Granted Patent B2

US 8,545,722 · App. 11/816,702 · Granted Oct 1, 2013

Abstract

Claims (16)

1. An illumination system, comprising:

a radiation source; and

a luminescent material comprising at least one phosphor capable of absorbing a portion of light emitted by the radiation source and emitting light of a wavelength different from that of the absorbed light;

wherein said at least one phosphor is a cerium(III)-activated alkaline earth oxonitridoaluminosilicate of general formula Ca 1−x-y A x Al 1+a-b B b Si 1−a N 3−a O a : Ce y , wherein A represents a variable and is selected from the group consisting of beryllium, magnesium, strontium, barium, zinc, manganese, lithium, sodium, potassium, rubidium, praseodymium, samarium, and europium, and B represents a variable and is selected from the group consisting of boron, gallium, and scandium and wherein 0≦x≦1; 0<y≦0.2; 0.001≦a≦1 and 0.001≦b≦1.

2. The illumination system according to claim 1 , wherein the radiation source is a light-emitting diode.

3. The illumination system according to claim 2 , wherein the radiation source is selected from those light emitting diodes having an emission with a peak emission wavelength in the range of 400 to 480 nm.

4. The illumination system according to claim 2 , wherein the radiation source is selected from those light emitting diodes having an emission with a peak emission wavelength in the range of 400 to 480 nm and the luminescent material comprises a cerium(III)-activated alkaline earth oxonitridoaluminosilicate of general formula Ca 1−x-y A x Al 1+a-b B b Si 1−a N 3−a O a :Ce y , wherein A represents a variable and is selected from the group consisting of beryllium, magnesium, strontium, barium, zinc, manganese, lithium, sodium, potassium, rubidium, praseodymium, samarium, europium, and B represents a variable and is selected from the group consisting of boron, gallium, scandium and wherein 0≦x≦1; 0<y≦0.2; 0.001≦a≦1 and 0.001≦b≦1 and a second phosphor.

5. The illumination system according to claim 4 , wherein said second phosphor is a red phosphor selected from the group consisting of (Ca 1-b Sr b )S:Eu, wherein 0≦b≦1 and (Sr 1−x-y Ba x Ca y ) 2-z Si 5-a Al a N 8-a O a :Eu z wherein 0≦a<5.0, 0<x≦1, 0≦y≦1 and 0<z≦1.0.

6. The illumination system according to claim 4 , wherein the second phosphor is a yellow to green phosphor selected from the group consisting of (Ba 1−x Sr x ) 2 SiO 4 :Eu, wherein 0≦x≦1, SrGa 2 S 4 :Eu, SrSi 2 N 2 O 2 :Eu, Ln 3 Al 5 O 12 :Ce and YAG:Ce 3+ .

7. The illumination system according to claim 2 , wherein the radiation source is selected from those light emitting diodes having an emission with a peak emission wavelength in the UV range of 200 to 400 nm and wherein the luminescent material comprises a cerium(III)-activated alkaline earth oxonitridoaluminosilicate of general formula Ca 1−x-y A x Al 1+a-b B b Si 1−a N 3−a O a :Ce y , wherein A represents a variable and is selected from the group consisting of beryllium, magnesium, strontium, barium, zinc, manganese, lithium, sodium, potassium, rubidium, praseodymium, samarium, and europium, and B represents a variable and is selected from the group consisting of boron, gallium, and scandium and wherein 0≦x≦1; 0<y≦0.2; 0.001≦a≦1 and 0.001≦b≦1.

8. The illumination system according to claim 2 , wherein the radiation source is selected from the light emitting diodes having an emission with a peak emission wavelength in the UV-range of 200 to 400 nm and wherein the luminescent material comprises a cerium(III)-activated alkaline earth oxonitridoaluminosilicate of general formula Ca 1−x-y A x Al 1+a-b B b Si 1−a N 3−a O a :Ce y , wherein A represents a variable and is selected from the group consisting of beryllium, magnesium, strontium, barium, zinc, manganese, lithium, sodium, potassium, rubidium, praseodymium, samarium, and europium, and B represents a variable and is selected from the group consisting of boron, gallium, and scandium and wherein 0≦x≦1; 0<y≦0.2; 0.001≦a≦1 and 0.001≦b≦1 and a second phosphor.

9. The illumination system according to claim 8 , wherein said second phosphor is a blue phosphor selected from the group consisting of BaMgAl 10 O 17 :Eu, Ba 5 SiO 4 (Cl,Br) 6 :Eu, CaLn 2 S 4 :Ce, (Sr,Ba,Ca) 5 (PO 4 ) 3 Cl:Eu and LaSi 3 N 5 :Ce.

10. The illumination system according to claim 8 , wherein the second phosphor is a red phosphor selected from the group consisting of (Ca 1−x Sr x )S:Eu, wherein 0≦x≦1 and (Sr 1-w-y Ba w Ca y ) 2-z Si 5-a Al a N 8-a O a :Eu z wherein 0≦a<5.0, 0<w≦1, 0<y≦1 and 0<z≦0.09.

11. The illumination system according to claim 8 , wherein the second phosphor is a yellow to green phosphor selected from the group consisting of (Ba 1−x Sr x ) 2 SiO 4 :Eu, wherein 0≦x≦1, SrGa 2 S 4 :Eu, SrSi 2 N 2 O 2 :Eu, Ln 3 Al 5 O 12 :Ce and YAG:Ce 3+ .

12. A phosphor capable of absorbing part of light emitted by a radiation source and emitting light of wavelength different from that of the absorbed light; wherein said phosphor is a cerium(III)-activated alkaline earth oxonitridoaluminosilicate of general formula Ca 1−x-y A x Al 1+a-b B b Si 1−a N 3−a O a :Ce y , wherein A represents a variable and is selected from the group consisting of beryllium, magnesium, strontium, barium, zinc, manganese, lithium, sodium, potassium, rubidium, praseodymium, samarium, europium, and B represents a variable and is selected from the group consisting of boron, gallium, scandium and wherein 0≦x≦1; 0<y≦0.2; 0.001≦a≦1 and 0.001≦b≦1.

13. The phosphor according to claim 12 , wherein said phosphor is a cerium(III)-activated alkaline earth oxonitridoaluminosilicate of general formula Ca 0.98 Al 1.01 B 0.01 Si 0.98 N 2.98 O 0.02 :Ce 0.02 .

Assignments (9)