Production of silicon quantum dots by an ultraviolet method with carboxylic acid or carboxlic acid salt reactants, which can be modified for further applications with possible methods in an aqueous medium with a silicon precursor using the ultraviolet (UV-Vis) technique.

Provided is a light-emitting device having a high luminous flux.

The light-emitting device comprises a light-emitting element 11 that has a dominant wavelength in a range of 380 nm or more and 485 nm or less, and a fluorescent material layer 31 that includes a fluorescent material emitting light by being excited by light emitted from the light-emitting element 11, and a neodymium compound, wherein the light-emitting device emits light having a dominant wavelength in a range of 584 nm or more and 780 nm or less.

A three-dimensional chiral nanostructure according to an embodiment of the present invention comprises: metal nanoparticles having a chiral structure: and a coating layer enclosing the metal nanoparticles. The metal nanoparticle is formed in a polyhedral structure having an R region and an S region in which atoms are arranged clockwise and counterclockwise, respectively, in the order of (111), (100), and (110) crystal faces on the basis of the chiral center, wherein at least a portion of the edges form a curve tilting and extending from the R or S region so that the metal nanoparticle has a chiral structure.

A three-dimensional chiral nanostructure according to an embodiment of the present invention comprises: metal nanoparticles having a chiral structure: and a coating layer enclosing the metal nanoparticles. The metal nanoparticle is formed in a polyhedral structure having an R region and an S region in which atoms are arranged clockwise and counterclockwise, respectively, in the order of (111), (100), and (110) crystal faces on the basis of the chiral center, wherein at least a portion of the edges form a curve tilting and extending from the R or S region so that the metal nanoparticle has a chiral structure.

The present invention discloses a nitrogen-containing luminescent particle, characterized in that a structure of the nitrogen-containing luminescent particle is divided into an oxygen poor zone, a transition zone, and an oxygen rich zone from a core to an outer surface of the particle depending on an increasing oxygen content, the oxygen poor zone being predominantly a nitride luminescent crystal or oxygen-containing solid solution thereof, the transition zone being predominantly a nitroxide material, the oxygen rich zone being predominantly an oxide material or oxynitride material; the nitride luminescent crystal or oxygen-containing solid solution thereof has a chemical formula of M.sub.m-m1A.sub.a1B.sub.b1O.sub.o1N.sub.n1:R.sub.m1, the nitroxide material has a chemical formula of M.sub.m-m2A.sub.a2B.sub.b2O.sub.o2N.sub.n2:R.sub.m2, the oxide material or oxynitride material has a chemical formula of M.sub.m-m3A.sub.a3B.sub.b3O.sub.o3N.sub.n3:R.sub.m3. The nitrogen-containing luminescent particle and the nitrogen-containing illuminant of the present invention have good chemical stability, good aging and light decay resistance, and high luminescent efficiency, and are useful for various luminescent devices. The manufacturing method of the present invention is easy and reliable, and useful for industrial mass production.

The present invention is a fluorescent material characterized by being represented by a composition of the following formula (1) and having a crystal lattice distortion obtained from a Williamson-Hall plot by X-ray diffraction within the range of 0.0005 to 0.0020. (Sr,Ca,M).sub.3-xMgSi.sub.2O.sub.8:Eu.sub.x formula (1) wherein M is at least one rare earth metal elements selected from the group consisting of Sc, Y, Gd, Tb and La, and 0.01≦x≦0.10. Also, the present invention is a light-emitting device including the fluorescent material, and a light source that emits light by irradiating the fluorescent material with excitation light. Furthermore, the present invention is a method for producing the fluorescent material, including the steps of: obtaining an aqueous slurry of a raw material; and spray-drying the aqueous slurry with hot air at 80 to 300° C.

The present invention provides a process for the preparation of phosphor aerogel of uniform size having high porosity, low density; high thermal insulation and high luminescence, which is useful for various applications like lighting, display, sensing and other applications.

More specifically, the present invention provides a simple and versatile process for the formation of monolithic gel, at room temperature, which on further drying at supercritical temperature and pressure result in dry aerogel. Further, annealing under mild reduced atmosphere from 1000°-1400° C. not only retains the porous network with uniform size particles but also crystallizes to form a phosphor aerogel having brightest luminescence with bulk density as low as 100 kg m-3, and strong enough to support a weight much higher than its own weight.

Disclosed is a light-emitting device which comprises: a light-emitting element for emitting a first light in a blue wavelength band; a first wavelength converter for converting the first light into a second light; a second wavelength converter for converting the first light into a third light; and a third wavelength converter for converting the first light into a fourth light, wherein the first to fourth lights have central wavelengths which satisfy the following relationship: [Expression 1] λ1<λ2<λ3<λ4 (wherein λ1 is the central wavelength of the first light; λ2 is the central wavelength of the second light; λ3 is the central wavelength of the third light; and λ4 is the central wavelength of the fourth light.).

The invention provides a lighting device configured to provide white lighting device light, the lighting device comprising (i) a light source, configured to provide blue light source light, and (ii) a luminescent material element, configured to absorb at least part of the blue light source light and to convert into luminescent material light, wherein the luminescent material element comprises a luminescent material which consists for at least 80 wt. % of a M.sub.2-2xEu.sub.2xSi.sub.5-yAl.sub.yO.sub.yN.sub.8-y phosphor, wherein M comprises one or more of Mg, Ca, Sr, Ba, with a molar ratio of (Mg+Ca+Sr)/(Ba)≦0.1, wherein x is in the range of 0.001-0.02, wherein y is in the range of ≦0.2, and wherein the white lighting device light comprises said blue light source light and said luminescent material light.

The invention provides a lighting device configured to provide white lighting device light, the lighting device comprising (i) a light source, configured to provide blue light source light, and (ii) a luminescent material element, configured to absorb at least part of the blue light source light and to convert into luminescent material light, wherein the luminescent material element comprises a luminescent material which consists for at least 80 wt. % of a M.sub.2-2xEu.sub.2xSi.sub.5-yAl.sub.yO.sub.yN.sub.8-y phosphor, wherein M comprises one or more of Mg, Ca, Sr, Ba, with a molar ratio of (Mg+Ca+Sr)/(Ba)≦0.1, wherein x is in the range of 0.001-0.02, wherein y is in the range of ≦0.2, and wherein the white lighting device light comprises said blue light source light and said luminescent material light.