Blue-green and green phosphors for lighting applications
First Claim
1. A method for producing a phosphor, the method comprising:
- providing amounts of oxygen-containing compounds of cerium, silicon, and at least one alkaline-earth metal selected from the group consisting of Sr, Ba, Ca, and combinations thereof;
mixing together the oxygen-containing compounds with a fluoride containing compound to form a mixture; and
then firing the mixture at a temperature between about 900°
C. and about 1700°
C. under a reducing atmosphere for a sufficient period of time to convert the mixture to a phosphor comprising a general formula of ((Sr1−
zMz)1−
(x+w)AwCex)3(Al1−
ySiy)O4+y+3(x−
w)F1−
y−
3(x−
w), wherein 0<
x≦
0.10, 0<
y≦
0.5, 0≦
z≦
0.5, 0swsx, A is Li, Na, K, or any combinations thereof, M is Ca, Ba, or any combinations thereof; and
light emitted by the phosphor is blue-green to green in color, having a peak emission wavelength between about 485 nm and about 540 nm, using a 405 nm excitation wavelength.
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Accused Products
Abstract
Embodiments of the present techniques provide a related family of phosphors that may be used in lighting systems to generate blue or blue-green light. The phosphors include systems having a general formula of: ((Sr1−zMz)1−(x+w)AwCex)3(Al1−ySiy)O4+y+3(x−w)F1−y−3(x−w) (I), wherein 0<x≦0.10, 0≦y≦0.5, 0≦z≦0.5, 0≦w≦x, A is Li, Na, K, Rb, or Ag or any combinations thereof, and M is Ca, Ba, Mg, Zn, or Sn or any combinations thereof. Advantageously, phosphors made accordingly to these formulations maintain emission intensity across a wide range of temperatures. The phosphors may be used in lighting systems, such as LEDs and fluorescent tubes, among others, to produce blue and blue/green light. Further, the phosphors may be used in blends with other phosphors, or in combined lighting systems, to produce white light suitable for illumination.
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Citations
26 Claims
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1. A method for producing a phosphor, the method comprising:
-
providing amounts of oxygen-containing compounds of cerium, silicon, and at least one alkaline-earth metal selected from the group consisting of Sr, Ba, Ca, and combinations thereof; mixing together the oxygen-containing compounds with a fluoride containing compound to form a mixture; and then firing the mixture at a temperature between about 900°
C. and about 1700°
C. under a reducing atmosphere for a sufficient period of time to convert the mixture to a phosphor comprising a general formula of ((Sr1−
zMz)1−
(x+w)AwCex)3(Al1−
ySiy)O4+y+3(x−
w)F1−
y−
3(x−
w), wherein 0<
x≦
0.10, 0<
y≦
0.5, 0≦
z≦
0.5, 0swsx, A is Li, Na, K, or any combinations thereof, M is Ca, Ba, or any combinations thereof; and
light emitted by the phosphor is blue-green to green in color, having a peak emission wavelength between about 485 nm and about 540 nm, using a 405 nm excitation wavelength. - View Dependent Claims (2)
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3. A phosphor of formula
((Sr1−- zMz)1−
(x+w)AwCex)3(Al1−
ySiy)O4+y+3(x−
w)F1−
y−
3(x−
w),wherein 0<
x≦
0.10;0<
y≦
0.5;0≦
z≦
0.5;0swsx; A is Li, Na, K, or a combination thereof; M is Ca, Ba, Mg, or a combination thereof; and light emitted by the phosphor under 405 nm excitation, is blue-green to green in color, having a peak emission wavelength between about 485 nm and about 540 nm, using a 405 nm excitation wavelength. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- zMz)1−
-
14. A phosphor blend comprising a blue-green to green phosphor having a peak emission wavelength between about 485 nm and about 540 nm, using a 405 nm excitation wavelength, of formula
((Sr1−- zMz)1−
x+w)AwCex)3(Al1−
ySiy)O4+y+3(x−
w)F1−
y−
(x−
w),wherein 0<
x≦
0.10;0<
y≦
0.5;0≦
z≦
0.5;0swsx; A is Li, Na, K, or a combination thereof; and M is Ca, Ba, Mg, or a combination thereof. - View Dependent Claims (15, 16, 17, 18, 19, 20)
- zMz)1−
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21. A lighting apparatus comprising:
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a light source configured to emit radiation with a peak intensity at a wavelength between about 250 nm and about 550 nm; and a phosphor composition comprising a blue-green to green phosphor having a peak emission wavelength between about 485 nm and about 540 nm, using a 405 nm excitation wavelength, configured to be radiationally coupled to the light source, of formula
((Sr1−
zMz)1−
(x+w)AwCex)3(Al1−
ySiy)O4+y+3(x−
w)F1−
y−
3(x−
w),wherein 0<
x≦
0.10;0<
y≦
0.5;0≦
z≦
0.5;0swsx; A is Li, Na, K, or a combination thereof; and M is Ca, Ba, Mg, or a combination thereof. - View Dependent Claims (22, 23, 24, 25, 26)
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Specification