Niigata University

Sumitomo Chemical Company, Limited

Lead Chemical Company, Limited

Kazuyoshi Uematsu

Kenji Toda

Mineo Sato

Yutaka Ito

Tetsu Umeda

Yoshiaki Kudo

Hideo Suda

Tadashi Ishigaki

Etsuko Minegishi

Shinichiro Kousaka

Yoshitaka Kawakami

Masatoshi Ota

There are provide a silicate-based phosphor excellent in emission intensity and a manufacturing method of the same. A manufacturing method of a silicate-based phosphor is characterized by: introducing in a vessel raw material powders having a compound containing light-emitting ions selected from at least one of Eu, Ce, Mn, and Tb; and firing the raw material powders while supplying SiO(0.5&#x2266;x&#x2266;1.9, preferably, 0.8&#x2266;x&#x2266;1.2) in a gas phase. The raw material powders preferably further contains at least one of an alkali metal compound, an alkaline-earth metal compound, a magnesium compound, and a rare-earth compound. The silicate-based phosphor is preferably MSiO:Eu(wherein M is one or more selected from a group consisting of Ca, Sr and Ba). The firing is preferably performed by supplying the SiOto the raw material powders in a gas atmosphere at a temperature of 1200 to 1700&#xb0; C. and subjecting the raw material powders to a gas-solid phase reaction at a temperature of 700 to 1700&#xb0; C.

Silicate-based phosphor and manufacturing method of silicate-based phosphor

Provided are phosphors that can exhibit higher emission luminance. Phosphors in which the activator is included in a compound represented by Formula xMO.MO.yMO(wherein Mrepresents one or more of a group comprising Ca, Sr and Ba, Mrepresents Mg and/or Zn, Mrepresents Si and/or Ge, x is a value in the range 4 to 6 and y is a value in the range 2 to 4). Phosphors represented by Formula MEuMMO(wherein M, Mand Mhave the same meanings as above, and z is a value in the range 0.0001 to 0.3). The above phosphors have the same crystal structure as bredigite.

Phosphors having high light emission luminescence

Provided is a fluorescent body for use in a near-ultraviolet excitation light-emitting element, comprising the compound given by formula (1), having part of element Mand/or Mtherein replaced by an activation element (M). MMPO(1) (Here, Mrepresents one or more elements chosen from the group comprising Ca, Sr, and Ba; Mrepresents one or more elements chosen from the group comprising Mg and Zn; a is a number between 1.5 and 2.5, inclusive; b is a number between 2.5 and 3.5, inclusive; and c is a number between 3.5 and 4.5, inclusive.) A fluorescent body in which Mis Sr and Mis Mg, and a fluorescent body in which Mis Eu are preferable. Also provided are a fluorescent paste having the fluorescent body, and a near-ultraviolet excitation light-emitting element having the fluorescent body and having a high luminescent intensity.

Fluorescent body for use in a near-ultraviolet excitation light-emitting element

A novel fluorescent substance for a light-emitting diode, emitting light of any one of three primary colors by excitation of an ultraviolet light-emitting diode. Alternatively, a novel fluorescent substance for a light-emitting diode, emitting light in a red region of a spectrum by excitation of a blue light-emitting diode. NaSrSiOis doped with Eu. Preferably, Euis added so as to account for 1 to 80 mol % in concentration in a host crystal, while sites of Siin NaSrSiO. are replaced by Aland/or Ga. Alternatively, CaSiOis doped with Ceand Tb. Preferably, Ceand Tbare added so as to account for 0.1 to 80 mol % and 0.1 to 20 mol % in concentration in a host crystal, respectively. Still alternatively, CaSiOis doped with Eu. Preferably, Euis added so as to account for 0.5 to 10 mol % in concentration in the host crystal.

Fluorescent substance for light-emitting diode

A novel method for measuring airborne radon and thoron capable of separately measuring radon and thoron with high sensitivity, having a small-sized device structure, and free of the influence from its measurement environment. In the method, by measuring Cherenkov light generated when airborne radon and thoron are adsorbed to an absorbent and then &#x3b2; rays emitted in process of disintegrations of radon and thoron pass through the absorbent, radon and thoron are measured. Based on a decay time of the Cherenkov light, a mixture ratio between radon and thoron is measured. As the absorbent, porous glass is preferably employed which is provided with fine pores of 0.3 to 30 nm in diameter.

Method for measuring randon and thoron in air

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Niigata, Japan

Kazuyoshi Uematsu