from 0.8 g/cm3 to 1.2 g/cm3.

Abstract: Provided is a light-emitting device that has a high emission efficiency, excellent stability and temperature properties, and that generates light having a high color rendering property sufficient for practical use. This semiconductor light-emitting device comprises a semiconductor light-emitting element that emits blue light, a green phosphor that absorbs the blue light and emits green light, and an orange phosphor that absorbs the blue light and emits orange light, and is characterized in that the orange phosphor is an Eu-activated ?-SiAlON phosphor having an emission spectrum peak wavelength within a range of 595 to 620 nm.

Abstract: In a light-emitting device, a 50%-area average diameter of primary particles of a Eu-activated ? SiAlON fluorescent material is 10 ?m or more, a scattering probability of scattering materials at a peak wavelength of excitation light emitted from an excitation light source is 0.1 mm?1 or more and 0.5 mm?1 or less, and the Eu-activated ? SiAlON fluorescent material is entrapped inside a transparent member in a dispersed state together with the scattering materials.

Abstract: The present invention provides a light emitting device that makes it possible to provide an image display apparatus having a wide color reproduction range. The light emitting device includes a light emitting element that emits blue light; a Mn2+-activated ?-AlON phosphor that is a green phosphor; and a Mn4+-activated phosphor that is a red phosphor. The green light emitted by the Mn2+-activated ?-AlON phosphor has an emission-spectrum peak wavelength of not less than 518 nm and not more than 528 nm.

Abstract: Provided is a light-emitting device that has a high emission efficiency, excellent stability and temperature properties, and that generates light having a high color rendering property sufficient for practical use. This semiconductor light-emitting device (1) comprises a semiconductor light-emitting element (2) that emits blue light, a green phosphor (14) that absorbs the blue light and emits green light, and an orange phosphor (13) that absorbs the blue light and emits orange light, and is characterized in that the orange phosphor is an Eu-activated ?-SiAlON phosphor having an emission spectrum peak wavelength within a range of 595 to 620 nm.

Abstract: The occurrence of a color irregularity in light that is emitted from a light-emitting device is suppressed together with being able to prevent a decline in the utilization efficiency of excitation light. A light-emitting device is provided with a phosphor section that absorbs excitation light and emits first fluorescence, and a phosphor section that absorbs excitation light that has passed through the phosphor section without being converted into first fluorescence by the phosphor section and emits second fluorescence. Also, the peak wavelength of the second fluorescence is approximate to the peak wavelength of the excitation light.

Abstract: Provided is a light emitting device with effectively improved color rendering properties. A light emitting device 1 includes: a light source 2 that emits light having the maximum intensity at a predetermined wavelength; a first phosphor (yellow phosphor) 51 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a first wavelength which is longer than the predetermined wavelength; and a second phosphor (red phosphor) 52 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a second wavelength which is longer than the first wavelength. An absolute value of wavelength dependency of an optical absorption rate of the second phosphor 52 at the first wavelength is set to not more than 0.6%/nm. Accordingly, the color rendering properties of the light emitted by the light emitting device 1 can be effectively improved.

Abstract: A wavelength converting member includes silica glass and a plurality of fluorescent material particles including an oxynitride or nitride fluorescent material and dispersed in the silica glass. The plurality of fluorescent material particles include at least two kinds of fluorescent material particles including (i) first fluorescent material particles that emit a fluorescence having a first peak wavelength and (ii) second fluorescent material particles that emit a fluorescence having a second peak wavelength. The wavelength converting member has a density within a range from 0.8 g/cm3 to 1.2 g/cm3.

Abstract: Provided is a light-emitting device that has a high emission efficiency, excellent stability and temperature properties, and that generates light having a high color rendering property sufficient for practical use. This semiconductor light-emitting device comprises a semiconductor light-emitting element that emits blue light, a green phosphor that absorbs the blue light and emits green light, and an orange phosphor that absorbs the blue light and emits orange light, and is characterized in that the orange phosphor is an Eu-activated ?-SiAlON phosphor having an emission spectrum peak wavelength within a range of 595 to 620 nm.

Abstract: Provided is a light emitting device with effectively improved color rendering properties. A light emitting device 1 includes: a light source 2 that emits light having the maximum intensity at a predetermined wavelength; a first phosphor (yellow phosphor) 51 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a first wavelength which is longer than the predetermined wavelength; and a second phosphor (red phosphor) 52 that absorbs the light emitted by the light source 2 and outputs fluorescent light having the maximum intensity at a second wavelength which is longer than the first wavelength. An absolute value of wavelength dependency of an optical absorption rate of the second phosphor 52 at the first wavelength is set to not more than 0.6%/nm. Accordingly, the color rendering properties of the light emitted by the light emitting device 1 can be effectively improved.

Abstract: In a light-emitting device, a 50%-area average diameter of primary particles of a Eu-activated ? SiAlON fluorescent material is 10 ?m or more, a scattering probability of scattering materials at a peak wavelength of excitation light emitted from an excitation light source is 0.1 mm?1 or more and 0.5 mm?1 or less, and the Eu-activated ? SiAlON fluorescent material is entrapped inside a transparent member in a dispersed state together with the scattering materials.