Kabushiki Kaisha Toshiba

Toshiba Materials Co., Ltd.

Samsung Electronics Co., Ltd.

Meiji Co., Ltd.

Alpad Corporation

Kunio Ishida

Ryosuke Hiramatsu

Masahiro Kato

Keiko Albessard

Yasushi Hattori

Shinya Nunoue

Atsushi Ishii

Yumi Fukuda

Aoi Okada

Iwao Mitsuishi

Naotoshi Matsuda

Takahiro Sato

Shigeya Kimura

Jun Tamura

Hironori Asai

Embodiments of the present invention provide a phosphor improved in the emission intensity maintenance ratio without impairing the emission intensity and further a light-emitting device employing that phosphor. The phosphor is activated by manganese and has a basic structure comprising at least one element selected from the group consisting of potassium, sodium and calcium; at least one element selected from the group consisting of silicon and titanium; and fluorine. In an IR absorption spectrum of the phosphor, the intensity ratio of the peak in 3570 to 3610 cmto that in 1200 to 1240 cmis 0.1 or less.

Phosphor, producing method thereof, and light-emitting device employing the phosphor

A red-light emitting phosphor is provided, having a basic composition represented by K(Si,Mn)Fand also having a particular Raman spectrum, wherein the intensity ratio I/I, which is a ratio of (I) the peak in a Raman shift of 600&#xb1;10 cmassigned to Mn&#x2014;F bonds in the crystal to that (I) in a Raman shift of 650&#xb1;10 cmassigned to Si&#x2014;F bonds in the crystal, is 0.09 to 0.22. This phosphor is produced by bringing a silicon source in contact with an aqueous reaction solution containing potassium permanganate and hydrogen fluoride, wherein a molar ratio of hydrogen fluoride to potassium permanganate is 87 to 127.

Phosphor, manufacturing method thereof, and light-emitting device using the phosphor

A phosphor comprising: Wherein the phosphor satisfies I (2,500-3,000)/I (1,200-1,240)&#x3c;0.04, when I (1,200-1,240) is an intensity of a highest peak in a range of 1,200-1,240 cmand I (2,500-3,000) is an intensity of a highest peak in a range of 2,500-3,000 cmin an infrared spectrum.

Phosphor and light-emitting device

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.

Light-emitting device with phosphor excited by blue excitation light

A light emitting device according to embodiments includes a light emitting element emitting light with a peak wavelength of 420&#x2dc;445 nm, a first phosphor emitting light with a peak wavelength of 485&#x2dc;530 nm, a second phosphor emitting light with a peak wavelength of 530&#x2dc;580 nm, and a third phosphor emitting light with a peak wavelength of 600&#x2dc;650 nm. The device emits light having an emission spectrum that has a local minimum value of light intensity between a wavelength of 450&#x2dc;470 nm or less, the local minimum value being 60% or less of a maximum value of light intensity at a longer wavelength side from the local minimum value, and the device emits light having a color temperature of 4600 K or higher and 5400 K or less.

Light emitting device with oxynitride phosphors

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 SrSiAlON. The host material is activated by Eu, and includes Sr and Ca to satisfy a relationship of 0.008&#x2266;M/(M+M)&#x2266;0.114, where Mis a number of moles of Ca and Mis a number of moles of Sr.

Luminescent material

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;(MEu)SiAlON&#x2003;&#x2003;(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(&#x3bc;m)&#x2266;&#x2266;(+1000)(&#x3bc;m).&#x2003;&#x2003;(2)

Light emitting device

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.

White light emitting device with red and green-yellow phosphor

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 MSiON, and when the first peak wavelength is denoted by &#x3bb;1 (nm), whereas the second peak wavelength is denoted by &#x3bb;2 (nm), 1100&#x2266;&#x3bb;1+&#x3bb;2 and &#x3bb;2&#x2212;&#x3bb;1&#x2266;60 are satisfied.

White light emitting device containing three fluorescent materials having different peak wavelengths

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.

Fluorescent substance, process for production of fluorescent substance, light-emitting device and light-emitting module

A light emitting device includes a board and a light emitting element mounted on the board, emitting light having a wavelength of 250 nm to 500 nm. A red fluorescent layer is formed on the element and includes a red phosphor (MEu)SiAlONhaving a semicircular shape with a radius r, where M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Aluminum, rare-earth elements, and IVB group elements. An intermediate layer is formed on the red fluorescent layer, being made of transparent resin, having a semicircular shape with a radius D; and a green fluorescent layer is formed on the intermediate layer, including a green phosphor, having a semicircular shape. A relationship between the radius r and the radius D is 2.0r(&#x3bc;m)&#x2266;D&#x2266;(r+1000)(&#x3bc;m).

A light emitting device according to one embodiment includes a light emitting element that emits light having a wavelength of 250 nm to 500 nm; plural red fluorescent layers that are formed above the light emitting element to include a red fluorescent material, the red fluorescent layers being disposed at predetermined intervals; and plural green fluorescent layers that are formed above the light emitting element to include a green fluorescent material, a distance between the light emitting element and the green fluorescent layers being larger than a distance between the light emitting element and the red fluorescent layers.

Growing community of inventors

Tokyo, Japan

Kunio Ishida