Phosphor Ceramic Element

Patent metadata

Field	Value
Publication number	US-2016355732-A1
Application number	US-201615177212-A
Country	US
Kind code	A1
Filing date	Jun 8, 2016
Priority date	Jun 8, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

A garnet ceramic phosphor with Ce and Mn co-doping, wherein calcium and silicon in the phosphor crystal host can be minimized for enhancing performance, is described herein. Also a ceramic phosphor element comprising a garnet phosphor having composition of formula 1 or 2 is described herein:
(A 1-x ,Ce x ) 3 (Al 1-y ,Mn y ) 5-w Si w O 12   (Formula 1)

(Lu 1-x Ce x ) 3 (Al 1-y ,Mn y ) 5-w Si w O 12   (Formula 2).

First claim

What is claimed is:

1 . A ceramic phosphor element comprising a garnet phosphor composition described by a formula:
(Lu 1-x ,Ce x ) 3 (Al 1-y ,Mn y ) 5-w Si w O 12 wherein x is greater than 0 and less than about 0.2; y is greater than 0 and less than 0.1; and w is greater than 0 and less than 0.455.

2 . The ceramic phosphor element of claim 1 , wherein x is in a range of about 0.0001 to about 0.15.

3 . The ceramic phosphor of claim 1 , wherein y is in a range of about 0.001 to about 0.1.

4 . The ceramic phosphor of claim 1 , wherein w is in a range of about 0.005 to about 0.3.

5 . The ceramic phosphor element of claim 1 , wherein the garnet phosphor composition is represented by the formula selected from the group consisting of Lu 2.994 Ce 0.006 Al 4.936 Mn 0.032 Si 0.032 O 12 , Lu 2.994 Ce 0.006 Al 4.900 Mn 0.050 Si 0.050 O 12 , Lu 2.970 Ce 0.030 Al 4.900 Mn 0.050 Si 0.050 O 12 , Lu 2.940 Ce 0.060 Al 4.900 Mn 0.050 Si 0.050 O 12 , Lu 2.910 Ce 0.090 Al 4.900 Mn 0.050 Si 0.050 O 12 , Lu 2.910 Ce 0.090 Al 4.852 Mn 0.074 Si 0.074 O 12 , Lu 2.910 Ce 0.090 Al 4.708 Mn 0.146 Si 0.146 O 12 , Lu 2.880 Ce 0.120 Al 4.9 Mn 0.050 Si 0.050 O 12 , Lu 2.880 Ce 0.120 Al 4.804 Mn 0.098 Si 0.098 O 12 , and Lu 2.850 Ce 0.150 Al 4.9 Mn 0.050 Si 0.050 O 12 .

6 . The ceramic phosphor element of claim 1 , having a transmittance of at least about 70% for light having a wavelength of 800 nm.

7 . The ceramic phosphor element of claim 1 , having an internal quantum efficiency of at least 75% based upon the absorption of light by the ceramic phosphor element when exposed to monochromatic light having a wavelength of 450 nm.

8 . The ceramic phosphor element of claim 1 , prepared by sintering a precursor under a reducing atmosphere.

9 . The ceramic phosphor element of claim 8 , wherein the sintering is carried out in an atmosphere containing H 2 dispersed in N 2 .

10 . The ceramic phosphor of claim 8 , wherein the sintering is carried out at a temperature in a range of about 1550° C. to 1900° C.

11 . The light emitting device outputting a warm-white light, comprising the ceramic phosphor element of claim 1 , disposed with respect to a light source so that a portion of any light emitted from the light source is absorbed by the ceramic phosphor element, and wherein absorption of light from the light source by the ceramic phosphor element results in emission of red-shifted light by the ceramic phosphor element.

12 . A method for making a ceramic phosphor element comprising:
(a) sintering a laminate at a temperature of about 1550° C. to about 1850° C.; (b) heating the laminate to a temperature of about 1300° C. to about 1500° C. under oxygen conditions at a near vacuum; and (c) further heating the laminate to a temperature of about 1200° C. to about 1500° C. under a reducing atmosphere; wherein the laminate contains a precursor composition so that the ceramic phosphor element resulting from the method has a formula:
(Lu 1-x ,Ce x ) 3 (Al 1-y ,Mn y ) 5-w Si w O 12
wherein x is greater than 0 and less than about 0.2; and y is greater than 0 and less than 0.1; and w is greater than 0 and less than 0.455.

Assignees

• Nitto Denko Corp

Inventors

• Miyagawa Hiroaki
• Sambandan Ekambaram
• Zhang Bin

Classifications

• C09K11/77744 Primary

  Aluminosilicates · CPC title

• C04B35/44 Primary

  based on aluminates · CPC title

• C04B35/634

  Polymers (C04B35/636 takes precedence) · CPC title

• C04B2235/9653

  Translucent or transparent ceramics other than alumina · CPC title

• C04B2235/6586

  Processes characterised by the flow of gas · CPC title